add interp path

src/core/SkPath.cpp

 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkBuffer.h"
 #include "SkCubicClipper.h"
 #include "SkErrorInternals.h"
@@ skipping 175 matching lines @@
         SkTSwap<uint8_t>(fFillType, that.fFillType);
         SkTSwap<uint8_t>(fConvexity, that.fConvexity);
         // Simulate SkTSwap<uint8_t>(fFirstDirection, that.fFirstDirection);
         uint8_t temp = fFirstDirection;
         fFirstDirection.store(that.fFirstDirection.load());
         that.fFirstDirection.store(temp);
         SkTSwap<SkBool8>(fIsVolatile, that.fIsVolatile);
     }
 }
 
+bool SkPath::isInterpolatable(const SkPath& compare) const {
+    int count = fPathRef->countVerbs();
+    if (count != compare.fPathRef->countVerbs()) {
+        return false;
+    }
+    if (!count) {
+        return true;
+    }
+    if (memcmp(fPathRef->verbsMemBegin(), compare.fPathRef->verbsMemBegin(),
+               count)) {
+        return false;
+    }
+    return !SkToBool(memcmp(fPathRef->conicWeights(), compare.fPathRef->conicWeights(),
+            fPathRef->countWeights() * sizeof(*fPathRef->conicWeights())));
+}
+
+bool SkPath::interpolate(const SkPath& ending, SkScalar weight, SkPath* out) const {
+    int verbCount = fPathRef->countVerbs();
+    if (verbCount != ending.fPathRef->countVerbs()) {
+        return false;
+    }
+    out->reset();
+    out->addPath(*this);
+    fPathRef->interpolate(*ending.fPathRef, weight, out->fPathRef);
+    return true;
+}
+
 static inline bool check_edge_against_rect(const SkPoint& p0,
                                            const SkPoint& p1,
                                            const SkRect& rect,
                                            SkPathPriv::FirstDirection dir) {
     const SkPoint* edgeBegin;
     SkVector v;
     if (SkPathPriv::kCW_FirstDirection == dir) {
         v = p1 - p0;
         edgeBegin = &p0;
     } else {
@@ skipping 2969 matching lines @@
         }
     } while (!done);
     return SkToBool(tangents.count()) ^ isInverse;
 }
 
 int SkPath::ConvertConicToQuads(const SkPoint& p0, const SkPoint& p1, const SkPoint& p2,
                                 SkScalar w, SkPoint pts[], int pow2) {
     const SkConic conic(p0, p1, p2, w);
     return conic.chopIntoQuadsPOW2(pts, pow2);
 }