Fix transformed stroke width in GrAALinearizingConvexPathRenderer.

src/gpu/GrAAConvexTessellator.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrAAConvexTessellator.h"
 #include "SkCanvas.h"
 #include "SkPath.h"
@@ skipping 183 matching lines @@
 // point two of the edges collapse and the process repeats on the new polygon.
 // The polygon state is captured in the Ring class while the GrAAConvexTessellator
 // controls the iteration. The CandidateVerts holds the formative points for the
 // next ring.
 bool GrAAConvexTessellator::tessellate(const SkMatrix& m, const SkPath& path) {
     if (!this->extractFromPath(m, path)) {
         return false;
     }
 
     SkScalar coverage = 1.0f;
+    SkScalar scaleFactor = 0.0f;
     if (fStrokeWidth >= 0.0f) {
+        SkASSERT(m.isSimilarity()); 
+        scaleFactor = m.getMaxScale(); // x and y scale are the same
+        SkScalar effectiveStrokeWidth = scaleFactor * fStrokeWidth;
         Ring outerStrokeRing;
-        this->createOuterRing(fInitialRing, fStrokeWidth / 2 - kAntialiasingRadius, coverage,
-                              &outerStrokeRing);
+        this->createOuterRing(fInitialRing, effectiveStrokeWidth / 2 - kAntialiasingRadius, 
+                              coverage, &outerStrokeRing);
         outerStrokeRing.init(*this);
         Ring outerAARing;
         this->createOuterRing(outerStrokeRing, kAntialiasingRadius * 2, 0.0f, &outerAARing);
     } else {
         Ring outerAARing;
         this->createOuterRing(fInitialRing, kAntialiasingRadius, 0.0f, &outerAARing);
     }
 
     // the bisectors are only needed for the computation of the outer ring
     fBisectors.rewind();
     if (fStrokeWidth >= 0.0f && fInitialRing.numPts() > 2) {
+        SkScalar effectiveStrokeWidth = scaleFactor * fStrokeWidth;
         Ring* insetStrokeRing;
-        SkScalar strokeDepth = fStrokeWidth / 2 - kAntialiasingRadius;
+        SkScalar strokeDepth = effectiveStrokeWidth / 2 - kAntialiasingRadius;
         if (this->createInsetRings(fInitialRing, 0.0f, coverage, strokeDepth, coverage, 
                              &insetStrokeRing)) {
             Ring* insetAARing;
             this->createInsetRings(*insetStrokeRing, strokeDepth, coverage, strokeDepth + 
                              kAntialiasingRadius * 2, 0.0f, &insetAARing);
         }
     } else {
         Ring* insetAARing;
         this->createInsetRings(fInitialRing, 0.0f, 0.5f, kAntialiasingRadius, 1.0f, &insetAARing);
     }
@@ skipping 782 matching lines @@
         SkString num;
         num.printf("%d", i);
         canvas->drawText(num.c_str(), num.size(), 
                          this->point(i).fX, this->point(i).fY+(kPointRadius/2.0f), 
                          paint);
     }
 }
 
 #endif