From 09916e877fc14723d7950f892e181df9f7d7f36f Mon Sep 17 00:00:00 2001 From: Ian Romanick Date: Fri, 22 Jul 2011 15:25:55 -0700 Subject: [PATCH] mesa: Add utility function to get base format from a GL compressed format Reviewed-by: Brian Paul --- src/mesa/main/texcompress.c | 88 +++++++++++++++++++++++++++++++++++++ src/mesa/main/texcompress.h | 3 ++ 2 files changed, 91 insertions(+) diff --git a/src/mesa/main/texcompress.c b/src/mesa/main/texcompress.c index d820ae92747..040be943e82 100644 --- a/src/mesa/main/texcompress.c +++ b/src/mesa/main/texcompress.c @@ -39,6 +39,94 @@ #include "texcompress.h" +/** + * Get the GL base format of a specified GL compressed texture format + * + * From page 232 of the OpenGL 3.3 (Compatiblity Profile) spec: + * + * "Compressed Internal Format Base Internal Format Type + * --------------------------- -------------------- --------- + * COMPRESSED_ALPHA ALPHA Generic + * COMPRESSED_LUMINANCE LUMINANCE Generic + * COMPRESSED_LUMINANCE_ALPHA LUMINANCE_ALPHA Generic + * COMPRESSED_INTENSITY INTENSITY Generic + * COMPRESSED_RED RED Generic + * COMPRESSED_RG RG Generic + * COMPRESSED_RGB RGB Generic + * COMPRESSED_RGBA RGBA Generic + * COMPRESSED_SRGB RGB Generic + * COMPRESSED_SRGB_ALPHA RGBA Generic + * COMPRESSED_SLUMINANCE LUMINANCE Generic + * COMPRESSED_SLUMINANCE_ALPHA LUMINANCE_ALPHA Generic + * COMPRESSED_RED_RGTC1 RED Specific + * COMPRESSED_SIGNED_RED_RGTC1 RED Specific + * COMPRESSED_RG_RGTC2 RG Specific + * COMPRESSED_SIGNED_RG_RGTC2 RG Specific" + * + * \return + * The base format of \c format if \c format is a compressed format (either + * generic or specific. Otherwise 0 is returned. + */ +GLenum +_mesa_gl_compressed_format_base_format(GLenum format) +{ + switch (format) { + case GL_COMPRESSED_RED: + case GL_COMPRESSED_RED_RGTC1: + case GL_COMPRESSED_SIGNED_RED_RGTC1: + return GL_RED; + + case GL_COMPRESSED_RG: + case GL_COMPRESSED_RG_RGTC2: + case GL_COMPRESSED_SIGNED_RG_RGTC2: + return GL_RG; + + case GL_COMPRESSED_RGB: + case GL_COMPRESSED_SRGB: + case GL_COMPRESSED_RGB_S3TC_DXT1_EXT: + case GL_COMPRESSED_RGB_FXT1_3DFX: + case GL_COMPRESSED_SRGB_S3TC_DXT1_EXT: + return GL_RGB; + + case GL_COMPRESSED_RGBA: + case GL_COMPRESSED_SRGB_ALPHA: + case GL_COMPRESSED_RGBA_BPTC_UNORM_ARB: + case GL_COMPRESSED_SRGB_ALPHA_BPTC_UNORM_ARB: + case GL_COMPRESSED_RGB_BPTC_SIGNED_FLOAT_ARB: + case GL_COMPRESSED_RGB_BPTC_UNSIGNED_FLOAT_ARB: + case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT: + case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT: + case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT: + case GL_COMPRESSED_RGBA_FXT1_3DFX: + case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT: + case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT: + case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT: + return GL_RGBA; + + case GL_COMPRESSED_ALPHA: + return GL_ALPHA; + + case GL_COMPRESSED_LUMINANCE: + case GL_COMPRESSED_SLUMINANCE: + case GL_COMPRESSED_LUMINANCE_LATC1_EXT: + case GL_COMPRESSED_SIGNED_LUMINANCE_LATC1_EXT: + return GL_LUMINANCE; + + case GL_COMPRESSED_LUMINANCE_ALPHA: + case GL_COMPRESSED_SLUMINANCE_ALPHA: + case GL_COMPRESSED_LUMINANCE_ALPHA_LATC2_EXT: + case GL_COMPRESSED_SIGNED_LUMINANCE_ALPHA_LATC2_EXT: + case GL_COMPRESSED_LUMINANCE_ALPHA_3DC_ATI: + return GL_LUMINANCE_ALPHA; + + case GL_COMPRESSED_INTENSITY: + return GL_INTENSITY; + + default: + return 0; + } +} + /** * Return list of (and count of) all specific texture compression * formats that are supported. diff --git a/src/mesa/main/texcompress.h b/src/mesa/main/texcompress.h index 19b08bbadf6..922da00912d 100644 --- a/src/mesa/main/texcompress.h +++ b/src/mesa/main/texcompress.h @@ -33,6 +33,9 @@ struct gl_context; #if _HAVE_FULL_GL +extern GLenum +_mesa_gl_compressed_format_base_format(GLenum format); + extern GLuint _mesa_get_compressed_formats(struct gl_context *ctx, GLint *formats, GLboolean all); -- 2.30.2