Initial checkin of the new Mozart compositor.

services/gfx/compositor/graph/snapshot.cc

+// 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/graph/snapshot.h"
+
+#include "base/logging.h"
+#include "services/gfx/compositor/graph/scene_def.h"
+#include "services/gfx/compositor/render/render_frame.h"
+#include "services/gfx/compositor/render/render_layer.h"
+#include "third_party/skia/include/core/SkRect.h"
+
+namespace compositor {
+
+Snapshot::Snapshot() {}
+
+Snapshot::~Snapshot() {}
+
+bool Snapshot::Invalidate() {
+  if (valid_) {
+    valid_ = false;
+    dependencies_.clear();
+    frame_.reset();
+    return true;
+  }
+  return false;
+}
+
+bool Snapshot::InvalidateScene(SceneDef* scene_def) {
+  DCHECK(scene_def);
+
+  if (valid_ && dependencies_.find(scene_def) != dependencies_.end()) {
+    return Invalidate();
+  }
+  return false;
+}
+
+SnapshotBuilder::SnapshotBuilder(std::ostream* block_log)
+    : block_log_(block_log), snapshot_(new Snapshot()) {}
+
+SnapshotBuilder::~SnapshotBuilder() {}
+
+void SnapshotBuilder::AddSceneDependency(SceneDef* scene) {
+  DCHECK(snapshot_);
+  snapshot_->dependencies_.insert(scene);
+}
+
+std::unique_ptr<Snapshot> SnapshotBuilder::Build(
+    SceneDef* root_scene,
+    const mojo::Rect& viewport,
+    const mojo::gfx::composition::FrameInfo& frame_info) {
+  DCHECK(snapshot_);
+  DCHECK(root_scene);
+
+  SkRect sk_viewport =
+      SkRect::MakeXYWH(viewport.x, viewport.y, viewport.width, viewport.height);
+  RenderLayerBuilder layer_builder(&sk_viewport);
+  if (root_scene->Snapshot(this, &layer_builder)) {
+    snapshot_->frame_ =
+        RenderFrame::Create(layer_builder.Build(), sk_viewport, frame_info);
+  } else {
+    snapshot_->valid_ = false;
+  }
+  return std::move(snapshot_);
+}
+
+}  // namespace compositor