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authorIan Romanick <ian.d.romanick@intel.com>2011-07-22 15:25:55 -0700
committerIan Romanick <ian.d.romanick@intel.com>2011-07-25 19:57:14 -0700
commit09916e877fc14723d7950f892e181df9f7d7f36f (patch)
tree51b0bbf652f91502ce3a0c08427329c05326ee7b /src
parent3daa2d97eb13f41de4cbab9301a167be85d48642 (diff)
mesa: Add utility function to get base format from a GL compressed format
Reviewed-by: Brian Paul <brianp@vmware.com>
Diffstat (limited to 'src')
-rw-r--r--src/mesa/main/texcompress.c88
-rw-r--r--src/mesa/main/texcompress.h3
2 files changed, 91 insertions, 0 deletions
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
@@ -40,6 +40,94 @@
/**
+ * 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);