From: Eric Anholt <anholt@FreeBSD.org>
Date: Thu, 27 Oct 2005 19:59:41 +0000 (+0000)
Subject: Bug #4900: Fix the non-fogcoord fog test on r100 (and rv200) at tcl_mode=1 by
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=512c994b92126a7575bb3cc327da40710b43f52c;p=mesa.git

Bug #4900: Fix the non-fogcoord fog test on r100 (and rv200) at tcl_mode=1 by
flipping the signs on two factors.  While this contradicts the DDK, it matches
what r200 does, and it fixes the test.
---

diff --git a/src/mesa/drivers/dri/radeon/radeon_state.c b/src/mesa/drivers/dri/radeon/radeon_state.c
index 681de914e83..e0c3286195d 100644
--- a/src/mesa/drivers/dri/radeon/radeon_state.c
+++ b/src/mesa/drivers/dri/radeon/radeon_state.c
@@ -361,7 +361,10 @@ static void radeonFogfv( GLcontext *ctx, GLenum pname, const GLfloat *param )
       switch (ctx->Fog.Mode) {
       case GL_EXP:
 	 c.f = 0.0;
-	 d.f = ctx->Fog.Density;
+	 /* While this is the opposite sign from the DDK, it makes the fog test
+	  * pass, and matches r200.
+	  */
+	 d.f = -ctx->Fog.Density;
 	 break;
       case GL_EXP2:
 	 c.f = 0.0;
@@ -373,7 +376,10 @@ static void radeonFogfv( GLcontext *ctx, GLenum pname, const GLfloat *param )
 	    d.f = 1.0F;
 	 } else {
 	    c.f = ctx->Fog.End/(ctx->Fog.End-ctx->Fog.Start);
-	    d.f = 1.0/(ctx->Fog.End-ctx->Fog.Start);
+	    /* While this is the opposite sign from the DDK, it makes the fog
+	     * test pass, and matches r200.
+	     */
+	    d.f = -1.0/(ctx->Fog.End-ctx->Fog.Start);
 	 }
 	 break;
       default: