widget/CompositorWidget.cpp

   1 /* This Source Code Form is subject to the terms of the Mozilla Public
   2  * License, v. 2.0. If a copy of the MPL was not distributed with this
   3  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   4
   5 #include "CompositorWidget.h"
   6 #include "GLConsts.h"
   7 #include "nsBaseWidget.h"
   8 #include "VsyncDispatcher.h"
   9
  10 namespace mozilla {
  11 namespace widget {
  12
  13 CompositorWidget::CompositorWidget(const layers::CompositorOptions& aOptions)
  14     : mOptions(aOptions) {}
  15
  16 CompositorWidget::~CompositorWidget() {}
  17
  18 already_AddRefed<gfx::DrawTarget> CompositorWidget::StartRemoteDrawing() {
  19   return nullptr;
  20 }
  21
  22 void CompositorWidget::CleanupRemoteDrawing() { mLastBackBuffer = nullptr; }
  23
  24 already_AddRefed<gfx::DrawTarget> CompositorWidget::GetBackBufferDrawTarget(
  25     gfx::DrawTarget* aScreenTarget, const LayoutDeviceIntRect& aRect,
  26     const LayoutDeviceIntRect& aClearRect) {
  27   MOZ_ASSERT(aScreenTarget);
  28   gfx::SurfaceFormat format =
  29       aScreenTarget->GetFormat() == gfx::SurfaceFormat::B8G8R8X8
  30           ? gfx::SurfaceFormat::B8G8R8X8
  31           : gfx::SurfaceFormat::B8G8R8A8;
  32   gfx::IntSize size = aRect.ToUnknownRect().Size();
  33   gfx::IntSize clientSize(GetClientSize().ToUnknownSize());
  34
  35   RefPtr<gfx::DrawTarget> target;
  36   // Re-use back buffer if possible
  37   if (mLastBackBuffer &&
  38       mLastBackBuffer->GetBackendType() == aScreenTarget->GetBackendType() &&
  39       mLastBackBuffer->GetFormat() == format &&
  40       size <= mLastBackBuffer->GetSize() &&
  41       mLastBackBuffer->GetSize() <= clientSize) {
  42     target = mLastBackBuffer;
  43     target->SetTransform(gfx::Matrix());
  44     if (!aClearRect.IsEmpty()) {
  45       gfx::IntRect clearRect =
  46           aClearRect.ToUnknownRect() - aRect.ToUnknownRect().TopLeft();
  47       target->ClearRect(gfx::Rect(clearRect.X(), clearRect.Y(),
  48                                   clearRect.Width(), clearRect.Height()));
  49     }
  50   } else {
  51     target = aScreenTarget->CreateSimilarDrawTarget(size, format);
  52     mLastBackBuffer = target;
  53   }
  54   return target.forget();
  55 }
  56
  57 already_AddRefed<gfx::SourceSurface> CompositorWidget::EndBackBufferDrawing() {
  58   RefPtr<gfx::SourceSurface> surface =
  59       mLastBackBuffer ? mLastBackBuffer->Snapshot() : nullptr;
  60   return surface.forget();
  61 }
  62
  63 uint32_t CompositorWidget::GetGLFrameBufferFormat() { return LOCAL_GL_RGBA; }
  64
  65 RefPtr<VsyncObserver> CompositorWidget::GetVsyncObserver() const {
  66   // This should only used when the widget is in the GPU process, and should be
  67   // implemented by IPDL-enabled CompositorWidgets.
  68   // GPU process does not have a CompositorVsyncDispatcher.
  69   MOZ_ASSERT_UNREACHABLE("Must be implemented by derived class");
  70   return nullptr;
  71 }
  72
  73 }  // namespace widget
  74 }  // namespace mozilla