| // Copyright 2014 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 COMPONENTS_DISPLAY_COMPOSITOR_GL_HELPER_READBACK_SUPPORT_H_ |
| #define COMPONENTS_DISPLAY_COMPOSITOR_GL_HELPER_READBACK_SUPPORT_H_ |
| |
| #include <stddef.h> |
| |
| #include <vector> |
| |
| #include "components/display_compositor/display_compositor_export.h" |
| #include "components/display_compositor/gl_helper.h" |
| |
| namespace display_compositor { |
| |
| class DISPLAY_COMPOSITOR_EXPORT GLHelperReadbackSupport { |
| public: |
| enum FormatSupport { SUPPORTED, SWIZZLE, NOT_SUPPORTED }; |
| |
| GLHelperReadbackSupport(gpu::gles2::GLES2Interface* gl); |
| |
| ~GLHelperReadbackSupport(); |
| |
| // For a given color type retrieve whether readback is supported and if so |
| // how it should be performed. The |format|, |type| and |bytes_per_pixel| are |
| // the values that should be used with glReadPixels to facilitate the |
| // readback. If |can_swizzle| is true then this method will return SWIZZLE if |
| // the data needs to be swizzled before using the returned |format| otherwise |
| // the method will return SUPPORTED to indicate that readback is permitted of |
| // this color othewise NOT_SUPPORTED will be returned. This method always |
| // overwrites the out values irrespective of the return value. |
| FormatSupport GetReadbackConfig(SkColorType color_type, |
| bool can_swizzle, |
| GLenum* format, |
| GLenum* type, |
| size_t* bytes_per_pixel); |
| // Provides the additional readback format/type pairing for a render target |
| // of a given format/type pairing |
| void GetAdditionalFormat(GLenum format, |
| GLenum type, |
| GLenum* format_out, |
| GLenum* type_out); |
| |
| private: |
| struct FormatCacheEntry { |
| GLenum format; |
| GLenum type; |
| GLenum read_format; |
| GLenum read_type; |
| }; |
| |
| // This populates the format_support_table with the list of supported |
| // formats. |
| void InitializeReadbackSupport(); |
| |
| // This api is called once per format and it is done in the |
| // InitializeReadbackSupport. We should not use this any where |
| // except the InitializeReadbackSupport.Calling this at other places |
| // can distrub the state of normal gl operations. |
| void CheckForReadbackSupport(SkColorType texture_format); |
| |
| // Helper functions for checking the supported texture formats. |
| // Avoid using this API in between texture operations, as this does some |
| // teture opertions (bind, attach) internally. |
| bool SupportsFormat(GLenum format, GLenum type); |
| |
| FormatSupport format_support_table_[kLastEnum_SkColorType + 1]; |
| |
| gpu::gles2::GLES2Interface* gl_; |
| std::vector<struct FormatCacheEntry> format_cache_; |
| }; |
| |
| } // namespace display_compositor |
| |
| #endif // COMPONENTS_DISPLAY_COMPOSITOR_GL_HELPER_READBACK_SUPPORT_H_ |