Fix bounds computation in GrAAHairlineRenderer

gm/hairlines.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "gm.h"
 #include "SkCanvas.h"
 #include "SkTArray.h"
@@ skipping 62 matching lines @@
             closedQuad->moveTo(0, -0);
             closedQuad->quadTo(SkIntToScalar(100), SkIntToScalar(100), 0, 0);
         }
 
         {
             SkPath* unevenClosedQuad = &fPaths.push_back();
             unevenClosedQuad->moveTo(0, -0);
             unevenClosedQuad->quadTo(SkIntToScalar(100), SkIntToScalar(100),
                                      SkIntToScalar(75), SkIntToScalar(75));
         }
+
+        // Two problem cases for gpu hairline renderer found by shapeops testing. These used
+        // to assert that the computed bounding box didn't contain all the vertices.
+        {
+            SkPath* problem1 = &fPaths.push_back();
+            problem1->moveTo(SkIntToScalar(4), SkIntToScalar(6));
+            problem1->cubicTo(SkIntToScalar(5), SkIntToScalar(6),
+                              SkIntToScalar(5), SkIntToScalar(4),
+                              SkIntToScalar(4), SkIntToScalar(0));
+            problem1->close();
+        }
+
+        {
+            SkPath* problem2 = &fPaths.push_back();
+            problem2->moveTo(SkIntToScalar(5), SkIntToScalar(1));
+            problem2->lineTo(SkFloatToScalar(4.32787323f), SkFloatToScalar(1.67212653f));
+            problem2->cubicTo(SkFloatToScalar(2.75223875f), SkFloatToScalar(3.24776125f),
+                              SkFloatToScalar(3.00581908f), SkFloatToScalar(4.51236057f),
+                              SkFloatToScalar(3.7580452f), SkFloatToScalar(4.37367964f));
+            problem2->cubicTo(SkFloatToScalar(4.66472578f), SkFloatToScalar(3.888381f),
+                              SkFloatToScalar(5.f), SkFloatToScalar(2.875f),
+                              SkFloatToScalar(5.f), SkFloatToScalar(1.f));
+            problem2->close();
+        }
     }
 
     virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
         static const SkAlpha kAlphaValue[] = { 0xFF, 0x40 };
 
         enum {
             kMargin = 5,
         };
         int wrapX = canvas->getDeviceSize().fWidth - kMargin;
 
@@ skipping 41 matching lines @@
     SkTArray<SkPath> fPaths;
     typedef GM INHERITED;
 };
 
 //////////////////////////////////////////////////////////////////////////////
 
 static GM* MyFactory(void*) { return new HairlinesGM; }
 static GMRegistry reg(MyFactory);
 
 }