Improve Ganesh helpers.

mojo/skia/ganesh_image_factory.cc

+// Copyright 2016 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 GL_GLEXT_PROTOTYPES
+#define GL_GLEXT_PROTOTYPES
+#endif
+
+#include "mojo/skia/ganesh_image_factory.h"
+
+#include "base/logging.h"
+#include "third_party/skia/include/core/SkImage.h"
+#include "third_party/skia/include/gpu/GrContext.h"
+#include "third_party/skia/include/gpu/GrTextureProvider.h"
+#include "third_party/skia/include/gpu/gl/GrGLTypes.h"
+
+namespace mojo {
+namespace skia {
+namespace {
+void ReleaseThunk(void* data) {
+  auto release_callback = static_cast<base::Closure*>(data);
+  release_callback->Run();
+  delete release_callback;
+}
+}  // namespace
+
+::skia::RefPtr<SkImage> CreateImageFromTexture(
+    const GaneshContext::Scope& scope,
+    uint32_t texture_id,
+    uint32_t width,
+    uint32_t height,
+    const base::Closure& release_callback) {
+  DCHECK(texture_id);
+  DCHECK(width);
+  DCHECK(height);
+
+  // TODO(jeffbrown): Give the caller more control over these parameters.
+  GrGLTextureInfo info;
+  info.fTarget = GL_TEXTURE_2D;
+  info.fID = texture_id;
+
+  GrBackendTextureDesc desc;
+  desc.fFlags = kRenderTarget_GrBackendTextureFlag;
+  desc.fWidth = width;
+  desc.fHeight = height;
+  desc.fConfig = kSkia8888_GrPixelConfig;
+  desc.fOrigin = kTopLeft_GrSurfaceOrigin;
+  desc.fTextureHandle = reinterpret_cast<GrBackendObject>(&info);
+  return ::skia::AdoptRef(SkImage::NewFromTexture(
+      scope.gr_context(), desc, kPremul_SkAlphaType, &ReleaseThunk,
+      new base::Closure(release_callback)));
+}
+
+MailboxTextureImageGenerator::MailboxTextureImageGenerator(
+    const GLbyte mailbox_name[GL_MAILBOX_SIZE_CHROMIUM],
+    GLuint sync_point,
+    uint32_t width,
+    uint32_t height)
+    : SkImageGenerator(SkImageInfo::MakeN32Premul(width, height)),
+      sync_point_(sync_point) {
+  DCHECK(mailbox_name);
+  memcpy(mailbox_name_, mailbox_name, GL_MAILBOX_SIZE_CHROMIUM);
+}
+
+MailboxTextureImageGenerator::~MailboxTextureImageGenerator() {}
+
+GrTexture* MailboxTextureImageGenerator::onGenerateTexture(
+    GrContext* context,
+    const SkIRect* subset) {
+  if (sync_point_)
+    glWaitSyncPointCHROMIUM(sync_point_);
+
+  GLuint texture_id =
+      glCreateAndConsumeTextureCHROMIUM(GL_TEXTURE_2D, mailbox_name_);
+  if (!texture_id)
+    return nullptr;
+
+  // TODO(jeffbrown): Give the caller more control over these parameters.
+  GrGLTextureInfo info;
+  info.fTarget = GL_TEXTURE_2D;
+  info.fID = texture_id;
+
+  GrBackendTextureDesc desc;
+  desc.fFlags = kRenderTarget_GrBackendTextureFlag;
+  desc.fWidth = getInfo().width();
+  desc.fHeight = getInfo().height();
+  desc.fConfig = kSkia8888_GrPixelConfig;
+  desc.fOrigin = kTopLeft_GrSurfaceOrigin;
+  desc.fTextureHandle = reinterpret_cast<GrBackendObject>(&info);
+  return context->textureProvider()->wrapBackendTexture(desc,
+                                                        kAdopt_GrWrapOwnership);
+}
+
+}  // namespace skia
+}  // namespace mojo