cc: Adding support for RGBA_4444 tile textures

cc/resources/raster_worker_pool.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/resources/raster_worker_pool.h"
 
 #include "base/json/json_writer.h"
 #include "base/metrics/histogram.h"
 #include "base/values.h"
 #include "cc/debug/benchmark_instrumentation.h"
 #include "cc/debug/devtools_instrumentation.h"
 #include "cc/debug/traced_value.h"
 #include "cc/resources/picture_pile_impl.h"
 #include "skia/ext/lazy_pixel_ref.h"
 #include "skia/ext/paint_simplifier.h"
+#include "third_party/skia/include/core/SkBitmap.h"
 
 namespace cc {
 
 namespace {
 
+// Subclass of Allocator that takes a suitably allocated pointer and uses
+// it as the pixel memory for the bitmap.
+class IdentityAllocator : public SkBitmap::Allocator {
+ public:
+  explicit IdentityAllocator(void* buffer) : buffer_(buffer) {}
+  virtual bool allocPixelRef(SkBitmap* dst, SkColorTable*) OVERRIDE {
+    dst->setPixels(buffer_);
+    return true;
+  }
+ private:
+  void* buffer_;
+};
+
 // Flag to indicate whether we should try and detect that
 // a tile is of solid color.
 const bool kUseColorEstimator = true;
 
 class DisableLCDTextFilter : public SkDrawFilter {
  public:
   // SkDrawFilter interface.
   virtual bool filter(SkPaint* paint, SkDrawFilter::Type type) OVERRIDE {
     if (type != SkDrawFilter::kText_Type)
       return true;
 
     paint->setLCDRenderText(false);
     return true;
   }
 };
 
+void ChangeBitmapConfigIfNeeded(const SkBitmap& bitmap,
+                                void* buffer,
+                                ResourceFormat format) {

[reveman, 2013/09/16 15:55:14]

You can remove the format parameter if you make this a member function of
RasterWorkerPoolTaskImpl. I think that would also make the name of the trace
event less cryptic.

[kaanb, 2013/09/16 18:36:37]

Done.

+  TRACE_EVENT0("cc", "ChangeBitmapConfigIfNeeded");
+  SkBitmap::Config config = SkBitmapConfigFromFormat(format);
+  if (bitmap.getConfig() != config) {
+    SkBitmap bitmap_dest;
+    IdentityAllocator allocator(buffer);
+    bitmap.copyTo(&bitmap_dest, config, &allocator);
+  }
+}
+
 class RasterWorkerPoolTaskImpl : public internal::RasterWorkerPoolTask {
  public:
   RasterWorkerPoolTaskImpl(const Resource* resource,
                            PicturePileImpl* picture_pile,
                            gfx::Rect content_rect,
                            float contents_scale,
                            RasterMode raster_mode,
                            bool is_tile_in_pending_tree_now_bin,
                            TileResolution tile_resolution,
                            int layer_id,
@@ skipping 35 matching lines @@
 
     // Record the solid color prediction.
     UMA_HISTOGRAM_BOOLEAN("Renderer4.SolidColorTilesAnalyzed",
                           analysis_.is_solid_color);
     rendering_stats_->AddAnalysisResult(duration, analysis_.is_solid_color);
 
     // Clear the flag if we're not using the estimator.
     analysis_.is_solid_color &= kUseColorEstimator;
   }
 
-  bool RunRasterOnThread(SkBaseDevice* device, unsigned thread_index) {
+  bool RunRasterOnThread(unsigned thread_index,
+                         void* buffer,
+                         gfx::Size size,
+                         int stride) {
     TRACE_EVENT2(
         benchmark_instrumentation::kCategory,
         benchmark_instrumentation::kRunRasterOnThread,
         benchmark_instrumentation::kData,
         TracedValue::FromValue(DataAsValue().release()),
         "raster_mode",
         TracedValue::FromValue(RasterModeAsValue(raster_mode_).release()));
 
     devtools_instrumentation::ScopedLayerTask raster_task(
         devtools_instrumentation::kRasterTask, layer_id_);
 
     DCHECK(picture_pile_.get());
-    DCHECK(device);
+    DCHECK(buffer);
 
     if (analysis_.is_solid_color)
       return false;
 
     PicturePileImpl* picture_clone =
         picture_pile_->GetCloneForDrawingOnThread(thread_index);
 
-    SkCanvas canvas(device);
+    SkBitmap bitmap;
+    switch (resource()->format()) {
+      case RGBA_4444:
+        // Use the default stride if we will eventually convert this
+        // bitmap to 4444.
+        bitmap.setConfig(SkBitmap::kARGB_8888_Config,
+                         size.width(),
+                         size.height());
+        bitmap.allocPixels();
+        break;
+      case RGBA_8888:
+      case BGRA_8888:
+        bitmap.setConfig(SkBitmap::kARGB_8888_Config,
+                         size.width(),
+                         size.height(),
+                         stride);
+        bitmap.setPixels(buffer);
+        break;
+      case LUMINANCE_8:
+        NOTREACHED();
+        break;
+    }
 
+    SkBitmapDevice device(bitmap);
+    SkCanvas canvas(&device);
     skia::RefPtr<SkDrawFilter> draw_filter;
     switch (raster_mode_) {
       case LOW_QUALITY_RASTER_MODE:
         draw_filter = skia::AdoptRef(new skia::PaintSimplifier);
         break;
       case HIGH_QUALITY_NO_LCD_RASTER_MODE:
         draw_filter = skia::AdoptRef(new DisableLCDTextFilter);
         break;
       case HIGH_QUALITY_RASTER_MODE:
         break;
@@ skipping 17 matching lines @@
       HISTOGRAM_CUSTOM_COUNTS(
           "Renderer4.PictureRasterTimeUS",
           raster_stats.total_rasterize_time.InMicroseconds(),
           0,
           100000,
           100);
     } else {
       picture_clone->RasterToBitmap(
           &canvas, content_rect_, contents_scale_, NULL);
     }
+
+    ChangeBitmapConfigIfNeeded(bitmap, buffer, resource()->format());
+
     return true;
   }
 
   // Overridden from internal::RasterWorkerPoolTask:
-  virtual bool RunOnWorkerThread(SkBaseDevice* device, unsigned thread_index)
+  virtual bool RunOnWorkerThread(unsigned thread_index,
+                                 void* buffer,
+                                 gfx::Size size,
+                                 int stride)
       OVERRIDE {
     RunAnalysisOnThread(thread_index);
-    return RunRasterOnThread(device, thread_index);
+    return RunRasterOnThread(thread_index, buffer, size, stride);
   }
   virtual void CompleteOnOriginThread() OVERRIDE {
     reply_.Run(analysis_, !HasFinishedRunning() || WasCanceled());
   }
 
  protected:
   virtual ~RasterWorkerPoolTaskImpl() {}
 
  private:
   scoped_ptr<base::Value> DataAsValue() const {
@@ skipping 364 matching lines @@
 
     internal::GraphNode* decode_node = CreateGraphNodeForTask(
         decode_task, priority, graph);
     decode_node->add_dependent(raster_node);
   }
 
   return raster_node;
 }
 
 }  // namespace cc