Optimize alpha software PictureDrawQuads.

cc/output/gl_renderer.cc

 // Copyright 2010 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/output/gl_renderer.h"
 
 #include <algorithm>
 #include <limits>
 #include <set>
 #include <string>
@@ skipping 19 matching lines @@
 #include "cc/quads/render_pass.h"
 #include "cc/quads/stream_video_draw_quad.h"
 #include "cc/quads/texture_draw_quad.h"
 #include "cc/resources/layer_quad.h"
 #include "cc/resources/scoped_resource.h"
 #include "cc/resources/sync_point_helper.h"
 #include "cc/trees/damage_tracker.h"
 #include "cc/trees/proxy.h"
 #include "cc/trees/single_thread_proxy.h"
 #include "gpu/GLES2/gl2extchromium.h"
+#include "skia/ext/opacity_draw_filter.h"
 #include "third_party/WebKit/public/platform/WebGraphicsContext3D.h"
 #include "third_party/khronos/GLES2/gl2.h"
 #include "third_party/khronos/GLES2/gl2ext.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "third_party/skia/include/core/SkColorFilter.h"
 #include "third_party/skia/include/core/SkSurface.h"
 #include "third_party/skia/include/gpu/GrContext.h"
 #include "third_party/skia/include/gpu/GrTexture.h"
 #include "third_party/skia/include/gpu/SkGpuDevice.h"
@@ skipping 1583 matching lines @@
   DrawQuadGeometry(frame,
                    quad->quadTransform(),
                    quad->rect,
                    program->vertex_shader().matrix_location());
 }
 
 void GLRenderer::DrawPictureQuadDirectToBackbuffer(
     const DrawingFrame* frame,
     const PictureDrawQuad* quad) {
   DCHECK(CanUseSkiaGPUBackend());
-  DCHECK_EQ(quad->opacity(), 1.f) << "Need to composite to a bitmap or a "
-                                     "render surface for non-1 opacity quads";
 
   // TODO(enne): This should be done more lazily / efficiently.
   gr_context_->resetContext();
 
   // Reset the canvas matrix to identity because the clip rect is in target
   // space.
   SkMatrix sk_identity;
   sk_identity.setIdentity();
   sk_canvas_->setMatrix(sk_identity);
 
   if (is_scissor_enabled_) {
     sk_canvas_->clipRect(gfx::RectToSkRect(scissor_rect_),
                          SkRegion::kReplace_Op);
   } else {
     sk_canvas_->clipRect(gfx::RectToSkRect(client_->DeviceViewport()),
                          SkRegion::kReplace_Op);
   }
 
   gfx::Transform contents_device_transform = frame->window_matrix *
     frame->projection_matrix * quad->quadTransform();
   contents_device_transform.Translate(quad->rect.x(),
                                       quad->rect.y());
   contents_device_transform.FlattenTo2d();
   SkMatrix sk_device_matrix;
   gfx::TransformToFlattenedSkMatrix(contents_device_transform,
                                     &sk_device_matrix);
   sk_canvas_->setMatrix(sk_device_matrix);
 
+  if (quad->opacity() != 1.0f)

[tomhudson, 2013/08/28 14:55:18]

Do you want to debug assert that sk_canvas_->getDrawFilter() == NULL?

[aelias_OOO_until_Jul13, 2013/08/28 18:50:35]

Done.

+    sk_canvas_->setDrawFilter(
+        new skia::OpacityDrawFilter(quad->opacity(), false));
+
   quad->picture_pile->RasterDirect(
       sk_canvas_.get(), quad->content_rect, quad->contents_scale, NULL);
 
   // Flush any drawing buffers that have been deferred.
   sk_canvas_->flush();
 
+  sk_canvas_->setDrawFilter(NULL);
+
   // TODO(enne): This should be done more lazily / efficiently.
   ReinitializeGLState();
 }
 
 void GLRenderer::DrawPictureQuad(const DrawingFrame* frame,
                                  const PictureDrawQuad* quad) {
   if (quad->can_draw_direct_to_backbuffer && CanUseSkiaGPUBackend()) {
     DrawPictureQuadDirectToBackbuffer(frame, quad);
     return;
   }
@@ skipping 1467 matching lines @@
   std::string unique_context_name = base::StringPrintf(
       "%s-Offscreen-%p",
       Settings().compositor_name.c_str(),
       context_);
   resource_provider()->offscreen_context_provider()->Context3d()->
     pushGroupMarkerEXT(unique_context_name.c_str());
 }
 
 
 }  // namespace cc