From the issues section of the GL_ARB_texture_compression_rgtc
extension:
15) What should glGetTexLevelParameter return for
GL_TEXTURE_GREEN_SIZE and GL_TEXTURE_BLUE_SIZE for the RGTC1
formats? What should glGetTexLevelParameter return for
GL_TEXTURE_BLUE_SIZE for the RGTC2 formats?
RESOLVED: Zero bits.
These formats always return 0.0 for these respective components
and have no bits devoted to these components.
Returning 8 bits for red size of RGTC1 and the red and green
sizes of RGTC2 makes sense because that's the maximum potential
precision for the uncompressed texels.
Thus, we need to return 8 bits for GL_TEXTURE_RED_SIZE on all RGTC
formats
and 8 bits for GL_TEXTURE_GREEN_SIZE on RGTC2 formats. BLUE should
be 0.
Fixes oglconform/rgtc/advanced.texture_fetch.tex_param.
Signed-off-by: Kenneth Graunke<kenn...@whitecape.org>
---
src/mesa/main/formats.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/src/mesa/main/formats.c b/src/mesa/main/formats.c
index cecb70c..ccc0b17 100644
--- a/src/mesa/main/formats.c
+++ b/src/mesa/main/formats.c
@@ -1319,7 +1319,7 @@ static struct gl_format_info
format_info[MESA_FORMAT_COUNT] =
"MESA_FORMAT_RED_RGTC1",
GL_RED,
GL_UNSIGNED_NORMALIZED,
- 4, 0, 0, 0,
+ 8, 0, 0, 0,
0, 0, 0, 0, 0,
4, 4, 8 /* 8 bytes per 4x4 block */
},
@@ -1328,7 +1328,7 @@ static struct gl_format_info
format_info[MESA_FORMAT_COUNT] =
"MESA_FORMAT_SIGNED_RED_RGTC1",
GL_RED,
GL_SIGNED_NORMALIZED,
- 4, 0, 0, 0,
+ 8, 0, 0, 0,
0, 0, 0, 0, 0,
4, 4, 8 /* 8 bytes per 4x4 block */
},
@@ -1337,7 +1337,7 @@ static struct gl_format_info
format_info[MESA_FORMAT_COUNT] =
"MESA_FORMAT_RG_RGTC2",
GL_RG,
GL_UNSIGNED_NORMALIZED,
- 4, 4, 0, 0,
+ 8, 8, 0, 0,
0, 0, 0, 0, 0,
4, 4, 16 /* 16 bytes per 4x4 block */
},
@@ -1346,7 +1346,7 @@ static struct gl_format_info
format_info[MESA_FORMAT_COUNT] =
"MESA_FORMAT_SIGNED_RG_RGTC2",
GL_RG,
GL_SIGNED_NORMALIZED,
- 4, 4, 0, 0,
+ 8, 8, 0, 0,
0, 0, 0, 0, 0,
4, 4, 16 /* 16 bytes per 4x4 block */
},
