diff options
author | 2013-07-09 15:03:59 +0000 | |
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committer | 2013-07-09 15:03:59 +0000 | |
commit | e1b75b4096c8ba9a569ae33d580806edd3c4a97a (patch) | |
tree | 1ca16b4c5d9d64925fc416bd5c88ed4cf73d810b | |
parent | 387db0a2e516ca01508f7d16433f84da2ea3b93b (diff) |
GM (and fix) for drawArc capping issue
https://codereview.chromium.org/18271003/
git-svn-id: http://skia.googlecode.com/svn/trunk@9928 2bbb7eff-a529-9590-31e7-b0007b416f81
-rw-r--r-- | gm/arcofzorro.cpp | 83 | ||||
-rw-r--r-- | gyp/gmslides.gypi | 1 | ||||
-rw-r--r-- | src/core/SkGeometry.cpp | 19 |
3 files changed, 95 insertions, 8 deletions
diff --git a/gm/arcofzorro.cpp b/gm/arcofzorro.cpp new file mode 100644 index 0000000000..1e38130595 --- /dev/null +++ b/gm/arcofzorro.cpp @@ -0,0 +1,83 @@ +/* + * Copyright 2013 Google Inc. + * + * Use of this source code is governed by a BSD-style license that can be + * found in the LICENSE file. + */ + +#include "gm.h" +#include "SkRandom.h" + +namespace skiagm { + +// This GM draws a lot of arcs in a 'Z' shape. It particularly exercises +// the 'drawArc' code near a singularly of its processing (i.e., near the +// edge of one of its underlying quads). +class ArcOfZorroGM : public GM { +public: + ArcOfZorroGM() { + this->setBGColor(0xFFCCCCCC); + } + +protected: + virtual SkString onShortName() SK_OVERRIDE { + return SkString("arcofzorro"); + } + + virtual SkISize onISize() SK_OVERRIDE { + return make_isize(1000, 1000); + } + + virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE { + SkMWCRandom rand; + + SkRect rect = SkRect::MakeXYWH(10, 10, 200, 200); + + SkPaint p; + + p.setStyle(SkPaint::kStroke_Style); + p.setStrokeWidth(35); + int xOffset = 0, yOffset = 0; + int direction = 0; + + for (float arc = 134.0f; arc < 136.0f; arc += 0.01f) { + SkColor color = rand.nextU(); + color |= 0xff000000; + p.setColor(color); + + canvas->save(); + canvas->translate(SkIntToScalar(xOffset), SkIntToScalar(yOffset)); + canvas->drawArc(rect, 0, arc, false, p); + canvas->restore(); + + switch (direction) { + case 0: + xOffset += 10; + if (xOffset >= 700) { + direction = 1; + } + break; + case 1: + xOffset -= 10; + yOffset += 10; + if (xOffset < 50) { + direction = 2; + } + break; + case 2: + xOffset += 10; + break; + } + } + + } + +private: + typedef GM INHERITED; +}; + +////////////////////////////////////////////////////////////////////////////// + +DEF_GM( return SkNEW(ArcOfZorroGM); ) + +} diff --git a/gyp/gmslides.gypi b/gyp/gmslides.gypi index 69516c0419..66f869f4f8 100644 --- a/gyp/gmslides.gypi +++ b/gyp/gmslides.gypi @@ -4,6 +4,7 @@ '../gm/aaclip.cpp', '../gm/aarectmodes.cpp', '../gm/alphagradients.cpp', + '../gm/arcofzorro.cpp', '../gm/arithmode.cpp', '../gm/bicubicfilter.cpp', '../gm/bigmatrix.cpp', diff --git a/src/core/SkGeometry.cpp b/src/core/SkGeometry.cpp index f67758d2b4..a12f961948 100644 --- a/src/core/SkGeometry.cpp +++ b/src/core/SkGeometry.cpp @@ -1205,11 +1205,13 @@ static SkScalar quad_solve(SkScalar a, SkScalar b, SkScalar c, SkScalar d) return count == 1 ? roots[0] : 0; } -/* given a quad-curve and a point (x,y), chop the quad at that point and return - the new quad's offCurve point. Should only return false if the computed pos - is the start of the curve (i.e. root == 0) +/* given a quad-curve and a point (x,y), chop the quad at that point and place + the new off-curve point and endpoint into 'dest'. The new end point is used + (rather than (x,y)) to compensate for numerical inaccuracies. + Should only return false if the computed pos is the start of the curve + (i.e. root == 0) */ -static bool quad_pt2OffCurve(const SkPoint quad[3], SkScalar x, SkScalar y, SkPoint* offCurve) +static bool truncate_last_curve(const SkPoint quad[3], SkScalar x, SkScalar y, SkPoint* dest) { const SkScalar* base; SkScalar value; @@ -1230,7 +1232,8 @@ static bool quad_pt2OffCurve(const SkPoint quad[3], SkScalar x, SkScalar y, SkPo { SkPoint tmp[5]; SkChopQuadAt(quad, tmp, t); - *offCurve = tmp[1]; + dest[0] = tmp[1]; + dest[1] = tmp[2]; return true; } else { /* t == 0 means either the value triggered a root outside of [0, 1) @@ -1247,7 +1250,8 @@ static bool quad_pt2OffCurve(const SkPoint quad[3], SkScalar x, SkScalar y, SkPo if ((base[0] < base[4] && value > base[2]) || (base[0] > base[4] && value < base[2])) // should root have been 1 { - *offCurve = quad[1]; + dest[0] = quad[1]; + dest[1].set(x, y); return true; } } @@ -1360,9 +1364,8 @@ int SkBuildQuadArc(const SkVector& uStart, const SkVector& uStop, memcpy(quadPoints, gQuadCirclePts, (wholeCount + 1) * sizeof(SkPoint)); const SkPoint* arc = &gQuadCirclePts[wholeCount]; - if (quad_pt2OffCurve(arc, x, y, &quadPoints[wholeCount + 1])) + if (truncate_last_curve(arc, x, y, &quadPoints[wholeCount + 1])) { - quadPoints[wholeCount + 2].set(x, y); wholeCount += 2; } pointCount = wholeCount + 1; |