gl_helper.h revision 2a99a7e74a7f215066514fe81d2bfa6639d9eddd 
1// Copyright (c) 2012 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#ifndef CONTENT_COMMON_GPU_CLIENT_GL_HELPER_H_
6#define CONTENT_COMMON_GPU_CLIENT_GL_HELPER_H_
7
8#include "base/atomicops.h"
9#include "base/basictypes.h"
10#include "base/callback.h"
11#include "base/memory/scoped_ptr.h"
12#include "third_party/WebKit/Source/Platform/chromium/public/WebGraphicsContext3D.h"
13
14namespace gfx {
15class Rect;
16class Size;
17}
18
19class SkRegion;
20
21namespace content {
22
23// Provides higher level operations on top of the WebKit::WebGraphicsContext3D
24// interfaces.
25class GLHelper {
26 public:
27  GLHelper(WebKit::WebGraphicsContext3D* context,
28           WebKit::WebGraphicsContext3D* context_for_thread);
29  virtual ~GLHelper();
30
31  WebKit::WebGraphicsContext3D* context() const;
32
33  // Copies the block of pixels specified with |src_subrect| from |src_texture|,
34  // scales it to |dst_size|, and writes it into |out|.
35  // |src_size| is the size of |src_texture|. The result is of format GL_BGRA
36  // and is potentially flipped vertically to make it a correct image
37  // representation.  |callback| is invoked with the copy result when the copy
38  // operation has completed.
39  void CropScaleReadbackAndCleanTexture(
40      WebKit::WebGLId src_texture,
41      const gfx::Size& src_size,
42      const gfx::Rect& src_subrect,
43      const gfx::Size& dst_size,
44      unsigned char* out,
45      const base::Callback<void(bool)>& callback);
46
47  // Copies the texture data out of |texture| into |out|.  |size| is the
48  // size of the texture.  No post processing is applied to the pixels.  The
49  // texture is assumed to have a format of GL_RGBA with a pixel type of
50  // GL_UNSIGNED_BYTE.  This is a blocking call that calls glReadPixels on this
51  // current context.
52  void ReadbackTextureSync(WebKit::WebGLId texture,
53                           const gfx::Rect& src_rect,
54                           unsigned char* out);
55
56  // Creates a copy of the specified texture. |size| is the size of the texture.
57  WebKit::WebGLId CopyTexture(WebKit::WebGLId texture,
58                              const gfx::Size& size);
59
60  // Creates a scaled copy of the specified texture. |src_size| is the size of
61  // the texture and |dst_size| is the size of the resulting copy.
62  WebKit::WebGLId CopyAndScaleTexture(WebKit::WebGLId texture,
63                                      const gfx::Size& src_size,
64                                      const gfx::Size& dst_size,
65                                      bool vertically_flip_texture);
66
67  // Returns the shader compiled from the source.
68  WebKit::WebGLId CompileShaderFromSource(const WebKit::WGC3Dchar* source,
69                                          WebKit::WGC3Denum type);
70
71  // Copies all pixels from |previous_texture| into |texture| that are
72  // inside the region covered by |old_damage| but not part of |new_damage|.
73  void CopySubBufferDamage(WebKit::WebGLId texture,
74                           WebKit::WebGLId previous_texture,
75                           const SkRegion& new_damage,
76                           const SkRegion& old_damage);
77
78 private:
79  class CopyTextureToImpl;
80
81  // Creates |copy_texture_to_impl_| if NULL.
82  void InitCopyTextToImpl();
83
84  WebKit::WebGraphicsContext3D* context_;
85  WebKit::WebGraphicsContext3D* context_for_thread_;
86  scoped_ptr<CopyTextureToImpl> copy_texture_to_impl_;
87
88  // The number of all GLHelper instances.
89  static base::subtle::Atomic32 count_;
90
91  DISALLOW_COPY_AND_ASSIGN(GLHelper);
92};
93
94}  // namespace content
95
96#endif  // CONTENT_COMMON_GPU_CLIENT_GL_HELPER_H_
97