| // Copyright (c) 2013 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_BROWSER_RENDERER_HOST_COMPOSITING_IOSURFACE_TRANSFORMER_MAC_H_ |
| #define CONTENT_BROWSER_RENDERER_HOST_COMPOSITING_IOSURFACE_TRANSFORMER_MAC_H_ |
| |
| #include <OpenGL/gl.h> |
| |
| #include "base/basictypes.h" |
| #include "content/browser/renderer_host/compositing_iosurface_shader_programs_mac.h" |
| #include "ui/gfx/size.h" |
| |
| namespace gfx { |
| class Rect; |
| } // namespace gfx |
| |
| namespace content { |
| |
| // Provides useful image filtering operations that are implemented efficiently |
| // using OpenGL shader programs. |
| // |
| // Note: All methods assume to be called within an active OpenGL context. |
| class CompositingIOSurfaceTransformer { |
| public: |
| // Construct a transformer that always uses the given parameters for texture |
| // bindings. |texture_target| is one of the valid enums to use with |
| // glBindTexture(). |
| // |src_texture_needs_y_flip| is true when the |src_texture| argument to any |
| // of the methods below uses upside-down Y coordinates. |
| // |shader_program_cache| is not owned by this instance. |
| CompositingIOSurfaceTransformer( |
| GLenum texture_target, bool src_texture_needs_y_flip, |
| CompositingIOSurfaceShaderPrograms* shader_program_cache); |
| |
| ~CompositingIOSurfaceTransformer(); |
| |
| // Delete any references to currently-cached OpenGL objects. This must be |
| // called within the OpenGL context just before destruction. |
| void ReleaseCachedGLObjects(); |
| |
| // Resize using bilinear interpolation. Returns false on error. Otherwise, |
| // the |texture| argument will point to the result. Ownership of the returned |
| // |texture| remains with CompositingIOSurfaceTransformer (i.e., the caller |
| // must not delete this texture). The |texture| remains valid until the next |
| // call to ResizeBilinear() or ReleaseCachedGLObjects(). |
| // |
| // If the src and dst sizes are identical, this becomes a simple copy into a |
| // new texture. |
| // |
| // Note: This implementation is faulty in that minifications by more than 2X |
| // will undergo aliasing. |
| bool ResizeBilinear(GLuint src_texture, const gfx::Rect& src_subrect, |
| const gfx::Size& dst_size, GLuint* texture); |
| |
| // Color format conversion from RGB to planar YV12 (also known as YUV420). |
| // |
| // YV12 is effectively a twelve bit per pixel format consisting of a full- |
| // size y (luminance) plane and half-width, half-height u and v (blue and |
| // red chrominance) planes. This method will return three off-screen |
| // textures, one for each plane, via the output arguments |texture_y|, |
| // |texture_u|, and |texture_v|. While the textures are in GL_RGBA format, |
| // they should be interpreted as the appropriate single-byte, planar format |
| // after reading the pixel data. The output arguments |packed_y_size| and |
| // |packed_uv_size| follow from these special semantics: They represent the |
| // size of their corresponding texture, if it was to be treated like RGBA |
| // pixel data. That means their widths are in terms of "quads," where one |
| // quad contains 4 Y (or U or V) pixels. |
| // |
| // Ownership of the returned textures remains with |
| // CompositingIOSurfaceTransformer (i.e., the caller must not delete the |
| // textures). The textures remain valid until the next call to |
| // TransformRGBToYV12() or ReleaseCachedGLObjects(). |
| // |
| // If |src_subrect|'s size does not match |dst_size|, the source will be |
| // bilinearly interpolated during conversion. |
| // |
| // Returns true if successful, and the caller is responsible for deleting the |
| // output textures. |
| bool TransformRGBToYV12( |
| GLuint src_texture, const gfx::Rect& src_subrect, |
| const gfx::Size& dst_size, |
| GLuint* texture_y, GLuint* texture_u, GLuint* texture_v, |
| gfx::Size* packed_y_size, gfx::Size* packed_uv_size); |
| |
| private: |
| enum CachedTexture { |
| RGBA_OUTPUT = 0, |
| Y_PLANE_OUTPUT, |
| UUVV_INTERMEDIATE, |
| U_PLANE_OUTPUT, |
| V_PLANE_OUTPUT, |
| NUM_CACHED_TEXTURES |
| }; |
| |
| // If necessary, generate the texture and/or resize it to the given |size|. |
| void PrepareTexture(CachedTexture which, const gfx::Size& size); |
| |
| // If necessary, generate a framebuffer object to be used as an intermediate |
| // destination for drawing. |
| void PrepareFramebuffer(); |
| |
| // Target to bind all input and output textures to (which defines the type of |
| // textures being created and read). Generally, this is |
| // GL_TEXTURE_RECTANGLE_ARB. |
| const GLenum texture_target_; |
| const bool src_texture_needs_y_flip_; |
| CompositingIOSurfaceShaderPrograms* const shader_program_cache_; |
| |
| // Cached OpenGL objects. |
| GLuint textures_[NUM_CACHED_TEXTURES]; |
| gfx::Size texture_sizes_[NUM_CACHED_TEXTURES]; |
| GLuint frame_buffer_; |
| |
| // Auto-detected and set once in the constructor. |
| bool system_supports_multiple_draw_buffers_; |
| |
| DISALLOW_COPY_AND_ASSIGN(CompositingIOSurfaceTransformer); |
| }; |
| |
| } // namespace content |
| |
| #endif // CONTENT_BROWSER_RENDERER_HOST_COMPOSITING_IOSURFACE_TRANSFORMER_MAC_H_ |