Initial checkin of the new Mozart compositor.

services/gfx/compositor/render/painting.cc

Index: services/gfx/compositor/render/painting.cc
diff --git a/services/gfx/compositor/render/painting.cc b/services/gfx/compositor/render/painting.cc
new file mode 100644
index 0000000000000000000000000000000000000000..de2aefe2a81a616ef421400f9ea1ce52ff0109ae
--- /dev/null
+++ b/services/gfx/compositor/render/painting.cc
@@ -0,0 +1,104 @@
+// Copyright 2015 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 "services/gfx/compositor/render/painting.h"
+
+#include "base/logging.h"
+#include "services/gfx/compositor/render/render_image.h"
+#include "services/gfx/compositor/render/render_layer.h"
+#include "third_party/skia/include/core/SkImage.h"
+#include "third_party/skia/include/core/SkPicture.h"
+
+namespace compositor {
+
+PaintingScope::PaintingScope(
+    const mojo::skia::GaneshContext::Scope& ganesh_scope,
+    PaintingCache* painting_cache)
+    : ganesh_scope_(ganesh_scope), painting_cache_(painting_cache) {
+  DCHECK(painting_cache_);
+  painting_cache_->BeginPainting(*this);
+}
+
+PaintingScope::~PaintingScope() {
+  painting_cache_->FinishPainting(*this);
+}
+
+PaintingCache::PaintingCache() {}
+
+PaintingCache::~PaintingCache() {
+  DCHECK(!painting_);
+  DCHECK(used_images_.empty());
+  DCHECK(cached_images_.empty());
+  DCHECK(used_pictures_.empty());
+  DCHECK(cached_pictures_.empty());
+}
+
+void PaintingCache::BeginPainting(const PaintingScope& painting_scope) {
+  DCHECK(!painting_);
+  DCHECK(used_images_.empty());
+  DCHECK(used_pictures_.empty());
+
+  painting_ = true;
+}
+
+void PaintingCache::FinishPainting(const PaintingScope& painting_scope) {
+  DCHECK(painting_);
+
+  painting_ = false;
+  cached_images_.clear();
+  cached_images_.swap(used_images_);
+  cached_pictures_.clear();
+  cached_pictures_.swap(used_pictures_);
+}
+
+void PaintingCache::Clear(const PaintingScope& painting_scope) {
+  used_images_.clear();
+  cached_images_.clear();
+  used_pictures_.clear();
+  cached_pictures_.clear();
+}
+
+skia::RefPtr<SkImage> PaintingCache::GetSkImage(
+    const PaintingScope& painting_scope,
+    const std::shared_ptr<RenderImage>& image) {
+  // Look in our recently used images.
+  auto used_it = used_images_.find(image);
+  if (used_it != used_images_.end())
+    return used_it->second;
+
+  // Look in our previously cached images.
+  auto cached_it = cached_images_.find(image);
+  if (cached_it != cached_images_.end()) {
+    used_images_.emplace(*cached_it);
+    return cached_it->second;
+  }
+
+  // Create the image.
+  skia::RefPtr<SkImage> result = image->CreateSkImage(painting_scope);
+  used_images_.emplace(std::make_pair(image, result));
+  return result;
+}
+
+skia::RefPtr<SkPicture> PaintingCache::GetSkPicture(
+    const PaintingScope& painting_scope,
+    const std::shared_ptr<RenderLayer>& layer) {
+  // Look in our recently used pictures.
+  auto used_it = used_pictures_.find(layer);
+  if (used_it != used_pictures_.end())
+    return used_it->second;
+
+  // Look in our previously cached pictures.
+  auto cached_it = cached_pictures_.find(layer);
+  if (cached_it != cached_pictures_.end()) {
+    used_pictures_.emplace(*cached_it);
+    return cached_it->second;
+  }
+
+  // Create the picture.
+  skia::RefPtr<SkPicture> result = layer->CreateSkPicture(painting_scope);
+  used_pictures_.emplace(std::make_pair(layer, result));
+  return result;
+}
+
+}  // namespace compositor