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