Fix GrAtlasTextBlob bounds management

src/gpu/batches/GrAtlasTextBatch.h

Index: src/gpu/batches/GrAtlasTextBatch.h
diff --git a/src/gpu/batches/GrAtlasTextBatch.h b/src/gpu/batches/GrAtlasTextBatch.h
index 8f20313378c4bc7b1842db4e06e788a65cee3c46..d54dc9ea5fb8d567adad47862a9e303f5b74dc44 100644
--- a/src/gpu/batches/GrAtlasTextBatch.h
+++ b/src/gpu/batches/GrAtlasTextBatch.h
@@ -84,14 +84,39 @@ public:
         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, and offset by an (X,Y) translate in
+            // device space.
+            SkMatrix boundsMatrix = geo.fBlob->fInitialViewMatrixInverse;
+

[robertphillips, 2016/01/21 17:46:44]

boundsMatrix.postTranslate(-geo.fBlob->fInitialX, -geo.fBlob->fInitialY);

?

+            SkMatrix invInitialTrans;
+            invInitialTrans.setTranslate(-geo.fBlob->fInitialX, -geo.fBlob->fInitialY);
+            boundsMatrix.postConcat(invInitialTrans);
+

[robertphillips, 2016/01/21 17:46:44]

same here ?

+            SkMatrix xyTrans;
+            xyTrans.setTranslate(geo.fBlob->fX, geo.fBlob->fY);
+            boundsMatrix.postConcat(xyTrans);
+
+            boundsMatrix.postConcat(geo.fBlob->fViewMatrix);
+            boundsMatrix.mapRect(&bounds);
+
+            // Due to floating point numerical inaccuracies, we have to round out here
+            SkRect roundedOutBounds;
+            bounds.roundOut(&roundedOutBounds);
+            this->setBounds(roundedOutBounds);
         }
     }