Fix GrAtlasTextBlob bounds management

src/gpu/batches/GrAtlasTextBatch.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 GrAtlasTextBatch_DEFINED
 #define GrAtlasTextBatch_DEFINED
 
@@ skipping 66 matching lines @@
     // is used to seed the batch with its initial geometry.  After seeding, the client should call
     // init() so the Batch can initialize itself
     Geometry& geometry() { return fGeoData[0]; }
 
     void init() {
         const Geometry& geo = fGeoData[0];
         fBatch.fColor = geo.fColor;
         fBatch.fViewMatrix = geo.fBlob->fViewMatrix;
 
         // We don't yet position distance field text on the cpu, so we have to map the vertex bounds
-        // into device space
+        // into device space.
+        // We handle vertex bounds differently for distance field text and bitmap text because
+        // the vertex bounds of bitmap text are in device space.  If we are flushing multiple runs
+        // from one blob then we are going to pay the price here of mapping the rect for each run.
         const Run& run = geo.fBlob->fRuns[geo.fRun];
+        SkRect bounds = run.fSubRunInfo[geo.fSubRun].vertexBounds();
         if (run.fSubRunInfo[geo.fSubRun].drawAsDistanceFields()) {
-            SkRect bounds = run.fVertexBounds;
+            // Distance field text is positioned with the (X,Y) as part of the glyph position,
+            // and currently the view matrix is applied on the GPU
+            bounds.offset(geo.fBlob->fX - geo.fBlob->fInitialX,
+                          geo.fBlob->fY - geo.fBlob->fInitialY);
             fBatch.fViewMatrix.mapRect(&bounds);
             this->setBounds(bounds);
         } else {
-            this->setBounds(run.fVertexBounds);
+            // Bitmap text is fully positioned on the CPU
+            SkMatrix boundsMatrix;
+            bounds.offset(-geo.fBlob->fInitialX, -geo.fBlob->fInitialY);
+            boundsMatrix.setConcat(fBatch.fViewMatrix, geo.fBlob->fInitialViewMatrixInverse);
+            boundsMatrix.mapRect(&bounds);
+
+            // Due to floating point numerical inaccuracies, we have to round out here
+            SkRect roundedOutBounds;
+            bounds.roundOut(&roundedOutBounds);
+            roundedOutBounds.offset(geo.fBlob->fX, geo.fBlob->fY);
+            this->setBounds(roundedOutBounds);
         }
     }
 
     const char* name() const override { return "TextBatch"; }
 
     SkString dumpInfo() const override;
 
 protected:
     void computePipelineOptimizations(GrInitInvariantOutput* color, 
                                       GrInitInvariantOutput* coverage,
@@ skipping 92 matching lines @@
     GrBatchFontCache* fFontCache;
 
     // Distance field properties
     SkAutoTUnref<const GrDistanceFieldAdjustTable> fDistanceAdjustTable;
     SkColor fFilteredColor;
 
     typedef GrVertexBatch INHERITED;
 };
 
 #endif