Add implementation of path ops

src/pathops/SkOpContour.h

Index: src/pathops/SkOpContour.h
===================================================================
--- src/pathops/SkOpContour.h	(revision 0)
+++ src/pathops/SkOpContour.h	(revision 0)
@@ -0,0 +1,253 @@
+/*
+ * Copyright 2013 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+#ifndef SkOpContour_DEFINED
+#define SkOpContour_DEFINED
+
+#include "SkOpSegment.h"
+#include "SkTArray.h"
+
+class SkIntersections;
+class SkOpContour;
+class SkPathWriter;
+
+struct SkCoincidence {
+    SkOpContour* fContours[2];
+    int fSegments[2];
+    double fTs[2][2];
+    SkPoint fPts[2];
+};
+
+class SkOpContour {
+public:
+    SkOpContour() {
+        reset();
+#if DEBUG_DUMP
+        fID = ++gContourID;
+#endif
+    }
+
+    bool operator<(const SkOpContour& rh) const {
+        return fBounds.fTop == rh.fBounds.fTop
+                ? fBounds.fLeft < rh.fBounds.fLeft
+                : fBounds.fTop < rh.fBounds.fTop;
+    }
+
+    void addCoincident(int index, SkOpContour* other, int otherIndex,
+                       const SkIntersections& ts, bool swap);
+    void addCoincidentPoints();
+
+    void addCross(const SkOpContour* crosser) {
+#ifdef DEBUG_CROSS
+        for (int index = 0; index < fCrosses.count(); ++index) {
+            SkASSERT(fCrosses[index] != crosser);
+        }
+#endif
+        *fCrosses.append() = crosser;
+    }
+
+    void addCubic(const SkPoint pts[4]) {
+        fSegments.push_back().addCubic(pts, fOperand, fXor);
+        fContainsCurves = fContainsCubics = true;
+    }
+
+    int addLine(const SkPoint pts[2]) {
+        fSegments.push_back().addLine(pts, fOperand, fXor);
+        return fSegments.count();
+    }
+
+    void addOtherT(int segIndex, int tIndex, double otherT, int otherIndex) {
+        fSegments[segIndex].addOtherT(tIndex, otherT, otherIndex);
+    }
+
+    int addQuad(const SkPoint pts[3]) {
+        fSegments.push_back().addQuad(pts, fOperand, fXor);
+        fContainsCurves = true;
+        return fSegments.count();
+    }
+
+    int addT(int segIndex, SkOpContour* other, int otherIndex, const SkPoint& pt, double newT) {
+        setContainsIntercepts();
+        return fSegments[segIndex].addT(&other->fSegments[otherIndex], pt, newT);
+    }
+
+    int addSelfT(int segIndex, SkOpContour* other, int otherIndex, const SkPoint& pt, double newT) {
+        setContainsIntercepts();
+        return fSegments[segIndex].addSelfT(&other->fSegments[otherIndex], pt, newT);
+    }
+
+    int addUnsortableT(int segIndex, SkOpContour* other, int otherIndex, bool start,
+                       const SkPoint& pt, double newT) {
+        return fSegments[segIndex].addUnsortableT(&other->fSegments[otherIndex], start, pt, newT);
+    }
+
+    const SkPathOpsBounds& bounds() const {
+        return fBounds;
+    }
+
+    void calcCoincidentWinding();
+
+    void complete() {
+        setBounds();
+        fContainsIntercepts = false;
+    }
+
+    bool containsCubics() const {
+        return fContainsCubics;
+    }
+
+    bool crosses(const SkOpContour* crosser) const {
+        for (int index = 0; index < fCrosses.count(); ++index) {
+            if (fCrosses[index] == crosser) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    bool done() const {
+        return fDone;
+    }
+
+    const SkPoint& end() const {
+        const SkOpSegment& segment = fSegments.back();
+        return segment.pts()[segment.verb()];
+    }
+
+    void findTooCloseToCall() {
+        int segmentCount = fSegments.count();
+        for (int sIndex = 0; sIndex < segmentCount; ++sIndex) {
+            fSegments[sIndex].findTooCloseToCall();
+        }
+    }
+
+    void fixOtherTIndex() {
+        int segmentCount = fSegments.count();
+        for (int sIndex = 0; sIndex < segmentCount; ++sIndex) {
+            fSegments[sIndex].fixOtherTIndex();
+        }
+    }
+
+    SkOpSegment* nonVerticalSegment(int& start, int& end);
+    
+    bool operand() const {
+        return fOperand;
+    }
+
+    void reset() {
+        fSegments.reset();
+        fBounds.set(SK_ScalarMax, SK_ScalarMax, SK_ScalarMax, SK_ScalarMax);
+        fContainsCurves = fContainsCubics = fContainsIntercepts = fDone = false;
+    }
+
+    void resolveCoincidence(SkTDArray<SkOpContour*>& contourList);
+
+    SkTArray<SkOpSegment>& segments() {
+        return fSegments;
+    }
+
+    void setContainsIntercepts() {
+        fContainsIntercepts = true;
+    }
+
+    void setOperand(bool isOp) {
+        fOperand = isOp;
+    }
+
+    void setOppXor(bool isOppXor) {
+        fOppXor = isOppXor;
+        int segmentCount = fSegments.count();
+        for (int test = 0; test < segmentCount; ++test) {
+            fSegments[test].setOppXor(isOppXor);
+        }
+    }
+
+    void setXor(bool isXor) {
+        fXor = isXor;
+    }
+
+    void sortSegments();
+    
+    const SkPoint& start() const {
+        return fSegments.front().pts()[0];
+    }
+    
+    void toPath(SkPathWriter& path) const;
+    
+    void toPartialBackward(SkPathWriter& path) const {
+        int segmentCount = fSegments.count();
+        for (int test = segmentCount - 1; test >= 0; --test) {
+            fSegments[test].addCurveTo(1, 0, path, true);
+        }
+    }
+
+    void toPartialForward(SkPathWriter& path) const {
+        int segmentCount = fSegments.count();
+        for (int test = 0; test < segmentCount; ++test) {
+            fSegments[test].addCurveTo(0, 1, path, true);
+        }
+    }
+
+    void topSortableSegment(const SkPoint& topLeft, SkPoint& bestXY, SkOpSegment*& topStart);
+    SkOpSegment* undoneSegment(int& start, int& end);
+
+    int updateSegment(int index, const SkPoint* pts) {
+        SkOpSegment& segment = fSegments[index];
+        segment.updatePts(pts);
+        return segment.verb() + 1;
+    }
+
+#if DEBUG_TEST
+    SkTArray<SkOpSegment>& debugSegments() {
+        return fSegments;
+    }
+#endif
+
+#if DEBUG_DUMP
+    void dump();
+#endif
+
+#if DEBUG_ACTIVE_SPANS
+    void debugShowActiveSpans() {
+        for (int index = 0; index < fSegments.count(); ++index) {
+            fSegments[index].debugShowActiveSpans();
+        }
+    }
+
+    void validateActiveSpans() {
+        for (int index = 0; index < fSegments.count(); ++index) {
+            fSegments[index].validateActiveSpans();
+        }
+    }
+#endif
+
+#if DEBUG_SHOW_WINDING
+    int debugShowWindingValues(int totalSegments, int ofInterest);
+    static void debugShowWindingValues(SkTDArray<SkOpContour*>& contourList);
+#endif
+
+private:
+    void setBounds();
+
+    SkTArray<SkOpSegment> fSegments;
+    SkTDArray<SkOpSegment*> fSortedSegments;
+    int fFirstSorted;
+    SkTDArray<SkCoincidence> fCoincidences;
+    SkTDArray<const SkOpContour*> fCrosses;
+    SkPathOpsBounds fBounds;
+    bool fContainsIntercepts; // FIXME: is this used by anybody?
+    bool fContainsCubics;
+    bool fContainsCurves;
+    bool fDone;
+    bool fOperand; // true for the second argument to a binary operator
+    bool fXor;
+    bool fOppXor;
+#if DEBUG_DUMP
+    int fID;
+#endif
+};
+
+#endif