drawBitmapImage can batch across AA rects

src/gpu/batches/GrAAFillRectBatch.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 "GrAAFillRectBatch.h"
 
 #include "GrColor.h"
@@ skipping 232 matching lines @@
             *((SkPoint*)((intptr_t)fan1Pos + 3 * vertexStride)) =
                 *((SkPoint*)((intptr_t)fan0Pos + 3 * vertexStride)) - vec[0] + vec[1];
             *((SkPoint*)((intptr_t)fan0Pos + 3 * vertexStride)) += vec[0] - vec[1];
         }
 
         Base::FillInAttributes(verts, vertexStride, fan0Pos, args);
 
         // Make verts point to vertex color and then set all the color and coverage vertex attrs
         // values.
         verts += sizeof(SkPoint);
+
+        // The coverage offset is always the last vertex attribute
+        intptr_t coverageOffset = vertexStride - sizeof(GrColor) - sizeof(SkPoint);
         for (int i = 0; i < 4; ++i) {
             if (tweakAlphaForCoverage) {
                 *reinterpret_cast<GrColor*>(verts + i * vertexStride) = 0;
             } else {
                 *reinterpret_cast<GrColor*>(verts + i * vertexStride) = args.fColor;
-                *reinterpret_cast<float*>(verts + i * vertexStride + sizeof(GrColor)) = 0;
+                *reinterpret_cast<float*>(verts + i * vertexStride + coverageOffset) = 0;
             }
         }
 
         int scale;
         if (inset < SK_ScalarHalf) {
             scale = SkScalarFloorToInt(512.0f * inset / (inset + SK_ScalarHalf));
             SkASSERT(scale >= 0 && scale <= 255);
         } else {
             scale = 0xff;
         }
 
         verts += 4 * vertexStride;
 
         float innerCoverage = GrNormalizeByteToFloat(scale);
         GrColor scaledColor = (0xff == scale) ? args.fColor : SkAlphaMulQ(args.fColor, scale);
 
         for (int i = 0; i < 4; ++i) {
             if (tweakAlphaForCoverage) {
                 *reinterpret_cast<GrColor*>(verts + i * vertexStride) = scaledColor;
             } else {
                 *reinterpret_cast<GrColor*>(verts + i * vertexStride) = args.fColor;
                 *reinterpret_cast<float*>(verts + i * vertexStride +
-                                          sizeof(GrColor)) = innerCoverage;
+                                          coverageOffset) = innerCoverage;
             }
         }
     }
 
     static const GrGeometryProcessor* CreateFillRectGP(
                                          bool tweakAlphaForCoverage,
                                          const SkMatrix& viewMatrix,
                                          bool usesLocalCoords,
                                          GrDefaultGeoProcFactory::LocalCoords::Type localCoordsType,
                                          bool coverageIgnored) {
@@ skipping 93 matching lines @@
 
     inline static void FillInAttributes(intptr_t vertices, size_t vertexStride,
                                         SkPoint* fan0Pos, const Geometry& args) {
         SkMatrix invViewMatrix;
         if (!args.fViewMatrix.invert(&invViewMatrix)) {
             SkASSERT(false);
             invViewMatrix = SkMatrix::I();
         }
         SkMatrix localCoordMatrix;
         localCoordMatrix.setConcat(args.fLocalMatrix, invViewMatrix);
-        SkPoint* fan0Loc = reinterpret_cast<SkPoint*>(vertices + vertexStride - sizeof(SkPoint));
+        SkPoint* fan0Loc = reinterpret_cast<SkPoint*>(vertices + sizeof(SkPoint) + sizeof(GrColor));
         localCoordMatrix.mapPointsWithStride(fan0Loc, fan0Pos, vertexStride, 8);
     }
 };
 
 typedef AAFillRectBatch<AAFillRectBatchNoLocalMatrixImp> AAFillRectBatchNoLocalMatrix;
 typedef AAFillRectBatch<AAFillRectBatchLocalMatrixImp> AAFillRectBatchLocalMatrix;
 
 namespace GrAAFillRectBatch {
 
 GrDrawBatch* Create(GrColor color,
@@ skipping 45 matching lines @@
 DRAW_BATCH_TEST_DEFINE(AAFillRectBatchLocalMatrix) {
     GrColor color = GrRandomColor(random);
     SkMatrix viewMatrix = GrTest::TestMatrixInvertible(random);
     SkMatrix localMatrix = GrTest::TestMatrix(random);
     SkRect rect = GrTest::TestRect(random);
     SkRect devRect = GrTest::TestRect(random);
     return GrAAFillRectBatch::Create(color, viewMatrix, localMatrix, rect, devRect);
 }
 
 #endif