remove unused reduce order code

BUG=

Review URL: https://codereview.chromium.org/85763002

git-svn-id: http://skia.googlecode.com/svn/trunk@12377 2bbb7eff-a529-9590-31e7-b0007b416f81

5 files changed, 35 insertions, 204 deletions

diff --git a/src/pathops/SkDCubicIntersection.cpp b/src/pathops/SkDCubicIntersection.cpp
index 27b16341a8..bb734e19da 100644
--- a/src/pathops/SkDCubicIntersection.cpp
+++ b/src/pathops/SkDCubicIntersection.cpp
@@ -30,7 +30,7 @@ static int quadPart(const SkDCubic& cubic, double tStart, double tEnd, SkReduceO
     SkDQuad quad = part.toQuad();
     // FIXME: should reduceOrder be looser in this use case if quartic is going to blow up on an
     // extremely shallow quadratic?
-    int order = reducer->reduce(quad, SkReduceOrder::kFill_Style);
+    int order = reducer->reduce(quad);
 #if DEBUG_QUAD_PART
     SkDebugf("%s cubic=(%1.9g,%1.9g %1.9g,%1.9g %1.9g,%1.9g %1.9g,%1.9g)"
             " t=(%1.9g,%1.9g)\n", __FUNCTION__, cubic[0].fX, cubic[0].fY,
diff --git a/src/pathops/SkDCubicToQuads.cpp b/src/pathops/SkDCubicToQuads.cpp
index 571f1d94ae..3cf63f31d0 100644
--- a/src/pathops/SkDCubicToQuads.cpp
+++ b/src/pathops/SkDCubicToQuads.cpp
@@ -118,7 +118,7 @@ static void addTs(const SkDCubic& cubic, double precision, double start, double
 // it would still take the prechopped cubic for reduce order and find cubic inflections
 void SkDCubic::toQuadraticTs(double precision, SkTArray<double, true>* ts) const {
     SkReduceOrder reducer;
-    int order = reducer.reduce(*this, SkReduceOrder::kAllow_Quadratics, SkReduceOrder::kFill_Style);
+    int order = reducer.reduce(*this, SkReduceOrder::kAllow_Quadratics);
     if (order < 3) {
         return;
     }
@@ -153,13 +153,11 @@ void SkDCubic::toQuadraticTs(double precision, SkTArray<double, true>* ts) const
     SkDCubicPair pair;
     if (inflections == 1) {
         pair = chopAt(inflectT[0]);
-        int orderP1 = reducer.reduce(pair.first(), SkReduceOrder::kNo_Quadratics,
-                SkReduceOrder::kFill_Style);
+        int orderP1 = reducer.reduce(pair.first(), SkReduceOrder::kNo_Quadratics);
         if (orderP1 < 2) {
             --inflections;
         } else {
-            int orderP2 = reducer.reduce(pair.second(), SkReduceOrder::kNo_Quadratics,
-                    SkReduceOrder::kFill_Style);
+            int orderP2 = reducer.reduce(pair.second(), SkReduceOrder::kNo_Quadratics);
             if (orderP2 < 2) {
                 --inflections;
             }
diff --git a/src/pathops/SkOpSegment.h b/src/pathops/SkOpSegment.h
index 55e516e35c..79d83b1155 100644
--- a/src/pathops/SkOpSegment.h
+++ b/src/pathops/SkOpSegment.h
@@ -183,7 +183,6 @@ public:
         return result;
     }
 
-    // OPTIMIZATION: mark as debugging only if used solely by tests
     double t(int tIndex) const {
         return fTs[tIndex].fT;
     }
@@ -212,13 +211,11 @@ public:
         return fTs[tIndex].fWindValue;
     }
 
+#if defined(SK_DEBUG) || DEBUG_WINDING
     SkScalar xAtT(int index) const {
         return xAtT(&fTs[index]);
     }
-
-    SkScalar xAtT(const SkOpSpan* span) const {
-        return xyAtT(span).fX;
-    }
+#endif
 
     const SkPoint& xyAtT(const SkOpSpan* span) const {
         return span->fPt;
@@ -228,13 +225,11 @@ public:
         return xyAtT(&fTs[index]);
     }
 
+#if defined(SK_DEBUG) || DEBUG_WINDING
     SkScalar yAtT(int index) const {
         return yAtT(&fTs[index]);
     }
-
-    SkScalar yAtT(const SkOpSpan* span) const {
-        return xyAtT(span).fY;
-    }
+#endif
 
     bool activeAngle(int index, int* done, SkTArray<SkOpAngle, true>* angles);
     SkPoint activeLeftTop(bool onlySortable, int* firstT) const;
@@ -403,6 +398,15 @@ private:
     static bool UseInnerWindingReverse(int outerWinding, int innerWinding);
     SkOpSpan* verifyOneWinding(const char* funName, int tIndex);
     SkOpSpan* verifyOneWindingU(const char* funName, int tIndex);
+
+    SkScalar xAtT(const SkOpSpan* span) const {
+        return xyAtT(span).fX;
+    }
+
+    SkScalar yAtT(const SkOpSpan* span) const {
+        return xyAtT(span).fY;
+    }
+
     void zeroSpan(SkOpSpan* span);
 
 #if DEBUG_SWAP_TOP
diff --git a/src/pathops/SkReduceOrder.cpp b/src/pathops/SkReduceOrder.cpp
index 3dfdc9daee..ada52761b5 100644
--- a/src/pathops/SkReduceOrder.cpp
+++ b/src/pathops/SkReduceOrder.cpp
@@ -13,12 +13,6 @@ int SkReduceOrder::reduce(const SkDLine& line) {
     return 1 + different;
 }
 
-static double interp_quad_coords(double a, double b, double c, double t) {
-    double ab = SkDInterp(a, b, t);
-    double bc = SkDInterp(b, c, t);
-    return SkDInterp(ab, bc, t);
-}
-
 static int coincident_line(const SkDQuad& quad, SkDQuad& reduction) {
     reduction[0] = reduction[1] = quad[0];
     return 1;
@@ -28,49 +22,19 @@ static int reductionLineCount(const SkDQuad& reduction) {
     return 1 + !reduction[0].approximatelyEqual(reduction[1]);
 }
 
-static int vertical_line(const SkDQuad& quad, SkReduceOrder::Style reduceStyle,
-        SkDQuad& reduction) {
-    double tValue;
+static int vertical_line(const SkDQuad& quad, SkDQuad& reduction) {
     reduction[0] = quad[0];
     reduction[1] = quad[2];
-    if (reduceStyle == SkReduceOrder::kFill_Style) {
-        return reductionLineCount(reduction);
-    }
-    int smaller = reduction[1].fY > reduction[0].fY;
-    int larger = smaller ^ 1;
-    if (SkDQuad::FindExtrema(quad[0].fY, quad[1].fY, quad[2].fY, &tValue)) {
-        double yExtrema = interp_quad_coords(quad[0].fY, quad[1].fY, quad[2].fY, tValue);
-        if (reduction[smaller].fY > yExtrema) {
-            reduction[smaller].fY = yExtrema;
-        } else if (reduction[larger].fY < yExtrema) {
-            reduction[larger].fY = yExtrema;
-        }
-    }
     return reductionLineCount(reduction);
 }
 
-static int horizontal_line(const SkDQuad& quad, SkReduceOrder::Style reduceStyle,
-        SkDQuad& reduction) {
-    double tValue;
+static int horizontal_line(const SkDQuad& quad, SkDQuad& reduction) {
     reduction[0] = quad[0];
     reduction[1] = quad[2];
-    if (reduceStyle == SkReduceOrder::kFill_Style) {
-        return reductionLineCount(reduction);
-    }
-    int smaller = reduction[1].fX > reduction[0].fX;
-    int larger = smaller ^ 1;
-    if (SkDQuad::FindExtrema(quad[0].fX, quad[1].fX, quad[2].fX, &tValue)) {
-        double xExtrema = interp_quad_coords(quad[0].fX, quad[1].fX, quad[2].fX, tValue);
-        if (reduction[smaller].fX > xExtrema) {
-            reduction[smaller].fX = xExtrema;
-        }  else if (reduction[larger].fX < xExtrema) {
-            reduction[larger].fX = xExtrema;
-        }
-    }
     return reductionLineCount(reduction);
 }
 
-static int check_linear(const SkDQuad& quad, SkReduceOrder::Style reduceStyle,
+static int check_linear(const SkDQuad& quad,
         int minX, int maxX, int minY, int maxY, SkDQuad& reduction) {
     int startIndex = 0;
     int endIndex = 2;
@@ -87,47 +51,6 @@ static int check_linear(const SkDQuad& quad, SkReduceOrder::Style reduceStyle,
     // four are colinear: return line formed by outside
     reduction[0] = quad[0];
     reduction[1] = quad[2];
-    if (reduceStyle == SkReduceOrder::kFill_Style) {
-        return reductionLineCount(reduction);
-    }
-    int sameSide;
-    bool useX = quad[maxX].fX - quad[minX].fX >= quad[maxY].fY - quad[minY].fY;
-    if (useX) {
-        sameSide = SkDSign(quad[0].fX - quad[1].fX) + SkDSign(quad[2].fX - quad[1].fX);
-    } else {
-        sameSide = SkDSign(quad[0].fY - quad[1].fY) + SkDSign(quad[2].fY - quad[1].fY);
-    }
-    if ((sameSide & 3) != 2) {
-        return reductionLineCount(reduction);
-    }
-    double tValue;
-    int root;
-    if (useX) {
-        root = SkDQuad::FindExtrema(quad[0].fX, quad[1].fX, quad[2].fX, &tValue);
-    } else {
-        root = SkDQuad::FindExtrema(quad[0].fY, quad[1].fY, quad[2].fY, &tValue);
-    }
-    if (root) {
-        SkDPoint extrema;
-        extrema.fX = interp_quad_coords(quad[0].fX, quad[1].fX, quad[2].fX, tValue);
-        extrema.fY = interp_quad_coords(quad[0].fY, quad[1].fY, quad[2].fY, tValue);
-        // sameSide > 0 means mid is smaller than either [0] or [2], so replace smaller
-        int replace;
-        if (useX) {
-            if ((extrema.fX < quad[0].fX) ^ (extrema.fX < quad[2].fX)) {
-                return reductionLineCount(reduction);
-            }
-            replace = ((extrema.fX < quad[0].fX) | (extrema.fX < quad[2].fX))
-                    ^ (quad[0].fX < quad[2].fX);
-        } else {
-            if ((extrema.fY < quad[0].fY) ^ (extrema.fY < quad[2].fY)) {
-                return reductionLineCount(reduction);
-            }
-            replace = ((extrema.fY < quad[0].fY) | (extrema.fY < quad[2].fY))
-                    ^ (quad[0].fY < quad[2].fY);
-        }
-        reduction[replace] = extrema;
-    }
     return reductionLineCount(reduction);
 }
 
@@ -137,7 +60,7 @@ static int check_linear(const SkDQuad& quad, SkReduceOrder::Style reduceStyle,
     // note that three points in a line doesn't simplify a cubic
 // look for approximation with single quadratic
     // save approximation with multiple quadratics for later
-int SkReduceOrder::reduce(const SkDQuad& quad, Style reduceStyle) {
+int SkReduceOrder::reduce(const SkDQuad& quad) {
     int index, minX, maxX, minY, maxY;
     int minXSet, minYSet;
     minX = maxX = minY = maxY = 0;
@@ -168,12 +91,12 @@ int SkReduceOrder::reduce(const SkDQuad& quad, Style reduceStyle) {
         if (minYSet == 0x7) {  // return 1 if all four are coincident
             return coincident_line(quad, fQuad);
         }
-        return vertical_line(quad, reduceStyle, fQuad);
+        return vertical_line(quad, fQuad);
     }
     if (minYSet == 0xF) {  // test for horizontal line
-        return horizontal_line(quad, reduceStyle, fQuad);
+        return horizontal_line(quad, fQuad);
     }
-    int result = check_linear(quad, reduceStyle, minX, maxX, minY, maxY, fQuad);
+    int result = check_linear(quad, minX, maxX, minY, maxY, fQuad);
     if (result) {
         return result;
     }
@@ -183,15 +106,6 @@ int SkReduceOrder::reduce(const SkDQuad& quad, Style reduceStyle) {
 
 ////////////////////////////////////////////////////////////////////////////////////
 
-static double interp_cubic_coords(const double* src, double t) {
-    double ab = SkDInterp(src[0], src[2], t);
-    double bc = SkDInterp(src[2], src[4], t);
-    double cd = SkDInterp(src[4], src[6], t);
-    double abc = SkDInterp(ab, bc, t);
-    double bcd = SkDInterp(bc, cd, t);
-    return SkDInterp(abc, bcd, t);
-}
-
 static int coincident_line(const SkDCubic& cubic, SkDCubic& reduction) {
     reduction[0] = reduction[1] = cubic[0];
     return 1;
@@ -201,51 +115,15 @@ static int reductionLineCount(const SkDCubic& reduction) {
     return 1 + !reduction[0].approximatelyEqual(reduction[1]);
 }
 
-static int vertical_line(const SkDCubic& cubic, SkReduceOrder::Style reduceStyle,
-                         SkDCubic& reduction) {
-    double tValues[2];
+static int vertical_line(const SkDCubic& cubic, SkDCubic& reduction) {
     reduction[0] = cubic[0];
     reduction[1] = cubic[3];
-    if (reduceStyle == SkReduceOrder::kFill_Style) {
-        return reductionLineCount(reduction);
-    }
-    int smaller = reduction[1].fY > reduction[0].fY;
-    int larger = smaller ^ 1;
-    int roots = SkDCubic::FindExtrema(cubic[0].fY, cubic[1].fY, cubic[2].fY, cubic[3].fY, tValues);
-    for (int index = 0; index < roots; ++index) {
-        double yExtrema = interp_cubic_coords(&cubic[0].fY, tValues[index]);
-        if (reduction[smaller].fY > yExtrema) {
-            reduction[smaller].fY = yExtrema;
-            continue;
-        }
-        if (reduction[larger].fY < yExtrema) {
-            reduction[larger].fY = yExtrema;
-        }
-    }
     return reductionLineCount(reduction);
 }
 
-static int horizontal_line(const SkDCubic& cubic, SkReduceOrder::Style reduceStyle,
-                           SkDCubic& reduction) {
-    double tValues[2];
+static int horizontal_line(const SkDCubic& cubic, SkDCubic& reduction) {
     reduction[0] = cubic[0];
     reduction[1] = cubic[3];
-    if (reduceStyle == SkReduceOrder::kFill_Style) {
-        return reductionLineCount(reduction);
-    }
-    int smaller = reduction[1].fX > reduction[0].fX;
-    int larger = smaller ^ 1;
-    int roots = SkDCubic::FindExtrema(cubic[0].fX, cubic[1].fX, cubic[2].fX, cubic[3].fX, tValues);
-    for (int index = 0; index < roots; ++index) {
-        double xExtrema = interp_cubic_coords(&cubic[0].fX, tValues[index]);
-        if (reduction[smaller].fX > xExtrema) {
-            reduction[smaller].fX = xExtrema;
-            continue;
-        }
-        if (reduction[larger].fX < xExtrema) {
-            reduction[larger].fX = xExtrema;
-        }
-    }
     return reductionLineCount(reduction);
 }
 
@@ -276,7 +154,7 @@ static int check_quadratic(const SkDCubic& cubic, SkDCubic& reduction) {
     return 3;
 }
 
-static int check_linear(const SkDCubic& cubic, SkReduceOrder::Style reduceStyle,
+static int check_linear(const SkDCubic& cubic,
         int minX, int maxX, int minY, int maxY, SkDCubic& reduction) {
     int startIndex = 0;
     int endIndex = 3;
@@ -293,50 +171,6 @@ static int check_linear(const SkDCubic& cubic, SkReduceOrder::Style reduceStyle,
     // four are colinear: return line formed by outside
     reduction[0] = cubic[0];
     reduction[1] = cubic[3];
-    if (reduceStyle == SkReduceOrder::kFill_Style) {
-        return reductionLineCount(reduction);
-    }
-    int sameSide1;
-    int sameSide2;
-    bool useX = cubic[maxX].fX - cubic[minX].fX >= cubic[maxY].fY - cubic[minY].fY;
-    if (useX) {
-        sameSide1 = SkDSign(cubic[0].fX - cubic[1].fX) + SkDSign(cubic[3].fX - cubic[1].fX);
-        sameSide2 = SkDSign(cubic[0].fX - cubic[2].fX) + SkDSign(cubic[3].fX - cubic[2].fX);
-    } else {
-        sameSide1 = SkDSign(cubic[0].fY - cubic[1].fY) + SkDSign(cubic[3].fY - cubic[1].fY);
-        sameSide2 = SkDSign(cubic[0].fY - cubic[2].fY) + SkDSign(cubic[3].fY - cubic[2].fY);
-    }
-    if (sameSide1 == sameSide2 && (sameSide1 & 3) != 2) {
-        return reductionLineCount(reduction);
-    }
-    double tValues[2];
-    int roots;
-    if (useX) {
-        roots = SkDCubic::FindExtrema(cubic[0].fX, cubic[1].fX, cubic[2].fX, cubic[3].fX, tValues);
-    } else {
-        roots = SkDCubic::FindExtrema(cubic[0].fY, cubic[1].fY, cubic[2].fY, cubic[3].fY, tValues);
-    }
-    for (int index = 0; index < roots; ++index) {
-        SkDPoint extrema;
-        extrema.fX = interp_cubic_coords(&cubic[0].fX, tValues[index]);
-        extrema.fY = interp_cubic_coords(&cubic[0].fY, tValues[index]);
-        // sameSide > 0 means mid is smaller than either [0] or [3], so replace smaller
-        int replace;
-        if (useX) {
-            if ((extrema.fX < cubic[0].fX) ^ (extrema.fX < cubic[3].fX)) {
-                continue;
-            }
-            replace = ((extrema.fX < cubic[0].fX) | (extrema.fX < cubic[3].fX))
-                    ^ (cubic[0].fX < cubic[3].fX);
-        } else {
-            if ((extrema.fY < cubic[0].fY) ^ (extrema.fY < cubic[3].fY)) {
-                continue;
-            }
-            replace = ((extrema.fY < cubic[0].fY) | (extrema.fY < cubic[3].fY))
-                    ^ (cubic[0].fY < cubic[3].fY);
-        }
-        reduction[replace] = extrema;
-    }
     return reductionLineCount(reduction);
 }
 
@@ -366,8 +200,7 @@ http://kaba.hilvi.org
     // note that three points in a line doesn't simplify a cubic
 // look for approximation with single quadratic
     // save approximation with multiple quadratics for later
-int SkReduceOrder::reduce(const SkDCubic& cubic, Quadratics allowQuadratics,
-        Style reduceStyle) {
+int SkReduceOrder::reduce(const SkDCubic& cubic, Quadratics allowQuadratics) {
     int index, minX, maxX, minY, maxY;
     int minXSet, minYSet;
     minX = maxX = minY = maxY = 0;
@@ -408,12 +241,12 @@ int SkReduceOrder::reduce(const SkDCubic& cubic, Quadratics allowQuadratics,
         if (minYSet == 0xF) {  // return 1 if all four are coincident
             return coincident_line(cubic, fCubic);
         }
-        return vertical_line(cubic, reduceStyle, fCubic);
+        return vertical_line(cubic, fCubic);
     }
     if (minYSet == 0xF) {  // test for horizontal line
-        return horizontal_line(cubic, reduceStyle, fCubic);
+        return horizontal_line(cubic, fCubic);
     }
-    int result = check_linear(cubic, reduceStyle, minX, maxX, minY, maxY, fCubic);
+    int result = check_linear(cubic, minX, maxX, minY, maxY, fCubic);
     if (result) {
         return result;
     }
@@ -429,7 +262,7 @@ SkPath::Verb SkReduceOrder::Quad(const SkPoint a[3], SkPoint* reducePts) {
     SkDQuad quad;
     quad.set(a);
     SkReduceOrder reducer;
-    int order = reducer.reduce(quad, kFill_Style);
+    int order = reducer.reduce(quad);
     if (order == 2) {  // quad became line
         for (int index = 0; index < order; ++index) {
             *reducePts++ = reducer.fLine[index].asSkPoint();
@@ -442,7 +275,7 @@ SkPath::Verb SkReduceOrder::Cubic(const SkPoint a[4], SkPoint* reducePts) {
     SkDCubic cubic;
     cubic.set(a);
     SkReduceOrder reducer;
-    int order = reducer.reduce(cubic, kAllow_Quadratics, kFill_Style);
+    int order = reducer.reduce(cubic, kAllow_Quadratics);
     if (order == 2 || order == 3) {  // cubic became line or quad
         for (int index = 0; index < order; ++index) {
             *reducePts++ = reducer.fQuad[index].asSkPoint();
diff --git a/src/pathops/SkReduceOrder.h b/src/pathops/SkReduceOrder.h
index c167951f8b..4ff9a1d127 100644
--- a/src/pathops/SkReduceOrder.h
+++ b/src/pathops/SkReduceOrder.h
@@ -18,14 +18,10 @@ union SkReduceOrder {
         kNo_Quadratics,
         kAllow_Quadratics
     };
-    enum Style {
-        kStroke_Style,
-        kFill_Style
-    };
 
-    int reduce(const SkDCubic& cubic, Quadratics, Style);
+    int reduce(const SkDCubic& cubic, Quadratics);
     int reduce(const SkDLine& line);
-    int reduce(const SkDQuad& quad, Style);
+    int reduce(const SkDQuad& quad);
 
     static SkPath::Verb Cubic(const SkPoint pts[4], SkPoint* reducePts);
     static SkPath::Verb Quad(const SkPoint pts[3], SkPoint* reducePts);