Add implementation of path ops

src/pathops/SkOpAngle.h

+/*
+ * Copyright 2012 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+#ifndef SkOpAngle_DEFINED
+#define SkOpAngle_DEFINED
+
+#include "SkLineParameters.h"
+#include "SkPathOpsCubic.h"
+#include "SkOpSpan.h"
+#include "SkPath.h"
+#include "SkTDArray.h"
+
+// sorting angles
+// given angles of {dx dy ddx ddy dddx dddy} sort them
+class SkOpAngle {
+public:
+    bool operator<(const SkOpAngle& rh) const;
+    double dx() const {
+        return fTangent1.dx();
+    }
+
+    double dy() const {
+        return fTangent1.dy();
+    }
+
+    int end() const {
+        return fEnd;
+    }
+
+    bool isHorizontal() const {
+        return dy() == 0 && fVerb == SkPath::kLine_Verb;
+    }
+
+    bool lengthen();
+    bool reverseLengthen();
+    void set(const SkPoint* orig, SkPath::Verb verb, const SkOpSegment* segment,
+            int start, int end, const SkTDArray<SkOpSpan>& spans);
+
+    void setSpans();
+    SkOpSegment* segment() const {
+        return const_cast<SkOpSegment*>(fSegment);
+    }
+
+    int sign() const {
+        return SkSign32(fStart - fEnd);
+    }
+
+    const SkTDArray<SkOpSpan>* spans() const {
+        return fSpans;
+    }
+
+    int start() const {
+        return fStart;
+    }
+
+    bool unsortable() const {
+        return fUnsortable;
+    }
+
+#if DEBUG_ANGLE
+    const SkPoint* pts() const {
+        return fPts;
+    }
+
+    SkPath::Verb verb() const {
+        return fVerb;
+    }
+
+    void debugShow(const SkPoint& a) const {
+        SkDebugf("    d=(%1.9g,%1.9g) side=%1.9g\n", dx(), dy(), fSide);
+    }
+#endif
+
+private:
+    const SkPoint* fPts;
+    SkDCubic fCurvePart;
+    SkPath::Verb fVerb;
+    double fSide;
+    SkLineParameters fTangent1;
+    const SkTDArray<SkOpSpan>* fSpans;
+    const SkOpSegment* fSegment;
+    int fStart;
+    int fEnd;
+    bool fReversed;
+    mutable bool fUnsortable; // this alone is editable by the less than operator
+};
+
+#endif