From 33599433c75c0ab433615d08ed7e4002146ba462 Mon Sep 17 00:00:00 2001 From: Carl Worth Date: Tue, 22 Jan 2013 13:25:37 -0800 Subject: [PATCH] i965: Use swizzles to force alpha to 1.0 for RED, RG, or RGB textures. We may be using a texture with actual RGBA storage for these formats, so force the alpha value read to 1.0. This commit fixes the following piglit (sub) tests: ARB_texture_float/fb-blending-formats GL_RGB16F_ARB EXT_framebuffer_object/fbo-blending-formats GL_RGB10 GL_RGB12 GL_RGB16 EXT_texture_snorm/fbo-blending-formats GL_RGB16_SNORM GL_RGB8_SNORM GL_RGB_SNORM These test improvements depend on the previous commit as well. That commit smashes alpha to 1.0 for the case of ReadPixels (so fixes "FBO testing" as reported by this test), while this commit smashes alpha to 1.0 for the case of texturing (fixed the "window testing" as reported by this test). Note: Haswell bypasses this swizzle code, so may require an independent fix for this bug. Reviewed-by: Eric Anholt --- src/mesa/drivers/dri/i965/brw_wm_surface_state.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) 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 5e99592f4a5..b1f1df11993 100644 --- a/src/mesa/drivers/dri/i965/brw_wm_surface_state.c +++ b/src/mesa/drivers/dri/i965/brw_wm_surface_state.c @@ -729,6 +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). + */ + switch (img->_BaseFormat) { + case GL_RED: + case GL_RG: + case GL_RGB: + swizzles[3] = SWIZZLE_ONE; + break; + } + return MAKE_SWIZZLE4(swizzles[GET_SWZ(t->_Swizzle, 0)], swizzles[GET_SWZ(t->_Swizzle, 1)], swizzles[GET_SWZ(t->_Swizzle, 2)], -- 2.30.2