// 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_SHADER_PROGRAMS_MAC_H_ #define CONTENT_BROWSER_RENDERER_HOST_COMPOSITING_IOSURFACE_SHADER_PROGRAMS_MAC_H_ #include <OpenGL/gl.h> #include "base/basictypes.h" #include "base/gtest_prod_util.h" namespace content { // Provides caching of the compile-and-link step for shader programs at runtime // since, once compiled and linked, the programs can be shared. Callers invoke // one of the UseXXX() methods to glUseProgram() the program and have its // uniform variables bound with the given parameters. // // Note: All public methods must be invoked within the the same GL context! class CompositingIOSurfaceShaderPrograms { public: CompositingIOSurfaceShaderPrograms(); ~CompositingIOSurfaceShaderPrograms(); // Reset the cache, deleting any references to currently-cached shader // programs. This must be called within an active OpenGL context just before // destruction. void Reset(); // Begin using the "blit" program, which is set up to sample the texture at // GL_TEXTURE_0. Returns false on error. bool UseBlitProgram(); // Begin using the program that just draws solid white very efficiently. // Returns false on error. bool UseSolidWhiteProgram(); // Begin using one of the two RGB-to-YV12 color conversion programs, as // specified by |pass_number| 1 or 2. The programs will sample the texture at // GL_TEXTURE0, and account for scaling in the X direction by |texel_scale_x|. // Returns false on error. bool UseRGBToYV12Program(int pass_number, float texel_scale_x); // |format| argument to use for glReadPixels() when reading back textures // generated by the RGBToYV12 program. GLenum rgb_to_yv12_output_format() const { return rgb_to_yv12_output_format_; } protected: FRIEND_TEST_ALL_PREFIXES(CompositingIOSurfaceTransformerTest, TransformsRGBToYV12); // Side effect: Calls Reset(), deleting any cached programs. void SetOutputFormatForTesting(GLenum format); private: enum { kNumShaderPrograms = 4 }; // Helper methods to cache uniform variable locations. GLuint GetShaderProgram(int which); void BindUniformTextureVariable(int which, int texture_unit_offset); void BindUniformTexelScaleXVariable(int which, float texel_scale_x); // Cached values for previously-compiled/linked shader programs, and the // locations of their uniform variables. GLuint shader_programs_[kNumShaderPrograms]; GLint texture_var_locations_[kNumShaderPrograms]; GLint texel_scale_x_var_locations_[kNumShaderPrograms]; // Byte order of the quads generated by the RGBToYV12 shader program. Must // always be GL_BGRA (default) or GL_RGBA (workaround case). GLenum rgb_to_yv12_output_format_; DISALLOW_COPY_AND_ASSIGN(CompositingIOSurfaceShaderPrograms); }; } // namespace content #endif // CONTENT_BROWSER_RENDERER_HOST_COMPOSITING_IOSURFACE_SHADER_PROGRAMS_MAC_H_