From: Brian Paul <brianp@vmware.com>
Date: Wed, 13 Jan 2010 16:29:43 +0000 (-0700)
Subject: llvmpipe: tweak subpixel_snap() arithmetic
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=212f3a6cb3cb49127a6e5588553fe2d327f46563;p=mesa.git

llvmpipe: tweak subpixel_snap() arithmetic

This adjustment fixes some rasterization differences between llvmpipe
and softpipe (and other renderers).
---

diff --git a/src/gallium/drivers/llvmpipe/lp_setup_tri.c b/src/gallium/drivers/llvmpipe/lp_setup_tri.c
index 9248125de8b..575265b0f50 100644
--- a/src/gallium/drivers/llvmpipe/lp_setup_tri.c
+++ b/src/gallium/drivers/llvmpipe/lp_setup_tri.c
@@ -237,7 +237,7 @@ static void setup_tri_coefficients( struct setup_context *setup,
 
 static inline int subpixel_snap( float a )
 {
-   return util_iround(FIXED_ONE * a);
+   return util_iround(FIXED_ONE * a - (FIXED_ONE / 2));
 }