Add support for hoisting layers in pictures drawn with a matrix

src/core/SkMultiPictureDraw.cpp

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 // Need to include something before #if SK_SUPPORT_GPU so that the Android
 // framework build, which gets its defines from SkTypes rather than a makefile,
 // has the definition before checking it.
 #include "SkCanvas.h"
+#include "SkCanvasPriv.h"
 #include "SkMultiPictureDraw.h"
 #include "SkPicture.h"
 #include "SkTaskGroup.h"
 
 #if SK_SUPPORT_GPU
 #include "GrLayerHoister.h"
 #include "GrRecordReplaceDraw.h"
 #include "GrRenderTarget.h"
 #endif
 
@@ skipping 82 matching lines @@
     // Start by collecting all the layers that are going to be atlased and render
     // them (if necessary). Hoisting the free floating layers is deferred until
     // drawing the canvas that requires them.
     SkTDArray<GrHoistedLayer> atlasedNeedRendering, atlasedRecycled;
 
     for (int i = 0; i < count; ++i) {
         const DrawData& data = fGPUDrawData[i];
         // we only expect 1 context for all the canvases
         SkASSERT(data.fCanvas->getGrContext() == context);
 
-        if (!data.fPaint && data.fMatrix.isIdentity()) {
+        if (!data.fPaint) {
             SkRect clipBounds;
             if (!data.fCanvas->getClipBounds(&clipBounds)) {
                 continue;
             }
 
+            SkMatrix initialMatrix = data.fCanvas->getTotalMatrix();
+            initialMatrix.preConcat(data.fMatrix);
+
             GrRenderTarget* rt = data.fCanvas->internal_private_accessTopLayerRenderTarget();
             SkASSERT(rt);
 
             // TODO: sorting the cacheable layers from smallest to largest
             // would improve the packing and reduce the number of swaps
             // TODO: another optimization would be to make a first pass to
             // lock any required layer that is already in the atlas
-            GrLayerHoister::FindLayersToAtlas(context, data.fPicture,
+            GrLayerHoister::FindLayersToAtlas(context, data.fPicture, initialMatrix,
                                               clipBounds,
                                               &atlasedNeedRendering, &atlasedRecycled,
                                               rt->numSamples());
         }
     }
 
     GrLayerHoister::DrawLayersToAtlas(context, atlasedNeedRendering);
 
     SkTDArray<GrHoistedLayer> needRendering, recycled;
 #endif
 
     for (int i = 0; i < count; ++i) {
         const DrawData& data = fGPUDrawData[i];
         SkCanvas* canvas = data.fCanvas;
         const SkPicture* picture = data.fPicture;
 
 #if !defined(SK_IGNORE_GPU_LAYER_HOISTING) && SK_SUPPORT_GPU
-        if (!data.fPaint && data.fMatrix.isIdentity()) {
+        if (!data.fPaint) {
 
             SkRect clipBounds;
             if (!canvas->getClipBounds(&clipBounds)) {
                 continue;
             }
 
+            SkAutoCanvasMatrixPaint acmp(canvas, &data.fMatrix, data.fPaint, picture->cullRect());
+
+            const SkMatrix initialMatrix = canvas->getTotalMatrix();
+
             GrRenderTarget* rt = data.fCanvas->internal_private_accessTopLayerRenderTarget();
             SkASSERT(rt);
 
             // Find the layers required by this canvas. It will return atlased
             // layers in the 'recycled' list since they have already been drawn.
-            GrLayerHoister::FindLayersToHoist(context, picture,
+            GrLayerHoister::FindLayersToHoist(context, picture, initialMatrix,
                                               clipBounds, &needRendering, &recycled,
                                               rt->numSamples());
 
             GrLayerHoister::DrawLayers(context, needRendering);
 
             GrReplacements replacements;
 
             GrLayerHoister::ConvertLayersToReplacements(needRendering, &replacements);
             GrLayerHoister::ConvertLayersToReplacements(recycled, &replacements);
 
-            const SkMatrix initialMatrix = canvas->getTotalMatrix();
-
             // Render the entire picture using new layers
             GrRecordReplaceDraw(picture, canvas, &replacements, initialMatrix, NULL);
 
             GrLayerHoister::UnlockLayers(context, needRendering);
             GrLayerHoister::UnlockLayers(context, recycled);
 
             needRendering.rewind();
             recycled.rewind();
         } else
 #endif
         {
             canvas->drawPicture(picture, &data.fMatrix, data.fPaint);
         }
     }
 
 #if !defined(SK_IGNORE_GPU_LAYER_HOISTING) && SK_SUPPORT_GPU
     GrLayerHoister::UnlockLayers(context, atlasedNeedRendering);
     GrLayerHoister::UnlockLayers(context, atlasedRecycled);
 #if !GR_CACHE_HOISTED_LAYERS
     GrLayerHoister::PurgeCache(context);
 #endif
 #endif
 }