experimental path-builder

include/core/SkPathIter.h

+/*
+ * Copyright 2015 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef SkPathIter_DEFINED
+#define SkPathIter_DEFINED
+
+#include "SkPathTypes.h"
+#include "SkPoint.h"
+
+class SkPath;
+
+class SkPathIter {
+public:
+    SkPathIter(const SkPoint pts[], const uint8_t verbs[], const SkScalar conicW[], int count)
+        : fCurrPts(pts)
+        , fNextPts(pts + 1)
+        , fConicW(conicW)
+        , fVerbs(verbs)
+        , fStopVerbs(verbs - count)
+        , fPrevPtsPerVerb(0)
+    {
+        if (count > 0) {
+            SkASSERT(kMove_SkPathVerb == verbs[-1]);
+        }
+    }
+
+    SkPathIter(const SkPath&);
+
+    bool            done() const { return fStopVerbs == fVerbs; }
+    SkPathVerb      currVerb() const { return (SkPathVerb)fVerbs[0]; }
+    const SkPoint*  currPts() const { return fCurrPts; }
+    SkScalar        currConicW() const { return *fConicW; }
+
+#if 0
+    bool next() {
+        if (fStopVerbs == fVerbs) {
+            return false;
+        }
+
+        static const uint8_t gPtsPerVerb[] = {
+            1,  // Move
+            1,  // Line
+            2,  // Quad
+            2,  // Conic
+            3,  // Cubic
+            0,  // Close
+        };
+
+        fCurrPts += fPrevPtsPerVerb;
+        SkPathVerb verb = (SkPathVerb)(*--fVerbs);
+        fNextPts += (fPrevPtsPerVerb = gPtsPerVerb[verb]);
+        fConicW += (kConic_SkPathVerb == verb);
+        return true;
+    }
+#else
+    bool next();
+#endif
+
+private:
+    const SkPoint*  fCurrPts;
+    const SkPoint*  fNextPts;
+    const SkScalar* fConicW;
+    const uint8_t*  fVerbs;
+    const uint8_t*  fStopVerbs;
+    int             fPrevPtsPerVerb;
+};
+
+#endif