diff options
| author | Carl Worth <[email protected]> | 2013-01-22 13:29:01 -0800 |
|---|---|---|
| committer | Carl Worth <[email protected]> | 2013-01-23 17:41:09 -0800 |
| commit | 8059c2ea9011110df3632e28a4311de9373b9b4e (patch) | |
| tree | 94a8133e65abd94394e402cdeed7d48d7568b5ae | |
| parent | 33599433c75c0ab433615d08ed7e4002146ba462 (diff) | |
i965: Use swizzles to force R, G, and B to 0.0 for ALPHA textures.
Similar to the previous commit, we may be using a texture with actual RGBA
storage for the GL_ALPHA format, so force the color values to 0.0.
This commit fixes the following piglit (sub) tests:
EXT_texture_snorm/fbo-blending-formats
GL_ALPHA16_SNORM
GL_ALPHA8_SNORM
GL_ALPHA_SNORM
Note: Haswell bypasses this swizzle code, so may require an independent fix
for this bug.
Reviewed-by: Eric Anholt <[email protected]>
| -rw-r--r-- | src/mesa/drivers/dri/i965/brw_wm_surface_state.c | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/src/mesa/drivers/dri/i965/brw_wm_surface_state.c b/src/mesa/drivers/dri/i965/brw_wm_surface_state.c index b1f1df11993..b772ef64e48 100644 --- a/src/mesa/drivers/dri/i965/brw_wm_surface_state.c +++ b/src/mesa/drivers/dri/i965/brw_wm_surface_state.c @@ -729,11 +729,18 @@ brw_get_texture_swizzle(const struct gl_texture_object *t) } } - /* For a format with no alpha channel, force the alpha result to - * 1.0. (This allows for an RGBA texture to be used for an RGB - * format, for example). + /* If the texture's format is alpha-only, force R, G, and B to + * 0.0. Similarly, if the texture's format has no alpha channel, + * force the alpha value read to 1.0. This allows for the + * implementation to use an RGBA texture for any of these formats + * without leaking any unexpected values. */ switch (img->_BaseFormat) { + case GL_ALPHA: + swizzles[0] = SWIZZLE_ZERO; + swizzles[1] = SWIZZLE_ZERO; + swizzles[2] = SWIZZLE_ZERO; + break; case GL_RED: case GL_RG: case GL_RGB: |