cc/mojo_embedder/viz_layer_context.h

// Copyright 2023 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CC_MOJO_EMBEDDER_VIZ_LAYER_CONTEXT_H_
#define CC_MOJO_EMBEDDER_VIZ_LAYER_CONTEXT_H_

#include <cstdint>
#include <map>
#include <set>
#include <string>

#include "base/memory/raw_ref.h"
#include "cc/mojo_embedder/mojo_embedder_export.h"
#include "cc/trees/layer_context.h"
#include "cc/trees/layer_tree_host_impl.h"
#include "cc/trees/property_tree.h"
#include "mojo/public/cpp/bindings/associated_receiver.h"
#include "mojo/public/cpp/bindings/associated_remote.h"
#include "services/viz/public/mojom/compositing/animation.mojom.h"
#include "services/viz/public/mojom/compositing/compositor_frame_sink.mojom.h"
#include "services/viz/public/mojom/compositing/layer_context.mojom.h"

namespace cc {

class AnimationTimeline;

namespace mojo_embedder {

// A client-side implementation of LayerContext which runs over a Mojo
// connection to a GPU-side LayerContext backend within Viz.
class CC_MOJO_EMBEDDER_EXPORT VizLayerContext
    : public LayerContext,
      public viz::mojom::LayerContextClient {
 public:
  // Constructs a VizLayerContext which submits content on behalf of
  // `frame_sink`. `client` must outlive this object.
  VizLayerContext(viz::mojom::CompositorFrameSink& frame_sink,
                  LayerTreeHostImpl& host_impl);
  ~VizLayerContext() override;

  // LayerContext:
  void SetVisible(bool visible) override;
  base::TimeTicks UpdateDisplayTreeFrom(
      LayerTreeImpl& tree,
      viz::ClientResourceProvider& resource_provider,
      viz::RasterContextProvider& context_provider,
      const gfx::Rect& viewport_damage_rect,
      const viz::LocalSurfaceId& target_local_surface_id) override;
  void UpdateDisplayTile(PictureLayerImpl& layer,
                         const Tile& tile,
                         viz::ClientResourceProvider& resource_provider,
                         viz::RasterContextProvider& context_provider,
                         bool update_damage) override;

  // viz::mojom::LayerContextClient:
  void OnRequestCommitForFrame(const viz::BeginFrameArgs& args) override;

 private:
  // Serializes any changes to animation state on `tree` since the last push to
  // Viz. Any serialized changes are added to `update`.
  void SerializeAnimationUpdates(LayerTreeImpl& tree,
                                 viz::mojom::LayerTreeUpdate& update);

  // Serializes any changes to `timeline` since the last push to Viz. If there
  // have been no changes, this returns null.
  viz::mojom::AnimationTimelinePtr MaybeSerializeAnimationTimeline(
      AnimationTimeline& timeline);

  void OnMojoConnectionError(uint32_t custom_reason,
                             const std::string& description);

  const raw_ref<LayerTreeHostImpl> host_impl_;

  mojo::AssociatedReceiver<viz::mojom::LayerContextClient> client_receiver_{
      this};
  mojo::AssociatedRemote<viz::mojom::LayerContext> service_;

  // Index of all timelines and animations which have been pushed to the display
  // tree already. This maps animation timeline ID to each timeline's set of
  // animation IDs.
  std::map<int32_t, std::set<int32_t>> pushed_animation_timelines_;

  // A newly created layer context requires a full sync. This is required
  // to handle context loss and recreation of the layer context.
  bool needs_full_sync_ = true;

  PropertyTrees last_committed_property_trees_{*host_impl_};

  base::WeakPtrFactory<VizLayerContext> weak_factory_{this};
};

}  // namespace mojo_embedder
}  // namespace cc

#endif  // CC_MOJO_EMBEDDER_VIZ_LAYER_CONTEXT_H_