Module: Mesa Branch: master Commit: d86efc075ed84a8c45bfb71cee56dcd18858f727 URL: http://cgit.freedesktop.org/mesa/mesa/commit/?id=d86efc075ed84a8c45bfb71cee56dcd18858f727
Author: Kenneth Graunke <[email protected]> Date: Fri Mar 15 14:48:24 2013 -0700 i965: Don't use texture swizzling to force alpha to 1.0 if unnecessary. Commit 33599433c7 began setting the texture swizzle mode to XYZ1 for RED, RG, and RGB textures in order to force alpha to 1.0 in case we actually stored the texture as RGBA. This had a unforseen performance implication: the shader precompile assumes that the texture swizzle mode will be XYZW for non-shadow sampler types. By setting it to XYZ1, this means every shader used with a RED, RG, or RGB texture has to be recompiled. This is a very common case. Unfortunately, there's no way to improve the precompile, since RGBA textures still need XYZW, and there's no way to know by looking at the shader source what texture formats might be used. However, we only need to smash alpha to 1.0 if the texture's memory format actually has alpha bits. If not, the sampler already returns 1.0 for us without any special swizzling. XRGB8888, for example, is a very common case where this occurs. This partially fixes a performance regression since commit 33599433c7. More work is required to fully fix it in all cases. This at least helps Warsow. NOTE: This is a candidate for the 9.1 branch. Reviewed-by: Carl Worth <[email protected]> Signed-off-by: Kenneth Graunke <[email protected]> --- src/mesa/drivers/dri/i965/brw_wm_surface_state.c | 3 ++- 1 files changed, 2 insertions(+), 1 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 932e472..7e4cc91 100644 --- a/src/mesa/drivers/dri/i965/brw_wm_surface_state.c +++ b/src/mesa/drivers/dri/i965/brw_wm_surface_state.c @@ -773,7 +773,8 @@ brw_get_texture_swizzle(const struct gl_context *ctx, case GL_RED: case GL_RG: case GL_RGB: - swizzles[3] = SWIZZLE_ONE; + if (_mesa_get_format_bits(img->TexFormat, GL_ALPHA_BITS) > 0) + swizzles[3] = SWIZZLE_ONE; break; } _______________________________________________ mesa-commit mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/mesa-commit
