diff options
Diffstat (limited to 'docs/SkPath_Reference.bmh')
| -rw-r--r-- | docs/SkPath_Reference.bmh | 5802 |
1 files changed, 5802 insertions, 0 deletions
diff --git a/docs/SkPath_Reference.bmh b/docs/SkPath_Reference.bmh new file mode 100644 index 0000000000..95067c71b5 --- /dev/null +++ b/docs/SkPath_Reference.bmh @@ -0,0 +1,5802 @@ +#Topic Path
+#Alias Path_Reference
+#Alias Paths
+
+Path contains Lines and Curves which can be stroked or filled. Contour is
+composed of a series of connected Lines and Curves. Path may contain zero,
+one, or more Contours.
+Each Line and Curve are described by Verb, Points, and optional Weight.
+
+Each pair of connected Lines and Curves share common Point; for instance, Path
+containing two connected Lines are described the Verb sequence:
+SkPath::kMove_Verb, SkPath::kLine_Verb, SkPath::kLine_Verb; and a Point sequence
+with three entries, sharing
+the middle entry as the end of the first Line and the start of the second Line.
+
+Path components Arc, Rect, Round_Rect, Circle, and Oval are composed of
+Lines and Curves with as many Verbs and Points required
+for an exact description. Once added to Path, these components may lose their
+identity; although Path can be inspected to determine if it decribes a single
+Rect, Oval, Round_Rect, and so on.
+
+#Example
+#Height 192
+#Description
+Path contains three Contours: Line, Circle, and Quad. Line is stroked but
+not filled. Circle is stroked and filled; Circle stroke forms a loop. Quad
+is stroked and filled, but since it is not closed, Quad does not stroke a loop.
+##
+void draw(SkCanvas* canvas) {
+ SkPaint paint;
+ paint.setAntiAlias(true);
+ SkPath path;
+ path.moveTo(124, 108);
+ path.lineTo(172, 24);
+ path.addCircle(50, 50, 30);
+ path.moveTo(36, 148);
+ path.quadTo(66, 188, 120, 136);
+ canvas->drawPath(path, paint);
+ paint.setStyle(SkPaint::kStroke_Style);
+ paint.setColor(SK_ColorBLUE);
+ paint.setStrokeWidth(3);
+ canvas->drawPath(path, paint);
+}
+##
+
+Path contains a Fill_Type which determines whether overlapping Contours
+form fills or holes. Fill_Type also determines whether area inside or outside
+Lines and Curves is filled.
+
+#Example
+#Height 192
+#Description
+Path is drawn filled, then stroked, then stroked and filled.
+##
+void draw(SkCanvas* canvas) {
+ SkPaint paint;
+ paint.setAntiAlias(true);
+ SkPath path;
+ path.moveTo(36, 48);
+ path.quadTo(66, 88, 120, 36);
+ canvas->drawPath(path, paint);
+ paint.setStyle(SkPaint::kStroke_Style);
+ paint.setColor(SK_ColorBLUE);
+ paint.setStrokeWidth(8);
+ canvas->translate(0, 50);
+ canvas->drawPath(path, paint);
+ paint.setStyle(SkPaint::kStrokeAndFill_Style);
+ paint.setColor(SK_ColorRED);
+ canvas->translate(0, 50);
+ canvas->drawPath(path, paint);
+}
+##
+
+Path contents are never shared. Copying Path by value effectively creates
+a new Path independent of the original. Internally, the copy does not duplicate
+its contents until it is edited, to reduce memory use and improve performance.
+
+#Subtopic Subtopics +#ToDo not all methods are in topics ## +#ToDo subtopics are not in topics ## +#Table +#Legend +# topics # description ## +#Legend ## +#Table ## +# Contour # A loop of lines and curves. ## +# Convexity # Whether Path contains simple loop. ## +# Last_Point # Final Point in Contour. ## +# Point_Array # All Points in Path. ## +# Verb # How Points and Contours are defined. ## +# Verb_Array # All Verbs in Path. ## +# Verb # How Points and Contours are defined. ## +# Weight # Strength of control Point in Conic. ## +#Subtopic ## +
+
+#Subtopic Contour +#Alias Contours +Contour contains one or more Verbs, and as many Points as +are required to satisfy Verb_Array. First Verb in Path is always +SkPath::kMove_Verb; each SkPath::kMove_Verb that follows starts a new Contour. + +#Example +#Description
+Each SkPath::moveTo starts a new Contour, and content after SkPath::close()
+also starts a new Contour. Since SkPath::conicTo wasn't preceded by
+SkPath::moveTo, the first Point of the third Contour starts at the last Point
+of the second Contour.
+##
+#Height 192
+ SkPaint paint;
+ paint.setAntiAlias(true);
+ canvas->drawString("1st contour", 150, 100, paint);
+ canvas->drawString("2nd contour", 130, 160, paint);
+ canvas->drawString("3rd contour", 40, 30, paint);
+ paint.setStyle(SkPaint::kStroke_Style);
+ SkPath path;
+ path.moveTo(124, 108);
+ path.lineTo(172, 24);
+ path.moveTo(36, 148);
+ path.quadTo(66, 188, 120, 136);
+ path.close();
+ path.conicTo(70, 20, 110, 40, 0.6f);
+ canvas->drawPath(path, paint);
+## + +If final Verb in Contour is SkPath::kClose_Verb, Line connects Last_Point in +Contour with first Point. A closed Contour, stroked, draws +Paint_Stroke_Join at Last_Point and first Point. Without SkPath::kClose_Verb +as final Verb, Last_Point and first Point are not connected; Contour +remains open. An open Contour, stroked, draws Paint_Stroke_Cap at +Last_Point and first Point. + +#Example +#Height 160
+#Description
+Path is drawn stroked, with an open Contour and a closed Contour.
+##
+void draw(SkCanvas* canvas) {
+ SkPaint paint;
+ paint.setAntiAlias(true);
+ paint.setStyle(SkPaint::kStroke_Style);
+ paint.setStrokeWidth(8);
+ SkPath path;
+ path.moveTo(36, 48);
+ path.quadTo(66, 88, 120, 36);
+ canvas->drawPath(path, paint);
+ path.close();
+ canvas->translate(0, 50);
+ canvas->drawPath(path, paint);
+}
+## + +#Subtopic Zero_Length +#Alias Zero_Length_Contour +Contour length is distance traveled from first Point to Last_Point, +plus, if Contour is closed, distance from Last_Point to first Point. +Even if Contour length is zero, stroked Lines are drawn if Paint_Stroke_Cap +makes them visible. + +#Example +#Height 64
+ SkPaint paint;
+ paint.setAntiAlias(true);
+ paint.setStyle(SkPaint::kStroke_Style);
+ paint.setStrokeWidth(8);
+ paint.setStrokeCap(SkPaint::kRound_Cap);
+ SkPath path;
+ path.moveTo(36, 48);
+ path.lineTo(36, 48);
+ canvas->drawPath(path, paint);
+ path.reset();
+ paint.setStrokeCap(SkPaint::kSquare_Cap);
+ path.moveTo(56, 48);
+ path.close();
+ canvas->drawPath(path, paint); +## + +#Subtopic Zero_Length ## + +#Subtopic Contour ## +
+# ------------------------------------------------------------------------------
+ +#Class SkPath
+
+#Topic Overview
+
+#Subtopic Constants +#ToDo incomplete ## +#Table +#Legend +# constants # description ## +#Legend ## +# AddPathMode # Sets addPath options. ## +# ArcSize # Sets arcTo(SkScalar rx, SkScalar ry, SkScalar xAxisRotate, ArcSize largeArc, Direction sweep, SkScalar x, SkScalar y) options. ## +# Convexity # Returns if Path is convex or concave. ## +# Direction # Sets Contour clockwise or counterclockwise. ## +# FillType # Sets winding rule and inverse fill. ## +# SegmentMask +# Verb # Controls how Path Points are interpreted. ## +#Table ## +#Subtopic ## +
+#Subtopic Classes_and_Structs +#Table +#Legend +# class or struct # description ## +#Legend ## +# Iter # Iterates through lines and curves, skipping degenerates. ## +# RawIter # Iterates through lines and curves, including degenerates. ## +#Table ## +#Subtopic ## +
+#Subtopic Constructors +#Table +#Legend +# # description ## +#Legend ## +# SkPath() # Constructs with default values. ## +# SkPath(const SkPath& path) # Makes a shallow copy. ## +# ~SkPath() # Decreases Reference_Count of owned objects. ## +#Table ## +#Subtopic ## + +#Subtopic Operators +#Table +#Legend +# operator # description ## +#Legend ## +# operator=(const SkPath& path) # Makes a shallow copy. ## +# operator==(const SkPath& a, const SkPath& b) # Compares paths for equality. ## +# operator!=(const SkPath& a, const SkPath& b) # Compares paths for inequality. ## +#Table ## +#Subtopic ## +
+#Subtopic Member_Functions
+#Table
+#Legend
+# function # description ##
+#Legend ##
+# ConvertConicToQuads # Approximates Conic with Quad array. ##
+# ConvertToNonInverseFillType # Returns Fill_Type representing inside geometry. ##
+# IsCubicDegenerate # Returns if Cubic is very small. ##
+# IsInverseFillType # Returns if Fill_Type represents outside geometry. ##
+# IsLineDegenerate # Returns if Line is very small. ##
+# IsQuadDegenerate # Returns if Quad is very small. ##
+# addArc # Adds one Contour containing Arc. ##
+# addCircle # Adds one Contour containing Circle. ##
+# addOval # Adds one Contour containing Oval. ##
+# addPath # Adds contents of Path. ##
+# addPoly # Adds one Contour containing connected lines. ##
+# addRRect # Adds one Contour containing Round_Rect. ##
+# addRect # Adds one Contour containing Rect. ##
+# addRoundRect # Adds one Contour containing Round_Rect with common corner radii. ##
+# arcTo # Appends Arc. ##
+# close() # Makes last Contour a loop. ##
+# computeTightBounds # Returns extent of geometry. ##
+# conicTo # Appends Conic. ##
+# conservativelyContainsRect # Returns true if Rect may be inside. ##
+# contains() # Returns if Point is in fill area. ##
+# countPoints # Returns Point_Array length. ##
+# countVerbs # Returns Verb_Array length. ##
+# cubicTo # Appends Cubic. ##
+# dump() # Sends text representation using floats to stdout. ##
+# dumpHex # Sends text representation using hexadecimal to stdout. ##
+# experimentalValidateRef # Experimental; debugging only. ##
+# getBounds # Returns maximum and minimum of Point_Array. ##
+# getConvexity # Returns geometry convexity, computing if necessary. ##
+# getConvexityOrUnknown # Returns geometry convexity if known. ##
+# getFillType # Returns Fill_Type: winding, even-odd, inverse. ##
+# getGenerationID # Returns unique ID. ##
+# getLastPt # Returns Last_Point. ##
+# getPoint # Returns entry from Point_Array. ##
+# getPoints # Returns Point_Array. ##
+# getSegmentMasks # Returns types in Verb_Array. ##
+# getVerbs # Returns Verb_Array. ##
+# incReserve # Hint to reserve space for additional data. ##
+# interpolate() # Interpolates between Path pair. ##
+# isConvex # Returns if geometry is convex. ##
+# isEmpty # Returns if verb count is zero. ##
+# isFinite # Returns if all Point values are finite. ##
+# isInterpolatable # Returns if pair contains equal counts of Verb_Array and Weights. ##
+# isInverseFillType # Returns if Fill_Type fills outside geometry. ##
+# isLastContourClosed # Returns if final Contour forms a loop. ##
+# isLine # Returns if describes Line. ##
+# isNestedFillRects # Returns if describes Rect pair, one inside the other. ##
+# isOval # Returns if describes Oval. ##
+# isRRect # Returns if describes Round_Rect. ##
+# isRect # Returns if describes Rect. ##
+# isVolatile # Returns if Device should not cache. ##
+# lineTo # Appends Line. ##
+# moveTo # Starts Contour. ##
+# offset() # Translates Point_Array. ##
+# quadTo # Appends Quad. ##
+# rArcTo # Appends Arc relative to Last_Point. ##
+# rConicTo # Appends Conic relative to Last_Point. ##
+# rCubicTo # Appends Cubic relative to Last_Point. ##
+# rLineTo # Appends Line relative to Last_Point. ##
+# rMoveTo # Starts Contour relative to Last_Point. ##
+# rQuadTo # Appends Quad relative to Last_Point. ##
+# readFromMemory # Initialize from buffer. ##
+# reset() # Removes Verb_Array, Point_Array, and Weights; frees memory. ##
+# reverseAddPath # Adds contents of Path back to front. ##
+# rewind() # Removes Verb_Array, Point_Array, and Weights; leaves memory allocated. ##
+# setConvexity # Sets if geometry is convex to avoid future computation. ##
+# setFillType # Sets Fill_Type: winding, even-odd, inverse. ##
+# setIsConvex # Deprecated. ##
+# setIsVolatile # Sets if Device should not cache. ##
+# setLastPt # Replaces Last_Point. ##
+# swap() # Exchanges Path pair. ##
+# toggleInverseFillType # Toggles Fill_Type between inside and outside geometry. ##
+# transform() # Applies Matrix to Point_Array and Weights. ##
+# unique() # Returns if data has single owner. ##
+# updateBoundsCache # Refresh result of getBounds. ##
+# writeToMemory # Copy data to buffer. ##
+#Table ##
+#Subtopic Path_Member_Functions ##
+#Topic Overview ##
+
+#Subtopic Verb +#Alias Verbs + +#Enum Verb
+
+#Code
+ enum Verb {
+ kMove_Verb
+ kLine_Verb
+ kQuad_Verb
+ kConic_Verb
+ kCubic_Verb
+ kClose_Verb
+ kDone_Verb
+ };
+##
+
+Verb instructs Path how to interpret one or more Point and optional Weight; +manage Contour, and terminate Path. + +#Const kMove_Verb 0
+ Starts new Contour at next Point.
+##
+#Const kLine_Verb 1
+ Adds Line from Last_Point to next Point.
+ Line is a straight segment from Point to Point.
+##
+#Const kQuad_Verb 2
+ Adds Quad from Last_Point, using control Point, and end Point.
+ Quad is a parabolic section within tangents from Last_Point to control Point,
+ and control Point to end Point.
+##
+#Const kConic_Verb 3
+ Adds Conic from Last_Point, using control Point, end Point, and Weight.
+ Conic is a elliptical, parabolic, or hyperbolic section within tangents
+ from Last_Point to control Point, and control Point to end Point, constrained
+ by Weight. Weight less than one is elliptical; equal to one is parabolic
+ (and identical to Quad); greater than one hyperbolic.
+##
+#Const kCubic_Verb 4
+ Adds Cubic from Last_Point, using two control Points, and end Point.
+ Cubic is a third-order Bezier section within tangents from Last_Point to
+ first control Point, and from second control Point to end Point.
+##
+#Const kClose_Verb 5
+ Closes Contour, connecting Last_Point to kMove_Verb Point.
+##
+#Const kDone_Verb 6
+ Terminates Path. Not in Verb_Array, but returned by Path iterator.
+## + +Each Verb has zero or more Points stored in Path. +Path iterator returns complete curve descriptions, duplicating shared Points +for consecutive entries. + +#Table +#Legend +# Verb # Allocated Points # Iterated Points # Weights ## +## +# kMove_Verb # 1 # 1 # 0 ## +# kLine_Verb # 1 # 2 # 0 ## +# kQuad_Verb # 2 # 3 # 0 ## +# kConic_Verb # 2 # 3 # 1 ## +# kCubic_Verb # 3 # 4 # 0 ## +# kClose_Verb # 0 # 1 # 0 ## +# kDone_Verb # -- # 0 # 0 ## +## +
+#Example
+void draw(SkCanvas* canvas) {
+ SkPath path;
+ path.lineTo(20, 20);
+ path.quadTo(-10, -10, 30, 30);
+ path.close();
+ path.cubicTo(1, 2, 3, 4, 5, 6);
+ path.conicTo(0, 0, 0, 0, 2);
+ uint8_t verbs[7];
+ int count = path.getVerbs(verbs, (int) SK_ARRAY_COUNT(verbs));
+ const char* verbStr[] = { "Move", "Line", "Quad", "Conic", "Cubic", "Close" };
+ SkDebugf("verb count: %d\nverbs: ", count);
+ for (int i = 0; i < count; ++i) {
+ SkDebugf("k%s_Verb ", verbStr[verbs[i]]);
+ }
+ SkDebugf("\n");
+}
+#StdOut
+verb count: 7
+verbs: kMove_Verb kLine_Verb kQuad_Verb kClose_Verb kMove_Verb kCubic_Verb kConic_Verb
+##
+##
+
+#Enum Verb ##
+#Subtopic Verb ##
+
+# ------------------------------------------------------------------------------
+#Subtopic Direction
+#Alias Directions
+
+#Enum Direction
+
+#Code
+ enum Direction {
+ kCW_Direction
+ kCCW_Direction
+ };
+##
+
+Direction describes whether Contour is clockwise or counterclockwise.
+When Path contains multiple overlapping Contours, Direction together with
+Fill_Type determines whether overlaps are filled or form holes.
+
+Direction also determines how Contour is measured. For instance, dashing
+measures along Path to determine where to start and stop stroke; Direction
+will change dashed results as it steps clockwise or counterclockwise.
+
+Closed Contours like Rect, Round_Rect, Circle, and Oval added with
+kCW_Direction travel clockwise; the same added with kCCW_Direction
+travel counterclockwise.
+
+#Const kCW_Direction
+ Contour travels in a clockwise direction.
+##
+#Const kCCW_Direction
+ Contour travels in a counterclockwise direction.
+##
+
+
+#Example
+#Height 100
+void draw(SkCanvas* canvas) {
+ const SkPoint arrow[] = { {40, -5}, {45, 0}, {40, 5} };
+ const SkRect rect = {10, 10, 90, 90};
+ SkPaint rectPaint;
+ rectPaint.setAntiAlias(true);
+ SkPaint textPaint(rectPaint);
+ textPaint.setTextAlign(SkPaint::kCenter_Align);
+ rectPaint.setStyle(SkPaint::kStroke_Style);
+ SkPaint arrowPaint(rectPaint);
+ SkPath arrowPath;
+ arrowPath.addPoly(arrow, SK_ARRAY_COUNT(arrow), true);
+ arrowPaint.setPathEffect(SkPath1DPathEffect::Make(arrowPath, 320, 0,
+ SkPath1DPathEffect::kRotate_Style));
+ for (auto direction : { SkPath::kCW_Direction, SkPath::kCCW_Direction } ) {
+ canvas->drawRect(rect, rectPaint);
+ for (unsigned start : { 0, 1, 2, 3 } ) {
+ SkPath path;
+ path.addRect(rect, direction, start);
+ canvas->drawPath(path, arrowPaint);
+ }
+ canvas->drawString(SkPath::kCW_Direction == direction ? "CW" : "CCW", rect.centerX(),
+ rect.centerY(), textPaint);
+ canvas->translate(120, 0);
+ }
+}
+##
+
+#SeeAlso arcTo rArcTo isRect isNestedFillRects addRect addOval
+
+#Enum Direction ##
+#Subtopic Direction ##
+
+# ------------------------------------------------------------------------------
+
+#Method SkPath()
+
+By default, Path has no Verbs, no Points, and no Weights.
+Fill_Type is set to kWinding_FillType.
+
+#Return empty Path. ##
+
+#Example
+ SkPath path;
+ SkDebugf("path is " "%s" "empty", path.isEmpty() ? "" : "not ");
+#StdOut
+path is empty
+##
+##
+
+#SeeAlso reset rewind
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method SkPath(const SkPath& path)
+
+Copy constructor makes two paths identical by value. Internally, path and
+the returned result share pointer values. The underlying Verb_Array, Point_Array
+and Weights are copied when modified.
+
+Creating a Path copy is very efficient and never allocates memory.
+Paths are always copied by value from the interface; the underlying shared
+pointers are not exposed.
+
+#Param path Path to copy by value. ##
+
+#Return Copy of Path. ##
+
+#Example
+#Description
+ Modifying one path does not effect another, even if they started as copies
+ of each other.
+##
+ SkPath path;
+ path.lineTo(20, 20);
+ SkPath path2(path);
+ path2.close();
+ SkDebugf("path verbs: %d\n", path.countVerbs());
+ SkDebugf("path2 verbs: %d\n", path2.countVerbs());
+ path.reset();
+ SkDebugf("after reset\n" "path verbs: %d\n", path.countVerbs());
+ SkDebugf("path2 verbs: %d\n", path2.countVerbs());
+#StdOut
+path verbs: 2
+path2 verbs: 3
+after reset
+path verbs: 0
+path2 verbs: 3
+##
+##
+
+#SeeAlso operator=(const SkPath& path)
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method ~SkPath()
+
+Releases ownership of any shared data and deletes data if Path is sole owner.
+
+#Example
+#Description
+delete calls Path destructor, but copy of original in path2 is unaffected.
+##
+void draw(SkCanvas* canvas) {
+ SkPath* path = new SkPath();
+ path->lineTo(20, 20);
+ SkPath path2(*path);
+ delete path;
+ SkDebugf("path2 is " "%s" "empty", path2.isEmpty() ? "" : "not ");
+}
+##
+
+#SeeAlso SkPath() SkPath(const SkPath& path) operator=(const SkPath& path)
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method SkPath& operator=(const SkPath& path)
+
+Path assignment makes two paths identical by value. Internally, assignment
+shares pointer values. The underlying Verb_Array, Point_Array and Weights
+are copied when modified.
+
+Copying Paths by assignment is very efficient and never allocates memory.
+Paths are always copied by value from the interface; the underlying shared
+pointers are not exposed.
+
+#Param path Verb_Array, Point_Array, Weights, amd Fill_Type to copy. ##
+
+#Return Path copied by value. ##
+
+#Example
+SkPath path1;
+path1.addRect({10, 20, 30, 40});
+SkPath path2 = path1;
+const SkRect& b1 = path1.getBounds();
+SkDebugf("path1 bounds = %g, %g, %g, %g\n", b1.fLeft, b1.fTop, b1.fRight, b1.fBottom);
+const SkRect& b2 = path2.getBounds();
+SkDebugf("path2 bounds = %g, %g, %g, %g\n", b2.fLeft, b2.fTop, b2.fRight, b2.fBottom);
+#StdOut
+path1 bounds = 10, 20, 30, 40
+path2 bounds = 10, 20, 30, 40
+#StdOut ##
+##
+
+#SeeAlso swap() SkPath(const SkPath& path)
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method friend SK_API bool operator==(const SkPath& a, const SkPath& b)
+
+Compares a and b; returns true if Fill_Type, Verb_Array, Point_Array, and Weights
+are equivalent.
+
+#Param a Path to compare. ##
+#Param b Path to compare. ##
+
+#Return true if Path pair are equivalent. ##
+
+#Example
+#Description
+Rewind removes Verb_Array but leaves storage; since storage is not compared,
+Path pair are equivalent.
+##
+void draw(SkCanvas* canvas) {
+ auto debugster = [](const char* prefix, const SkPath& a, const SkPath& b) -> void {
+ SkDebugf("%s one %c= two\n", prefix, a == b ? '=' : '!');
+ };
+ SkPath one;
+ SkPath two;
+ debugster("empty", one, two);
+ one.moveTo(0, 0);
+ debugster("moveTo", one, two);
+ one.rewind();
+ debugster("rewind", one, two);
+ one.moveTo(0, 0);
+ one.reset();
+ debugster("reset", one, two);
+}
+#StdOut
+empty one == two
+moveTo one != two
+rewind one == two
+reset one == two
+##
+##
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method friend bool operator!=(const SkPath& a, const SkPath& b)
+
+Compares a and b; returns true if Fill_Type, Verb_Array, Point_Array, and Weights
+are not equivalent.
+
+#Param a Path to compare. ##
+#Param b Path to compare. ##
+
+#Return true if Path pair are not equivalent. ##
+
+#Example
+#Description
+Path pair are equal though their convexity is not equal.
+##
+void draw(SkCanvas* canvas) {
+ auto debugster = [](const char* prefix, const SkPath& a, const SkPath& b) -> void {
+ SkDebugf("%s one %c= two\n", prefix, a != b ? '!' : '=');
+ };
+ SkPath one;
+ SkPath two;
+ debugster("empty", one, two);
+ one.addRect({10, 20, 30, 40});
+ two.addRect({10, 20, 30, 40});
+ debugster("addRect", one, two);
+ one.setConvexity(SkPath::kConcave_Convexity);
+ debugster("setConvexity", one, two);
+ SkDebugf("convexity %c=\n", one.getConvexity() == two.getConvexity() ? '=' : '!');
+}
+#StdOut
+empty one == two
+addRect one == two
+setConvexity one == two
+convexity !=
+##
+##
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method bool isInterpolatable(const SkPath& compare) const
+
+Return true if Paths contain equal Verbs and equal Weights.
+If Paths contain one or more Conics, the Weights must match.
+
+conicTo may add different Verbs depending on Conic_Weight, so it is not
+trival to interpolate a pair of Paths containing Conics with different
+Conic_Weight values.
+
+#Param compare Path to compare. ##
+
+#Return true if Paths Verb_Array and Weights are equivalent. ##
+
+#Example
+ SkPath path, path2;
+ path.moveTo(20, 20);
+ path.lineTo(40, 40);
+ path.lineTo(20, 20);
+ path.lineTo(40, 40);
+ path.close();
+ path2.addRect({20, 20, 40, 40});
+ SkDebugf("paths are " "%s" "interpolatable", path.isInterpolatable(path2) ? "" : "not ");
+#StdOut
+paths are interpolatable
+##
+##
+
+#SeeAlso isInterpolatable
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method bool interpolate(const SkPath& ending, SkScalar weight, SkPath* out) const
+
+Interpolate between Paths with equal sized Point_Arrays.
+Copy Verb_Array and Weights to out,
+and set out Point_Array to a weighted average of this Point_Array and ending
+Point_Array, using the formula:
+#Formula
+(this->points * weight) + ending->points * (1 - weight)
+##
+
+interpolate() returns false and leaves out unchanged if Point_Array is not
+the same size as ending Point_Array. Call isInterpolatable to check Path
+compatibility prior to calling interpolate().
+
+#Param ending Point_Array averaged with this Point_Array. ##
+#Param weight Most useful when between zero (ending Point_Array) and
+ one (this Point_Array); will work with values outside of this
+ range.
+##
+#Param out ##
+
+#Return true if Paths contain same number of Points. ##
+
+#Example
+#Height 60
+void draw(SkCanvas* canvas) {
+ SkPaint paint;
+ paint.setAntiAlias(true);
+ paint.setStyle(SkPaint::kStroke_Style);
+ SkPath path, path2;
+ path.moveTo(20, 20);
+ path.lineTo(40, 40);
+ path.lineTo(20, 40);
+ path.lineTo(40, 20);
+ path.close();
+ path2.addRect({20, 20, 40, 40});
+ for (SkScalar i = 0; i <= 1; i += 1.f / 6) {
+ SkPath interp;
+ path.interpolate(path2, i, &interp);
+ canvas->drawPath(interp, paint);
+ canvas->translate(30, 0);
+ }
+}
+##
+
+#SeeAlso isInterpolatable
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method bool unique() const
+
+#Private
+To be deprecated; only valid for Android framework.
+##
+
+#Return true if Path has one owner. ##
+
+##
+
+# ------------------------------------------------------------------------------
+#Subtopic Fill_Type + +#Enum FillType
+
+#Code
+ enum FillType {
+ kWinding_FillType
+ kEvenOdd_FillType
+ kInverseWinding_FillType
+ kInverseEvenOdd_FillType
+ };
+##
+ +Fill_Type selects the rule used to fill Path. Path set to kWinding_FillType +fills if the sum of Contour edges is not zero, where clockwise edges add one, and +counterclockwise edges subtract one. Path set to kEvenOdd_FillType fills if the +number of Contour edges is odd. Each Fill_Type has an inverse variant that +reverses the rule: +kInverseWinding_FillType fills where the sum of Contour edges is zero; +kInverseEvenOdd_FillType fills where the number of Contour edges is even. + +#Example +#Height 100 +#Description +The top row has two clockwise rectangles. The second row has one clockwise and +one counterclockwise rectangle. The even-odd variants draw the same. The +winding variants draw the top rectangle overlap, which has a winding of 2, the +same as the outer parts of the top rectangles, which have a winding of 1. +## +void draw(SkCanvas* canvas) {
+ SkPath path;
+ path.addRect({10, 10, 30, 30}, SkPath::kCW_Direction);
+ path.addRect({20, 20, 40, 40}, SkPath::kCW_Direction);
+ path.addRect({10, 60, 30, 80}, SkPath::kCW_Direction);
+ path.addRect({20, 70, 40, 90}, SkPath::kCCW_Direction);
+ SkPaint strokePaint;
+ strokePaint.setStyle(SkPaint::kStroke_Style);
+ SkRect clipRect = {0, 0, 51, 100};
+ canvas->drawPath(path, strokePaint);
+ SkPaint fillPaint;
+ for (auto fillType : { SkPath::kWinding_FillType, SkPath::kEvenOdd_FillType,
+ SkPath::kInverseWinding_FillType, SkPath::kInverseEvenOdd_FillType } ) {
+ canvas->translate(51, 0);
+ canvas->save();
+ canvas->clipRect(clipRect);
+ path.setFillType(fillType);
+ canvas->drawPath(path, fillPaint);
+ canvas->restore();
+ }
+} +## +
+#Const kWinding_FillType
+Specifies fill as area is enclosed by a non-zero sum of Contour Directions.
+##
+#Const kEvenOdd_FillType
+Specifies fill as area enclosed by an odd number of Contours.
+##
+#Const kInverseWinding_FillType
+Specifies fill as area is enclosed by a zero sum of Contour Directions.
+##
+#Const kInverseEvenOdd_FillType
+Specifies fill as area enclosed by an even number of Contours.
+##
+
+#Example
+#Height 230
+void draw(SkCanvas* canvas) {
+ SkPath path;
+ path.addRect({20, 10, 80, 70}, SkPath::kCW_Direction);
+ path.addRect({40, 30, 100, 90}, SkPath::kCW_Direction);
+ SkPaint strokePaint;
+ strokePaint.setStyle(SkPaint::kStroke_Style);
+ SkRect clipRect = {0, 0, 128, 128};
+ canvas->drawPath(path, strokePaint);
+ canvas->drawLine({0, 50}, {120, 50}, strokePaint);
+ SkPaint textPaint;
+ textPaint.setAntiAlias(true);
+ textPaint.setTextAlign(SkPaint::kCenter_Align);
+ SkScalar textHPos[] = { 10, 30, 60, 90, 110 };
+ canvas->drawPosTextH("01210", 5, textHPos, 48, textPaint);
+ textPaint.setTextSize(18);
+ canvas->translate(0, 128);
+ canvas->scale(.5f, .5f);
+ canvas->drawString("inverse", 384, 150, textPaint);
+ SkPaint fillPaint;
+ for (auto fillType : { SkPath::kWinding_FillType, SkPath::kEvenOdd_FillType,
+ SkPath::kInverseWinding_FillType, SkPath::kInverseEvenOdd_FillType } ) {
+ canvas->save();
+ canvas->clipRect(clipRect);
+ path.setFillType(fillType);
+ canvas->drawPath(path, fillPaint);
+ canvas->restore();
+ canvas->drawString(fillType & 1 ? "even-odd" : "winding", 64, 170, textPaint);
+ canvas->translate(128, 0);
+ }
+}
+##
+
+#SeeAlso SkPaint::Style Direction getFillType setFillType
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method FillType getFillType() const
+
+Returns FillType, the rule used to fill Path. FillType of a new Path is
+kWinding_FillType.
+
+#Return one of: kWinding_FillType, kEvenOdd_FillType, kInverseWinding_FillType,
+kInverseEvenOdd_FillType.
+##
+
+#Example
+ SkPath path;
+ SkDebugf("default path fill type is %s\n",
+ path.getFillType() == SkPath::kWinding_FillType ? "kWinding_FillType" :
+ path.getFillType() == SkPath::kEvenOdd_FillType ? "kEvenOdd_FillType" :
+ path.getFillType() == SkPath::kInverseWinding_FillType ? "kInverseWinding_FillType" :
+ "kInverseEvenOdd_FillType");
+#StdOut
+default path fill type is kWinding_FillType
+##
+##
+
+#SeeAlso FillType setFillType isInverseFillType
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method void setFillType(FillType ft)
+
+Sets FillType, the rule used to fill Path. While setFillType does not check
+that ft is legal, values outside of FillType are not supported.
+
+#Param ft one of: kWinding_FillType, kEvenOdd_FillType, kInverseWinding_FillType,
+kInverseEvenOdd_FillType.
+##
+
+#Example
+#Description
+If empty Path is set to inverse FillType, it fills all pixels.
+##
+#Height 64
+ SkPath path;
+ path.setFillType(SkPath::kInverseWinding_FillType);
+ SkPaint paint;
+ paint.setColor(SK_ColorBLUE);
+ canvas->drawPath(path, paint);
+##
+
+#SeeAlso FillType getFillType toggleInverseFillType
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method bool isInverseFillType() const
+
+Returns if FillType describes area outside Path geometry. The inverse fill area
+extends indefinitely.
+
+#Return true if FillType is kInverseWinding_FillType or kInverseEvenOdd_FillType. ##
+
+#Example
+ SkPath path;
+ SkDebugf("default path fill type is inverse: %s\n",
+ path.isInverseFillType() ? "true" : "false");
+#StdOut
+default path fill type is inverse: false
+##
+##
+
+#SeeAlso FillType getFillType setFillType toggleInverseFillType
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method void toggleInverseFillType()
+
+Replace FillType with its inverse. The inverse of FillType describes the area
+unmodified by the original FillType.
+
+#Table
+#Legend
+# FillType # toggled FillType ##
+##
+# kWinding_FillType # kInverseWinding_FillType ##
+# kEvenOdd_FillType # kInverseEvenOdd_FillType ##
+# kInverseWinding_FillType # kWinding_FillType ##
+# kInverseEvenOdd_FillType # kEvenOdd_FillType ##
+##
+
+#Example
+#Description
+Path drawn normally and through its inverse touches every pixel once.
+##
+#Height 100
+SkPath path;
+SkPaint paint;
+paint.setColor(SK_ColorRED);
+paint.setTextSize(80); +paint.getTextPath("ABC", 3, 20, 80, &path); +canvas->drawPath(path, paint);
+path.toggleInverseFillType();
+paint.setColor(SK_ColorGREEN);
+canvas->drawPath(path, paint);
+##
+
+#SeeAlso FillType getFillType setFillType isInverseFillType
+
+##
+
+#Subtopic Fill_Type ## +
+# ------------------------------------------------------------------------------
+ +#Subtopic Convexity +
+#Enum Convexity
+
+#Code
+ enum Convexity {
+ kUnknown_Convexity,
+ kConvex_Convexity,
+ kConcave_Convexity
+ };
+##
+
+Path is convex if it contains one Contour and Contour loops no more than +360 degrees, and Contour angles all have same Direction. Convex Path +may have better performance and require fewer resources on GPU_Surface. + +Path is concave when either at least one Direction change is clockwise and
+another is counterclockwise, or the sum of the changes in Direction is not 360
+degrees.
+
+Initially Path Convexity is kUnknown_Convexity. Path Convexity is computed
+if needed by destination Surface.
+
+#Const kUnknown_Convexity
+ Indicates Convexity has not been determined.
+##
+#Const kConvex_Convexity
+ Path has one Contour made of a simple geometry without indentations.
+##
+#Const kConcave_Convexity
+ Path has more than one Contour, or a geometry with indentations.
+##
+
+#Example
+void draw(SkCanvas* canvas) {
+ SkPaint paint;
+ SkPoint quad[] = {{70, 70}, {20, 20}, {120, 20}, {120, 120}};
+ const char* labels[] = { "unknown", "convex", "concave" };
+ for (SkScalar x : { 40, 100 } ) {
+ SkPath path;
+ quad[0].fX = x;
+ path.addPoly(quad, SK_ARRAY_COUNT(quad), true);
+ canvas->drawPath(path, paint);
+ canvas->drawString(labels[(int) path.getConvexity()], 30, 100, paint);
+ canvas->translate(100, 100);
+ }
+}
+##
+
+#SeeAlso Contour Direction getConvexity getConvexityOrUnknown setConvexity isConvex
+
+#Enum Convexity ##
+
+#Method Convexity getConvexity() const
+
+Computes Convexity if required, and returns stored value.
+Convexity is computed if stored value is kUnknown_Convexity,
+or if Path has been altered since Convexity was computed or set.
+
+#Return Computed or stored Convexity. ##
+
+#Example
+void draw(SkCanvas* canvas) {
+ auto debugster = [](const char* prefix, const SkPath& path) -> void {
+ SkDebugf("%s path convexity is %s\n", prefix,
+ SkPath::kUnknown_Convexity == path.getConvexity() ? "unknown" :
+ SkPath::kConvex_Convexity == path.getConvexity() ? "convex" : "concave"); };
+ SkPath path;
+ debugster("initial", path);
+ path.lineTo(50, 0);
+ debugster("first line", path);
+ path.lineTo(50, 50);
+ debugster("second line", path);
+ path.lineTo(100, 50);
+ debugster("third line", path);
+}
+##
+
+#SeeAlso Convexity Contour Direction getConvexityOrUnknown setConvexity isConvex
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method Convexity getConvexityOrUnknown() const
+
+Returns last computed Convexity, or kUnknown_Convexity if
+Path has been altered since Convexity was computed or set.
+
+#Return Stored Convexity. ##
+
+#Example
+#Description
+Convexity is unknown unless getConvexity is called without a subsequent call
+that alters the path.
+##
+void draw(SkCanvas* canvas) {
+ auto debugster = [](const char* prefix, const SkPath& path) -> void {
+ SkDebugf("%s path convexity is %s\n", prefix,
+ SkPath::kUnknown_Convexity == path.getConvexityOrUnknown() ? "unknown" :
+ SkPath::kConvex_Convexity == path.getConvexityOrUnknown() ? "convex" : "concave"); };
+ SkPath path;
+ debugster("initial", path);
+ path.lineTo(50, 0);
+ debugster("first line", path);
+ path.getConvexity();
+ path.lineTo(50, 50);
+ debugster("second line", path);
+ path.lineTo(100, 50);
+ path.getConvexity();
+ debugster("third line", path);
+}
+##
+
+#SeeAlso Convexity Contour Direction getConvexity setConvexity isConvex
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method void setConvexity(Convexity convexity)
+
+Stores convexity so that it is later returned by getConvexity or getConvexityOrUnknown.
+convexity may differ from getConvexity, although setting an incorrect value may
+cause incorrect or inefficient drawing.
+
+If convexity is kUnknown_Convexity: getConvexity will
+compute Convexity, and getConvexityOrUnknown will return kUnknown_Convexity.
+
+If convexity is kConvex_Convexity or kConcave_Convexity, getConvexity
+and getConvexityOrUnknown will return convexity until the path is
+altered.
+
+#Param convexity One of kUnknown_Convexity, kConvex_Convexity, or kConcave_Convexity. ##
+
+#Example
+void draw(SkCanvas* canvas) {
+ auto debugster = [](const char* prefix, const SkPath& path) -> void {
+ SkDebugf("%s path convexity is %s\n", prefix,
+ SkPath::kUnknown_Convexity == path.getConvexity() ? "unknown" :
+ SkPath::kConvex_Convexity == path.getConvexity() ? "convex" : "concave"); };
+ SkPoint quad[] = {{70, 70}, {20, 20}, {120, 20}, {120, 120}};
+ SkPath path;
+ path.addPoly(quad, SK_ARRAY_COUNT(quad), true);
+ debugster("initial", path);
+ path.setConvexity(SkPath::kConcave_Convexity);
+ debugster("after forcing concave", path);
+ path.setConvexity(SkPath::kUnknown_Convexity);
+ debugster("after forcing unknown", path);
+}
+##
+
+#SeeAlso Convexity Contour Direction getConvexity getConvexityOrUnknown isConvex
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method bool isConvex() const
+
+Computes Convexity if required, and returns true if value is kConvex_Convexity.
+If setConvexity was called with kConvex_Convexity or kConcave_Convexity, and
+the path has not been altered, Convexity is not recomputed.
+
+#Return true if Convexity stored or computed is kConvex_Convexity. ##
+
+#Example
+#Description
+Concave shape is erroneously considered convex after a forced call to
+setConvexity.
+##
+void draw(SkCanvas* canvas) {
+ SkPaint paint;
+ SkPoint quad[] = {{70, 70}, {20, 20}, {120, 20}, {120, 120}};
+ for (SkScalar x : { 40, 100 } ) {
+ SkPath path;
+ quad[0].fX = x;
+ path.addPoly(quad, SK_ARRAY_COUNT(quad), true);
+ path.setConvexity(SkPath::kConvex_Convexity);
+ canvas->drawPath(path, paint);
+ canvas->drawString(path.isConvex() ? "convex" : "not convex", 30, 100, paint);
+ canvas->translate(100, 100);
+ }
+}
+##
+
+#SeeAlso Convexity Contour Direction getConvexity getConvexityOrUnknown setConvexity
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method void setIsConvex(bool isConvex)
+
+#Deprecated
+Use setConvexity.
+##
+
+##
+
+#Subtopic Convexity ##
+
+# ------------------------------------------------------------------------------
+
+#Method bool isOval(SkRect* rect, Direction* dir = nullptr,
+ unsigned* start = nullptr) const
+
+Path is Oval if constructed by addCircle, addOval; and in some cases,
+addRoundRect, addRRect. Path constructed with conicTo or rConicTo will not
+return true though Path draws Oval.
+
+isOval triggers performance optimizations on some GPU_Surface implementations.
+
+#Param rect storage for bounding Rect of Oval. Oval is Circle if rect width
+equals rect height. Unwritten if Path is not Oval. May be nullptr.
+##
+#Param dir storage for Direction; kCW_Direction if clockwise, kCCW_Direction if
+counterclockwise. Unwritten if Path is not Oval. May be nullptr.
+##
+#Param start storage for start of Oval: 0 for top,
+1 for right, 2 for bottom, 3 for left. Unwritten if Path is not Oval. May be nullptr.
+##
+
+#Return true if Path was constructed by method that reduces to Oval. ##
+
+#Example
+void draw(SkCanvas* canvas) {
+ SkPaint paint;
+ SkPath path;
+ path.addOval({20, 20, 220, 220}, SkPath::kCW_Direction, 1);
+ SkRect bounds;
+ SkPath::Direction direction;
+ unsigned start;
+ path.isOval(&bounds, &direction, &start);
+ paint.setColor(0xFF9FBFFF);
+ canvas->drawRect(bounds, paint);
+ paint.setColor(0x3f000000);
+ canvas->drawPath(path, paint);
+ paint.setColor(SK_ColorBLACK);
+ canvas->rotate(start * 90, bounds.centerX(), bounds.centerY());
+ char startText = '0' + start;
+ paint.setTextSize(20);
+ canvas->drawText(&startText, 1, bounds.centerX(), bounds.fTop + 20, paint);
+ paint.setStyle(SkPaint::kStroke_Style);
+ paint.setStrokeWidth(4);
+ path.reset();
+ path.addArc(bounds, -90, SkPath::kCW_Direction == direction ? 90 : -90);
+ path.rLineTo(20, -20);
+ canvas->drawPath(path, paint);
+}
+##
+
+#SeeAlso Oval addCircle addOval
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method bool isRRect(SkRRect* rrect, Direction* dir = nullptr,
+ unsigned* start = nullptr) const
+
+Path is Round_Rect if constructed by addRoundRect, addRRect; and if construction
+is not empty, not Rect, and not Oval. Path constructed with other other calls
+will not return true though Path draws Round_Rect.
+
+isRRect triggers performance optimizations on some GPU_Surface implementations.
+
+#Param rrect storage for bounding Rect of Round_Rect.
+Unwritten if Path is not Round_Rect. May be nullptr.
+##
+#Param dir storage for Direction; kCW_Direction if clockwise, kCCW_Direction if
+counterclockwise. Unwritten if Path is not Round_Rect. May be nullptr.
+##
+#Param start storage for start of Round_Rect: 0 for top,
+1 for right, 2 for bottom, 3 for left. Unwritten if Path is not Round_Rect. May be nullptr.
+##
+
+#Return true for Round_Rect Path constructed by addRoundRect or addRRect. ##
+
+#Example
+void draw(SkCanvas* canvas) {
+ SkPaint paint;
+ SkPath path;
+ path.addRRect(SkRRect::MakeRectXY({20, 20, 220, 220}, 30, 50), SkPath::kCCW_Direction, 3);
+ SkRRect rrect;
+ SkPath::Direction direction;
+ unsigned start;
+ path.isRRect(&rrect, &direction, &start);
+ const SkRect& bounds = rrect.rect();
+ paint.setColor(0xFF9FBFFF);
+ canvas->drawRect(bounds, paint);
+ paint.setColor(0x3f000000);
+ canvas->drawPath(path, paint);
+ paint.setColor(SK_ColorBLACK);
+ canvas->rotate(start * 90, bounds.centerX(), bounds.centerY());
+ char startText = '0' + start;
+ paint.setTextSize(20);
+ canvas->drawText(&startText, 1, bounds.centerX(), bounds.fTop + 20, paint);
+ paint.setStyle(SkPaint::kStroke_Style);
+ paint.setStrokeWidth(4);
+ path.reset();
+ path.addArc(bounds, -90, SkPath::kCW_Direction == direction ? 90 : -90);
+ path.rLineTo(20, -20);
+ canvas->drawPath(path, paint);
+}
+##
+
+#SeeAlso Round_Rect addRoundRect addRRect
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method void reset()
+
+Sets Path to its intial state.
+Removes Verb_Array, Point_Array, and Weights, and sets FillType to kWinding_FillType.
+Internal storage associated with Path is released.
+
+#Example
+ SkPath path1, path2;
+ path1.setFillType(SkPath::kInverseWinding_FillType);
+ path1.addRect({10, 20, 30, 40});
+ SkDebugf("path1 %c= path2\n", path1 == path2 ? '=' : '!');
+ path1.reset();
+ SkDebugf("path1 %c= path2\n", path1 == path2 ? '=' : '!');
+##
+
+#SeeAlso rewind()
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method void rewind()
+
+Sets Path to its intial state, preserving internal storage.
+Removes Verb_Array, Point_Array, and Weights, and sets FillType to kWinding_FillType.
+Internal storage associated with Path is retained.
+
+Use rewind() instead of reset() if Path storage will be reused and performance
+is critical.
+
+#Example
+#Description
+Although path1 retains its internal storage, it is indistinguishable from
+a newly initialized path.
+##
+ SkPath path1, path2;
+ path1.setFillType(SkPath::kInverseWinding_FillType);
+ path1.addRect({10, 20, 30, 40});
+ SkDebugf("path1 %c= path2\n", path1 == path2 ? '=' : '!');
+ path1.rewind();
+ SkDebugf("path1 %c= path2\n", path1 == path2 ? '=' : '!');
+##
+
+#SeeAlso reset()
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method bool isEmpty() const
+
+Empty Path may have FillType but has no SkPoint, Verb, or Conic_Weight.
+SkPath() constructs empty Path; reset() and (rewind) make Path empty.
+
+#Return true if the path contains no Verb array. ##
+
+#Example
+void draw(SkCanvas* canvas) {
+ auto debugster = [](const char* prefix, const SkPath& path) -> void {
+ SkDebugf("%s path is %s" "empty\n", prefix, path.isEmpty() ? "" : "not ");
+ };
+ SkPath path;
+ debugster("initial", path);
+ path.moveTo(0, 0);
+ debugster("after moveTo", path);
+ path.rewind();
+ debugster("after rewind", path);
+ path.lineTo(0, 0);
+ debugster("after lineTo", path);
+ path.reset();
+ debugster("after reset", path);
+}
+#StdOut
+initial path is empty
+after moveTo path is not empty
+after rewind path is empty
+after lineTo path is not empty
+after reset path is empty
+##
+##
+
+#SeeAlso SkPath() reset() rewind()
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method bool isLastContourClosed() const
+
+Contour is closed if Path Verb array was last modified by close(). When stroked,
+closed Contour draws Paint_Stroke_Join instead of Paint_Stroke_Cap at first and last Point.
+
+#Return true if the last Contour ends with a kClose_Verb. ##
+
+#Example
+#Description
+close() has no effect if Path is empty; isLastContourClosed() returns
+false until Path has geometry followed by close().
+##
+void draw(SkCanvas* canvas) {
+ auto debugster = [](const char* prefix, const SkPath& path) -> void {
+ SkDebugf("%s last contour is %s" "closed\n", prefix,
+ path.isLastContourClosed() ? "" : "not ");
+ };
+ SkPath path;
+ debugster("initial", path);
+ path.close();
+ debugster("after close", path);
+ path.lineTo(0, 0);
+ debugster("after lineTo", path);
+ path.close();
+ debugster("after close", path);
+}
+#StdOut
+initial last contour is not closed
+after close last contour is not closed
+after lineTo last contour is not closed
+after close last contour is closed
+##
+##
+
+#SeeAlso close()
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method bool isFinite() const
+
+Finite Point array values are between negative SK_ScalarMax and
+positive SK_ScalarMax. Any Point array value of
+SK_ScalarInfinity, SK_ScalarNegativeInfinity, or SK_ScalarNaN
+cause isFinite to return false.
+
+#Return true if all Point values are finite. ##
+
+#Example
+void draw(SkCanvas* canvas) {
+ auto debugster = [](const char* prefix, const SkPath& path) -> void {
+ SkDebugf("%s path is %s" "finite\n", prefix, path.isFinite() ? "" : "not ");
+ };
+ SkPath path;
+ debugster("initial", path);
+ path.lineTo(SK_ScalarMax, SK_ScalarMax);
+ debugster("after line", path);
+ SkMatrix matrix;
+ matrix.setScale(2, 2);
+ path.transform(matrix);
+ debugster("after scale", path);
+}
+#StdOut
+initial path is finite
+after line path is finite
+after scale path is not finite
+##
+##
+
+#SeeAlso SkScalar
+##
+
+# ------------------------------------------------------------------------------
+
+#Method bool isVolatile() const
+
+Returns true if the path is volatile; it will not be altered or discarded
+by the caller after it is drawn. Paths by default have volatile set false, allowing
+Surface to attach a cache of data which speeds repeated drawing. If true, Surface
+may not speed repeated drawing.
+
+#Return true if caller will alter Path after drawing. ##
+
+#Example
+ SkPath path;
+ SkDebugf("volatile by default is %s\n", path.isVolatile() ? "true" : "false");
+#StdOut
+volatile by default is false
+##
+##
+
+#SeeAlso setIsVolatile
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method void setIsVolatile(bool isVolatile)
+
+Specify whether Path is volatile; whether it will be altered or discarded
+by the caller after it is drawn. Paths by default have volatile set false, allowing
+Device to attach a cache of data which speeds repeated drawing.
+
+Mark temporary paths, discarded or modified after use, as volatile
+to inform Device that the path need not be cached.
+
+Mark animating Path volatile to improve performance.
+Mark unchanging Path non-volative to improve repeated rendering.
+
+Raster_Surface Path draws are affected by volatile for some shadows.
+GPU_Surface Path draws are affected by volatile for some shadows and concave geometries.
+
+#Param isVolatile true if caller will alter Path after drawing. ##
+
+#Example
+#Height 50
+#Width 50
+ SkPaint paint;
+ paint.setStyle(SkPaint::kStroke_Style);
+ SkPath path;
+ path.setIsVolatile(true);
+ path.lineTo(40, 40);
+ canvas->drawPath(path, paint);
+ path.rewind();
+ path.moveTo(0, 40);
+ path.lineTo(40, 0);
+ canvas->drawPath(path, paint);
+##
+
+#ToDo tie example to bench to show how volatile affects speed or dm to show resource usage ##
+
+#SeeAlso isVolatile
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method static bool IsLineDegenerate(const SkPoint& p1, const SkPoint& p2, bool exact)
+
+Test if Line between Point pair is degenerate.
+Line with no length or that moves a very short distance is degenerate; it is
+treated as a point.
+
+#Param p1 Line start point. ##
+#Param p2 Line end point. ##
+#Param exact If true, returns true only if p1 equals p2. If false, returns true
+ if p1 equals or nearly equals p2.
+##
+
+#Return true if Line is degenerate; its length is effectively zero. ##
+
+#Example
+#Description
+As single precision floats, 100 and 100.000001f have the same bit representation,
+and are exactly equal. 100 and 100.0001f have different bit representations, and
+are not exactly equal, but are nearly equal.
+##
+void draw(SkCanvas* canvas) {
+ SkPoint points[] = { {100, 100}, {100.000001f, 100.000001f}, {100.0001f, 100.0001f} };
+ for (size_t i = 0; i < SK_ARRAY_COUNT(points) - 1; ++i) {
+ for (bool exact : { false, true } ) {
+ SkDebugf("line from (%1.8g,%1.8g) to (%1.8g,%1.8g) is %s" "degenerate, %s\n",
+ points[i].fX, points[i].fY, points[i + 1].fX, points[i + 1].fY,
+ SkPath::IsLineDegenerate(points[i], points[i + 1], exact)
+ ? "" : "not ", exact ? "exactly" : "nearly");
+ }
+ }
+}
+#StdOut
+line from (100,100) to (100,100) is degenerate, nearly
+line from (100,100) to (100,100) is degenerate, exactly
+line from (100,100) to (100.0001,100.0001) is degenerate, nearly
+line from (100,100) to (100.0001,100.0001) is not degenerate, exactly
+#StdOut ##
+##
+
+#SeeAlso IsQuadDegenerate IsCubicDegenerate SkPoint::equalsWithinTolerance
+##
+
+# ------------------------------------------------------------------------------
+
+#Method static bool IsQuadDegenerate(const SkPoint& p1, const SkPoint& p2,
+ const SkPoint& p3, bool exact)
+
+Test if Quad is degenerate.
+Quad with no length or that moves a very short distance is degenerate; it is
+treated as a point.
+
+#Param p1 Quad start point. ##
+#Param p2 Quad control point. ##
+#Param p3 Quad end point. ##
+#Param exact If true, returns true only if p1, p2, and p3 are equal.
+ If false, returns true if p1, p2, and p3 are equal or nearly equal.
+##
+
+#Return true if Quad is degenerate; its length is effectively zero. ##
+
+#Example
+#Description
+As single precision floats: 100, 100.00001f, and 100.00002f have different bit representations
+but nearly the same value. Translating all three by 1000 gives them the same bit representation;
+the fractional portion of the number can't be represented by the float and is lost.
+##
+void draw(SkCanvas* canvas) {
+ auto debugster = [](const SkPath& path, bool exact) -> void {
+ SkDebugf("quad (%1.8g,%1.8g), (%1.8g,%1.8g), (%1.8g,%1.8g) is %s" "degenerate, %s\n",
+ path.getPoint(0).fX, path.getPoint(0).fY, path.getPoint(1).fX,
+ path.getPoint(1).fY, path.getPoint(2).fX, path.getPoint(2).fY,
+ SkPath::IsQuadDegenerate(path.getPoint(0), path.getPoint(1), path.getPoint(2), exact) ?
+ "" : "not ", exact ? "exactly" : "nearly");
+ };
+ SkPath path, offset;
+ path.moveTo({100, 100});
+ path.quadTo({100.00001f, 100.00001f}, {100.00002f, 100.00002f});
+ offset.addPath(path, 1000, 1000);
+ for (bool exact : { false, true } ) {
+ debugster(path, exact);
+ debugster(offset, exact);
+ }
+}
+#StdOut
+quad (100,100), (100.00001,100.00001), (100.00002,100.00002) is degenerate, nearly
+quad (1100,1100), (1100,1100), (1100,1100) is degenerate, nearly
+quad (100,100), (100.00001,100.00001), (100.00002,100.00002) is not degenerate, exactly
+quad (1100,1100), (1100,1100), (1100,1100) is degenerate, exactly
+#StdOut ##
+##
+
+#SeeAlso IsLineDegenerate IsCubicDegenerate SkPoint::equalsWithinTolerance
+##
+
+# ------------------------------------------------------------------------------
+
+#Method static bool IsCubicDegenerate(const SkPoint& p1, const SkPoint& p2,
+ const SkPoint& p3, const SkPoint& p4, bool exact)
+
+Test if Cubic is degenerate.
+Cubic with no length or that moves a very short distance is degenerate; it is
+treated as a point.
+
+#Param p1 Cubic start point. ##
+#Param p2 Cubic control point 1. ##
+#Param p3 Cubic control point 2. ##
+#Param p4 Cubic end point. ##
+#Param exact If true, returns true only if p1, p2, p3, and p4 are equal.
+ If false, returns true if p1, p2, p3, and p4 are equal or nearly equal.
+##
+
+#Return true if Cubic is degenerate; its length is effectively zero. ##
+
+#Example
+void draw(SkCanvas* canvas) {
+ SkPoint points[] = {{1, 0}, {0, 0}, {0, 0}, {0, 0}};
+ SkScalar step = 1;
+ SkScalar prior, length, degenerate;
+ do {
+ prior = points[0].fX;
+ step /= 2;
+ if (SkPath::IsCubicDegenerate(points[0], points[1], points[2], points[3], false)) {
+ degenerate = prior;
+ points[0].fX += step;
+ } else {
+ length = prior;
+ points[0].fX -= step;
+ }
+ } while (prior != points[0].fX);
+ SkDebugf("%1.8g is degenerate\n", degenerate);
+ SkDebugf("%1.8g is length\n", length);
+}
+#StdOut
+0.00024414062 is degenerate
+0.00024414065 is length
+#StdOut ##
+##
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method bool isLine(SkPoint line[2]) const
+
+Returns true if Path contains only one Line;
+Path_Verb array has two entries: kMove_Verb, kLine_Verb.
+If Path contains one Line and line is not nullptr, line is set to
+Line start point and Line end point.
+Returns false if Path is not one Line; line is unaltered.
+
+#Param line storage for Line. May be nullptr. ##
+
+#Return true if Path contains exactly one Line. ##
+
+#Example
+void draw(SkCanvas* canvas) {
+ auto debugster = [](const char* prefix, const SkPath& path) -> void {
+ SkPoint line[2];
+ if (path.isLine(line)) {
+ SkDebugf("%s is line (%1.8g,%1.8g) (%1.8g,%1.8g)\n", prefix,
+ line[0].fX, line[0].fY, line[1].fX, line[1].fY);
+ } else {
+ SkDebugf("%s is not line\n", prefix);
+ }
+ };
+ SkPath path;
+ debugster("empty", path);
+ path.lineTo(0, 0);
+ debugster("zero line", path);
+ path.rewind();
+ path.moveTo(10, 10);
+ path.lineTo(20, 20);
+ debugster("line", path);
+ path.moveTo(20, 20);
+ debugster("second move", path);
+}
+#StdOut
+empty is not line
+zero line is line (0,0) (0,0)
+line is line (10,10) (20,20)
+second move is not line
+##
+##
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Subtopic Point_Array +#Alias Point_Arrays + +Point_Array contains Points satisfying the allocated Points for +each Verb in Verb_Array. For instance, Path containing one Contour with Line +and Quad is described by Verb_Array: move to, line to, quad to; and +one Point for move, one Point for Line, two Points for Quad; totaling four Points. + +Point_Array may be read directly from Path with getPoints, or inspected with +getPoint, with Iter, or with RawIter. +
+#Method int getPoints(SkPoint points[], int max) const
+
+Returns number of points in Path. Up to max points are copied.
+points may be nullptr; then, max must be zero.
+If max is greater than number of points, excess points storage is unaltered.
+
+#Param points storage for Path Point array. May be nullptr. ##
+#Param max Number of points alloted in points storage; must be greater than or equal to zero. ##
+
+#Return Path Point array length. ##
+
+#Example
+void draw(SkCanvas* canvas) {
+ auto debugster = [](const char* prefix, const SkPath& path, SkPoint* points, int max) -> void {
+ int count = path.getPoints(points, max);
+ SkDebugf("%s point count: %d ", prefix, count);
+ for (int i = 0; i < SkTMin(count, max) && points; ++i) {
+ SkDebugf("(%1.8g,%1.8g) ", points[i].fX, points[i].fY);
+ }
+ SkDebugf("\n");
+ };
+ SkPath path;
+ path.lineTo(20, 20);
+ path.lineTo(-10, -10);
+ SkPoint points[3];
+ debugster("no points", path, nullptr, 0);
+ debugster("zero max", path, points, 0);
+ debugster("too small", path, points, 2);
+ debugster("just right", path, points, path.countPoints());
+}
+#StdOut
+no points point count: 3
+zero max point count: 3
+too small point count: 3 (0,0) (20,20)
+just right point count: 3 (0,0) (20,20) (-10,-10)
+##
+##
+
+#SeeAlso countPoints getPoint
+##
+
+#Method int countPoints() const
+
+Returns the number of points in Path.
+Point count is initially zero.
+
+#Return Path Point array length. ##
+
+#Example
+void draw(SkCanvas* canvas) {
+ auto debugster = [](const char* prefix, const SkPath& path) -> void {
+ SkDebugf("%s point count: %d\n", prefix, path.countPoints());
+ };
+ SkPath path;
+ debugster("empty", path);
+ path.lineTo(0, 0);
+ debugster("zero line", path);
+ path.rewind();
+ path.moveTo(10, 10);
+ path.lineTo(20, 20);
+ debugster("line", path);
+ path.moveTo(20, 20);
+ debugster("second move", path);
+}
+#StdOut
+empty point count: 0
+zero line point count: 2
+line point count: 2
+second move point count: 3
+##
+##
+
+#SeeAlso getPoints
+##
+
+#Method SkPoint getPoint(int index) const
+
+Returns Point at index in Point_Array. Valid range for index is
+0 to countPoints - 1.
+If the index is out of range, getPoint returns (0, 0).
+
+#Param index Point_Array element selector. ##
+
+#Return Point_Array value or (0, 0). ##
+
+#Example
+void draw(SkCanvas* canvas) {
+ auto debugster = [](const char* prefix, const SkPath& path) -> void {
+ SkDebugf("%s point count: %d\n", prefix, path.countPoints());
+ };
+ SkPath path;
+ path.lineTo(20, 20);
+ path.offset(-10, -10);
+ for (int i= 0; i < path.countPoints(); ++i) {
+ SkDebugf("point %d: (%1.8g,%1.8g)\n", i, path.getPoint(i).fX, path.getPoint(i).fY);
+ }
+}
+#StdOut
+point 0: (-10,-10)
+point 1: (10,10)
+##
+##
+
+#SeeAlso countPoints getPoints
+##
+
+
+#Subtopic Point_Array ##
+
+# ------------------------------------------------------------------------------
+#Subtopic Verb_Array + +Verb_Array always starts with kMove_Verb. +If kClose_Verb is not the last entry, it is always followed by kMove_Verb; +the quantity of kMove_Verb equals the Contour count. +Verb_Array does not include or count kDone_Verb; it is a convenience +returned when iterating through Verb_Array. + +Verb_Array may be read directly from Path with getVerbs, or inspected with Iter, +or with RawIter. +
+#Method int countVerbs() const
+
+Returns the number of Verbs: kMove_Verb, kLine_Verb, kQuad_Verb, kConic_Verb,
+kCubic_Verb, and kClose_Verb; added to Path.
+
+#Return Length of Verb_Array. ##
+
+#Example
+SkPath path;
+SkDebugf("empty verb count: %d\n", path.countVerbs());
+path.addRoundRect({10, 20, 30, 40}, 5, 5);
+SkDebugf("round rect verb count: %d\n", path.countVerbs());
+#StdOut
+empty verb count: 0
+round rect verb count: 10
+##
+##
+
+#SeeAlso getVerbs Iter RawIter
+
+##
+
+#Method int getVerbs(uint8_t verbs[], int max) const
+
+Returns the number of verbs in the path. Up to max verbs are copied. The
+verbs are copied as one byte per verb.
+
+#Param verbs If not null, receives up to max verbs ##
+#Param max The maximum number of verbs to copy into verbs ##
+
+#Return the actual number of verbs in the path ##
+
+#Example
+void draw(SkCanvas* canvas) {
+ auto debugster = [](const char* prefix, const SkPath& path, uint8_t* verbs, int max) -> void {
+ int count = path.getVerbs(verbs, max);
+ SkDebugf("%s verb count: %d ", prefix, count);
+ const char* verbStr[] = { "move", "line", "quad", "conic", "cubic", "close" };
+ for (int i = 0; i < SkTMin(count, max) && verbs; ++i) {
+ SkDebugf("%s ", verbStr[verbs[i]]);
+ }
+ SkDebugf("\n");
+ };
+ SkPath path;
+ path.lineTo(20, 20);
+ path.lineTo(-10, -10);
+ uint8_t verbs[3];
+ debugster("no verbs", path, nullptr, 0);
+ debugster("zero max", path, verbs, 0);
+ debugster("too small", path, verbs, 2);
+ debugster("just right", path, verbs, path.countVerbs());
+}
+#StdOut
+no verbs verb count: 3
+zero max verb count: 3
+too small verb count: 3 move line
+just right verb count: 3 move line line
+##
+##
+
+#SeeAlso countVerbs getPoints Iter RawIter
+##
+ +#Subtopic Verb_Array ## +
+# ------------------------------------------------------------------------------
+
+#Method void swap(SkPath& other)
+
+Exchanges the Verb_Array, Point_Array, Weights, and Fill_Type with other.
+Cached state is also exchanged. swap() internally exchanges pointers, so
+it is lightweight and does not allocate memory.
+
+swap() usage has largely been replaced by operator=(const SkPath& path).
+Paths do not copy their content on assignment util they are written to,
+making assignment as efficient as swap().
+
+#Param other Path exchanged by value. ##
+
+#Example
+SkPath path1, path2;
+path1.addRect({10, 20, 30, 40});
+path1.swap(path2);
+const SkRect& b1 = path1.getBounds();
+SkDebugf("path1 bounds = %g, %g, %g, %g\n", b1.fLeft, b1.fTop, b1.fRight, b1.fBottom);
+const SkRect& b2 = path2.getBounds();
+SkDebugf("path2 bounds = %g, %g, %g, %g\n", b2.fLeft, b2.fTop, b2.fRight, b2.fBottom);
+#StdOut
+path1 bounds = 0, 0, 0, 0
+path2 bounds = 10, 20, 30, 40
+#StdOut ##
+##
+
+#SeeAlso operator=(const SkPath& path)
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method const SkRect& getBounds() const
+
+Returns minimum and maximum x and y values of Point_Array. If Path contains
+no points, getBounds returns (0, 0, 0, 0). Returned bounds width and height may
+be larger or smaller than area affected when Path is drawn.
+
+getBounds includes all Points added to Path, including Points associated with
+kMove_Verb that define empty Contours.
+
+#Return bounds of all Points in Point_Array. ##
+
+#Example
+#Description
+Bounds of upright Circle can be predicted from center and radius.
+Bounds of rotated Circle includes control Points outside of filled area.
+##
+ auto debugster = [](const char* prefix, const SkPath& path) -> void {
+ const SkRect& bounds = path.getBounds();
+ SkDebugf("%s bounds = %g, %g, %g, %g\n", prefix,
+ bounds.fLeft, bounds.fTop, bounds.fRight, bounds.fBottom);
+ };
+ SkPath path;
+ debugster("empty", path);
+ path.addCircle(50, 45, 25);
+ debugster("circle", path);
+ SkMatrix matrix;
+ matrix.setRotate(45, 50, 45);
+ path.transform(matrix);
+ debugster("rotated circle", path);
+#StdOut
+empty bounds = 0, 0, 0, 0
+circle bounds = 25, 20, 75, 70
+rotated circle bounds = 14.6447, 9.64466, 85.3553, 80.3553
+##
+##
+
+#SeeAlso computeTightBounds updateBoundsCache
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method void updateBoundsCache() const
+
+Update internal bounds so that subsequent calls to getBounds are instantaneous.
+Unaltered copies of Path may also access cached bounds through getBounds.
+
+For now, updateBoundsCache is identical to getBounds, where the
+returned value is ignored.
+
+updateBoundsCache prepares a Path subsequently drawn from multiple threads,
+to avoid a race condition where each draw separately computes the bounds.
+
+#Example
+ double times[2] = { 0, 0 };
+ for (int i = 0; i < 10000; ++i) {
+ SkPath path;
+ for (int j = 1; j < 100; ++ j) {
+ path.addCircle(50 + j, 45 + j, 25 + j);
+ }
+ if (1 & i) {
+ path.updateBoundsCache();
+ }
+ double start = SkTime::GetNSecs();
+ (void) path.getBounds();
+ times[1 & i] += SkTime::GetNSecs() - start;
+ }
+ SkDebugf("uncached avg: %g ms\n", times[0] * 1e-6);
+ SkDebugf("cached avg: %g ms\n", times[1] * 1e-6);
+#StdOut
+#Volatile
+uncached avg: 0.18048 ms
+cached avg: 0.182784 ms
+##
+##
+
+#SeeAlso getBounds
+#ToDo the results don't make sense, need to profile to figure this out ##
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method SkRect computeTightBounds() const
+
+Returns minimum and maximum x and y values of the lines and curves in Path.
+If Path contains no points, computeTightBounds returns (0, 0, 0, 0).
+Returned bounds width and height may be larger or smaller than area affected
+when Path is drawn.
+
+computeTightBounds behaves identically to getBounds when Path contains
+only lines. If Path contains curves, compute computeTightBounds includes
+the maximum extent of the Quad, Conic, or Cubic; is slower,
+and does not cache the result.
+
+Like getBounds, computeTightBounds includes Points associated with
+kMove_Verb that define empty Contours.
+
+#Return ##
+
+#Example
+ auto debugster = [](const char* prefix, const SkPath& path) -> void {
+ const SkRect& bounds = path.computeTightBounds();
+ SkDebugf("%s bounds = %g, %g, %g, %g\n", prefix,
+ bounds.fLeft, bounds.fTop, bounds.fRight, bounds.fBottom);
+ };
+ SkPath path;
+ debugster("empty", path);
+ path.addCircle(50, 45, 25);
+ debugster("circle", path);
+ SkMatrix matrix;
+ matrix.setRotate(45, 50, 45);
+ path.transform(matrix);
+ debugster("rotated circle", path);
+#StdOut
+empty bounds = 0, 0, 0, 0
+circle bounds = 25, 20, 75, 70
+rotated circle bounds = 25, 20, 75, 70
+##
+##
+
+#SeeAlso getBounds
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method bool conservativelyContainsRect(const SkRect& rect) const
+
+Returns true if rect is contained by Path.
+May return false when rect is contained by Path.
+
+For now, only returns true if Path has one Contour and is convex.
+rect may share points and edges with Path and be contained.
+If rect is empty, that is, it has zero width or height; conservativelyContainsRect
+returns true if the Point or Line described by rect is contained by Path.
+
+#Param rect Rect, Line, or Point checked for containment. ##
+
+#Return true if rect is contained. ##
+
+#Example
+#Height 140
+#Description
+Rect is drawn in blue if it is contained by red Path.
+##
+void draw(SkCanvas* canvas) {
+ SkPath path;
+ path.addRoundRect({10, 20, 54, 120}, 10, 20);
+ SkRect tests[] = {
+ { 10, 40, 54, 80 },
+ { 25, 20, 39, 120 },
+ { 15, 25, 49, 115 },
+ { 13, 27, 51, 113 },
+ };
+ for (unsigned i = 0; i < SK_ARRAY_COUNT(tests); ++i) {
+ SkPaint paint;
+ paint.setColor(SK_ColorRED);
+ canvas->drawPath(path, paint);
+ bool rectInPath = path.conservativelyContainsRect(tests[i]);
+ paint.setColor(rectInPath ? SK_ColorBLUE : SK_ColorBLACK);
+ canvas->drawRect(tests[i], paint);
+ canvas->translate(64, 0);
+ }
+}
+##
+
+#SeeAlso contains Op Rect Convexity
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method void incReserve(unsigned extraPtCount)
+
+grows Path Verb_Array and Point_Array to contain extraPtCount additional Points.
+incReserve may improve performance and use less memory by
+reducing the number and size of allocations when creating Path.
+
+#Param extraPtCount number of additional Points to preallocate. ##
+
+#Example
+#Height 192
+void draw(SkCanvas* canvas) {
+ auto addPoly = [](int sides, SkScalar size, SkPath* path) -> void {
+ path->moveTo(size, 0);
+ for (int i = 1; i < sides; i++) {
+ SkScalar c, s = SkScalarSinCos(SK_ScalarPI * 2 * i / sides, &c);
+ path->lineTo(c * size, s * size);
+ }
+ path->close();
+ };
+ SkPath path;
+ path.incReserve(3 + 4 + 5 + 6 + 7 + 8 + 9);
+ for (int sides = 3; sides < 10; ++sides) {
+ addPoly(sides, sides, &path);
+ }
+ SkMatrix matrix;
+ matrix.setScale(10, 10, -10, -10);
+ path.transform(matrix);
+ SkPaint paint;
+ paint.setStyle(SkPaint::kStroke_Style);
+ canvas->drawPath(path, paint);
+}
+##
+
+#SeeAlso Point_Array
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method void moveTo(SkScalar x, SkScalar y)
+
+Adds beginning of Contour at Point (x, y).
+
+#Param x x-coordinate of Contour start. ##
+#Param y y-coordinate of Contour start. ##
+
+#Example
+ #Width 140
+ #Height 100
+ void draw(SkCanvas* canvas) {
+ SkRect rect = { 20, 20, 120, 80 };
+ SkPath path;
+ path.addRect(rect);
+ path.moveTo(rect.fLeft, rect.fTop);
+ path.lineTo(rect.fRight, rect.fBottom);
+ path.moveTo(rect.fLeft, rect.fBottom);
+ path.lineTo(rect.fRight, rect.fTop);
+ SkPaint paint;
+ paint.setStyle(SkPaint::kStroke_Style);
+ canvas->drawPath(path, paint);
+ }
+##
+
+#SeeAlso Contour lineTo rMoveTo quadTo conicTo cubicTo close()
+
+##
+
+#Method void moveTo(const SkPoint& p)
+
+Adds beginning of Contour at Point p.
+
+#Param p Contour start. ##
+
+#Example
+ #Width 128
+ #Height 128
+void draw(SkCanvas* canvas) {
+ SkPoint data[][3] = {{{30,40},{60,60},{90,30}}, {{30,120},{60,100},{90,120}},
+ {{60,100},{60,40},{70,30}}, {{60,40},{50,20},{70,30}}};
+ SkPath path;
+ for (unsigned i = 0; i < SK_ARRAY_COUNT(data); ++i) {
+ path.moveTo(data[i][0]);
+ path.lineTo(data[i][1]);
+ path.lineTo(data[i][2]);
+ }
+ SkPaint paint;
+ paint.setStyle(SkPaint::kStroke_Style);
+ canvas->drawPath(path, paint);
+}
+##
+
+#SeeAlso Contour lineTo rMoveTo quadTo conicTo cubicTo close()
+
+##
+
+#Method void rMoveTo(SkScalar dx, SkScalar dy)
+
+Adds beginning of Contour relative to Last_Point.
+If Path is empty, starts Contour at (dx, dy).
+Otherwise, start Contour at Last_Point offset by (dx, dy).
+rMoveTo stands for relative move to.
+
+#Param dx offset from Last_Point x to Contour start x. ##
+#Param dy offset from Last_Point y to Contour start y. ##
+
+#Example
+ #Height 100
+ SkPath path;
+ path.addRect({20, 20, 80, 80}, SkPath::kCW_Direction, 2);
+ path.rMoveTo(25, 2);
+ SkVector arrow[] = {{0, -4}, {-20, 0}, {0, -3}, {-5, 5}, {5, 5}, {0, -3}, {20, 0}};
+ for (unsigned i = 0; i < SK_ARRAY_COUNT(arrow); ++i) {
+ path.rLineTo(arrow[i].fX, arrow[i].fY);
+ }
+ SkPaint paint;
+ canvas->drawPath(path, paint);
+ SkPoint lastPt;
+ path.getLastPt(&lastPt);
+ canvas->drawString("start", lastPt.fX, lastPt.fY, paint);
+##
+
+#SeeAlso Contour lineTo moveTo quadTo conicTo cubicTo close()
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method void lineTo(SkScalar x, SkScalar y)
+
+Adds Line from Last_Point to (x, y). If Path is empty, or last Verb is
+kClose_Verb, Last_Point is set to (0, 0) before adding Line.
+
+lineTo appends kMove_Verb to Verb_Array and (0, 0) to Point_Array, if needed.
+lineTo then appends kLine_Verb to Verb_Array and (x, y) to Point_Array.
+
+#Param x end of added Line in x. ##
+#Param y end of added Line in y. ##
+
+#Example
+#Height 100
+###$
+void draw(SkCanvas* canvas) {
+ SkPaint paint;
+ paint.setAntiAlias(true);
+ paint.setTextSize(72);
+ canvas->drawString("#", 120, 80, paint);
+ paint.setStyle(SkPaint::kStroke_Style);
+ paint.setStrokeWidth(5);
+ SkPath path;
+ SkPoint hash[] = {{58, 28}, {43, 80}, {37, 45}, {85, 45}};
+ SkVector offsets[] = {{0, 0}, {17, 0}, {0, 0}, {-5, 17}};
+ unsigned o = 0;
+ for (unsigned i = 0; i < SK_ARRAY_COUNT(hash); i += 2) {
+ for (unsigned j = 0; j < 2; o++, j++) {
+ path.moveTo(hash[i].fX + offsets[o].fX, hash[i].fY + offsets[o].fY);
+ path.lineTo(hash[i + 1].fX + offsets[o].fX, hash[i + 1].fY + offsets[o].fY);
+ }
+ }
+ canvas->drawPath(path, paint);
+}
+$$$#
+##
+
+#SeeAlso Contour moveTo rLineTo addRect
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method void lineTo(const SkPoint& p)
+
+Adds Line from Last_Point to Point p. If Path is empty, or last Verb is
+kClose_Verb, Last_Point is set to (0, 0) before adding Line.
+
+lineTo first appends kMove_Verb to Verb_Array and (0, 0) to Point_Array, if needed.
+lineTo then appends kLine_Verb to Verb_Array and Point p to Point_Array.
+
+#Param p end Point of added Line. ##
+
+#Example
+#Height 100
+ SkPath path;
+ SkVector oxo[] = {{25, 25}, {35, 35}, {25, 35}, {35, 25},
+ {40, 20}, {40, 80}, {60, 20}, {60, 80},
+ {20, 40}, {80, 40}, {20, 60}, {80, 60}};
+ for (unsigned i = 0; i < SK_ARRAY_COUNT(oxo); i += 2) {
+ path.moveTo(oxo[i]);
+ path.lineTo(oxo[i + 1]);
+ }
+ SkPaint paint;
+ paint.setStyle(SkPaint::kStroke_Style);
+ canvas->drawPath(path, paint);
+##
+
+#SeeAlso Contour moveTo rLineTo addRect
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method void rLineTo(SkScalar dx, SkScalar dy)
+
+Adds Line from Last_Point to Vector (dx, dy). If Path is empty, or last Verb is
+kClose_Verb, Last_Point is set to (0, 0) before adding Line.
+
+rLineTo first appends kMove_Verb to Verb_Array and (0, 0) to Point_Array, if needed.
+rLineTo then appends kLine_Verb to Verb_Array and Line end to Point_Array.
+Line end is Last_Point plus Vector (dx, dy).
+rLineTo stands for relative line to.
+
+#Param dx offset from Last_Point x to Line end x. ##
+#Param dy offset from Last_Point y to Line end y. ##
+
+#Example
+#Height 128
+void draw(SkCanvas* canvas) {
+ SkPaint paint;
+ paint.setAntiAlias(true);
+ paint.setStyle(SkPaint::kStroke_Style);
+ SkPath path;
+ path.moveTo(10, 98);
+ SkScalar x = 0, y = 0;
+ for (int i = 10; i < 100; i += 5) {
+ x += i * ((i & 2) - 1);
+ y += i * (((i + 1) & 2) - 1);
+ path.rLineTo(x, y);
+
+ }
+ canvas->drawPath(path, paint);
+}
+##
+
+#SeeAlso Contour moveTo lineTo addRect
+
+##
+
+# ------------------------------------------------------------------------------
+#Topic Quad + +Quad describes a quadratic Bezier, a second-order curve identical to a section +of a parabola. Quad begins at a start Point, curves towards a control Point, +and then curves to an end Point. + +#Example +#Height 110 +void draw(SkCanvas* canvas) {
+ SkPaint paint;
+ paint.setAntiAlias(true);
+ paint.setStyle(SkPaint::kStroke_Style);
+ SkPoint quadPts[] = {{20, 90}, {120, 10}, {220, 90}};
+ canvas->drawLine(quadPts[0], quadPts[1], paint);
+ canvas->drawLine(quadPts[1], quadPts[2], paint);
+ SkPath path;
+ path.moveTo(quadPts[0]);
+ path.quadTo(quadPts[1], quadPts[2]);
+ paint.setStrokeWidth(3);
+ canvas->drawPath(path, paint);
+}
+## + +Quad is a special case of Conic where Conic_Weight is set to one. + +Quad is always contained by the triangle connecting its three Points. Quad +begins tangent to the line between start Point and control Point, and ends +tangent to the line between control Point and end Point. + +#Example +#Height 160 +void draw(SkCanvas* canvas) {
+ SkPaint paint;
+ paint.setAntiAlias(true);
+ paint.setStyle(SkPaint::kStroke_Style);
+ SkPoint quadPts[] = {{20, 150}, {120, 10}, {220, 150}};
+ SkColor colors[] = { 0xff88ff00, 0xff0088bb, 0xff6600cc, 0xffbb3377 };
+ for (unsigned i = 0; i < SK_ARRAY_COUNT(colors); ++i) {
+ paint.setColor(0x7fffffff & colors[i]);
+ paint.setStrokeWidth(1);
+ canvas->drawLine(quadPts[0], quadPts[1], paint);
+ canvas->drawLine(quadPts[1], quadPts[2], paint);
+ SkPath path;
+ path.moveTo(quadPts[0]);
+ path.quadTo(quadPts[1], quadPts[2]);
+ paint.setStrokeWidth(3);
+ paint.setColor(colors[i]);
+ canvas->drawPath(path, paint);
+ quadPts[1].fY += 30;
+ }
+} +## +
+#Method void quadTo(SkScalar x1, SkScalar y1, SkScalar x2, SkScalar y2)
+
+ Adds Quad from Last_Point towards (x1, y1), to (x2, y2).
+ If Path is empty, or last Verb is kClose_Verb, Last_Point is set to (0, 0)
+ before adding Quad.
+
+ quadTo appends kMove_Verb to Verb_Array and (0, 0) to Point_Array, if needed.
+ quadTo then appends kQuad_Verb to Verb_Array; and (x1, y1), (x2, y2)
+ to Point_Array.
+
+ #Param x1 control Point of Quad in x. ##
+ #Param y1 control Point of Quad in y. ##
+ #Param x2 end Point of Quad in x. ##
+ #Param y2 end Point of Quad in y. ##
+
+ #Example
+ void draw(SkCanvas* canvas) {
+ SkPaint paint;
+ paint.setAntiAlias(true);
+ paint.setStyle(SkPaint::kStroke_Style);
+ SkPath path;
+ path.moveTo(0, -10);
+ for (int i = 0; i < 128; i += 16) {
+ path.quadTo( 10 + i, -10 - i, 10 + i, 0);
+ path.quadTo( 14 + i, 14 + i, 0, 14 + i);
+ path.quadTo(-18 - i, 18 + i, -18 - i, 0);
+ path.quadTo(-22 - i, -22 - i, 0, -22 - i);
+ }
+ path.offset(128, 128);
+ canvas->drawPath(path, paint); + }
+ ##
+
+ #SeeAlso Contour moveTo conicTo rQuadTo
+
+##
+
+#Method void quadTo(const SkPoint& p1, const SkPoint& p2)
+
+ Adds Quad from Last_Point towards Point p1, to Point p2.
+ If Path is empty, or last Verb is kClose_Verb, Last_Point is set to (0, 0)
+ before adding Quad.
+
+ quadTo appends kMove_Verb to Verb_Array and (0, 0) to Point_Array, if needed.
+ quadTo then appends kQuad_Verb to Verb_Array; and Points p1, p2
+ to Point_Array.
+
+ #Param p1 control Point of added Quad. ##
+ #Param p2 end Point of added Quad. ##
+
+ #Example
+ void draw(SkCanvas* canvas) {
+ SkPaint paint;
+ paint.setStyle(SkPaint::kStroke_Style);
+ paint.setAntiAlias(true);
+ SkPath path;
+ SkPoint pts[] = {{128, 10}, {10, 214}, {236, 214}};
+ path.moveTo(pts[1]);
+ for (int i = 0; i < 3; ++i) {
+ path.quadTo(pts[i % 3], pts[(i + 2) % 3]);
+ }
+ canvas->drawPath(path, paint);
+ }
+ ##
+
+ #SeeAlso Contour moveTo conicTo rQuadTo
+
+##
+
+#Method void rQuadTo(SkScalar dx1, SkScalar dy1, SkScalar dx2, SkScalar dy2)
+
+ Adds Quad from Last_Point towards Vector (dx1, dy1), to Vector (dx2, dy2).
+ If Path is empty, or last Verb
+ is kClose_Verb, Last_Point is set to (0, 0) before adding Quad.
+
+ rQuadTo first appends kMove_Verb to Verb_Array and (0, 0) to Point_Array,
+ if needed. rQuadTo then appends kQuad_Verb to Verb_Array; and appends Quad
+ control and Quad end to Point_Array.
+ Quad control is Last_Point plus Vector (dx1, dy1).
+ Quad end is Last_Point plus Vector (dx2, dy2).
+ rQuadTo stands for relative quad to.
+
+ #Param dx1 offset from Last_Point x to Quad control x. ##
+ #Param dy1 offset from Last_Point x to Quad control y. ##
+ #Param dx2 offset from Last_Point x to Quad end x. ##
+ #Param dy2 offset from Last_Point x to Quad end y. ##
+
+ #Example
+ void draw(SkCanvas* canvas) {
+ SkPaint paint;
+ paint.setAntiAlias(true);
+ SkPath path;
+ path.moveTo(128, 20);
+ path.rQuadTo(-6, 10, -7, 10);
+ for (int i = 1; i < 32; i += 4) {
+ path.rQuadTo(10 + i, 10 + i, 10 + i * 4, 10);
+ path.rQuadTo(-10 - i, 10 + i, -10 - (i + 2) * 4, 10);
+ }
+ path.quadTo(92, 220, 128, 215);
+ canvas->drawPath(path, paint);
+ }
+ ##
+
+ #SeeAlso Contour moveTo conicTo quadTo
+
+##
+
+#Topic Quad ## +
+# ------------------------------------------------------------------------------
+
+#Topic Conic +#Alias Conics + +Conic describes a conical section: a piece of an ellipse, or a piece of a +parabola, or a piece of a hyperbola. Conic begins at a start Point, +curves towards a control Point, and then curves to an end Point. The influence +of the control Point is determined by Conic_Weight. + +Each Conic in Path adds two Points and one Weight. Weights in Path may be +inspected with Iter, or with RawIter. + +#Subtopic Weight +#Alias Weights + +Weight determines both the strength of the control Point and the type of Conic. +If Weight is exactly one, then Conic is identical to Quad; it is always a +parabolic segment. + + + +#Example +#Description +When Conic weight is one, Quad is added to path; the two are identical. +## +void draw(SkCanvas* canvas) {
+ const char* verbNames[] = { "move", "line", "quad", "conic", "cubic", "close", "done" };
+ const int pointCount[] = { 1 , 2 , 3 , 3 , 4 , 1 , 0 };
+ SkPath path;
+ path.conicTo(20, 30, 50, 60, 1);
+ SkPath::Iter iter(path, false);
+ SkPath::Verb verb;
+ do {
+ SkPoint points[4];
+ verb = iter.next(points);
+ SkDebugf("%s ", verbNames[(int) verb]);
+ for (int i = 0; i < pointCount[(int) verb]; ++i) {
+ SkDebugf("{%g, %g}, ", points[i].fX, points[i].fY);
+ }
+ if (SkPath::kConic_Verb == verb) {
+ SkDebugf("weight = %g", iter.conicWeight());
+ }
+ SkDebugf("\n");
+ } while (SkPath::kDone_Verb != verb);
+} +#StdOut +move {0, 0},
+quad {0, 0}, {20, 30}, {50, 60},
+done +## +## + +If weight is less than one, Conic is an elliptical segment. + +#Example +#Description +A 90 degree circular arc has the weight +#Formula +1 / sqrt(2) +## + . +## +void draw(SkCanvas* canvas) {
+ const char* verbNames[] = { "move", "line", "quad", "conic", "cubic", "close", "done" };
+ const int pointCount[] = { 1 , 2 , 3 , 3 , 4 , 1 , 0 };
+ SkPath path;
+ path.arcTo(20, 0, 20, 20, 20);
+ SkPath::Iter iter(path, false);
+ SkPath::Verb verb;
+ do {
+ SkPoint points[4];
+ verb = iter.next(points);
+ SkDebugf("%s ", verbNames[(int) verb]);
+ for (int i = 0; i < pointCount[(int) verb]; ++i) {
+ SkDebugf("{%g, %g}, ", points[i].fX, points[i].fY);
+ }
+ if (SkPath::kConic_Verb == verb) {
+ SkDebugf("weight = %g", iter.conicWeight());
+ }
+ SkDebugf("\n");
+ } while (SkPath::kDone_Verb != verb);
+} +#StdOut +move {0, 0},
+conic {0, 0}, {20, 0}, {20, 20}, weight = 0.707107
+done +## +## + +If weight is greater than one, Conic is a hyperbolic segment. As w gets large, +a hyperbolic segment can be approximated by straight lines connecting the +control Point with the end Points. + +#Example +void draw(SkCanvas* canvas) {
+ const char* verbNames[] = { "move", "line", "quad", "conic", "cubic", "close", "done" };
+ const int pointCount[] = { 1 , 2 , 3 , 3 , 4 , 1 , 0 };
+ SkPath path;
+ path.conicTo(20, 0, 20, 20, SK_ScalarInfinity);
+ SkPath::Iter iter(path, false);
+ SkPath::Verb verb;
+ do {
+ SkPoint points[4];
+ verb = iter.next(points);
+ SkDebugf("%s ", verbNames[(int) verb]);
+ for (int i = 0; i < pointCount[(int) verb]; ++i) {
+ SkDebugf("{%g, %g}, ", points[i].fX, points[i].fY);
+ }
+ if (SkPath::kConic_Verb == verb) {
+ SkDebugf("weight = %g", iter.conicWeight());
+ }
+ SkDebugf("\n");
+ } while (SkPath::kDone_Verb != verb);
+} +#StdOut +move {0, 0},
+line {0, 0}, {20, 0},
+line {20, 0}, {20, 20},
+done +## +## + +#Subtopic Weight ## +
+#Method void conicTo(SkScalar x1, SkScalar y1, SkScalar x2, SkScalar y2,
+ SkScalar w)
+
+ Adds Conic from Last_Point towards (x1, y1), to (x2, y2), weighted by w.
+ If Path is empty, or last Verb is kClose_Verb, Last_Point is set to (0, 0)
+ before adding Conic.
+
+ conicTo appends kMove_Verb to Verb_Array and (0, 0) to Point_Array, if needed.
+
+ If w is finite and not one, conicTo then appends kConic_Verb to Verb_Array;
+ and (x1, y1), (x2, y2) to Point_Array; and w to Weights.
+
+ If w is one, conicTo appends kQuad_Verb to Verb_Array, and
+ (x1, y1), (x2, y2) to Point_Array.
+
+ If w is not finite, conicTo appends kLine_Verb twice to Verb_Array, and
+ (x1, y1), (x2, y2) to Point_Array.
+
+ #Param x1 control Point of Conic in x. ##
+ #Param y1 control Point of Conic in y. ##
+ #Param x2 end Point of Conic in x. ##
+ #Param y2 end Point of Conic in y. ##
+ #Param w weight of added Conic. ##
+
+ #Example
+ #Height 160 + #Description
+ As weight increases, curve is pulled towards control point.
+ The bottom two curves are elliptical; the next is parabolic; the
+ top curve is hyperbolic.
+ ##
+void draw(SkCanvas* canvas) {
+ SkPaint paint;
+ paint.setAntiAlias(true);
+ paint.setStyle(SkPaint::kStroke_Style);
+ SkPoint conicPts[] = {{20, 150}, {120, 10}, {220, 150}};
+ canvas->drawLine(conicPts[0], conicPts[1], paint);
+ canvas->drawLine(conicPts[1], conicPts[2], paint);
+ SkColor colors[] = { 0xff88ff00, 0xff0088bb, 0xff6600cc, 0xffbb3377 };
+ paint.setStrokeWidth(3);
+ SkScalar weight = 0.5f;
+ for (unsigned i = 0; i < SK_ARRAY_COUNT(colors); ++i) {
+ SkPath path;
+ path.moveTo(conicPts[0]);
+ path.conicTo(conicPts[1], conicPts[2], weight);
+ paint.setColor(colors[i]);
+ canvas->drawPath(path, paint);
+ weight += 0.25f;
+ }
+}
+ ##
+
+ #SeeAlso rConicTo arcTo addArc quadTo
+
+##
+
+#Method void conicTo(const SkPoint& p1, const SkPoint& p2, SkScalar w)
+
+ Adds Conic from Last_Point towards Point p1, to Point p2, weighted by w.
+ If Path is empty, or last Verb is kClose_Verb, Last_Point is set to (0, 0)
+ before adding Conic.
+
+ conicTo appends kMove_Verb to Verb_Array and (0, 0) to Point_Array, if needed.
+
+ If w is finite and not one, conicTo then appends kConic_Verb to Verb_Array;
+ and Points p1, p2 to Point_Array; and w to Weights.
+
+ If w is one, conicTo appends kQuad_Verb to Verb_Array, and Points p1, p2
+ to Point_Array.
+
+ If w is not finite, conicTo appends kLine_Verb twice to Verb_Array, and
+ Points p1, p2 to Point_Array.
+
+ #Param p1 control Point of added Conic. ##
+ #Param p2 end Point of added Conic. ##
+ #Param w weight of added Conic. ##
+
+ #Example
+ #Height 128 + #Description
+ Conics and arcs use identical representations. As the arc sweep increases
+ the conic weight also increases, but remains smaller than one.
+ ##
+void draw(SkCanvas* canvas) {
+ SkPaint paint;
+ paint.setAntiAlias(true);
+ paint.setStyle(SkPaint::kStroke_Style);
+ SkRect oval = {0, 20, 120, 140};
+ SkPath path;
+ for (int i = 0; i < 4; ++i) {
+ path.moveTo(oval.centerX(), oval.fTop);
+ path.arcTo(oval, -90, 90 - 20 * i, false);
+ oval.inset(15, 15);
+ }
+ path.offset(100, 0);
+ SkScalar conicWeights[] = { 0.707107f, 0.819152f, 0.906308f, 0.965926f };
+ SkPoint conicPts[][3] = { { {40, 20}, {100, 20}, {100, 80} },
+ { {40, 35}, {71.509f, 35}, {82.286f, 64.6091f} },
+ { {40, 50}, {53.9892f, 50}, {62.981f, 60.7164f} },
+ { {40, 65}, {44.0192f, 65}, {47.5f, 67.0096f} } };
+ for (int i = 0; i < 4; ++i) {
+ path.moveTo(conicPts[i][0]);
+ path.conicTo(conicPts[i][1], conicPts[i][2], conicWeights[i]);
+ }
+ canvas->drawPath(path, paint);
+}
+ ##
+
+ #SeeAlso rConicTo arcTo addArc quadTo
+
+##
+
+#Method void rConicTo(SkScalar dx1, SkScalar dy1, SkScalar dx2, SkScalar dy2,
+ SkScalar w)
+
+ Adds Conic from Last_Point towards Vector (dx1, dy1), to Vector (dx2, dy2),
+ weighted by w. If Path is empty, or last Verb
+ is kClose_Verb, Last_Point is set to (0, 0) before adding Conic.
+
+ rConicTo first appends kMove_Verb to Verb_Array and (0, 0) to Point_Array,
+ if needed.
+
+ If w is finite and not one, rConicTo then appends kConic_Verb to Verb_Array,
+ and w is recorded as Conic_Weight; otherwise, if w is one, rConicTo appends
+ kQuad_Verb to Verb_Array; or if w is not finite, rConicTo appends kLine_Verb
+ twice to Verb_Array.
+
+ In all cases rConicTo then appends Points control and end to Point_Array.
+ control is Last_Point plus Vector (dx1, dy1).
+ end is Last_Point plus Vector (dx2, dy2).
+
+ rConicTo stands for relative conic to.
+
+ #Param dx1 offset from Last_Point x to Conic control x. ##
+ #Param dy1 offset from Last_Point x to Conic control y. ##
+ #Param dx2 offset from Last_Point x to Conic end x. ##
+ #Param dy2 offset from Last_Point x to Conic end y. ##
+ #Param w weight of added Conic. ##
+
+ #Example
+ #Height 140
+ void draw(SkCanvas* canvas) {
+ SkPaint paint;
+ paint.setAntiAlias(true);
+ paint.setStyle(SkPaint::kStroke_Style);
+ SkPath path;
+ path.moveTo(20, 80);
+ path.rConicTo( 60, 0, 60, 60, 0.707107f);
+ path.rConicTo( 0, -60, 60, -60, 0.707107f);
+ path.rConicTo(-60, 0, -60, -60, 0.707107f);
+ path.rConicTo( 0, 60, -60, 60, 0.707107f);
+ canvas->drawPath(path, paint);
+ }
+ ##
+
+ #SeeAlso conicTo arcTo addArc quadTo
+
+##
+
+#Topic Conic ##
+
+# ------------------------------------------------------------------------------
+#Topic Cubic +#Alias Cubics + +Cubic describes a cubic Bezier, a third-order curve. +Cubic begins at a start Point, curving towards the first control Point; +and curves from the end Point towards the second control Point. + +#Example +#Height 160 +void draw(SkCanvas* canvas) {
+ SkPaint paint;
+ paint.setAntiAlias(true);
+ paint.setStyle(SkPaint::kStroke_Style);
+ SkPoint cubicPts[] = {{20, 150}, {90, 10}, {160, 150}, {230, 10}};
+ SkColor colors[] = { 0xff88ff00, 0xff0088bb, 0xff6600cc, 0xffbb3377 };
+ for (unsigned i = 0; i < SK_ARRAY_COUNT(colors); ++i) {
+ paint.setColor(0x7fffffff & colors[i]);
+ paint.setStrokeWidth(1);
+ for (unsigned j = 0; j < 3; ++j) {
+ canvas->drawLine(cubicPts[j], cubicPts[j + 1], paint);
+ }
+ SkPath path;
+ path.moveTo(cubicPts[0]);
+ path.cubicTo(cubicPts[1], cubicPts[2], cubicPts[3]);
+ paint.setStrokeWidth(3);
+ paint.setColor(colors[i]);
+ canvas->drawPath(path, paint);
+ cubicPts[1].fY += 30;
+ cubicPts[2].fX += 30;
+ }
+} +## +
+#Method void cubicTo(SkScalar x1, SkScalar y1, SkScalar x2, SkScalar y2,
+ SkScalar x3, SkScalar y3)
+
+Adds Cubic from Last_Point towards (x1, y1), then towards (x2, y2), ending at
+(x3, y3). If Path is empty, or last Verb is kClose_Verb, Last_Point is set to
+(0, 0) before adding Cubic.
+
+cubicTo appends kMove_Verb to Verb_Array and (0, 0) to Point_Array, if needed.
+cubicTo then appends kCubic_Verb to Verb_Array; and (x1, y1), (x2, y2), (x3, y3)
+to Point_Array.
+
+#Param x1 first control Point of Cubic in x. ##
+#Param y1 first control Point of Cubic in y. ##
+#Param x2 second control Point of Cubic in x. ##
+#Param y2 second control Point of Cubic in y. ##
+#Param x3 end Point of Cubic in x. ##
+#Param y3 end Point of Cubic in y. ##
+
+#Example
+void draw(SkCanvas* canvas) {
+ SkPaint paint;
+ paint.setAntiAlias(true);
+ paint.setStyle(SkPaint::kStroke_Style);
+ SkPath path;
+ path.moveTo(0, -10);
+ for (int i = 0; i < 128; i += 16) {
+ SkScalar c = i * 0.5f;
+ path.cubicTo( 10 + c, -10 - i, 10 + i, -10 - c, 10 + i, 0);
+ path.cubicTo( 14 + i, 14 + c, 14 + c, 14 + i, 0, 14 + i);
+ path.cubicTo(-18 - c, 18 + i, -18 - i, 18 + c, -18 - i, 0);
+ path.cubicTo(-22 - i, -22 - c, -22 - c, -22 - i, 0, -22 - i);
+ }
+ path.offset(128, 128);
+ canvas->drawPath(path, paint);
+}
+##
+
+#SeeAlso Contour moveTo rCubicTo quadTo
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method void cubicTo(const SkPoint& p1, const SkPoint& p2, const SkPoint& p3)
+
+Adds Cubic from Last_Point towards Point p1, then towards Point p2, ending at
+Point p3. If Path is empty, or last Verb is kClose_Verb, Last_Point is set to
+(0, 0) before adding Cubic.
+
+cubicTo appends kMove_Verb to Verb_Array and (0, 0) to Point_Array, if needed.
+cubicTo then appends kCubic_Verb to Verb_Array; and Points p1, p2, p3
+to Point_Array.
+
+#Param p1 first control Point of Cubic. ##
+#Param p2 second control Point of Cubic. ##
+#Param p3 end Point of Cubic. ##
+
+#Example
+#Height 84
+ SkPaint paint;
+ paint.setAntiAlias(true);
+ paint.setStyle(SkPaint::kStroke_Style);
+ SkPoint pts[] = { {20, 20}, {300, 80}, {-140, 90}, {220, 10} };
+ SkPath path;
+ path.moveTo(pts[0]);
+ path.cubicTo(pts[1], pts[2], pts[3]);
+ canvas->drawPath(path, paint);
+##
+
+#SeeAlso Contour moveTo rCubicTo quadTo
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method void rCubicTo(SkScalar x1, SkScalar y1, SkScalar x2, SkScalar y2,
+ SkScalar x3, SkScalar y3)
+
+ Adds Cubic from Last_Point towards Vector (dx1, dy1), then towards
+ Vector (dx2, dy2), to Vector (dx3, dy3).
+ If Path is empty, or last Verb
+ is kClose_Verb, Last_Point is set to (0, 0) before adding Cubic.
+
+ rCubicTo first appends kMove_Verb to Verb_Array and (0, 0) to Point_Array,
+ if needed. rCubicTo then appends kCubic_Verb to Verb_Array; and appends Cubic
+ control and Cubic end to Point_Array.
+ Cubic control is Last_Point plus Vector (dx1, dy1).
+ Cubic end is Last_Point plus Vector (dx2, dy2).
+ rCubicTo stands for relative cubic to.
+
+ #Param x1 offset from Last_Point x to first Cubic control x. ##
+ #Param y1 offset from Last_Point x to first Cubic control y. ##
+ #Param x2 offset from Last_Point x to second Cubic control x. ##
+ #Param y2 offset from Last_Point x to second Cubic control y. ##
+ #Param x3 offset from Last_Point x to Cubic end x. ##
+ #Param y3 offset from Last_Point x to Cubic end y. ##
+
+#Example
+ void draw(SkCanvas* canvas) {
+ SkPaint paint;
+ paint.setAntiAlias(true);
+ paint.setStyle(SkPaint::kStroke_Style);
+ SkPath path;
+ path.moveTo(24, 108);
+ for (int i = 0; i < 16; i++) {
+ SkScalar sx, sy;
+ sx = SkScalarSinCos(i * SK_ScalarPI / 8, &sy);
+ path.rCubicTo(40 * sx, 4 * sy, 4 * sx, 40 * sy, 40 * sx, 40 * sy);
+ }
+ canvas->drawPath(path, paint);
+ }
+##
+
+#SeeAlso Contour moveTo cubicTo quadTo
+
+##
+
+#Topic Cubic ##
+
+# ------------------------------------------------------------------------------
+
+#Topic Arc
+
+Arc can be constructed in a number of ways. Arc may be described by part of Oval and angles,
+by start point and end point, and by radius and tangent lines. Each construction has advantages,
+and some constructions correspond to Arc drawing in graphics standards.
+
+All Arc draws are implemented by one or more Conic draws. When Conic_Weight is less than one,
+Conic describes an Arc of some Oval or Circle.
+
+arcTo(const SkRect& oval, SkScalar startAngle, SkScalar sweepAngle, bool forceMoveTo)
+describes Arc as a piece of Oval, beginning at start angle, sweeping clockwise or counterclockwise,
+which may continue Contour or start a new one. This construction is similar to PostScript and
+HTML_Canvas arcs. Variation addArc always starts new Contour. Canvas::drawArc draws without
+requiring Path.
+
+arcTo(SkScalar x1, SkScalar y1, SkScalar x2, SkScalar y2, SkScalar radius)
+describes Arc as tangent to the line (x0, y0), (x1, y1) and tangent to the line (x1, y1), (x2, y2)
+where (x0, y0) is the last Point added to Path. This construction is similar to PostScript and
+HTML_Canvas arcs.
+
+arcTo(SkScalar rx, SkScalar ry, SkScalar xAxisRotate, ArcSize largeArc, Direction sweep,
+ SkScalar x, SkScalar y)
+describes Arc as part of Oval with radii (rx, ry), beginning at
+last Point added to Path and ending at (x, y). More than one Arc satisfies this criteria,
+so additional values choose a single solution. This construction is similar to SVG arcs.
+
+conicTo describes Arc of less than 180 degrees as a pair of tangent lines and Conic_Weight.
+conicTo can represent any Arc with a sweep less than 180 degrees at any rotation. All arcTo
+constructions are converted to Conic data when added to Path.
+
+#ToDo allow example to hide source and not be exposed as fiddle since markdown / html can't
+ do the kind of table shown in the illustration.
+ example is spaced correctly on fiddle but spacing is too wide on pc
+##
+
+#Example
+#Height 300
+#Width 600
+#Description
+#List
+# <sup>1</sup> arcTo(const SkRect& oval, SkScalar startAngle, SkScalar sweepAngle, bool forceMoveTo) ##
+# <sup>2</sup> parameter sets force MoveTo ##
+# <sup>3</sup> start angle must be multiple of 90 degrees. ##
+# <sup>4</sup> arcTo(SkScalar x1, SkScalar y1, SkScalar x2, SkScalar y2, SkScalar radius) ##
+# <sup>5</sup> arcTo(SkScalar rx, SkScalar ry, SkScalar xAxisRotate, ArcSize largeArc,
+ Direction sweep, SkScalar x, SkScalar y) ##
+#List ##
+#Description ##
+#Function
+struct data {
+ const char* name;
+ char super;
+ int yn[10];
+};
+
+const data dataSet[] = {
+{ "arcTo sweep", '1', {1, 3, 1, 0, 0, 0, 0, 1, 0, 0 }},
+{ "drawArc", 0, {1, -1, 1, 1, 1, 1, 1, 0, 0, 0 }},
+{ "addArc", 0, {1, 1, 1, 4, 0, 1, 1, 1, 0, 0 }},
+{ "arcTo tangents", '4', {0, 0, 0, 0, 0, 0, 0, 1, 1, 0 }},
+{ "arcTo radii", '5', {1, 0, 1, 0, 0, 0, 0, 1, 1, 0 }},
+{ "conicTo", 0, {1, 1, 0, 0, 0, 0, 0, 1, 1, 1 }}
+};
+
+#define __degree_symbol__ "\xC2" "\xB0"
+
+const char* headers[] = {
+ "Oval part",
+ "force moveTo",
+ "can draw 180" __degree_symbol__,
+ "can draw 360" __degree_symbol__,
+ "can draw greater than 360" __degree_symbol__,
+ "ignored if radius is zero",
+ "ignored if sweep is zero",
+ "requires Path",
+ "describes rotation",
+ "describes perspective",
+};
+
+const char* yna[] = {
+ "n/a",
+ "no",
+ "yes"
+};
+
+##
+void draw(SkCanvas* canvas) {
+ SkPaint lp;
+ lp.setAntiAlias(true);
+ SkPaint tp(lp);
+ SkPaint sp(tp);
+ SkPaint bp(tp);
+ bp.setFakeBoldText(true);
+ sp.setTextSize(10);
+ lp.setColor(SK_ColorGRAY);
+ canvas->translate(0, 32);
+ const int tl = 115;
+ for (unsigned col = 0; col <= SK_ARRAY_COUNT(headers); ++col) {
+ canvas->drawLine(tl + col * 35, 100, tl + col * 35, 250, lp);
+ if (0 == col) {
+ continue;
+ }
+ canvas->drawLine(tl + col * 35, 100, tl + 100 + col * 35, 0, lp);
+ SkPath path;
+ path.moveTo(tl - 3 + col * 35, 103);
+ path.lineTo(tl + 124 + col * 35, -24);
+ canvas->drawTextOnPathHV(headers[col -1], strlen(headers[col -1]), path, 0, -9, bp);
+ }
+ for (unsigned row = 0; row <= SK_ARRAY_COUNT(dataSet); ++row) {
+ if (0 == row) {
+ canvas->drawLine(tl, 100, tl + 350, 100, lp);
+ } else {
+ canvas->drawLine(5, 100 + row * 25, tl + 350, 100 + row * 25, lp);
+ }
+ if (row == SK_ARRAY_COUNT(dataSet)) {
+ break;
+ }
+ canvas->drawString(dataSet[row].name, 5, 117 + row * 25, bp);
+ if (dataSet[row].super) {
+ SkScalar width = bp.measureText(dataSet[row].name, strlen(dataSet[row].name));
+ canvas->drawText(&dataSet[row].super, 1, 8 + width, 112 + row * 25, sp);
+ }
+ for (unsigned col = 0; col < SK_ARRAY_COUNT(headers); ++col) {
+ int val = dataSet[row].yn[col];
+ canvas->drawString(yna[SkTMin(2, val + 1)], tl + 5 + col * 35, 117 + row * 25, tp);
+ if (val > 1) {
+ char supe = '0' + val - 1;
+ canvas->drawText(&supe, 1, tl + 25 + col * 35, 112 + row * 25, sp);
+ }
+ }
+ }
+}
+#Example ##
+
+#Example
+#Height 128
+#Description
+#ToDo make this a list or table ##
+1 describes an arc from an oval, a starting angle, and a sweep angle.
+2 is similar to 1, but does not require building a path to draw.
+3 is similar to 1, but always begins new Contour.
+4 describes an arc from a pair of tangent lines and a radius.
+5 describes an arc from Oval center, arc start Point and arc end Point.
+6 describes an arc from a pair of tangent lines and a Conic_Weight.
+##
+void draw(SkCanvas* canvas) {
+ SkRect oval = {8, 8, 56, 56};
+ SkPaint ovalPaint;
+ ovalPaint.setAntiAlias(true);
+ SkPaint textPaint(ovalPaint);
+ ovalPaint.setStyle(SkPaint::kStroke_Style);
+ SkPaint arcPaint(ovalPaint);
+ arcPaint.setStrokeWidth(5);
+ arcPaint.setColor(SK_ColorBLUE);
+ canvas->translate(-64, 0);
+ for (char arcStyle = '1'; arcStyle <= '6'; ++arcStyle) {
+ '4' == arcStyle ? canvas->translate(-96, 55) : canvas->translate(64, 0);
+ canvas->drawText(&arcStyle, 1, 30, 36, textPaint);
+ canvas->drawOval(oval, ovalPaint);
+ SkPath path;
+ path.moveTo({56, 32});
+ switch (arcStyle) {
+ case '1':
+ path.arcTo(oval, 0, 90, false);
+ break;
+ case '2':
+ canvas->drawArc(oval, 0, 90, false, arcPaint);
+ continue;
+ case '3':
+ path.addArc(oval, 0, 90);
+ break;
+ case '4':
+ path.arcTo({56, 56}, {32, 56}, 24);
+ break;
+ case '5':
+ path.arcTo({24, 24}, 0, SkPath::kSmall_ArcSize, SkPath::kCW_Direction, {32, 56});
+ break;
+ case '6':
+ path.conicTo({56, 56}, {32, 56}, SK_ScalarRoot2Over2);
+ break;
+ }
+ canvas->drawPath(path, arcPaint);
+ }
+}
+#Example ##
+
+
+#Method void arcTo(const SkRect& oval, SkScalar startAngle, SkScalar sweepAngle, bool forceMoveTo)
+
+Append Arc to Path. Arc added is part of ellipse
+bounded by oval, from startAngle through sweepAngle. Both startAngle and
+sweepAngle are measured in degrees, where zero degrees is aligned with the
+positive x-axis, and positive sweeps extends Arc clockwise.
+
+arcTo adds Line connecting Path last Point to initial Arc Point if forceMoveTo
+is false and Path is not empty. Otherwise, added Contour begins with first point
+of Arc. Angles greater than -360 and less than 360 are treated modulo 360.
+
+#Param oval bounds of ellipse containing Arc. ##
+#Param startAngle starting angle of Arc in degrees. ##
+#Param sweepAngle sweep, in degrees. Positive is clockwise; treated modulo 360. ##
+#Param forceMoveTo true to start a new contour with Arc. ##
+
+#Example
+#Height 200
+#Description
+arcTo continues a previous contour when forceMoveTo is false and when Path
+is not empty.
+##
+void draw(SkCanvas* canvas) {
+ SkPaint paint;
+ SkPath path;
+ paint.setStyle(SkPaint::kStroke_Style);
+ paint.setStrokeWidth(4);
+ path.moveTo(0, 0);
+ path.arcTo({20, 20, 120, 120}, -90, 90, false);
+ canvas->drawPath(path, paint);
+ path.rewind();
+ path.arcTo({120, 20, 220, 120}, -90, 90, false);
+ canvas->drawPath(path, paint);
+ path.rewind();
+ path.moveTo(0, 0);
+ path.arcTo({20, 120, 120, 220}, -90, 90, true);
+ canvas->drawPath(path, paint);
+}
+##
+
+#SeeAlso addArc SkCanvas::drawArc conicTo
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method void arcTo(SkScalar x1, SkScalar y1, SkScalar x2, SkScalar y2, SkScalar radius)
+
+Append Arc to Path, after appending Line if needed. Arc is implemented by Conic
+weighted to describe part of Circle. Arc is contained by tangent from
+last Path point (x0, y0) to (x1, y1), and tangent from (x1, y1) to (x2, y2). Arc
+is part of Circle sized to radius, positioned so it touches both tangent lines.
+
+#ToDo allow example to hide source and not be exposed as fiddle ##
+
+#Example
+#Height 226
+void draw(SkCanvas* canvas) {
+ SkPaint tangentPaint;
+ tangentPaint.setAntiAlias(true);
+ SkPaint textPaint(tangentPaint);
+ tangentPaint.setStyle(SkPaint::kStroke_Style);
+ tangentPaint.setColor(SK_ColorGRAY);
+ SkPaint arcPaint(tangentPaint);
+ arcPaint.setStrokeWidth(5);
+ arcPaint.setColor(SK_ColorBLUE);
+ SkPath path;
+ SkPoint pts[] = { {56, 20}, {200, 20}, {90, 190} };
+ SkScalar radius = 50;
+ path.moveTo(pts[0]);
+ path.arcTo(pts[1], pts[2], radius);
+ canvas->drawLine(pts[0], pts[1], tangentPaint);
+ canvas->drawLine(pts[1], pts[2], tangentPaint);
+ SkPoint lastPt;
+ (void) path.getLastPt(&lastPt);
+ SkVector radial = pts[2] - pts[1];
+ radial.setLength(radius);
+ SkPoint center = { lastPt.fX - radial.fY, lastPt.fY + radial.fX };
+ canvas->drawCircle(center, radius, tangentPaint);
+ canvas->drawLine(lastPt, center, tangentPaint);
+ radial = pts[1] - pts[0];
+ radial.setLength(radius);
+ SkPoint arcStart = { center.fX + radial.fY, center.fY - radial.fX };
+ canvas->drawLine(center, arcStart, tangentPaint);
+ canvas->drawPath(path, arcPaint);
+ textPaint.setTextAlign(SkPaint::kRight_Align);
+ canvas->drawString("(x0, y0)", pts[0].fX - 5, pts[0].fY, textPaint);
+ textPaint.setTextAlign(SkPaint::kLeft_Align);
+ canvas->drawString("(x1, y1)", pts[1].fX + 5, pts[1].fY, textPaint);
+ textPaint.setTextAlign(SkPaint::kCenter_Align);
+ canvas->drawString("(x2, y2)", pts[2].fX, pts[2].fY + 15, textPaint);
+ textPaint.setTextAlign(SkPaint::kRight_Align);
+ canvas->drawString("radius", center.fX + 15, center.fY + 25, textPaint);
+ canvas->drawString("radius", center.fX - 3, center.fY - 16, textPaint);
+}
+##
+
+If last Path Point does not start Arc, arcTo appends connecting Line to Path.
+The length of Vector from (x1, y1) to (x2, y2) does not affect Arc.
+
+#Example
+#Height 128
+void draw(SkCanvas* canvas) {
+ SkPaint tangentPaint;
+ tangentPaint.setAntiAlias(true);
+ SkPaint textPaint(tangentPaint);
+ tangentPaint.setStyle(SkPaint::kStroke_Style);
+ tangentPaint.setColor(SK_ColorGRAY);
+ SkPaint arcPaint(tangentPaint);
+ arcPaint.setStrokeWidth(5);
+ arcPaint.setColor(SK_ColorBLUE);
+ SkPath path;
+ SkPoint pts[] = { {156, 20}, {200, 20}, {170, 50} };
+ SkScalar radius = 50;
+ path.moveTo(pts[0]);
+ path.arcTo(pts[1], pts[2], radius);
+ canvas->drawLine(pts[0], pts[1], tangentPaint);
+ canvas->drawLine(pts[1], pts[2], tangentPaint);
+ SkPoint lastPt;
+ (void) path.getLastPt(&lastPt);
+ SkVector radial = pts[2] - pts[1];
+ radial.setLength(radius);
+ SkPoint center = { lastPt.fX - radial.fY, lastPt.fY + radial.fX };
+ canvas->drawLine(lastPt, center, tangentPaint);
+ radial = pts[1] - pts[0];
+ radial.setLength(radius);
+ SkPoint arcStart = { center.fX + radial.fY, center.fY - radial.fX };
+ canvas->drawLine(center, arcStart, tangentPaint);
+ canvas->drawPath(path, arcPaint);
+ textPaint.setTextAlign(SkPaint::kCenter_Align);
+ canvas->drawString("(x0, y0)", pts[0].fX, pts[0].fY - 7, textPaint);
+ textPaint.setTextAlign(SkPaint::kLeft_Align);
+ canvas->drawString("(x1, y1)", pts[1].fX + 5, pts[1].fY, textPaint);
+ textPaint.setTextAlign(SkPaint::kCenter_Align);
+ canvas->drawString("(x2, y2)", pts[2].fX, pts[2].fY + 15, textPaint);
+ textPaint.setTextAlign(SkPaint::kRight_Align);
+ canvas->drawString("radius", center.fX + 15, center.fY + 25, textPaint);
+ canvas->drawString("radius", center.fX - 5, center.fY - 20, textPaint);
+}
+##
+
+Arc sweep is always less than 180 degrees. If radius is zero, or if
+tangents are nearly parallel, arcTo appends Line from last Path Point to (x1, y1).
+
+arcTo appends at most one Line and one Conic.
+arcTo implements the functionality of PostScript_arct and HTML_Canvas_arcTo.
+
+#Param x1 x common to pair of tangents. ##
+#Param y1 y common to pair of tangents. ##
+#Param x2 x end of second tangent. ##
+#Param y2 y end of second tangent. ##
+#Param radius distance from Arc to Circle center. ##
+
+#Example
+#Description
+arcTo is represented by Line and circular Conic in Path.
+##
+void draw(SkCanvas* canvas) {
+ SkPath path;
+ path.moveTo({156, 20});
+ path.arcTo(200, 20, 170, 50, 50);
+ SkPath::Iter iter(path, false);
+ SkPoint p[4];
+ SkPath::Verb verb;
+ while (SkPath::kDone_Verb != (verb = iter.next(p))) {
+ switch (verb) {
+ case SkPath::kMove_Verb:
+ SkDebugf("move to (%g,%g)\n", p[0].fX, p[0].fY);
+ break;
+ case SkPath::kLine_Verb:
+ SkDebugf("line (%g,%g),(%g,%g)\n", p[0].fX, p[0].fY, p[1].fX, p[1].fY);
+ break;
+ case SkPath::kConic_Verb:
+ SkDebugf("conic (%g,%g),(%g,%g),(%g,%g) weight %g\n",
+ p[0].fX, p[0].fY, p[1].fX, p[1].fY, p[2].fX, p[2].fY, iter.conicWeight());
+ break;
+ default:
+ SkDebugf("unexpected verb\n");
+ }
+ }
+}
+#StdOut
+move to (156,20)
+line (156,20),(79.2893,20)
+conic (79.2893,20),(200,20),(114.645,105.355) weight 0.382683
+##
+##
+
+#SeeAlso conicTo
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method void arcTo(const SkPoint p1, const SkPoint p2, SkScalar radius)
+
+Append Arc to Path, after appending Line if needed. Arc is implemented by Conic
+weighted to describe part of Circle. Arc is contained by tangent from
+last Path point to p1, and tangent from p1 to p2. Arc
+is part of Circle sized to radius, positioned so it touches both tangent lines.
+
+If last Path Point does not start Arc, arcTo appends connecting Line to Path.
+The length of Vector from p1 to p2 does not affect Arc.
+
+Arc sweep is always less than 180 degrees. If radius is zero, or if
+tangents are nearly parallel, arcTo appends Line from last Path Point to p1.
+
+arcTo appends at most one Line and one Conic.
+arcTo implements the functionality of PostScript_arct and HTML_Canvas_arcTo.
+
+#Param p1 Point common to pair of tangents. ##
+#Param p2 end of second tangent. ##
+#Param radius distance from Arc to Circle center. ##
+
+#Example
+#Description
+Because tangent lines are parallel, arcTo appends line from last Path Point to
+p1, but does not append a circular Conic.
+##
+void draw(SkCanvas* canvas) {
+ SkPath path;
+ path.moveTo({156, 20});
+ path.arcTo({200, 20}, {170, 20}, 50);
+ SkPath::Iter iter(path, false);
+ SkPoint p[4];
+ SkPath::Verb verb;
+ while (SkPath::kDone_Verb != (verb = iter.next(p))) {
+ switch (verb) {
+ case SkPath::kMove_Verb:
+ SkDebugf("move to (%g,%g)\n", p[0].fX, p[0].fY);
+ break;
+ case SkPath::kLine_Verb:
+ SkDebugf("line (%g,%g),(%g,%g)\n", p[0].fX, p[0].fY, p[1].fX, p[1].fY);
+ break;
+ case SkPath::kConic_Verb:
+ SkDebugf("conic (%g,%g),(%g,%g),(%g,%g) weight %g\n",
+ p[0].fX, p[0].fY, p[1].fX, p[1].fY, p[2].fX, p[2].fY, iter.conicWeight());
+ break;
+ default:
+ SkDebugf("unexpected verb\n");
+ }
+ }
+}
+#StdOut
+move to (156,20)
+line (156,20),(200,20)
+##
+##
+
+#SeeAlso conicTo
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Enum ArcSize
+
+#Code
+ enum ArcSize {
+ kSmall_ArcSize
+ kLarge_ArcSize
+ };
+##
+
+Four Oval parts with radii (rx, ry) start at last Path Point and ends at (x, y).
+ArcSize and Direction select one of the four Oval parts.
+
+#Const kSmall_ArcSize 0
+Smaller of Arc pair.
+##
+#Const kLarge_ArcSize 1
+Larger of Arc pair.
+##
+
+#Example
+#Height 160
+#Description
+Arc begins at top of Oval pair and ends at bottom. Arc can take four routes to get there.
+Two routes are large, and two routes are counterclockwise. The one route both large
+and counterclockwise is blue.
+##
+void draw(SkCanvas* canvas) {
+ SkPaint paint;
+ paint.setAntiAlias(true);
+ paint.setStyle(SkPaint::kStroke_Style);
+ for (auto sweep: { SkPath::kCW_Direction, SkPath::kCCW_Direction } ) {
+ for (auto arcSize : { SkPath::kSmall_ArcSize, SkPath::kLarge_ArcSize } ) {
+ SkPath path;
+ path.moveTo({120, 50});
+ path.arcTo(70, 40, 30, arcSize, sweep, 156, 100);
+ if (SkPath::kCCW_Direction == sweep && SkPath::kLarge_ArcSize == arcSize) {
+ paint.setColor(SK_ColorBLUE);
+ paint.setStrokeWidth(3);
+ }
+ canvas->drawPath(path, paint);
+ }
+ }
+}
+##
+
+#SeeAlso arcTo Direction
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method void arcTo(SkScalar rx, SkScalar ry, SkScalar xAxisRotate, ArcSize largeArc,
+ Direction sweep, SkScalar x, SkScalar y)
+
+Append Arc to Path. Arc is implemented by one or more Conic weighted to describe part of Oval
+with radii (rx, ry) rotated by xAxisRotate degrees. Arc curves from last Path Point to (x, y),
+choosing one of four possible routes: clockwise or counterclockwise, and smaller or larger.
+
+Arc sweep is always less than 360 degrees. arcTo appends Line to (x, y) if either radii are zero,
+or if last Path Point equals (x, y). arcTo scales radii (rx, ry) to fit last Path Point and
+(x, y) if both are greater than zero but too small.
+
+arcTo appends up to four Conic curves.
+arcTo implements the functionatlity of SVG_Arc, although SVG sweep-flag value is
+opposite the integer value of sweep; SVG sweep-flag uses 1 for clockwise, while kCW_Direction
+cast to int is zero.
+
+#Param rx radius in x before x-axis rotation. ##
+#Param ry radius in y before x-axis rotation. ##
+#Param xAxisRotate x-axis rotation in degrees; positve values are clockwise. ##
+#Param largeArc chooses smaller or larger Arc. ##
+#Param sweep chooses clockwise or counterclockwise Arc. ##
+#Param x end of Arc. ##
+#Param y end of Arc. ##
+
+#Example
+#Height 160
+void draw(SkCanvas* canvas) {
+ SkPaint paint;
+ paint.setAntiAlias(true);
+ paint.setStyle(SkPaint::kStroke_Style);
+ for (auto sweep: { SkPath::kCW_Direction, SkPath::kCCW_Direction } ) {
+ for (auto arcSize : { SkPath::kSmall_ArcSize, SkPath::kLarge_ArcSize } ) {
+ SkPath path;
+ path.moveTo({120, 50});
+ path.arcTo(70, 40, 30, arcSize, sweep, 120.1, 50);
+ if (SkPath::kCCW_Direction == sweep && SkPath::kLarge_ArcSize == arcSize) {
+ paint.setColor(SK_ColorBLUE);
+ paint.setStrokeWidth(3);
+ }
+ canvas->drawPath(path, paint);
+ }
+ }
+}
+##
+
+#SeeAlso rArcTo ArcSize Direction
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method void arcTo(const SkPoint r, SkScalar xAxisRotate, ArcSize largeArc, Direction sweep,
+ const SkPoint xy)
+
+Append Arc to Path. Arc is implemented by one or more Conic weighted to describe part of Oval
+with radii (r.fX, r.fY) rotated by xAxisRotate degrees. Arc curves from last Path Point to
+(xy.fX, xy.fY), choosing one of four possible routes: clockwise or counterclockwise,
+and smaller or larger.
+
+Arc sweep is always less than 360 degrees. arcTo appends Line to xy if either radii are zero,
+or if last Path Point equals (x, y). arcTo scales radii r to fit last Path Point and
+xy if both are greater than zero but too small.
+
+arcTo appends up to four Conic curves.
+arcTo implements the functionatlity of SVG_Arc, although SVG sweep-flag value is
+opposite the integer value of sweep; SVG sweep-flag uses 1 for clockwise, while kCW_Direction
+cast to int is zero.
+
+#Param r radii in x and y before x-axis rotation. ##
+#Param xAxisRotate x-axis rotation in degrees; positve values are clockwise. ##
+#Param largeArc chooses smaller or larger Arc. ##
+#Param sweep chooses clockwise or counterclockwise Arc. ##
+#Param xy end of Arc. ##
+
+#Example
+#Height 108
+void draw(SkCanvas* canvas) {
+ SkPaint paint;
+ SkPath path;
+ const SkPoint starts[] = {{20, 20}, {120, 20}, {70, 60}};
+ for (auto start : starts) {
+ path.moveTo(start.fX, start.fY);
+ path.rArcTo(20, 20, 0, SkPath::kSmall_ArcSize, SkPath::kCCW_Direction, 60, 0);
+ }
+ canvas->drawPath(path, paint);
+}
+##
+
+#SeeAlso rArcTo ArcSize Direction
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method void rArcTo(SkScalar rx, SkScalar ry, SkScalar xAxisRotate, ArcSize largeArc,
+ Direction sweep, SkScalar dx, SkScalar dy)
+
+Append Arc to Path, relative to last Path Point. Arc is implemented by one or
+more Conic, weighted to describe part of Oval with radii (r.fX, r.fY) rotated by
+xAxisRotate degrees. Arc curves from last Path Point (x0, y0) to
+(x0 + dx, y0 + dy), choosing one of four possible routes: clockwise or
+counterclockwise, and smaller or larger. If Path is empty, the start Arc Point
+is (0, 0).
+
+Arc sweep is always less than 360 degrees. arcTo appends Line to xy if either
+radii are zero, or if last Path Point equals (x, y). arcTo scales radii r to fit
+last Path Point and xy if both are greater than zero but too small.
+
+arcTo appends up to four Conic curves.
+arcTo implements the functionatlity of SVG_Arc, although SVG sweep-flag value is
+opposite the integer value of sweep; SVG sweep-flag uses 1 for clockwise, while
+kCW_Direction cast to int is zero.
+
+#Param rx radius in x before x-axis rotation. ##
+#Param ry radius in y before x-axis rotation. ##
+#Param xAxisRotate x-axis rotation in degrees; positve values are clockwise. ##
+#Param largeArc chooses smaller or larger Arc. ##
+#Param sweep chooses clockwise or counterclockwise Arc. ##
+#Param dx x offset end of Arc from last Path Point. ##
+#Param dy y offset end of Arc from last Path Point. ##
+
+#Example
+#Height 108
+void draw(SkCanvas* canvas) {
+ SkPaint paint;
+ SkPath path;
+ const SkPoint starts[] = {{20, 20}, {120, 20}, {70, 60}};
+ for (auto start : starts) {
+ path.moveTo(start.fX, start.fY);
+ path.rArcTo(20, 20, 0, SkPath::kSmall_ArcSize, SkPath::kCCW_Direction, 60, 0);
+ }
+ canvas->drawPath(path, paint);
+}
+##
+
+#SeeAlso arcTo ArcSize Direction
+
+##
+
+#Topic Arc ##
+
+# ------------------------------------------------------------------------------
+
+#Method void close()
+
+Append kClose_Verb to Path. A closed Contour connects the first and last Point
+with Line, forming a continous loop. Open and closed Contour draw the same
+with SkPaint::kFill_Style. With SkPaint::kStroke_Style, open Contour draws
+Paint_Stroke_Cap at Contour start and end; closed Contour draws
+Paint_Stroke_Join at Contour start and end.
+
+close() has no effect if Path is empty or last Path Verb is kClose_Verb.
+
+#Example
+void draw(SkCanvas* canvas) {
+ SkPaint paint;
+ paint.setStrokeWidth(15);
+ paint.setStrokeCap(SkPaint::kRound_Cap);
+ SkPath path;
+ const SkPoint points[] = {{20, 20}, {70, 20}, {40, 90}};
+ path.addPoly(points, SK_ARRAY_COUNT(points), false);
+ for (int loop = 0; loop < 2; ++loop) {
+ for (auto style : {SkPaint::kStroke_Style, SkPaint::kFill_Style,
+ SkPaint::kStrokeAndFill_Style} ) {
+ paint.setStyle(style);
+ canvas->drawPath(path, paint);
+ canvas->translate(85, 0);
+ }
+ path.close();
+ canvas->translate(-255, 128);
+ }
+}
+##
+
+#SeeAlso
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method static bool IsInverseFillType(FillType fill)
+
+Returns true if fill is inverted and Path with fill represents area outside
+of its geometric bounds.
+
+#Table
+#Legend
+# FillType # is inverse ##
+##
+# kWinding_FillType # false ##
+# kEvenOdd_FillType # false ##
+# kInverseWinding_FillType # true ##
+# kInverseEvenOdd_FillType # true ##
+##
+
+#Param fill one of: kWinding_FillType, kEvenOdd_FillType,
+ kInverseWinding_FillType, kInverseEvenOdd_FillType.
+##
+
+#Return true if Path fills outside its bounds. ##
+
+#Example
+#Function
+#define nameValue(fill) { SkPath::fill, #fill }
+
+##
+void draw(SkCanvas* canvas) {
+ struct {
+ SkPath::FillType fill;
+ const char* name;
+ } fills[] = {
+ nameValue(kWinding_FillType),
+ nameValue(kEvenOdd_FillType),
+ nameValue(kInverseWinding_FillType),
+ nameValue(kInverseEvenOdd_FillType),
+ };
+ for (auto fill: fills ) {
+ SkDebugf("IsInverseFillType(%s) == %s\n", fill.name, SkPath::IsInverseFillType(fill.fill) ?
+ "true" : "false");
+ }
+}
+#StdOut
+IsInverseFillType(kWinding_FillType) == false
+IsInverseFillType(kEvenOdd_FillType) == false
+IsInverseFillType(kInverseWinding_FillType) == true
+IsInverseFillType(kInverseEvenOdd_FillType) == true
+##
+##
+
+#SeeAlso FillType getFillType setFillType ConvertToNonInverseFillType
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method static FillType ConvertToNonInverseFillType(FillType fill)
+
+Returns equivalent Fill_Type representing Path fill inside its bounds.
+.
+
+#Table
+#Legend
+# FillType # inside FillType ##
+##
+# kWinding_FillType # kWinding_FillType ##
+# kEvenOdd_FillType # kEvenOdd_FillType ##
+# kInverseWinding_FillType # kWinding_FillType ##
+# kInverseEvenOdd_FillType # kEvenOdd_FillType ##
+##
+
+#Param fill one of: kWinding_FillType, kEvenOdd_FillType,
+ kInverseWinding_FillType, kInverseEvenOdd_FillType.
+##
+
+#Return fill, or kWinding_FillType or kEvenOdd_FillType if fill is inverted. ##
+
+#Example
+#Function
+#define nameValue(fill) { SkPath::fill, #fill }
+
+##
+void draw(SkCanvas* canvas) {
+ struct {
+ SkPath::FillType fill;
+ const char* name;
+ } fills[] = {
+ nameValue(kWinding_FillType),
+ nameValue(kEvenOdd_FillType),
+ nameValue(kInverseWinding_FillType),
+ nameValue(kInverseEvenOdd_FillType),
+ };
+ for (unsigned i = 0; i < SK_ARRAY_COUNT(fills); ++i) {
+ if (fills[i].fill != (SkPath::FillType) i) {
+ SkDebugf("fills array order does not match FillType enum order");
+ break;
+ }
+ SkDebugf("ConvertToNonInverseFillType(%s) == %s\n", fills[i].name,
+ fills[(int) SkPath::ConvertToNonInverseFillType(fills[i].fill)].name);
+ }
+}
+#StdOut
+ConvertToNonInverseFillType(kWinding_FillType) == kWinding_FillType
+ConvertToNonInverseFillType(kEvenOdd_FillType) == kEvenOdd_FillType
+ConvertToNonInverseFillType(kInverseWinding_FillType) == kWinding_FillType
+ConvertToNonInverseFillType(kInverseEvenOdd_FillType) == kEvenOdd_FillType
+##
+##
+
+#SeeAlso FillType getFillType setFillType IsInverseFillType
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method static int ConvertConicToQuads(const SkPoint& p0, const SkPoint& p1, const SkPoint& p2,
+ SkScalar w, SkPoint pts[], int pow2)
+
+Approximates Conic with Quad array. Conic is constructed from start Point p0,
+control Point p1, end Point p2, and weight w.
+Quad array is stored in pts; this storage is supplied by caller.
+Maximum Quad count is 2 to the pow2.
+Every third point in array shares last Point of previous Quad and first Point of
+next Quad. Maximum pts storage size is given by:
+#Formula
+(1 + 2 * (1 << pow2)) * sizeof(SkPoint)
+##
+ConvertConicToQuads returns Quad count used the approximation, which may be smaller
+than the number requested.
+
+Conic_Weight determines the amount of influence Conic control point has on the curve.
+w less than one represents an elliptical section. w greater than one represents
+a hyperbolic section. w equal to one represents a parabolic section.
+
+Two Quad curves are sufficient to approximate an elliptical Conic with a sweep
+of up to 90 degrees; in this case, set pow2 to one.
+
+#Param p0 Conic start Point. ##
+#Param p1 Conic control Point. ##
+#Param p2 Conic end Point. ##
+#Param w Conic weight. ##
+#Param pts storage for Quad array. ##
+#Param pow2 Quad count, as power of two, normally 0 to 5 (1 to 32 Quad curves). ##
+
+#Return Number of Quad curves written to pts. ##
+
+#Example
+#Description
+A pair of Quad curves are drawn in red on top of the elliptical Conic curve in black.
+The middle curve is nearly circular. The top-right curve is parabolic, which can
+be drawn exactly with a single Quad.
+##
+void draw(SkCanvas* canvas) {
+ SkPaint conicPaint;
+ conicPaint.setAntiAlias(true);
+ conicPaint.setStyle(SkPaint::kStroke_Style);
+ SkPaint quadPaint(conicPaint);
+ quadPaint.setColor(SK_ColorRED);
+ SkPoint conic[] = { {20, 170}, {80, 170}, {80, 230} };
+ for (auto weight : { .25f, .5f, .707f, .85f, 1.f } ) {
+ SkPoint quads[5];
+ SkPath::ConvertConicToQuads(conic[0], conic[1], conic[2], weight, quads, 1);
+ SkPath path;
+ path.moveTo(conic[0]);
+ path.conicTo(conic[1], conic[2], weight);
+ canvas->drawPath(path, conicPaint);
+ path.rewind();
+ path.moveTo(quads[0]);
+ path.quadTo(quads[1], quads[2]);
+ path.quadTo(quads[3], quads[4]);
+ canvas->drawPath(path, quadPaint);
+ canvas->translate(50, -50);
+ }
+}
+##
+
+#SeeAlso Conic Quad
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method bool isRect(SkRect* rect, bool* isClosed = NULL, Direction* direction = NULL) const
+
+Returns true if Path is eqivalent to Rect when filled.
+If isRect returns false: rect, isClosed, and direction are unchanged.
+If isRect returns true: rect, isClosed, and direction are written to if not nullptr.
+
+rect may be smaller than the Path bounds. Path bounds may include kMove_Verb points
+that do not alter the area drawn by the returned rect.
+
+#Param rect storage for bounds of Rect; may be nullptr. ##
+#Param isClosed storage set to true if Path is closed; may be nullptr ##
+#Param direction storage set to Rect direction; may be nullptr. ##
+
+#Return true if Path contains Rect. ##
+
+#Example
+#Description
+After addRect, isRect returns true. Following moveTo permits isRect to return true, but
+following lineTo does not. addPoly returns true even though rect is not closed, and one
+side of rect is made up of consecutive line segments.
+##
+void draw(SkCanvas* canvas) {
+ auto debugster = [](const char* prefix, const SkPath& path) -> void {
+ SkRect rect;
+ SkPath::Direction direction;
+ bool isClosed;
+ path.isRect(&rect, &isClosed, &direction) ?
+ SkDebugf("%s is rect (%g, %g, %g, %g); is %s" "closed; direction %s\n", prefix,
+ rect.fLeft, rect.fTop, rect.fRight, rect.fBottom, isClosed ? "" : "not ",
+ SkPath::kCW_Direction == direction ? "CW" : "CCW") :
+ SkDebugf("%s is not rect\n", prefix);
+ };
+ SkPath path;
+ debugster("empty", path);
+ path.addRect({10, 20, 30, 40});
+ debugster("addRect", path);
+ path.moveTo(60, 70);
+ debugster("moveTo", path);
+ path.lineTo(60, 70);
+ debugster("lineTo", path);
+ path.reset();
+ const SkPoint pts[] = { {0, 0}, {0, 80}, {80, 80}, {80, 0}, {40, 0}, {20, 0} };
+ path.addPoly(pts, SK_ARRAY_COUNT(pts), false);
+ debugster("addPoly", path);
+}
+#StdOut
+empty is not rect
+addRect is rect (10, 20, 30, 40); is closed; direction CW
+moveTo is rect (10, 20, 30, 40); is closed; direction CW
+lineTo is not rect
+addPoly is rect (0, 0, 80, 80); is not closed; direction CCW
+##
+##
+
+#SeeAlso computeTightBounds conservativelyContainsRect getBounds isConvex isLastContourClosed isNestedFillRects
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method bool isNestedFillRects(SkRect rect[2], Direction dirs[2] = NULL) const
+
+Returns true if Path is equivalent to nested Rect pair when filled.
+If isNestedFillRects returns false, rect and dirs are unchanged.
+If isNestedFillRects returns true, rect and dirs are written to if not nullptr:
+setting rect[0] to outer Rect, and rect[1] to inner Rect;
+setting dirs[0] to Direction of outer Rect, and dirs[1] to Direction of inner
+Rect.
+
+#Param rect storage for Rect pair; may be nullptr. ##
+#Param dirs storage for Direction pair; may be nullptr. ##
+
+#Return true if Path contains nested Rect pair. ##
+
+#Example
+void draw(SkCanvas* canvas) {
+ SkPaint paint;
+ paint.setStyle(SkPaint::kStroke_Style);
+ paint.setStrokeWidth(5);
+ SkPath path;
+ path.addRect({10, 20, 30, 40});
+ paint.getFillPath(path, &path);
+ SkRect rects[2];
+ SkPath::Direction directions[2];
+ if (path.isNestedFillRects(rects, directions)) {
+ for (int i = 0; i < 2; ++i) {
+ SkDebugf("%s (%g, %g, %g, %g); direction %s\n", i ? "inner" : "outer",
+ rects[i].fLeft, rects[i].fTop, rects[i].fRight, rects[i].fBottom,
+ SkPath::kCW_Direction == directions[i] ? "CW" : "CCW");
+ }
+ } else {
+ SkDebugf("is not nested rectangles\n");
+ }
+}
+#StdOut
+outer (7.5, 17.5, 32.5, 42.5); direction CW
+inner (12.5, 22.5, 27.5, 37.5); direction CCW
+##
+##
+
+#SeeAlso computeTightBounds conservativelyContainsRect getBounds isConvex isLastContourClosed isRect
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method void addRect(const SkRect& rect, Direction dir = kCW_Direction)
+
+Add Rect to Path, appending kMove_Verb, three kLine_Verb, and kClose_Verb,
+starting with top-left corner of Rect; followed by top-right, bottom-right,
+and bottom-left if dir is kCW_Direction; or followed by bottom-left,
+bottom-right, and top-right if dir is kCCW_Direction.
+
+#Param rect Rect to add as a closed contour. ##
+#Param dir Direction to wind added contour. ##
+
+#Example
+#Description
+The left Rect dashes starting at the top-left corner, to the right.
+The right Rect dashes starting at the top-left corner, towards the bottom.
+##
+#Height 128
+void draw(SkCanvas* canvas) {
+ SkPaint paint;
+ paint.setStrokeWidth(15);
+ paint.setStrokeCap(SkPaint::kSquare_Cap);
+ float intervals[] = { 5, 21.75f };
+ paint.setStyle(SkPaint::kStroke_Style);
+ paint.setPathEffect(SkDashPathEffect::Make(intervals, SK_ARRAY_COUNT(intervals), 0));
+ SkPath path;
+ path.addRect({20, 20, 100, 100}, SkPath::kCW_Direction);
+ canvas->drawPath(path, paint);
+ path.rewind();
+ path.addRect({140, 20, 220, 100}, SkPath::kCCW_Direction);
+ canvas->drawPath(path, paint);
+}
+##
+
+#SeeAlso SkCanvas::drawRect Direction
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method void addRect(const SkRect& rect, Direction dir, unsigned start)
+
+Add Rect to Path, appending kMove_Verb, three kLine_Verb, and kClose_Verb.
+If dir is kCW_Direction, Rect corners are added clockwise; if dir is
+kCCW_Direction, Rect corners are added counterclockwise.
+start determines the first corner added.
+
+#Table
+#Legend
+# start # first corner ##
+#Legend ##
+# 0 # top-left ##
+# 1 # top-right ##
+# 2 # bottom-right ##
+# 3 # bottom-left ##
+#Table ##
+
+#Param rect Rect to add as a closed contour. ##
+#Param dir Direction to wind added contour. ##
+#Param start Initial corner of Rect to add. ##
+
+#Example
+#Height 128
+#Description
+The arrow is just after the initial corner and points towards the next
+corner appended to Path.
+##
+void draw(SkCanvas* canvas) {
+ const SkPoint arrow[] = { {5, -5}, {15, -5}, {20, 0}, {15, 5}, {5, 5}, {10, 0} };
+ const SkRect rect = {10, 10, 54, 54};
+ SkPaint rectPaint;
+ rectPaint.setAntiAlias(true);
+ rectPaint.setStyle(SkPaint::kStroke_Style);
+ SkPaint arrowPaint(rectPaint);
+ SkPath arrowPath;
+ arrowPath.addPoly(arrow, SK_ARRAY_COUNT(arrow), true);
+ arrowPaint.setPathEffect(SkPath1DPathEffect::Make(arrowPath, 176, 0,
+ SkPath1DPathEffect::kRotate_Style));
+ for (auto direction : { SkPath::kCW_Direction, SkPath::kCCW_Direction } ) {
+ for (unsigned start : { 0, 1, 2, 3 } ) {
+ SkPath path;
+ path.addRect(rect, direction, start);
+ canvas->drawPath(path, rectPaint);
+ canvas->drawPath(path, arrowPaint);
+ canvas->translate(64, 0);
+ }
+ canvas->translate(-256, 64);
+ }
+}
+##
+
+#SeeAlso SkCanvas::drawRect Direction
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method void addRect(SkScalar left, SkScalar top, SkScalar right, SkScalar bottom,
+ Direction dir = kCW_Direction)
+
+Add Rect (left, top, right, bottom) to Path,
+appending kMove_Verb, three kLine_Verb, and kClose_Verb,
+starting with top-left corner of Rect; followed by top-right, bottom-right,
+and bottom-left if dir is kCW_Direction; or followed by bottom-left,
+bottom-right, and top-right if dir is kCCW_Direction.
+
+#Param left smaller x of Rect. ##
+#Param top smaller y of Rect. ##
+#Param right larger x of Rect. ##
+#Param bottom larger y of Rect. ##
+#Param dir Direction to wind added contour. ##
+
+#Example
+#Description
+The left Rect dashes start at the top-left corner, and continue to the right.
+The right Rect dashes start at the top-left corner, and continue down.
+##
+#Height 128
+void draw(SkCanvas* canvas) {
+ SkPaint paint;
+ paint.setStrokeWidth(15);
+ paint.setStrokeCap(SkPaint::kSquare_Cap);
+ float intervals[] = { 5, 21.75f };
+ paint.setStyle(SkPaint::kStroke_Style);
+ paint.setPathEffect(SkDashPathEffect::Make(intervals, SK_ARRAY_COUNT(intervals), 0));
+ for (auto direction : { SkPath::kCW_Direction, SkPath::kCCW_Direction } ) {
+ SkPath path;
+ path.addRect(20, 20, 100, 100, direction);
+ canvas->drawPath(path, paint);
+ canvas->translate(128, 0);
+ }
+}
+##
+
+#SeeAlso SkCanvas::drawRect Direction
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method void addOval(const SkRect& oval, Direction dir = kCW_Direction)
+
+Add Oval to path, appending kMove_Verb, four kConic_Verb, and kClose_Verb.
+Oval is upright ellipse bounded by Rect oval with radii equal to half oval width
+and half oval height. Oval begins at (oval.fRight, oval.centerY()) and continues
+clockwise if dir is kCW_Direction, counterclockwise if dir is kCCW_Direction.
+
+This form is identical to addOval(oval, dir, 1).
+
+#Param oval bounds of ellipse added. ##
+#Param dir Direction to wind ellipse. ##
+
+#Example
+#Height 120
+ SkPaint paint;
+ SkPath oval;
+ oval.addOval({20, 20, 160, 80});
+ canvas->drawPath(oval, paint);
+##
+
+#SeeAlso SkCanvas::drawOval Direction Oval
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method void addOval(const SkRect& oval, Direction dir, unsigned start)
+
+Add Oval to Path, appending kMove_Verb, four kConic_Verb, and kClose_Verb.
+Oval is upright ellipse bounded by Rect oval with radii equal to half oval width
+and half oval height. Oval begins at start and continues
+clockwise if dir is kCW_Direction, counterclockwise if dir is kCCW_Direction.
+
+#Table
+#Legend
+# start # Point ##
+#Legend ##
+# 0 # oval.centerX(), oval.fTop ##
+# 1 # oval.fRight, oval.centerY() ##
+# 2 # oval.centerX(), oval.fBottom ##
+# 3 # oval.fLeft, oval.centerY() ##
+#Table ##
+
+#Param oval bounds of ellipse added. ##
+#Param dir Direction to wind ellipse. ##
+#Param start index of initial point of ellipse. ##
+
+#Example
+#Height 160
+void draw(SkCanvas* canvas) {
+ const SkPoint arrow[] = { {0, -5}, {10, 0}, {0, 5} };
+ const SkRect rect = {10, 10, 54, 54};
+ SkPaint ovalPaint;
+ ovalPaint.setAntiAlias(true);
+ SkPaint textPaint(ovalPaint);
+ textPaint.setTextAlign(SkPaint::kCenter_Align);
+ ovalPaint.setStyle(SkPaint::kStroke_Style);
+ SkPaint arrowPaint(ovalPaint);
+ SkPath arrowPath;
+ arrowPath.addPoly(arrow, SK_ARRAY_COUNT(arrow), true);
+ arrowPaint.setPathEffect(SkPath1DPathEffect::Make(arrowPath, 176, 0,
+ SkPath1DPathEffect::kRotate_Style));
+ for (auto direction : { SkPath::kCW_Direction, SkPath::kCCW_Direction } ) {
+ for (unsigned start : { 0, 1, 2, 3 } ) {
+ SkPath path;
+ path.addOval(rect, direction, start);
+ canvas->drawPath(path, ovalPaint);
+ canvas->drawPath(path, arrowPaint);
+ canvas->drawText(&"0123"[start], 1, rect.centerX(), rect.centerY() + 5, textPaint);
+ canvas->translate(64, 0);
+ }
+ canvas->translate(-256, 72);
+ canvas->drawString(SkPath::kCW_Direction == direction ? "clockwise" : "counterclockwise",
+ 128, 0, textPaint);
+ }
+}
+##
+
+#SeeAlso SkCanvas::drawOval Direction Oval
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method void addCircle(SkScalar x, SkScalar y, SkScalar radius,
+ Direction dir = kCW_Direction)
+
+Add Circle centered at (x, y) of size radius to Path, appending kMove_Verb,
+four kConic_Verb, and kClose_Verb. Circle begins at (x + radius, y) and
+continues clockwise if dir is kCW_Direction, counterclockwise if dir is
+kCCW_Direction.
+
+addCircle has no effect if radius is zero or negative.
+
+#Param x center of Circle. ##
+#Param y center of Circle. ##
+#Param radius distance from center to edge. ##
+#Param dir Direction to wind Circle. ##
+
+#Example
+void draw(SkCanvas* canvas) {
+ SkPaint paint;
+ paint.setAntiAlias(true);
+ paint.setStyle(SkPaint::kStroke_Style);
+ paint.setStrokeWidth(10);
+ for (int size = 10; size < 300; size += 20) {
+ SkPath path;
+ path.addCircle(128, 128, size, SkPath::kCW_Direction);
+ canvas->drawPath(path, paint);
+ }
+}
+##
+
+#SeeAlso SkCanvas::drawCircle Direction Circle
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method void addArc(const SkRect& oval, SkScalar startAngle, SkScalar sweepAngle)
+
+Append Arc to Path, as the start of new Contour. Arc added is part of ellipse
+bounded by oval, from startAngle through sweepAngle. Both startAngle and
+sweepAngle are measured in degrees, where zero degrees is aligned with the
+positive x-axis, and positive sweeps extends Arc clockwise.
+
+If sweepAngle <= -360, or sweepAngle >= 360; and startAngle modulo 90 is nearly
+zero, append Oval instead of Arc. Otherwise, sweepAngle values are treated
+modulo 360, and Arc may or may not draw depending on numeric rounding.
+
+#Param oval bounds of ellipse containing Arc. ##
+#Param startAngle starting angle of Arc in degrees. ##
+#Param sweepAngle sweep, in degrees. Positive is clockwise; treated modulo 360. ##
+
+#Example
+#Description
+The middle row of the left and right columns draw differently from the entries
+above and below because sweepAngle is outside of the range of +/-360,
+and startAngle modulo 90 is not zero.
+##
+void draw(SkCanvas* canvas) {
+ SkPaint paint;
+ for (auto start : { 0, 90, 135, 180, 270 } ) {
+ for (auto sweep : { -450.f, -180.f, -90.f, 90.f, 180.f, 360.1f } ) {
+ SkPath path;
+ path.addArc({10, 10, 35, 45}, start, sweep);
+ canvas->drawPath(path, paint);
+ canvas->translate(252 / 6, 0);
+ }
+ canvas->translate(-252, 255 / 5);
+ }
+}
+##
+
+#SeeAlso Arc arcTo SkCanvas::drawArc
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method void addRoundRect(const SkRect& rect, SkScalar rx, SkScalar ry,
+ Direction dir = kCW_Direction)
+
+Append Round_Rect to Path, creating a new closed Contour. Round_Rect has bounds
+equal to rect; each corner is 90 degrees of an ellipse with radii (rx, ry). If
+dir is kCW_Direction, Round_Rect starts at top-left of the lower-left corner and
+winds clockwise. If dir is kCCW_Direction, Round_Rect starts at the bottom-left
+of the upper-left corner and winds counterclockwise.
+
+If either rx or ry is too large, rx and ry are scaled uniformly until the
+corners fit. If rx or ry is less than or equal to zero, addRoundRect appends
+Rect rect to Path.
+
+After appending, Path may be empty, or may contain: Rect, Oval, or RoundRect.
+
+#Param rect bounds of Round_Rect. ##
+#Param rx x-radius of rounded corners on the Round_Rect ##
+#Param ry y-radius of rounded corners on the Round_Rect ##
+#Param dir Direction to wind Round_Rect. ##
+
+#Example
+#Description
+If either radius is zero, path contains Rect and is drawn red.
+If sides are only radii, path contains Oval and is drawn blue.
+All remaining path draws are convex, and are drawn in gray; no
+paths constructed from addRoundRect are concave, so none are
+drawn in green.
+##
+void draw(SkCanvas* canvas) {
+ SkPaint paint;
+ paint.setAntiAlias(true);
+ for (auto xradius : { 0, 7, 13, 20 } ) {
+ for (auto yradius : { 0, 9, 18, 40 } ) {
+ SkPath path;
+ path.addRoundRect({10, 10, 36, 46}, xradius, yradius);
+ paint.setColor(path.isRect(nullptr) ? SK_ColorRED : path.isOval(nullptr) ?
+ SK_ColorBLUE : path.isConvex() ? SK_ColorGRAY : SK_ColorGREEN);
+ canvas->drawPath(path, paint);
+ canvas->translate(64, 0);
+ }
+ canvas->translate(-256, 64);
+ }
+}
+##
+
+#SeeAlso addRRect SkCanvas::drawRoundRect
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method void addRoundRect(const SkRect& rect, const SkScalar radii[],
+ Direction dir = kCW_Direction)
+
+Append Round_Rect to Path, creating a new closed Contour. Round_Rect has bounds
+equal to rect; each corner is 90 degrees of an ellipse with radii from the
+array.
+
+#Table
+#Legend
+# radii index # location ##
+#Legend ##
+# 0 # x-radius of top-left corner ##
+# 1 # y-radius of top-left corner ##
+# 2 # x-radius of top-right corner ##
+# 3 # y-radius of top-right corner ##
+# 4 # x-radius of bottom-right corner ##
+# 5 # y-radius of bottom-right corner ##
+# 6 # x-radius of bottom-left corner ##
+# 7 # y-radius of bottom-left corner ##
+#Table ##
+
+If dir is kCW_Direction, Round_Rect starts at top-left of the lower-left corner
+and winds clockwise. If dir is kCCW_Direction, Round_Rect starts at the
+bottom-left of the upper-left corner and winds counterclockwise.
+
+If both radii on any side of rect exceed its length, all radii are scaled
+uniformly until the corners fit. If either radius of a corner is less than or
+equal to zero, both are treated as zero.
+
+After appending, Path may be empty, or may contain: Rect, Oval, or RoundRect.
+
+#Param rect bounds of Round_Rect. ##
+#Param radii array of 8 SkScalar values, a radius pair for each corner. ##
+#Param dir Direction to wind Round_Rect. ##
+
+#Example
+void draw(SkCanvas* canvas) {
+ SkPaint paint;
+ paint.setAntiAlias(true);
+ SkScalar radii[] = { 80, 100, 0, 0, 40, 60, 0, 0 };
+ SkPath path;
+ SkMatrix rotate90;
+ rotate90.setRotate(90, 128, 128);
+ for (int i = 0; i < 4; ++i) {
+ path.addRoundRect({10, 10, 110, 110}, radii);
+ path.transform(rotate90);
+ }
+ canvas->drawPath(path, paint);
+}
+##
+
+#SeeAlso addRRect SkCanvas::drawRoundRect
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method void addRRect(const SkRRect& rrect, Direction dir = kCW_Direction)
+
+Add rrect to Path, creating a new closed Contour. If
+dir is kCW_Direction, rrect starts at top-left of the lower-left corner and
+winds clockwise. If dir is kCCW_Direction, rrect starts at the bottom-left
+of the upper-left corner and winds counterclockwise.
+
+After appending, Path may be empty, or may contain: Rect, Oval, or RRect.
+
+#Param rrect bounds and radii of rounded rectangle. ##
+#Param dir Direction to wind Round_Rect. ##
+
+#Example
+void draw(SkCanvas* canvas) {
+ SkPaint paint;
+ paint.setAntiAlias(true);
+ SkRRect rrect;
+ SkVector radii[] = {{50, 50}, {0, 0}, {0, 0}, {50, 50}};
+ rrect.setRectRadii({10, 10, 110, 110}, radii);
+ SkPath path;
+ SkMatrix rotate90;
+ rotate90.setRotate(90, 128, 128);
+ for (int i = 0; i < 4; ++i) {
+ path.addRRect(rrect);
+ path.transform(rotate90);
+ }
+ canvas->drawPath(path, paint);
+}
+##
+
+#SeeAlso addRoundRect SkCanvas::drawRRect
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method void addRRect(const SkRRect& rrect, Direction dir, unsigned start)
+
+Add rrect to Path, creating a new closed Contour. If dir is kCW_Direction, rrect
+winds clockwise; if dir is kCCW_Direction, rrect winds counterclockwise.
+start determines the first point of rrect to add.
+
+#Table
+#Legend
+# start # location ##
+#Legend ##
+# 0 # right of top-left corner ##
+# 1 # left of top-right corner ##
+# 2 # bottom of top-right corner ##
+# 3 # top of bottom-right corner ##
+# 4 # left of bottom-right corner ##
+# 5 # right of bottom-left corner ##
+# 6 # top of bottom-left corner ##
+# 7 # bottom of top-left corner ##
+#Table ##
+
+After appending, Path may be empty, or may contain: Rect, Oval, or RRect.
+
+#Param rrect bounds and radii of rounded rectangle. ##
+#Param dir Direction to wind RRect. ##
+#Param start Index of initial point of RRect. ##
+
+#Example
+void draw(SkCanvas* canvas) {
+ SkPaint paint;
+ paint.setAntiAlias(true);
+ SkRRect rrect;
+ rrect.setRectXY({40, 40, 215, 215}, 50, 50);
+ SkPath path;
+ path.addRRect(rrect);
+ canvas->drawPath(path, paint);
+ for (int start = 0; start < 8; ++start) {
+ SkPath textPath;
+ textPath.addRRect(rrect, SkPath::kCW_Direction, start);
+ canvas->drawTextOnPathHV(&"01234567"[start], 1, textPath, 0, -5, paint);
+ }
+}
+##
+
+#SeeAlso addRoundRect SkCanvas::drawRRect
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method void addPoly(const SkPoint pts[], int count, bool close)
+
+Add Contour created from Line Array. Given count pts, addPoly adds
+count - 1 Line segments. Contour added starts at pt[0], then adds a line
+for every additional Point in pts array. If close is true, addPoly
+appends kClose_Verb to Path, connecting pts[count - 1] and pts[0].
+
+If count is zero, append kMove_Verb to path.
+addPoly has no effect if count is less than one.
+
+#Param pts Array of Line sharing end and start Point. ##
+#Param count Length of Point array. ##
+#Param close true to add Line connecting Contour end and start. ##
+
+#Example
+void draw(SkCanvas* canvas) {
+ SkPaint paint;
+ paint.setStrokeWidth(15);
+ paint.setStrokeCap(SkPaint::kRound_Cap);
+ const SkPoint points[] = {{20, 20}, {70, 20}, {40, 90}};
+ for (bool close : { false, true } ) {
+ SkPath path;
+ path.addPoly(points, SK_ARRAY_COUNT(points), close);
+ for (auto style : {SkPaint::kStroke_Style, SkPaint::kFill_Style,
+ SkPaint::kStrokeAndFill_Style} ) {
+ paint.setStyle(style);
+ canvas->drawPath(path, paint);
+ canvas->translate(85, 0);
+ }
+ canvas->translate(-255, 128);
+ }
+}
+##
+
+#SeeAlso SkCanvas::drawPoints
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Enum AddPathMode
+
+#Code
+ enum AddPathMode {
+ kAppend_AddPathMode
+ kExtend_AddPathMode
+ };
+##
+
+AddPathMode chooses how addPath appends. Adding one Path to another can extend
+the last Contour or start a new Contour.
+
+#Const kAppend_AddPathMode
+ Path Verbs, Points, and Weights are appended to destination unaltered.
+ Since Path Verb_Array begins with kMove_Verb if src is not empty, this
+ starts a new Contour.
+##
+#Const kExtend_AddPathMode
+ If destination is closed or empty, start a new Contour. If destination
+ is not empty, add Line from Last_Point to added Path first Point. Skip added
+ Path initial kMove_Verb, then append remining Verbs, Points, and Weights.
+##
+
+#Example
+#Description
+test is built from path, open on the top row, and closed on the bottom row.
+The left column uses kAppend_AddPathMode; the right uses kExtend_AddPathMode.
+The top right composition is made up of one contour; the other three have two.
+##
+#Height 180
+ SkPath path, path2; + path.moveTo(20, 20); + path.lineTo(20, 40); + path.lineTo(40, 20); + path2.moveTo(60, 60); + path2.lineTo(80, 60); + path2.lineTo(80, 40); + SkPaint paint; + paint.setStyle(SkPaint::kStroke_Style); + for (int i = 0; i < 2; i++) { + for (auto addPathMode : { SkPath::kAppend_AddPathMode, SkPath::kExtend_AddPathMode } ) { + SkPath test(path); + test.addPath(path2, addPathMode); + canvas->drawPath(test, paint); + canvas->translate(100, 0); + } + canvas->translate(-200, 100); + path.close(); + } +##
+
+#SeeAlso addPath reverseAddPath
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method void addPath(const SkPath& src, SkScalar dx, SkScalar dy,
+ AddPathMode mode = kAppend_AddPathMode)
+
+Append src to Path, offset by (dx, dy).
+
+If mode is kAppend_AddPathMode, src Verb_Array, Point_Array, and Weights are
+added unaltered. If mode is kExtend_AddPathMode, add Line before appending
+Verbs, Points, and Weights.
+
+#Param src Path Verbs, Points, and Weights to add. ##
+#Param dx offset added to src Point_Array x coordinates. ##
+#Param dy offset added to src Point_Array y coordinates. ##
+#Param mode kAppend_AddPathMode or kExtend_AddPathMode. ##
+
+#Example
+#Height 180
+ SkPaint paint; + paint.setTextSize(128); + paint.setFakeBoldText(true); + SkPath dest, text; + paint.getTextPath("O", 1, 50, 120, &text); + for (int i = 0; i < 3; i++) { + dest.addPath(text, i * 20, i * 20); + } + Simplify(dest, &dest); + paint.setStyle(SkPaint::kStroke_Style); + paint.setStrokeWidth(3); + canvas->drawPath(dest, paint); +##
+
+#SeeAlso AddPathMode offset() reverseAddPath
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method void addPath(const SkPath& src, AddPathMode mode = kAppend_AddPathMode)
+
+Append src to Path.
+
+If mode is kAppend_AddPathMode, src Verb_Array, Point_Array, and Weights are
+added unaltered. If mode is kExtend_AddPathMode, add Line before appending
+Verbs, Points, and Weights.
+
+#Param src Path Verbs, Points, and Weights to add. ##
+#Param mode kAppend_AddPathMode or kExtend_AddPathMode. ##
+
+#Example
+#Height 80
+ SkPaint paint; + paint.setStyle(SkPaint::kStroke_Style); + SkPath dest, path; + path.addOval({-80, 20, 0, 60}, SkPath::kCW_Direction, 1); + for (int i = 0; i < 2; i++) { + dest.addPath(path, SkPath::kExtend_AddPathMode); + dest.offset(100, 0); + } + canvas->drawPath(dest, paint);
+##
+
+#SeeAlso AddPathMode reverseAddPath
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method void addPath(const SkPath& src, const SkMatrix& matrix, AddPathMode mode = kAppend_AddPathMode)
+
+Append src to Path, transformed by matrix. Transformed curves may have different
+Verbs, Points, and Weights.
+
+If mode is kAppend_AddPathMode, src Verb_Array, Point_Array, and Weights are
+added unaltered. If mode is kExtend_AddPathMode, add Line before appending
+Verbs, Points, and Weights.
+
+#Param src Path Verbs, Points, and Weights to add. ##
+#Param matrix Transform applied to src. ##
+#Param mode kAppend_AddPathMode or kExtend_AddPathMode. ##
+
+#Example
+#Height 160
+ SkPaint paint; + paint.setStyle(SkPaint::kStroke_Style); + SkPath dest, path; + path.addOval({20, 20, 200, 120}, SkPath::kCW_Direction, 1); + for (int i = 0; i < 6; i++) { + SkMatrix matrix; + matrix.reset(); + matrix.setPerspX(i / 400.f); + dest.addPath(path, matrix); + } + canvas->drawPath(dest, paint); +##
+
+#SeeAlso AddPathMode transform() offset() reverseAddPath
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method void reverseAddPath(const SkPath& src)
+
+Append src to Path, from back to front.
+Reversed src always appends a new Contour to Path.
+
+#Param src Path Verbs, Points, and Weights to add. ##
+
+#Example
+#Height 200
+ SkPath path; + path.moveTo(20, 20); + path.lineTo(20, 40); + path.lineTo(40, 20); + SkPaint paint; + paint.setStyle(SkPaint::kStroke_Style); + for (int i = 0; i < 2; i++) { + SkPath path2; + path2.moveTo(60, 60); + path2.lineTo(80, 60); + path2.lineTo(80, 40); + for (int j = 0; j < 2; j++) { + SkPath test(path); + test.reverseAddPath(path2); + canvas->drawPath(test, paint); + canvas->translate(100, 0); + path2.close(); + } + canvas->translate(-200, 100); + path.close(); + } +##
+
+#SeeAlso AddPathMode transform() offset() addPath
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method void offset(SkScalar dx, SkScalar dy, SkPath* dst) const
+
+Offset Point_Array by (dx, dy). Offset Path replaces dst.
+If dst is nullptr, Path is replaced by offset data.
+
+#Param dx offset added to Point_Array x coordinates. ##
+#Param dy offset added to Point_Array y coordinates. ##
+#Param dst overwritten, translated copy of Path; may be nullptr. ##
+
+#Example
+#Height 60
+ SkPath pattern; + pattern.moveTo(20, 20); + pattern.lineTo(20, 40); + pattern.lineTo(40, 20); + SkPaint paint; + paint.setStyle(SkPaint::kStroke_Style); + for (int i = 0; i < 10; i++) { + SkPath path; + pattern.offset(20 * i, 0, &path); + canvas->drawPath(path, paint); + } +##
+
+#SeeAlso addPath transform
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method void offset(SkScalar dx, SkScalar dy)
+
+Offset Point_Array by (dx, dy). Path is replaced by offset data.
+
+#Param dx offset added to Point_Array x coordinates. ##
+#Param dy offset added to Point_Array y coordinates. ##
+
+#Example
+#Height 60
+ SkPath path; + path.moveTo(20, 20); + path.lineTo(20, 40); + path.lineTo(40, 20); + SkPaint paint; + paint.setStyle(SkPaint::kStroke_Style); + for (int i = 0; i < 10; i++) { + canvas->drawPath(path, paint); + path.offset(20, 0); + } +##
+
+#SeeAlso addPath transform SkCanvas::translate()
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method void transform(const SkMatrix& matrix, SkPath* dst) const
+
+Transform Verb_Array, Point_Array, and weight by matrix.
+transform may change Verbs and increase their number.
+Transformed Path replaces dst; if dst is nullptr, original data
+is replaced.
+
+#Param matrix Matrix to apply to Path. ##
+#Param dst overwritten, transformed copy of Path; may be nullptr. ##
+
+#Example
+#Height 200 + SkPath pattern; + pattern.moveTo(100, 100); + pattern.lineTo(100, 20); + pattern.lineTo(20, 100); + SkPaint paint; + paint.setStyle(SkPaint::kStroke_Style); + for (int i = 0; i < 10; i++) { + SkPath path; + SkMatrix matrix; + matrix.setRotate(36 * i, 100, 100); + pattern.transform(matrix, &path); + canvas->drawPath(path, paint); + }
+##
+
+#SeeAlso addPath offset SkCanvas::concat() SkMatrix
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method void transform(const SkMatrix& matrix)
+
+Transform Verb_Array, Point_Array, and weight by matrix.
+transform may change Verbs and increase their number.
+Path is replaced by transformed data.
+
+#Param matrix Matrix to apply to Path. ##
+
+#Example
+#Height 200 + SkPath path; + path.moveTo(100, 100); + path.quadTo(100, 20, 20, 100); + SkPaint paint; + paint.setStyle(SkPaint::kStroke_Style); + for (int i = 0; i < 10; i++) { + SkMatrix matrix; + matrix.setRotate(36, 100, 100); + path.transform(matrix); + canvas->drawPath(path, paint); + }
+##
+
+#SeeAlso addPath offset SkCanvas::concat() SkMatrix
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Subtopic Last_Point + +Path is defined cumulatively, often by adding a segment to the end of last +Contour. Last_Point of Contour is shared as first Point of added Line or Curve. +Last_Point can be read and written directly with getLastPt and setLastPt. + +#Method bool getLastPt(SkPoint* lastPt) const
+
+ Returns Last_Point on Path in lastPt. Returns false if Point_Array is empty,
+ storing (0, 0) if lastPt is not nullptr.
+
+ #Param lastPt storage for final Point in Point_Array; may be nullptr. ##
+
+ #Return true if Point_Array contains one or more Points. ##
+
+ #Example
+ SkPath path; + path.moveTo(100, 100); + path.quadTo(100, 20, 20, 100); + SkMatrix matrix; + matrix.setRotate(36, 100, 100); + path.transform(matrix); + SkPoint last; + path.getLastPt(&last); + SkDebugf("last point: %g, %g\n", last.fX, last.fY);
+ #StdOut
+ last point: 35.2786, 52.9772
+ ##
+ ##
+
+ #SeeAlso setLastPt
+
+##
+
+#Method void setLastPt(SkScalar x, SkScalar y)
+
+ Set Last_Point to (x, y). If Point_Array is empty, append kMove_Verb to
+ Verb_Array and (x, y) to Point_Array.
+
+ #Param x set x-coordinate of Last_Point. ##
+ #Param y set y-coordinate of Last_Point. ##
+
+ #Example
+ #Height 128
+ SkPaint paint; + paint.setTextSize(128); + SkPath path; + paint.getTextPath("@", 1, 60, 100, &path); + path.setLastPt(20, 120); + canvas->drawPath(path, paint);
+ ##
+
+ #SeeAlso getLastPt
+
+##
+
+#Method void setLastPt(const SkPoint& p)
+
+ Set the last point on the path. If no points have been added, moveTo(p)
+ is automatically called.
+
+ #Param p set value of Last_Point. ##
+
+ #Example
+ #Height 128
+ SkPaint paint; + paint.setTextSize(128); + SkPath path, path2; + paint.getTextPath("A", 1, 60, 100, &path); + paint.getTextPath("Z", 1, 60, 100, &path2); + SkPoint pt, pt2; + path.getLastPt(&pt); + path2.getLastPt(&pt2); + path.setLastPt(pt2); + path2.setLastPt(pt); + canvas->drawPath(path, paint); + canvas->drawPath(path2, paint); + ##
+
+ #SeeAlso getLastPt
+
+##
+
+#Subtopic Last_Point ##
+
+# ------------------------------------------------------------------------------
+
+#Enum SegmentMask
+
+#Code
+ enum SegmentMask {
+ kLine_SegmentMask = 1 << 0
+ kQuad_SegmentMask = 1 << 1
+ kConic_SegmentMask = 1 << 2
+ kCubic_SegmentMask = 1 << 3
+ };
+##
+
+SegmentMask constants correspond to each drawing Verb type in Path; for
+instance, if Path only contains Lines, only the kLine_SegmentMask bit is set.
+
+#Bug 6785 ##
+#Const kLine_SegmentMask 1
+Set if Verb_Array contains kLine_Verb.
+##
+#Const kQuad_SegmentMask 2
+Set if Verb_Array contains kQuad_Verb. Note that conicTo may add a Quad.
+##
+#Const kConic_SegmentMask 4
+Set if Verb_Array contains kConic_Verb.
+##
+#Const kCubic_SegmentMask 8
+Set if Verb_Array contains kCubic_Verb.
+##
+
+#Example
+#Description
+When conicTo has a weight of one, Quad is added to Path.
+##
+ SkPath path;
+ path.conicTo(10, 10, 20, 30, 1);
+ SkDebugf("Path kConic_SegmentMask is %s\n", path.getSegmentMasks() &
+ SkPath::kConic_SegmentMask ? "set" : "clear");
+ SkDebugf("Path kQuad_SegmentMask is %s\n", path.getSegmentMasks() &
+ SkPath::kQuad_SegmentMask ? "set" : "clear");
+#StdOut
+Path kConic_SegmentMask is clear
+Path kQuad_SegmentMask is set
+##
+##
+
+#SeeAlso getSegmentMasks Verb
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method uint32_t getSegmentMasks() const
+
+Returns a mask, where each set bit corresponds to a SegmentMask constant
+if Path contains one or more Verbs of that type.
+Returns zero if Path contains no Lines, Quads, Conics, or Cubics.
+
+getSegmentMasks() returns a cached result; it is very fast.
+
+#Return SegmentMask bits or zero. ##
+
+#Example
+SkPath path;
+path.quadTo(20, 30, 40, 50);
+path.close();
+const char* masks[] = { "line", "quad", "conic", "cubic" };
+int index = 0;
+for (auto mask : { SkPath::kLine_SegmentMask, SkPath::kQuad_SegmentMask,
+ SkPath::kConic_SegmentMask, SkPath::kCubic_SegmentMask } ) {
+ if (mask & path.getSegmentMasks()) {
+ SkDebugf("mask %s set\n", masks[index]);
+ }
+ ++index;
+}
+#StdOut
+mask quad set
+##
+##
+
+#SeeAlso getSegmentMasks Verb
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method bool contains(SkScalar x, SkScalar y) const
+
+Returns true if the point (x, y) is contained by Path, taking into
+account FillType.
+
+#Table
+#Legend
+# FillType # contains() returns true if Point is enclosed by ##
+##
+# kWinding_FillType # a non-zero sum of Contour Directions. ##
+# kEvenOdd_FillType # an odd number of Contours. ##
+# kInverseWinding_FillType # a zero sum of Contour Directions. ##
+# kInverseEvenOdd_FillType # and even number of Contours. ##
+##
+
+#Param x x-coordinate of containment test. ##
+#Param y y-coordinate of containment test. ##
+
+#Return true if Point is in Path. ##
+
+#Example
+SkPath path;
+SkPaint paint;
+paint.setTextSize(256);
+paint.getTextPath("&", 1, 30, 220, &path);
+for (int y = 2; y < 256; y += 9) {
+ for (int x = 2; x < 256; x += 9) {
+ int coverage = 0;
+ for (int iy = -4; iy <= 4; iy += 2) {
+ for (int ix = -4; ix <= 4; ix += 2) {
+ coverage += path.contains(x + ix, y + iy);
+ }
+ }
+ paint.setColor(SkColorSetARGB(0x5f, 0xff * coverage / 25, 0, 0xff * (25 - coverage) / 25));
+ canvas->drawCircle(x, y, 8, paint);
+ }
+}
+##
+
+#SeeAlso conservativelyContainsRect Fill_Type Op
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method void dump(SkWStream* stream, bool forceClose, bool dumpAsHex) const
+
+Writes text representation of Path to stream. If stream is nullptr, dump() writes to
+stdout. Set forceClose to true to get
+edges used to fill Path. Set dumpAsHex true to get exact binary representations
+of floating point numbers used in Point_Array and Weights.
+
+#Param stream writable Stream receiving Path text representation; may be nullptr. ##
+#Param forceClose true if missing kClose_Verb is output. ##
+#Param dumpAsHex true if SkScalar values are written as hexidecimal. ##
+
+#Example
+ SkPath path;
+ path.quadTo(20, 30, 40, 50);
+ for (bool forceClose : { false, true } ) {
+ for (bool dumpAsHex : { false, true } ) {
+ path.dump(nullptr, forceClose, dumpAsHex);
+ SkDebugf("\n");
+ }
+ }
+#StdOut
+path.setFillType(SkPath::kWinding_FillType);
+path.moveTo(0, 0);
+path.quadTo(20, 30, 40, 50);
+
+path.setFillType(SkPath::kWinding_FillType);
+path.moveTo(SkBits2Float(0x00000000), SkBits2Float(0x00000000)); // 0, 0
+path.quadTo(SkBits2Float(0x41a00000), SkBits2Float(0x41f00000), SkBits2Float(0x42200000), SkBits2Float(0x42480000)); // 20, 30, 40, 50
+
+path.setFillType(SkPath::kWinding_FillType);
+path.moveTo(0, 0);
+path.quadTo(20, 30, 40, 50);
+path.lineTo(0, 0);
+path.close();
+
+path.setFillType(SkPath::kWinding_FillType);
+path.moveTo(SkBits2Float(0x00000000), SkBits2Float(0x00000000)); // 0, 0
+path.quadTo(SkBits2Float(0x41a00000), SkBits2Float(0x41f00000), SkBits2Float(0x42200000), SkBits2Float(0x42480000)); // 20, 30, 40, 50
+path.lineTo(SkBits2Float(0x00000000), SkBits2Float(0x00000000)); // 0, 0
+path.close();
+##
+##
+
+#SeeAlso SkRect::dump() SkRRect::dump() SkPathMeasure::dump()
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method void dump() const
+
+Writes text representation of Path to stdout. The representation may be
+directly compiled as C++ code. Floating point values are written
+with limited precision; it may not be possible to reconstruct original Path
+from output.
+
+#Example
+SkPath path, copy;
+path.lineTo(6.f / 7, 2.f / 3);
+path.dump();
+copy.setFillType(SkPath::kWinding_FillType);
+copy.moveTo(0, 0);
+copy.lineTo(0.857143f, 0.666667f);
+SkDebugf("path is " "%s" "equal to copy\n", path == copy ? "" : "not ");
+#StdOut
+path.setFillType(SkPath::kWinding_FillType);
+path.moveTo(0, 0);
+path.lineTo(0.857143f, 0.666667f);
+path is not equal to copy
+##
+##
+
+#SeeAlso dumpHex SkRect::dump() SkRRect::dump() SkPathMeasure::dump() writeToMemory
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method void dumpHex() const
+
+Writes text representation of Path to stdout. The representation may be
+directly compiled as C++ code. Floating point values are written
+in hexadecimal to preserve their exact bit pattern. The output reconstructs the
+original Path.
+
+Use dumpHex when submitting #A bug reports against Skia # http://bug.skia.org ##.
+Slight value changes in Point_Array may cause the bug to disappear.
+
+#Example
+SkPath path, copy;
+path.lineTo(6.f / 7, 2.f / 3);
+path.dumpHex();
+copy.setFillType(SkPath::kWinding_FillType);
+copy.moveTo(SkBits2Float(0x00000000), SkBits2Float(0x00000000)); // 0, 0
+copy.lineTo(SkBits2Float(0x3f5b6db7), SkBits2Float(0x3f2aaaab)); // 0.857143f, 0.666667f
+SkDebugf("path is " "%s" "equal to copy\n", path == copy ? "" : "not ");
+#StdOut
+path.setFillType(SkPath::kWinding_FillType);
+path.moveTo(SkBits2Float(0x00000000), SkBits2Float(0x00000000)); // 0, 0
+path.lineTo(SkBits2Float(0x3f5b6db7), SkBits2Float(0x3f2aaaab)); // 0.857143f, 0.666667f
+path is equal to copy
+##
+##
+
+#SeeAlso dump SkRect::dumpHex() SkRRect::dumpHex() writeToMemory
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method size_t writeToMemory(void* buffer) const
+
+Write Path to buffer, returning the number of bytes written.
+Pass nullptr to obtain the storage size.
+
+writeToMemory writes Fill_Type, Verb_Array, Point_Array, Conic_Weight, and
+additionally writes computed information like Convexity and bounds.
+
+writeToMemory should only be used in concert with readFromMemory.
+The format used for Path in memory is not guaranteed.
+
+#Param buffer storage for Path; may be nullptr. ##
+
+#Return size of storage required for Path; always a multiple of 4. ##
+
+#Example
+void draw(SkCanvas* canvas) {
+ SkPath path, copy;
+ path.lineTo(6.f / 7, 2.f / 3);
+ size_t size = path.writeToMemory(nullptr);
+ SkTDArray<char> storage;
+ storage.setCount(size);
+ path.writeToMemory(storage.begin());
+ copy.readFromMemory(storage.begin(), size);
+ SkDebugf("path is " "%s" "equal to copy\n", path == copy ? "" : "not ");
+}
+##
+
+#SeeAlso readFromMemory dump dumpHex
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method size_t readFromMemory(const void* buffer, size_t length)
+
+Initializes Path from buffer of size length. Returns zero if the buffer is
+data is inconsistent, or the length is too small.
+
+readFromMemory reads Fill_Type, Verb_Array, Point_Array, Conic_Weight, and
+additionally reads computed information like Convexity and bounds.
+
+readFromMemory should only be used in concert with writeToMemory.
+The format used for Path in memory is not guaranteed.
+
+#Param buffer storage for Path. ##
+#Param length buffer size in bytes; must be multiple of 4. ##
+
+#Return number of bytes read, or zero on failure. ##
+
+#Example
+void draw(SkCanvas* canvas) {
+ SkPath path, copy;
+ path.lineTo(6.f / 7, 2.f / 3);
+ size_t size = path.writeToMemory(nullptr);
+ SkTDArray<char> storage;
+ storage.setCount(size);
+ path.writeToMemory(storage.begin());
+ size_t wrongSize = size - 4;
+ size_t bytesRead = copy.readFromMemory(storage.begin(), wrongSize);
+ SkDebugf("length = %u; returned by readFromMemory = %u\n", wrongSize, bytesRead);
+ size_t largerSize = size + 4;
+ bytesRead = copy.readFromMemory(storage.begin(), largerSize);
+ SkDebugf("length = %u; returned by readFromMemory = %u\n", largerSize, bytesRead);
+}
+#StdOut
+length = 60; returned by readFromMemory = 0
+length = 68; returned by readFromMemory = 64
+##
+##
+
+#SeeAlso writeToMemory
+
+##
+
+# ------------------------------------------------------------------------------
+#Topic Generation_ID
+#Alias Generation_IDs
+
+Generation_ID provides a quick way to check if Verb_Array, Point_Array, or
+Conic_Weight has changed. Generation_ID is not a hash; identical Paths will
+not necessarily have matching Generation_IDs.
+
+Empty Paths have a Generation_ID of one.
+
+#Method uint32_t getGenerationID() const
+
+Returns a non-zero, globally unique value. A different value is returned
+if Verb_Array, Point_Array, or Conic_Weight changes.
+
+Setting Fill_Type does not change Generation_ID.
+
+Each time the path is modified, a different Generation_ID will be returned.
+
+#Bug 1762
+Fill_Type does affect Generation_ID on Android framework.
+##
+
+#Return non-zero, globally unique value. ##
+
+#Example
+SkPath path;
+SkDebugf("empty genID = %u\n", path.getGenerationID());
+path.lineTo(1, 2);
+SkDebugf("1st lineTo genID = %u\n", path.getGenerationID());
+path.rewind();
+SkDebugf("empty genID = %u\n", path.getGenerationID());
+path.lineTo(1, 2);
+SkDebugf("2nd lineTo genID = %u\n", path.getGenerationID());
+#StdOut
+empty genID = 1
+1st lineTo genID = 2
+empty genID = 1
+2nd lineTo genID = 3
+##
+##
+
+#SeeAlso operator==(const SkPath& a, const SkPath& b)
+
+##
+
+#Topic ##
+
+# ------------------------------------------------------------------------------
+
+#Method void validate() const
+
+Debugging check to see if Path data is consistent.
+Not currently maintained.
+
+#NoExample
+##
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Method void experimentalValidateRef() const
+
+#Private
+Debugging check to see if Path data is consistent.
+Not ready for public use.
+##
+
+##
+
+# ------------------------------------------------------------------------------
+
+#Class Iter + +Iterates through Verb_Array, and associated Point_Array and Conic_Weight. +Provides options to treat open Contours as closed, and to ignore +degenerate data. + +#Example +#Height 128 +#Description +Ignoring the actual Verbs and replacing them with quads rounds the +path of the glyph. +## +void draw(SkCanvas* canvas) {
+ SkPaint paint;
+ paint.setAntiAlias(true);
+ paint.setTextSize(256);
+ SkPath asterisk, path;
+ paint.getTextPath("*", 1, 50, 192, &asterisk);
+ SkPath::Iter iter(asterisk, true);
+ SkPoint start[4], pts[4];
+ iter.next(start); // skip moveTo
+ iter.next(start); // first quadTo
+ path.moveTo((start[0] + start[1]) * 0.5f);
+ while (SkPath::kClose_Verb != iter.next(pts)) {
+ path.quadTo(pts[0], (pts[0] + pts[1]) * 0.5f);
+ }
+ path.quadTo(start[0], (start[0] + start[1]) * 0.5f);
+ canvas->drawPath(path, paint);
+} +## + +#SeeAlso RawIter + +#Method Iter() + +Initializes Iter with an empty Path. next() on Iter returns kDone_Verb. +Call setPath to initialize Iter at a later time. + +#Return Iter of empty Path. ## + +#Example +void draw(SkCanvas* canvas) {
+ SkPath::Iter iter;
+ SkPoint points[4];
+ SkDebugf("iter is " "%s" "done\n", SkPath::kDone_Verb == iter.next(points) ? "" : "not ");
+ SkPath path;
+ iter.setPath(path, false);
+ SkDebugf("iter is " "%s" "done\n", SkPath::kDone_Verb == iter.next(points) ? "" : "not ");
+} +#StdOut
+iter is done
+iter is done
+##
+## + +#SeeAlso setPath + +## + +#Method Iter(const SkPath& path, bool forceClose) + +Sets Iter to return elements of Verb_Array, Point_Array, and Conic_Weight in path. +If forceClose is true, Iter will add kLine_Verb and kClose_Verb after each +open Contour. path is not altered. + +#Param path Path to iterate. ## +#Param forceClose true if open Contours generate kClose_Verb. ## + +#Return Iter of path. ## + +#Example +void draw(SkCanvas* canvas) {
+ auto debugster = [](const char* prefix, SkPath::Iter& iter) -> void {
+ SkDebugf("%s:\n", prefix);
+ const char* verbStr[] = { "Move", "Line", "Quad", "Conic", "Cubic", "Close", "Done" };
+ const int pointCount[] = { 1 , 2 , 3 , 3 , 4 , 1 , 0 };
+ SkPath::Verb verb;
+ do {
+ SkPoint points[4];
+ verb = iter.next(points);
+ SkDebugf("k%s_Verb ", verbStr[(int) verb]);
+ for (int i = 0; i < pointCount[(int) verb]; ++i) {
+ SkDebugf("{%g, %g}, ", points[i].fX, points[i].fY);
+ }
+ if (SkPath::kConic_Verb == verb) {
+ SkDebugf("weight = %g", iter.conicWeight());
+ }
+ SkDebugf("\n");
+ } while (SkPath::kDone_Verb != verb);
+ SkDebugf("\n");
+ };
+
+ SkPath path;
+ path.quadTo(10, 20, 30, 40);
+ SkPath::Iter openIter(path, false);
+ debugster("open", openIter);
+ SkPath::Iter closedIter(path, true);
+ debugster("closed", closedIter);
+} +#StdOut +open: +kMove_Verb {0, 0},
+kQuad_Verb {0, 0}, {10, 20}, {30, 40},
+kDone_Verb
+
+closed:
+kMove_Verb {0, 0},
+kQuad_Verb {0, 0}, {10, 20}, {30, 40},
+kLine_Verb {30, 40}, {0, 0},
+kClose_Verb {0, 0},
+kDone_Verb +## +## + +#SeeAlso setPath + +## + +#Method void setPath(const SkPath& path, bool forceClose) + +Sets Iter to return elements of Verb_Array, Point_Array, and Conic_Weight in path. +If forceClose is true, Iter will add kLine_Verb and kClose_Verb after each +open Contour. path is not altered. + +#Param path Path to iterate. ## +#Param forceClose true if open Contours generate kClose_Verb. ## + +#Example +void draw(SkCanvas* canvas) {
+ auto debugster = [](const char* prefix, SkPath::Iter& iter) -> void {
+ SkDebugf("%s:\n", prefix);
+ const char* verbStr[] = { "Move", "Line", "Quad", "Conic", "Cubic", "Close", "Done" };
+ const int pointCount[] = { 1 , 2 , 3 , 3 , 4 , 1 , 0 };
+ SkPath::Verb verb;
+ do {
+ SkPoint points[4];
+ verb = iter.next(points);
+ SkDebugf("k%s_Verb ", verbStr[(int) verb]);
+ for (int i = 0; i < pointCount[(int) verb]; ++i) {
+ SkDebugf("{%g, %g}, ", points[i].fX, points[i].fY);
+ }
+ if (SkPath::kConic_Verb == verb) {
+ SkDebugf("weight = %g", iter.conicWeight());
+ }
+ SkDebugf("\n");
+ } while (SkPath::kDone_Verb != verb);
+ SkDebugf("\n");
+ };
+
+ SkPath path;
+ path.quadTo(10, 20, 30, 40);
+ SkPath::Iter iter(path, false);
+ debugster("quad open", iter);
+ SkPath path2;
+ path2.conicTo(1, 2, 3, 4, .5f);
+ iter.setPath(path2, true);
+ debugster("conic closed", iter);
+} +#StdOut +quad open:
+kMove_Verb {0, 0},
+kQuad_Verb {0, 0}, {10, 20}, {30, 40},
+kDone_Verb
+
+conic closed:
+kMove_Verb {0, 0},
+kConic_Verb {0, 0}, {1, 2}, {3, 4}, weight = 0.5
+kLine_Verb {3, 4}, {0, 0},
+kClose_Verb {0, 0},
+kDone_Verb +## +## + +#SeeAlso Iter(const SkPath& path, bool forceClose) + +## + +#Method Verb next(SkPoint pts[4], bool doConsumeDegenerates = true, bool exact = false) + + Returns next Verb in Verb_Array, and advances Iter. + When Verb_Array is exhausted, returns kDone_Verb. +Zero to four Points are stored in pts, depending on the returned Verb. +If doConsumeDegenerates is true, skip consecutive kMove_Verb entries, returning +only the last in the series; and skip very small Lines, Quads, and Conics; and +skip kClose_Verb following kMove_Verb. +if doConsumeDegenerates is true and exact is true, only skip Lines, Quads, and +Conics with zero lengths. + + #Param pts Storage for Point data describing returned Verb. ## + #Param doConsumeDegenerates If true, skip degenerate Verbs. ## + #Param exact If true, skip zero length curves. Has no effect if doConsumeDegenerates + is false. + ## + + #Return next Verb from Verb_Array. ## + +#Example +#Description +skip degenerate skips the first in a kMove_Verb pair, the kMove_Verb +followed by the kClose_Verb, the zero length Line and the very small Line. + +skip degenerate if exact skips the same as skip degenerate, but shows +the very small Line. + +skip none shows all of the Verbs and Points in Path. +## +void draw(SkCanvas* canvas) {
+ auto debugster = [](const char* prefix, const SkPath& path, bool degen, bool exact) -> void {
+ SkPath::Iter iter(path, false);
+ SkDebugf("%s:\n", prefix);
+ const char* verbStr[] = { "Move", "Line", "Quad", "Conic", "Cubic", "Close", "Done" };
+ const int pointCount[] = { 1 , 2 , 3 , 3 , 4 , 1 , 0 };
+ SkPath::Verb verb;
+ do {
+ SkPoint points[4];
+ verb = iter.next(points, degen, exact);
+ SkDebugf("k%s_Verb ", verbStr[(int) verb]);
+ for (int i = 0; i < pointCount[(int) verb]; ++i) {
+ SkDebugf("{%1.8g, %1.8g}, ", points[i].fX, points[i].fY);
+ }
+ SkDebugf("\n");
+ } while (SkPath::kDone_Verb != verb);
+ SkDebugf("\n");
+ };
+
+ SkPath path;
+ path.moveTo(10, 10);
+ path.moveTo(20, 20);
+ path.quadTo(10, 20, 30, 40);
+ path.moveTo(1, 1);
+ path.close();
+ path.moveTo(30, 30);
+ path.lineTo(30, 30);
+ path.moveTo(30, 30);
+ path.lineTo(30.00001f, 30);
+ debugster("skip degenerate", path, true, false);
+ debugster("skip degenerate if exact", path, true, true);
+ debugster("skip none", path, false, false);
+} +#StdOut +skip degenerate:
+kMove_Verb {20, 20},
+kQuad_Verb {20, 20}, {10, 20}, {30, 40},
+kDone_Verb
+
+skip degenerate if exact:
+kMove_Verb {20, 20},
+kQuad_Verb {20, 20}, {10, 20}, {30, 40},
+kMove_Verb {30, 30},
+kLine_Verb {30, 30}, {30.00001, 30},
+kDone_Verb
+
+skip none:
+kMove_Verb {10, 10},
+kMove_Verb {20, 20},
+kQuad_Verb {20, 20}, {10, 20}, {30, 40},
+kMove_Verb {1, 1},
+kClose_Verb {1, 1},
+kMove_Verb {30, 30},
+kLine_Verb {30, 30}, {30, 30},
+kMove_Verb {30, 30},
+kLine_Verb {30, 30}, {30.00001, 30},
+kDone_Verb
+## +## + +#SeeAlso Verb IsLineDegenerate IsCubicDegenerate IsQuadDegenerate + +## + +#Method SkScalar conicWeight() const + + Returns Conic_Weight if next() returned kConic_Verb. + + If next() has not been called, or next() did not return kConic_Verb, + result is undefined. + + #Return Conic_Weight for Conic Points returned by next(). ## + + #Example + void draw(SkCanvas* canvas) {
+ SkPath path;
+ path.conicTo(1, 2, 3, 4, .5f);
+ SkPath::Iter iter(path, false);
+ SkPoint p[4];
+ SkDebugf("first verb is " "%s" "move\n", SkPath::kMove_Verb == iter.next(p) ? "" : "not ");
+ SkDebugf("next verb is " "%s" "conic\n", SkPath::kConic_Verb == iter.next(p) ? "" : "not ");
+ SkDebugf("conic points: {%g,%g}, {%g,%g}, {%g,%g}\n", p[0].fX, p[0].fY, p[1].fX, p[1].fY,
+ p[2].fX, p[2].fY);
+ SkDebugf("conic weight: %g\n", iter.conicWeight());
+ } + #StdOut +first verb is move
+next verb is conic
+conic points: {0,0}, {1,2}, {3,4}
+conic weight: 0.5 + ## + ## + + #SeeAlso Conic_Weight + +## + +#Method bool isCloseLine() const + + Returns true if last kLine_Verb returned by next() was generated + by kClose_Verb. When true, the end point returned by next() is + also the start point of Contour. + + If next() has not been called, or next() did not return kLine_Verb, + result is undefined. + + #Return true if last kLine_Verb was generated by kClose_Verb. ## + + #Example +void draw(SkCanvas* canvas) {
+ SkPath path;
+ path.moveTo(6, 7);
+ path.conicTo(1, 2, 3, 4, .5f);
+ path.close();
+ SkPath::Iter iter(path, false);
+ SkPoint p[4];
+ SkDebugf("1st verb is " "%s" "move\n", SkPath::kMove_Verb == iter.next(p) ? "" : "not ");
+ SkDebugf("moveTo point: {%g,%g}\n", p[0].fX, p[0].fY);
+ SkDebugf("2nd verb is " "%s" "conic\n", SkPath::kConic_Verb == iter.next(p) ? "" : "not ");
+ SkDebugf("3rd verb is " "%s" "line\n", SkPath::kLine_Verb == iter.next(p) ? "" : "not ");
+ SkDebugf("line points: {%g,%g}, {%g,%g}\n", p[0].fX, p[0].fY, p[1].fX, p[1].fY);
+ SkDebugf("line " "%s" "generated by close\n", iter.isCloseLine() ? "" : "not ");
+ SkDebugf("4th verb is " "%s" "close\n", SkPath::kClose_Verb == iter.next(p) ? "" : "not ");
+} + #StdOut +1st verb is move
+moveTo point: {6,7}
+2nd verb is conic
+3rd verb is line
+line points: {3,4}, {6,7}
+line generated by close
+4th verb is close + ## + ## + + #SeeAlso close() +## + +#Method bool isClosedContour() const + +Returns true if subsequent calls to next() return kClose_Verb before returning +kMove_Verb. if true, Contour Iter is processing may end with kClose_Verb, or +Iter may have been initialized with force close set to true. + +#Return true if Contour is closed. ## + +#Example +void draw(SkCanvas* canvas) {
+ for (bool forceClose : { false, true } ) {
+ SkPath path;
+ path.conicTo(1, 2, 3, 4, .5f);
+ SkPath::Iter iter(path, forceClose);
+ SkDebugf("without close(), forceClose is %s: isClosedContour returns %s\n",
+ forceClose ? "true " : "false", iter.isClosedContour() ? "true" : "false");
+ path.close();
+ iter.setPath(path, forceClose);
+ SkDebugf("with close(), forceClose is %s: isClosedContour returns %s\n",
+ forceClose ? "true " : "false", iter.isClosedContour() ? "true" : "false");
+ }
+} +#StdOut +without close(), forceClose is false: isClosedContour returns false
+with close(), forceClose is false: isClosedContour returns true
+without close(), forceClose is true : isClosedContour returns true
+with close(), forceClose is true : isClosedContour returns true +## +## + +#SeeAlso Iter(const SkPath& path, bool forceClose) + +## +
+#Class Iter ##
+
+#Class RawIter + +Iterates through Verb_Array, and associated Point_Array and Conic_Weight. +Verb_Array, Point_Array, and Conic_Weight are returned unaltered. + + #Method RawIter() + + Initializes RawIter with an empty Path. next() on RawIter returns kDone_Verb. + Call setPath to initialize Iter at a later time. + + #Return RawIter of empty Path. ##
+
+ #NoExample
+ ##
+ ##
+ + #Method RawIter(const SkPath& path) + + + Sets RawIter to return elements of Verb_Array, Point_Array, and Conic_Weight in path. + + #Param path Path to iterate. ## + + #Return RawIter of path. ## +
+ #NoExample
+ ##
+ ##
+ + #Method void setPath(const SkPath& path) + + Sets Iter to return elements of Verb_Array, Point_Array, and Conic_Weight in path. + + #Param path Path to iterate. ## +
+ #NoExample
+ ##
+ ##
+ + #Method Verb next(SkPoint pts[4]) + + Returns next Verb in Verb_Array, and advances RawIter. + When Verb_Array is exhausted, returns kDone_Verb. + Zero to four Points are stored in pts, depending on the returned Verb. + + #Param pts Storage for Point data describing returned Verb. ## + + #Return next Verb from Verb_Array. ## + + #Example + void draw(SkCanvas* canvas) {
+ SkPath path;
+ path.moveTo(50, 60);
+ path.quadTo(10, 20, 30, 40);
+ path.close();
+ path.lineTo(30, 30);
+ path.conicTo(1, 2, 3, 4, .5f);
+ path.cubicTo(-1, -2, -3, -4, -5, -6);
+ SkPath::RawIter iter(path);
+ const char* verbStr[] = { "Move", "Line", "Quad", "Conic", "Cubic", "Close", "Done" };
+ const int pointCount[] = { 1 , 2 , 3 , 3 , 4 , 1 , 0 };
+ SkPath::Verb verb;
+ do {
+ SkPoint points[4];
+ verb = iter.next(points);
+ SkDebugf("k%s_Verb ", verbStr[(int) verb]);
+ for (int i = 0; i < pointCount[(int) verb]; ++i) {
+ SkDebugf("{%1.8g, %1.8g}, ", points[i].fX, points[i].fY);
+ }
+ if (SkPath::kConic_Verb == verb) {
+ SkDebugf("weight = %g", iter.conicWeight());
+ }
+ SkDebugf("\n");
+ } while (SkPath::kDone_Verb != verb);
+ } + #StdOut + kMove_Verb {50, 60},
+ kQuad_Verb {50, 60}, {10, 20}, {30, 40},
+ kClose_Verb {50, 60},
+ kMove_Verb {50, 60},
+ kLine_Verb {50, 60}, {30, 30},
+ kConic_Verb {30, 30}, {1, 2}, {3, 4}, weight = 0.5
+ kCubic_Verb {3, 4}, {-1, -2}, {-3, -4}, {-5, -6},
+ kDone_Verb + ## + ## + + #SeeAlso peek() + + ##
+ + #Method Verb peek() const + + Returns next Verb, but does not advance RawIter. + + #Return next Verb from Verb_Array. ## + + #Example + SkPath path;
+ path.quadTo(10, 20, 30, 40);
+ path.conicTo(1, 2, 3, 4, .5f);
+ path.cubicTo(1, 2, 3, 4, .5, 6);
+ SkPath::RawIter iter(path);
+ SkPath::Verb verb, peek = iter.peek();
+ const char* verbStr[] = { "Move", "Line", "Quad", "Conic", "Cubic", "Close", "Done" };
+ do {
+ SkPoint points[4];
+ verb = iter.next(points);
+ SkDebugf("peek %s %c= verb %s\n", verbStr[peek], peek == verb ? '=' : '!', verbStr[verb]);
+ peek = iter.peek();
+ } while (SkPath::kDone_Verb != verb); + SkDebugf("peek %s %c= verb %s\n", verbStr[peek], peek == verb ? '=' : '!', verbStr[verb]);
+ #StdOut
+ #Volatile
+ peek Move == verb Move
+ peek Quad == verb Quad
+ peek Conic == verb Conic
+ peek Cubic == verb Cubic
+ peek Done == verb Done
+ peek Done == verb Done
+ ##
+ ## + + #Bug 6832 + StdOut isn't really volatile, it just produces the wrong result. + A simple fix changes the output of hairlines and needs to be + investigated to see if the change is correct or not. + https://skia-review.googlesource.com/c/21340/ + ## + + #SeeAlso next() + + ##
+ + #Method SkScalar conicWeight() const
+
+ Returns Conic_Weight if next() returned kConic_Verb. + + If next() has not been called, or next() did not return kConic_Verb, + result is undefined. +
+ #Return Conic_Weight for Conic Points returned by next(). ## + + #Example + void draw(SkCanvas* canvas) {
+ SkPath path;
+ path.conicTo(1, 2, 3, 4, .5f);
+ SkPath::RawIter iter(path);
+ SkPoint p[4];
+ SkDebugf("first verb is " "%s" "move\n", SkPath::kMove_Verb == iter.next(p) ? "" : "not ");
+ SkDebugf("next verb is " "%s" "conic\n", SkPath::kConic_Verb == iter.next(p) ? "" : "not ");
+ SkDebugf("conic points: {%g,%g}, {%g,%g}, {%g,%g}\n", p[0].fX, p[0].fY, p[1].fX, p[1].fY,
+ p[2].fX, p[2].fY);
+ SkDebugf("conic weight: %g\n", iter.conicWeight());
+ } + #StdOut + first verb is move
+ next verb is conic
+ conic points: {0,0}, {1,2}, {3,4}
+ conic weight: 0.5 + ## + ## + + #SeeAlso Conic_Weight +
+ ##
+
+#Class RawIter ##
+
+#Class SkPath ##
+
+#Topic Path ##
|