media: Add GLES2DecoderHelper

media/gpu/gles2_decoder_helper.cc

Index: media/gpu/gles2_decoder_helper.cc
diff --git a/media/gpu/gles2_decoder_helper.cc b/media/gpu/gles2_decoder_helper.cc
new file mode 100644
index 0000000000000000000000000000000000000000..25726f9a5edb236de5784522ea8d1a3f3e967a41
--- /dev/null
+++ b/media/gpu/gles2_decoder_helper.cc
@@ -0,0 +1,124 @@
+// 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 "media/gpu/gles2_decoder_helper.h"
+
+#include "base/macros.h"
+#include "base/memory/ptr_util.h"
+#include "base/threading/thread_checker.h"
+#include "gpu/command_buffer/common/mailbox.h"
+#include "gpu/command_buffer/service/context_group.h"
+#include "gpu/command_buffer/service/gles2_cmd_decoder.h"
+#include "gpu/command_buffer/service/mailbox_manager.h"
+#include "gpu/command_buffer/service/texture_manager.h"
+#include "ui/gl/gl_context.h"
+
+namespace media {
+
+class GLES2DecoderHelperImpl : public GLES2DecoderHelper {
+ public:
+  explicit GLES2DecoderHelperImpl(gpu::gles2::GLES2Decoder* decoder)
+      : decoder_(decoder) {}
+
+  bool MakeContextCurrent() override {
+    DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
+    return decoder_->MakeCurrent();
+  }
+
+  scoped_refptr<gpu::gles2::TextureRef> CreateTexture(GLenum target,
+                                                      GLenum internal_format,
+                                                      GLsizei width,
+                                                      GLsizei height,
+                                                      GLenum format,
+                                                      GLenum type) override {
+    DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
+    DCHECK(decoder_->GetGLContext()->IsCurrent(nullptr));
+    gpu::gles2::ContextGroup* group = decoder_->GetContextGroup();
+    gpu::gles2::TextureManager* texture_manager = group->texture_manager();
+    // TODO(sandersd): Support GLES2DecoderPassthroughImpl.
+    DCHECK(texture_manager);
+
+    // We can't use texture_manager->CreateTexture(), since it requires a unique
+    // |client_id|. Instead we create the texture directly, and create our own
+    // TextureRef for it.
+    GLuint texture_id;
+    glGenTextures(1, &texture_id);
+    glBindTexture(target, texture_id);
+
+    scoped_refptr<gpu::gles2::TextureRef> texture_ref =
+        gpu::gles2::TextureRef::Create(texture_manager, 0, texture_id);
+    texture_manager->SetTarget(texture_ref.get(), target);
+    texture_manager->SetLevelInfo(texture_ref.get(),  // ref
+                                  target,             // target
+                                  0,                  // level
+                                  internal_format,    // internal_format
+                                  width,              // width
+                                  height,             // height
+                                  1,                  // depth
+                                  0,                  // border
+                                  format,             // format
+                                  type,               // type
+                                  gfx::Rect());       // cleared_rect
+
+    texture_manager->SetParameteri(__func__, decoder_->GetErrorState(),
+                                   texture_ref.get(), GL_TEXTURE_MAG_FILTER,
+                                   GL_LINEAR);
+    texture_manager->SetParameteri(__func__, decoder_->GetErrorState(),
+                                   texture_ref.get(), GL_TEXTURE_MIN_FILTER,
+                                   GL_LINEAR);
+
+    texture_manager->SetParameteri(__func__, decoder_->GetErrorState(),
+                                   texture_ref.get(), GL_TEXTURE_WRAP_S,
+                                   GL_CLAMP_TO_EDGE);
+    texture_manager->SetParameteri(__func__, decoder_->GetErrorState(),
+                                   texture_ref.get(), GL_TEXTURE_WRAP_T,
+                                   GL_CLAMP_TO_EDGE);
+
+    texture_manager->SetParameteri(__func__, decoder_->GetErrorState(),
+                                   texture_ref.get(), GL_TEXTURE_BASE_LEVEL, 0);
+    texture_manager->SetParameteri(__func__, decoder_->GetErrorState(),
+                                   texture_ref.get(), GL_TEXTURE_MAX_LEVEL, 0);
+
+    // TODO(sandersd): Do we always want to allocate for GL_TEXTURE_2D?
+    if (target == GL_TEXTURE_2D) {
+      glTexImage2D(target,           // target
+                   0,                // level
+                   internal_format,  // internal_format
+                   width,            // width
+                   height,           // height
+                   0,                // border
+                   format,           // format
+                   type,             // type
+                   nullptr);         // data
+    }
+
+    decoder_->RestoreActiveTextureUnitBinding(target);
+    return texture_ref;
+  }
+
+  gpu::Mailbox CreateMailbox(gpu::gles2::TextureRef* texture_ref) override {
+    DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
+    gpu::gles2::ContextGroup* group = decoder_->GetContextGroup();
+    gpu::gles2::MailboxManager* mailbox_manager = group->mailbox_manager();
+    gpu::Mailbox mailbox = gpu::Mailbox::Generate();
+    mailbox_manager->ProduceTexture(mailbox, texture_ref->texture());
+    return mailbox;
+  }
+
+ private:
+  gpu::gles2::GLES2Decoder* decoder_;
+  THREAD_CHECKER(thread_checker_);
+
+  DISALLOW_COPY_AND_ASSIGN(GLES2DecoderHelperImpl);
+};
+
+// static
+std::unique_ptr<GLES2DecoderHelper> GLES2DecoderHelper::Create(
+    gpu::gles2::GLES2Decoder* decoder) {
+  if (!decoder)
+    return nullptr;
+  return base::MakeUnique<GLES2DecoderHelperImpl>(decoder);
+}
+
+}  // namespace media