// Copyright 2014 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.

#include "content/browser/compositor/gpu_browser_compositor_output_surface.h"

#include <utility>

#include "build/build_config.h"
#include "cc/output/compositor_frame.h"
#include "cc/output/output_surface_client.h"
#include "content/browser/compositor/browser_compositor_overlay_candidate_validator.h"
#include "content/browser/compositor/reflector_impl.h"
#include "content/browser/compositor/reflector_texture.h"
#include "content/browser/renderer_host/render_widget_host_impl.h"
#include "content/common/gpu/client/context_provider_command_buffer.h"
#include "gpu/command_buffer/client/context_support.h"

namespace content {

GpuBrowserCompositorOutputSurface::GpuBrowserCompositorOutputSurface(
    const scoped_refptr<ContextProviderCommandBuffer>& context,
    const scoped_refptr<ContextProviderCommandBuffer>& worker_context,
    const scoped_refptr<ui::CompositorVSyncManager>& vsync_manager,
    scoped_ptr<BrowserCompositorOverlayCandidateValidator>
        overlay_candidate_validator)
    : BrowserCompositorOutputSurface(context,
                                     worker_context,
                                     vsync_manager,
                                     std::move(overlay_candidate_validator)),
#if defined(OS_MACOSX)
      should_show_frames_state_(SHOULD_SHOW_FRAMES),
#endif
      swap_buffers_completion_callback_(base::Bind(
          &GpuBrowserCompositorOutputSurface::OnGpuSwapBuffersCompleted,
          base::Unretained(this))),
      update_vsync_parameters_callback_(base::Bind(
          &BrowserCompositorOutputSurface::OnUpdateVSyncParametersFromGpu,
          base::Unretained(this))) {
}

GpuBrowserCompositorOutputSurface::~GpuBrowserCompositorOutputSurface() {}

CommandBufferProxyImpl*
GpuBrowserCompositorOutputSurface::GetCommandBufferProxy() {
  ContextProviderCommandBuffer* provider_command_buffer =
      static_cast<content::ContextProviderCommandBuffer*>(
          context_provider_.get());
  CommandBufferProxyImpl* command_buffer_proxy =
      provider_command_buffer->GetCommandBufferProxy();
  DCHECK(command_buffer_proxy);
  return command_buffer_proxy;
}

bool GpuBrowserCompositorOutputSurface::BindToClient(
    cc::OutputSurfaceClient* client) {
  if (!BrowserCompositorOutputSurface::BindToClient(client))
    return false;

  GetCommandBufferProxy()->SetSwapBuffersCompletionCallback(
      swap_buffers_completion_callback_.callback());
  GetCommandBufferProxy()->SetUpdateVSyncParametersCallback(
      update_vsync_parameters_callback_.callback());
  if (capabilities_.uses_default_gl_framebuffer) {
    capabilities_.flipped_output_surface =
        context_provider()->ContextCapabilities().gpu.flips_vertically;
  }
  return true;
}

void GpuBrowserCompositorOutputSurface::OnReflectorChanged() {
  if (!reflector_) {
    reflector_texture_.reset();
  } else {
    reflector_texture_.reset(new ReflectorTexture(context_provider()));
    reflector_->OnSourceTextureMailboxUpdated(reflector_texture_->mailbox());
  }
}

void GpuBrowserCompositorOutputSurface::SwapBuffers(
    cc::CompositorFrame* frame) {
  DCHECK(frame->gl_frame_data);

  GetCommandBufferProxy()->SetLatencyInfo(frame->metadata.latency_info);

  if (reflector_) {
    if (frame->gl_frame_data->sub_buffer_rect ==
        gfx::Rect(frame->gl_frame_data->size)) {
      reflector_texture_->CopyTextureFullImage(SurfaceSize());
      reflector_->OnSourceSwapBuffers();
    } else {
      const gfx::Rect& rect = frame->gl_frame_data->sub_buffer_rect;
      reflector_texture_->CopyTextureSubImage(rect);
      reflector_->OnSourcePostSubBuffer(rect);
    }
  }

  if (frame->gl_frame_data->sub_buffer_rect ==
      gfx::Rect(frame->gl_frame_data->size)) {
    context_provider_->ContextSupport()->Swap();
  } else {
    context_provider_->ContextSupport()->PartialSwapBuffers(
        frame->gl_frame_data->sub_buffer_rect);
  }

  client_->DidSwapBuffers();

#if defined(OS_MACOSX)
  if (should_show_frames_state_ ==
      SHOULD_NOT_SHOW_FRAMES_NO_SWAP_AFTER_SUSPENDED) {
    should_show_frames_state_ = SHOULD_SHOW_FRAMES;
  }
#endif
}

void GpuBrowserCompositorOutputSurface::OnGpuSwapBuffersCompleted(
    const std::vector<ui::LatencyInfo>& latency_info,
    gfx::SwapResult result) {
  RenderWidgetHostImpl::CompositorFrameDrawn(latency_info);
  OnSwapBuffersComplete();
}

#if defined(OS_MACOSX)
void GpuBrowserCompositorOutputSurface::SetSurfaceSuspendedForRecycle(
    bool suspended) {
  if (suspended) {
    // It may be that there are frames in-flight from the GPU process back to
    // the browser. Make sure that these frames are not displayed by ignoring
    // them in GpuProcessHostUIShim, until the browser issues a SwapBuffers for
    // the new content.
    should_show_frames_state_ = SHOULD_NOT_SHOW_FRAMES_SUSPENDED;
  } else {
    // Discard the backbuffer before drawing the new frame. This is necessary
    // only when using a ImageTransportSurfaceFBO with a
    // CALayerStorageProvider. Discarding the backbuffer results in the next
    // frame using a new CALayer and CAContext, which guarantees that the
    // browser will not flash stale content when adding the remote CALayer to
    // the NSView hierarchy (it could flash stale content because the system
    // window server is not synchronized with any signals we control or
    // observe).
    if (should_show_frames_state_ == SHOULD_NOT_SHOW_FRAMES_SUSPENDED) {
      DiscardBackbuffer();
      should_show_frames_state_ =
          SHOULD_NOT_SHOW_FRAMES_NO_SWAP_AFTER_SUSPENDED;
    }
  }
}

bool GpuBrowserCompositorOutputSurface::
    SurfaceShouldNotShowFramesAfterSuspendForRecycle() const {
  return should_show_frames_state_ != SHOULD_SHOW_FRAMES;
}
#endif

bool GpuBrowserCompositorOutputSurface::SurfaceIsSuspendForRecycle() const {
#if defined(OS_MACOSX)
  return should_show_frames_state_ == SHOULD_NOT_SHOW_FRAMES_SUSPENDED;
#else
  return false;
#endif
}

}  // namespace content