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106 lines
3.0 KiB
106 lines
3.0 KiB
Name |
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MESA_bgra |
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Name Strings |
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GL_MESA_bgra |
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Contact |
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Gert Wollny (gert.wollny 'at' collabora.com) |
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Notice |
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Copyright (c) 2021 Collabora LTD |
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Copyright (c) 2009-2013 The Khronos Group Inc. Copyright terms at |
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http://www.khronos.org/registry/speccopyright.html |
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Version |
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Version 1, 2021/04/30. |
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Based on EXT_bgra version 1, modified 1997/05/19. |
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Number |
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TBD |
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Dependencies |
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OpenGL ES 2.0 is required. |
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Written based on the wording of the OpenGL ES 3.2 specification. |
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There are interactions with the extensions EXT_clear_texture. |
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Overview |
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MESA_bgra extends the list of combinations host-memory color formats |
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with internal formats to include BGRA and BGR as acceptable formats |
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with RGB8/SRGB8 and RGBA/sRGB8_ALPHA8 as internal formats respectively. |
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This feature is of interest in virtualized environments, where the host |
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supports OpenGL ES only, and the virtualized guest is supposed to support |
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a subset of OpenGL including textures created with the format BGRA. |
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IP Status |
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Open-source; freely implementable. |
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Issues |
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None. |
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New Procedures and Functions |
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None |
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New Tokens |
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Accepted by the <format> parameter of TexImage2D and TexSubImage2D: |
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GL_BGR_EXT 0x80E0 |
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GL_BGRA_EXT 0x80E1 |
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Additions to Chapter 8 of the GLES 3.2 Specification (Textures and Samplers) |
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Add to table 8.2 (Pixels data formats, valid combinations of format, |
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type, and unsized internalformat). |
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Format Type External Internal Format |
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Bytes |
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per Pixel |
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------------------------------------------------------------- |
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BGRA UNSIGNED_BYTE 4 RGBA |
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BGR UNSIGNED_BYTE 3 RGB |
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Add to table 8.5 (Pixels data formats). |
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Format Name Elements Meaning and Order Target Buffer |
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------------------------------------------------------------- |
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BGR_EXT B, G, R Color |
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BGRA_EXT B, G, R, A Color |
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Add to table 8.9 (Effective internal format correspondig to |
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external format). |
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Format Type Effective |
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Internal format |
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------------------------------------------------------------- |
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BGRA_EXT UNSIGNED_BYTE RGBA8 |
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BGR_EXT UNSIGNED_BYTE RGB8 |
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Interactions with EXT_clear_texture |
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When EXT_clear_texture is supported the accepted formats for |
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ClearTextureEXT and ClearSubTextureEXT are extended to include |
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the entries added above. |
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Revision History |
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Original draft, revision 1.0, May 4, 2021 (Gert Wollny) |
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rewrite EXT_bgra against OpenGL ES 3.2 instead of OpenGL 1,0. |
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Revision 1.1 (May 5. 2021): Add the new tokens, and fix |
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Clear*Texture function names.
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