Module: Mesa Branch: master Commit: 8059c2ea9011110df3632e28a4311de9373b9b4e URL: http://cgit.freedesktop.org/mesa/mesa/commit/?id=8059c2ea9011110df3632e28a4311de9373b9b4e
Author: Carl Worth <[email protected]> Date: Tue Jan 22 13:29:01 2013 -0800 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]> --- 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 b1f1df1..b772ef6 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: _______________________________________________ mesa-commit mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/mesa-commit
