Add RGB565 Texture readback support in gl_helper

content/common/gpu/client/gl_helper.h

 // Copyright (c) 2012 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 CONTENT_COMMON_GPU_CLIENT_GL_HELPER_H_
 #define CONTENT_COMMON_GPU_CLIENT_GL_HELPER_H_
 
 #include "base/atomicops.h"
 #include "base/basictypes.h"
 #include "base/callback.h"
 #include "base/memory/scoped_ptr.h"
 #include "content/common/content_export.h"
 #include "gpu/command_buffer/client/gles2_interface.h"
+#include "third_party/skia/include/core/SkBitmap.h"
 
 namespace gfx {
 class Rect;
 class Size;
 }
 
 namespace gpu {
 class ContextSupport;
 struct Mailbox;
 }
@@ skipping 150 matching lines @@
   // representation.  |callback| is invoked with the copy result when the copy
   // operation has completed.
   // Note that the src_texture will have the min/mag filter set to GL_LINEAR
   // and wrap_s/t set to CLAMP_TO_EDGE in this call.
   void CropScaleReadbackAndCleanTexture(
       GLuint src_texture,
       const gfx::Size& src_size,
       const gfx::Rect& src_subrect,
       const gfx::Size& dst_size,
       unsigned char* out,
+      bool readback_config_rgb565,
       const base::Callback<void(bool)>& callback);
 
   // Copies the block of pixels specified with |src_subrect| from |src_mailbox|,
   // scales it to |dst_size|, and writes it into |out|.
   // |src_size| is the size of |src_mailbox|. The result is of format GL_BGRA
   // and is potentially flipped vertically to make it a correct image
   // representation.  |callback| is invoked with the copy result when the copy
   // operation has completed.
   // Note that the texture bound to src_mailbox will have the min/mag filter set
   // to GL_LINEAR and wrap_s/t set to CLAMP_TO_EDGE in this call. src_mailbox is
   // assumed to be GL_TEXTURE_2D.
   void CropScaleReadbackAndCleanMailbox(
       const gpu::Mailbox& src_mailbox,
       uint32 sync_point,
       const gfx::Size& src_size,
       const gfx::Rect& src_subrect,
       const gfx::Size& dst_size,
       unsigned char* out,
+      bool readback_config_rgb565,
       const base::Callback<void(bool)>& callback);
 
   // Copies the texture data out of |texture| into |out|.  |size| is the
   // size of the texture.  No post processing is applied to the pixels.  The
   // texture is assumed to have a format of GL_RGBA with a pixel type of
   // GL_UNSIGNED_BYTE.  This is a blocking call that calls glReadPixels on the
   // current OpenGL context.
   void ReadbackTextureSync(GLuint texture,
                            const gfx::Rect& src_rect,
-                           unsigned char* out);
+                           unsigned char* out,
+                           SkBitmap::Config format);
 
   // Creates a copy of the specified texture. |size| is the size of the texture.
   // Note that the src_texture will have the min/mag filter set to GL_LINEAR
   // and wrap_s/t set to CLAMP_TO_EDGE in this call.
   GLuint CopyTexture(GLuint texture, const gfx::Size& size);
 
   // Creates a scaled copy of the specified texture. |src_size| is the size of
   // the texture and |dst_size| is the size of the resulting copy.
   // Note that the src_texture will have the min/mag filter set to GL_LINEAR
   // and wrap_s/t set to CLAMP_TO_EDGE in this call.
@@ skipping 37 matching lines @@
   // Resizes the texture's size to |size|.
   void ResizeTexture(GLuint texture, const gfx::Size& size);
 
   // Copies the framebuffer data given in |rect| to |texture|.
   void CopyTextureSubImage(GLuint texture, const gfx::Rect& rect);
 
   // Copies the all framebuffer data to |texture|. |size| specifies the
   // size of the framebuffer.
   void CopyTextureFullImage(GLuint texture, const gfx::Size& size);
 
+  // Check whether rgb565 readback is supported or not.
+  bool CanUseRgb565Readback();
+
   // A scaler will cache all intermediate textures and programs
   // needed to scale from a specified size to a destination size.
   // If the source or destination sizes changes, you must create
   // a new scaler.
   class CONTENT_EXPORT ScalerInterface {
    public:
     ScalerInterface() {}
     virtual ~ScalerInterface() {}
 
     // Note that the src_texture will have the min/mag filter set to GL_LINEAR
@@ skipping 40 matching lines @@
 
   // Creates |copy_texture_to_impl_| if NULL.
   void InitCopyTextToImpl();
   // Creates |scaler_impl_| if NULL.
   void InitScalerImpl();
 
   gpu::gles2::GLES2Interface* gl_;
   gpu::ContextSupport* context_support_;
   scoped_ptr<CopyTextureToImpl> copy_texture_to_impl_;
   scoped_ptr<GLHelperScaling> scaler_impl_;
+  bool initialized_565_format_check_;
+  bool support_565_format_;
 
   DISALLOW_COPY_AND_ASSIGN(GLHelper);
 };
 
 // Similar to a ScalerInterface, a yuv readback pipeline will
 // cache a scaler and all intermediate textures and frame buffers
 // needed to scale, crop, letterbox and read back a texture from
 // the GPU into CPU-accessible RAM. A single readback pipeline
 // can handle multiple outstanding readbacks at the same time, but
 // if the source or destination sizes change, you'll need to create
 // a new readback pipeline.
 class CONTENT_EXPORT ReadbackYUVInterface {
  public:
   ReadbackYUVInterface() {}
   virtual ~ReadbackYUVInterface() {}
 
   // Note that |target| must use YV12 format.
   virtual void ReadbackYUV(const gpu::Mailbox& mailbox,
                            uint32 sync_point,
                            const scoped_refptr<media::VideoFrame>& target,
                            const base::Callback<void(bool)>& callback) = 0;
   virtual GLHelper::ScalerInterface* scaler() = 0;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_COMMON_GPU_CLIENT_GL_HELPER_H_