chromium/src/third_party/blink/renderer/platform/graphics/gpu_memory_buffer_image_copy.cc

// Copyright 2017 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 "third_party/blink/renderer/platform/graphics/gpu_memory_buffer_image_copy.h"
#include "gpu/GLES2/gl2extchromium.h"
#include "gpu/command_buffer/client/gpu_memory_buffer_manager.h"
#include "third_party/blink/public/platform/platform.h"
#include "third_party/blink/public/platform/web_graphics_context_3d_provider.h"
#include "third_party/blink/renderer/platform/graphics/graphics_types_3d.h"
#include "third_party/blink/renderer/platform/graphics/image.h"
#include "third_party/blink/renderer/platform/graphics/static_bitmap_image.h"

#include "third_party/blink/renderer/platform/instrumentation/tracing/trace_event.h"

namespace blink {

GpuMemoryBufferImageCopy::GpuMemoryBufferImageCopy(
    gpu::gles2::GLES2Interface* gl)
    : gl_(gl) {}

GpuMemoryBufferImageCopy::~GpuMemoryBufferImageCopy() {}

bool GpuMemoryBufferImageCopy::EnsureMemoryBuffer(int width, int height) {
  // Create a new memorybuffer if the size has changed, or we don't have one.
  if (last_width_ != width || last_height_ != height || !gpu_memory_buffer_) {
    gpu::GpuMemoryBufferManager* gpu_memory_buffer_manager =
        Platform::Current()->GetGpuMemoryBufferManager();
    if (!gpu_memory_buffer_manager)
      return false;

    gpu_memory_buffer_ = gpu_memory_buffer_manager->CreateGpuMemoryBuffer(
        gfx::Size(width, height), gfx::BufferFormat::RGBA_8888,
        gfx::BufferUsage::SCANOUT, gpu::kNullSurfaceHandle);
    if (!gpu_memory_buffer_)
      return false;

    last_width_ = width;
    last_height_ = height;
  }
  return true;
}

gfx::GpuMemoryBuffer* GpuMemoryBufferImageCopy::CopyImage(Image* image) {
  if (!image)
    return nullptr;

  TRACE_EVENT0("gpu", "GpuMemoryBufferImageCopy::CopyImage");

  int width = image->width();
  int height = image->height();
  if (!EnsureMemoryBuffer(width, height))
    return nullptr;

  // Bind the write framebuffer to our memory buffer.
  GLuint image_id = gl_->CreateImageCHROMIUM(
      gpu_memory_buffer_->AsClientBuffer(), width, height, GL_RGBA);
  if (!image_id)
    return nullptr;
  GLuint dest_texture_id;
  gl_->GenTextures(1, &dest_texture_id);
  GLenum target = GL_TEXTURE_2D;
  {
    gl_->BindTexture(target, dest_texture_id);
    gl_->TexParameteri(target, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
    gl_->TexParameteri(target, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
    gl_->TexParameteri(target, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
    gl_->TexParameteri(target, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
    gl_->BindTexImage2DCHROMIUM(target, image_id);
  }
  gl_->BindTexture(GL_TEXTURE_2D, 0);

  // Bind the read framebuffer to our image.
  StaticBitmapImage* static_image = static_cast<StaticBitmapImage*>(image);
  auto mailbox_holder = static_image->GetMailboxHolder();

  // Not strictly necessary since we are on the same context, but keeping
  // for cleanliness and in case we ever move off the same context.
  gl_->WaitSyncTokenCHROMIUM(mailbox_holder.sync_token.GetData());

  GLuint source_texture_id;
  if (mailbox_holder.mailbox.IsSharedImage()) {
    source_texture_id = gl_->CreateAndTexStorage2DSharedImageCHROMIUM(
        mailbox_holder.mailbox.name);
    gl_->BeginSharedImageAccessDirectCHROMIUM(
        source_texture_id, GL_SHARED_IMAGE_ACCESS_MODE_READ_CHROMIUM);
  } else {
    source_texture_id =
        gl_->CreateAndConsumeTextureCHROMIUM(mailbox_holder.mailbox.name);
  }

  gl_->BindTexture(GL_TEXTURE_2D, 0);

  gl_->CopySubTextureCHROMIUM(source_texture_id, 0, GL_TEXTURE_2D,
                              dest_texture_id, 0, 0, 0, 0, 0, width, height,
                              false, false, false);

  // Cleanup the read framebuffer, associated image and texture.
  gl_->BindTexture(GL_TEXTURE_2D, 0);
  if (mailbox_holder.mailbox.IsSharedImage())
    gl_->EndSharedImageAccessDirectCHROMIUM(source_texture_id);
  gl_->DeleteTextures(1, &source_texture_id);

  gpu::SyncToken copy_done_sync_token;
  gl_->GenSyncTokenCHROMIUM(copy_done_sync_token.GetData());
  static_image->UpdateSyncToken(copy_done_sync_token);

  // Cleanup the draw framebuffer, associated image and texture.
  gl_->BindTexture(target, dest_texture_id);
  gl_->ReleaseTexImage2DCHROMIUM(target, image_id);
  gl_->DestroyImageCHROMIUM(image_id);
  gl_->DeleteTextures(1, &dest_texture_id);
  gl_->BindTexture(target, 0);

  gl_->ShallowFlushCHROMIUM();
  return gpu_memory_buffer_.get();
}

}  // namespace blink