media/gpu/android/texture_owner.h

// Copyright 2018 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.

#ifndef MEDIA_GPU_ANDROID_TEXTURE_OWNER_H_
#define MEDIA_GPU_ANDROID_TEXTURE_OWNER_H_

#include <android/hardware_buffer.h>

#include "base/memory/ref_counted.h"
#include "base/memory/ref_counted_delete_on_sequence.h"
#include "base/single_thread_task_runner.h"
#include "media/gpu/media_gpu_export.h"
#include "ui/gl/android/scoped_java_surface.h"
#include "ui/gl/gl_bindings.h"
#include "ui/gl/gl_context.h"
#include "ui/gl/gl_image.h"
#include "ui/gl/gl_surface.h"

namespace base {
namespace android {
class ScopedHardwareBufferFenceSync;
}  // namespace android
}  // namespace base

namespace gpu {
class SharedContextState;
class TextureBase;
namespace gles2 {
class AbstractTexture;
}  // namespace gles2
}  // namespace gpu

namespace media {

// A Texture wrapper interface that creates and maintains ownership of the
// attached GL or Vulkan texture. The texture is destroyed with the object.
// It should only be accessed on the thread it was created on, with the
// exception of CreateJavaSurface(), which can be called on any thread. It's
// safe to keep and drop refptrs to it on any thread; it will be automatically
// destructed on the thread it was constructed on.
class MEDIA_GPU_EXPORT TextureOwner
    : public base::RefCountedDeleteOnSequence<TextureOwner> {
 public:
  // Creates a GL texture using the current platform GL context and returns a
  // new TextureOwner attached to it. Returns null on failure.
  // |texture| should be either from CreateAbstractTexture() or a mock.  The
  // corresponding GL context must be current.
  // Mode indicates which framework API to use and whether the video textures
  // created using this owner should be hardware protected.
  enum class Mode {
    kAImageReaderSecure,
    kAImageReaderInsecure,
    kSurfaceTextureInsecure
  };
  static scoped_refptr<TextureOwner> Create(
      std::unique_ptr<gpu::gles2::AbstractTexture> texture,
      Mode mode);

  // Create a texture that's appropriate for a TextureOwner.
  static std::unique_ptr<gpu::gles2::AbstractTexture> CreateTexture(
      gpu::SharedContextState* context_state);

  scoped_refptr<base::SingleThreadTaskRunner> task_runner() {
    return task_runner_;
  }

  // Returns the GL texture id that the TextureOwner is attached to.
  GLuint GetTextureId() const;
  gpu::TextureBase* GetTextureBase() const;
  virtual gl::GLContext* GetContext() const = 0;
  virtual gl::GLSurface* GetSurface() const = 0;

  // Create a java surface for the TextureOwner.
  virtual gl::ScopedJavaSurface CreateJavaSurface() const = 0;

  // Update the texture image using the latest available image data.
  virtual void UpdateTexImage() = 0;

  // Ensures that the latest texture image is bound to the texture target.
  // Should only be used if the TextureOwner requires explicit binding of the
  // image after an update.
  virtual void EnsureTexImageBound() = 0;

  // Transformation matrix if any associated with the texture image.
  virtual void GetTransformMatrix(float mtx[16]) = 0;
  virtual void ReleaseBackBuffers() = 0;

  // Sets the expectation of onFrameAVailable for a new frame because a buffer
  // was just released to this surface.
  virtual void SetReleaseTimeToNow() = 0;

  // Ignores a pending release that was previously indicated with
  // SetReleaseTimeToNow(). TODO(watk): This doesn't seem necessary. It
  // actually may be detrimental because the next time we release a buffer we
  // may confuse its onFrameAvailable with the one we're ignoring.
  virtual void IgnorePendingRelease() = 0;

  // Whether we're expecting onFrameAvailable. True when SetReleaseTimeToNow()
  // was called but neither IgnorePendingRelease() nor WaitForFrameAvailable()
  // have been called since.
  virtual bool IsExpectingFrameAvailable() = 0;

  // Waits for onFrameAvailable until it's been 5ms since the buffer was
  // released. This must only be called if IsExpectingFrameAvailable().
  virtual void WaitForFrameAvailable() = 0;

  // Retrieves the AHardwareBuffer from the latest available image data.
  // Note that the object must be used and destroyed on the same thread the
  // TextureOwner is bound to.
  virtual std::unique_ptr<base::android::ScopedHardwareBufferFenceSync>
  GetAHardwareBuffer() = 0;

  bool binds_texture_on_update() const { return binds_texture_on_update_; }

 protected:
  friend class base::RefCountedDeleteOnSequence<TextureOwner>;
  friend class base::DeleteHelper<TextureOwner>;

  // |texture| is the texture that we'll own.
  TextureOwner(bool binds_texture_on_update,
               std::unique_ptr<gpu::gles2::AbstractTexture> texture);
  virtual ~TextureOwner();

  // Drop |texture_| immediately.  Will call OnTextureDestroyed immediately if
  // it hasn't been called before (e.g., due to lost context).
  // Subclasses must call this before they complete destruction, else
  // OnTextureDestroyed might be called when we drop |texture_|, which is not
  // defined once subclass destruction has completed.
  void ClearAbstractTexture();

  // Called when |texture_| signals that the platform texture will be destroyed.
  // See AbstractTexture::SetCleanupCallback.
  virtual void OnTextureDestroyed(gpu::gles2::AbstractTexture*) = 0;

  gpu::gles2::AbstractTexture* texture() const { return texture_.get(); }

 private:
  // Set to true if the updating the image for this owner will automatically
  // bind it to the texture target.
  const bool binds_texture_on_update_;

  std::unique_ptr<gpu::gles2::AbstractTexture> texture_;
  scoped_refptr<base::SingleThreadTaskRunner> task_runner_;

  DISALLOW_COPY_AND_ASSIGN(TextureOwner);
};

}  // namespace media

#endif  // MEDIA_GPU_ANDROID_TEXTURE_OWNER_H_