new files for pathops geometric intersection

src/pathops/SkOpCoincidence.h

+/*
+ * 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 SkOpCoincidence_DEFINED
+#define SkOpCoincidence_DEFINED
+
+#include "SkOpTAllocator.h"
+#include "SkOpSpan.h"
+
+class SkOpPtT;
+
+struct SkCoincidentSpans {
+    SkCoincidentSpans* fNext;
+    SkOpPtT* fCoinPtTStart;
+    SkOpPtT* fCoinPtTEnd;
+    SkOpPtT* fOppPtTStart;
+    SkOpPtT* fOppPtTEnd;
+    bool fFlipped;
+};
+
+class SkOpCoincidence {
+public:
+    SkOpCoincidence()
+        : fHead(NULL) {
+    }
+
+    void add(SkOpPtT* coinPtTStart, SkOpPtT* coinPtTEnd, SkOpPtT* oppPtTStart,
+             SkOpPtT* oppPtTEnd, bool flipped, SkChunkAlloc* allocator);
+    void apply();
+    bool contains(SkOpPtT* coinPtTStart, SkOpPtT* coinPtTEnd, SkOpPtT* oppPtTStart,
+                  SkOpPtT* oppPtTEnd, bool flipped);
+    void dump() const;
+    void mark();
+
+    SkCoincidentSpans* fHead;
+};
+
+#endif