/* 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/. */

#include "CompositorWidget.h"

#include "GLConsts.h"

#include "nsBaseWidget.h"

#include "VsyncDispatcher.h"

namespace mozilla {

namespace widget {

CompositorWidget::CompositorWidget(const layers::CompositorOptions& aOptions)

  : mOptions(aOptions)

{

}

CompositorWidget::~CompositorWidget()

{

}

already_AddRefed<gfx::DrawTarget>

CompositorWidget::StartRemoteDrawing()

{

  return nullptr;

}

void

CompositorWidget::CleanupRemoteDrawing()

{

  mLastBackBuffer = nullptr;

}

already_AddRefed<gfx::DrawTarget>

CompositorWidget::GetBackBufferDrawTarget(gfx::DrawTarget* aScreenTarget,

                                          const LayoutDeviceIntRect& aRect,

                                          const LayoutDeviceIntRect& aClearRect)

{

  MOZ_ASSERT(aScreenTarget);

  gfx::SurfaceFormat format =

    aScreenTarget->GetFormat() == gfx::SurfaceFormat::B8G8R8X8 ? gfx::SurfaceFormat::B8G8R8X8 : gfx::SurfaceFormat::B8G8R8A8;

  gfx::IntSize size = aRect.ToUnknownRect().Size();

  gfx::IntSize clientSize(GetClientSize().ToUnknownSize());

  RefPtr<gfx::DrawTarget> target;

  // Re-use back buffer if possible

  if (mLastBackBuffer &&

      mLastBackBuffer->GetBackendType() == aScreenTarget->GetBackendType() &&

      mLastBackBuffer->GetFormat() == format &&

      size <= mLastBackBuffer->GetSize() &&

      mLastBackBuffer->GetSize() <= clientSize) {

    target = mLastBackBuffer;

    target->SetTransform(gfx::Matrix());

    if (!aClearRect.IsEmpty()) {

      gfx::IntRect clearRect = aClearRect.ToUnknownRect() - aRect.ToUnknownRect().TopLeft();

      target->ClearRect(gfx::Rect(clearRect.X(), clearRect.Y(), clearRect.Width(), clearRect.Height()));

    }

  } else {

    target = aScreenTarget->CreateSimilarDrawTarget(size, format);

    mLastBackBuffer = target;

  }

  return target.forget();

}

already_AddRefed<gfx::SourceSurface>

CompositorWidget::EndBackBufferDrawing()

{

  RefPtr<gfx::SourceSurface> surface = mLastBackBuffer ? mLastBackBuffer->Snapshot() : nullptr;

  return surface.forget();

}

uint32_t

CompositorWidget::GetGLFrameBufferFormat()

{

  return LOCAL_GL_RGBA;

}

RefPtr<VsyncObserver>

CompositorWidget::GetVsyncObserver() const

{

  // This should only used when the widget is in the GPU process, and should be

  // implemented by IPDL-enabled CompositorWidgets.

  // GPU process does not have a CompositorVsyncDispatcher.

  MOZ_ASSERT_UNREACHABLE("Must be implemented by derived class");

  return nullptr;

}

} // namespace widget

} // namespace mozilla