From: havoc <havoc@d7cf8633-e32d-0410-b094-e92efae38249>
Date: Sat, 23 Aug 2003 08:32:29 +0000 (+0000)
Subject: negate the dnormal instead of negating the dotproduct result
X-Git-Tag: xonotic-v0.1.0preview~6421
X-Git-Url: https://git.rm.cloudns.org/?a=commitdiff_plain;h=d1526d3184f33308aacd38c94a838f02bb3c8517;p=xonotic%2Fdarkplaces.git

negate the dnormal instead of negating the dotproduct result


git-svn-id: svn://svn.icculus.org/twilight/trunk/darkplaces@3410 d7cf8633-e32d-0410-b094-e92efae38249
---

diff --git a/r_light.c b/r_light.c
index bd1bf3a8..f5bbc46f 100644
--- a/r_light.c
+++ b/r_light.c
@@ -540,7 +540,9 @@ void R_LightModel_CalcVertexColors(const float *ambientcolor4f, const float *dif
 	float color[4], v[3], dot, dist2, f, dnormal[3];
 	nearlight_t *nl;
 	usediffuse = DotProduct(diffusecolor, diffusecolor) > 0;
-	VectorCopy(diffusenormal, dnormal);
+	// negate the diffuse normal to avoid the need to negate the
+	// dotproduct on each vertex
+	VectorNegate(diffusenormal, dnormal);
 	if (usediffuse)
 		VectorNormalize(dnormal);
 	// directional shading code here
@@ -551,7 +553,7 @@ void R_LightModel_CalcVertexColors(const float *ambientcolor4f, const float *dif
 		// silly directional diffuse shading
 		if (usediffuse)
 		{
-			dot = -DotProduct(normal3f, dnormal);
+			dot = DotProduct(normal3f, dnormal);
 			if (dot > 0)
 				VectorMA(color, dot, diffusecolor, color);
 		}