gecko/gfx/layers/client/CanvasClient.h

/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef MOZILLA_GFX_CANVASCLIENT_H
#define MOZILLA_GFX_CANVASCLIENT_H

#include "mozilla/layers/TextureClient.h"
#include "mozilla/layers/CompositableClient.h"

namespace mozilla {

namespace layers {

class BasicCanvasLayer;
class TextureIdentifier;

/**
 * Compositable client for 2d and webgl canvas.
 */
class CanvasClient : public CompositableClient
{
public:
  /**
   * Creates, configures, and returns a new canvas client. If necessary, a
   * message will be sent to the compositor to create a corresponding image
   * host.
   */
  static TemporaryRef<CanvasClient> CreateCanvasClient(LayersBackend aBackendType,
                                                       CompositableType aImageHostType,
                                                       CompositableForwarder* aFwd,
                                                       TextureFlags aFlags);

  CanvasClient(CompositableForwarder* aFwd, TextureFlags aFlags)
  : CompositableClient(aFwd), mFlags(aFlags)
  {}

  virtual ~CanvasClient() {}

  virtual void Update(gfx::IntSize aSize, BasicCanvasLayer* aLayer) = 0;

  virtual void SetBuffer(const TextureIdentifier& aTextureIdentifier,
                         const SurfaceDescriptor& aBuffer);
  virtual void Updated()
  {
    mTextureClient->Updated();
  }
protected:
  RefPtr<TextureClient> mTextureClient;
  TextureFlags mFlags;
};

// Used for 2D canvases and WebGL canvas on non-GL systems where readback is requried.
class CanvasClient2D : public CanvasClient
{
public:
  CanvasClient2D(CompositableForwarder* aLayerForwarder,
                 TextureFlags aFlags);

  CompositableType GetType() const MOZ_OVERRIDE
  {
    return BUFFER_IMAGE_SINGLE;
  }

  virtual void Update(gfx::IntSize aSize, BasicCanvasLayer* aLayer);
};

// Used for GL canvases where we don't need to do any readback, i.e., with a
// GL backend.
class CanvasClientWebGL : public CanvasClient
{
public:
  CanvasClientWebGL(CompositableForwarder* aFwd,
                    TextureFlags aFlags);

  CompositableType GetType() const MOZ_OVERRIDE
  {
    return BUFFER_IMAGE_BUFFERED;
  }

  virtual void Update(gfx::IntSize aSize, BasicCanvasLayer* aLayer);
};

}
}

#endif