From: divverent <divverent@d7cf8633-e32d-0410-b094-e92efae38249>
Date: Wed, 13 Oct 2010 17:18:55 +0000 (+0000)
Subject: adjust for left handed coordinate system in a reflected view
X-Git-Tag: xonotic-v0.1.0preview~56^2~96
X-Git-Url: http://git.xonotic.org/?a=commitdiff_plain;h=5e15507f0fc13b7f22d39bf2cc77b16d606e8660;p=xonotic%2Fdarkplaces.git

adjust for left handed coordinate system in a reflected view

git-svn-id: svn://svn.icculus.org/twilight/trunk/darkplaces@10521 d7cf8633-e32d-0410-b094-e92efae38249
---

diff --git a/gl_rmain.c b/gl_rmain.c
index 7b251da3..a066f6cd 100644
--- a/gl_rmain.c
+++ b/gl_rmain.c
@@ -8012,7 +8012,7 @@ static void R_View_SetFrustum(const int *scissor)
 {
 	int i;
 	double fpx, fnx, fpy, fny;
-	vec3_t forward, left, up, origin;
+	vec3_t forward, left, up, origin, v;
 
 	if(scissor)
 	{
@@ -8109,6 +8109,18 @@ static void R_View_SetFrustum(const int *scissor)
 		CrossProduct(r_refdef.view.frustumcorner[0], r_refdef.view.frustumcorner[1], r_refdef.view.frustum[2].normal);
 		CrossProduct(r_refdef.view.frustumcorner[3], r_refdef.view.frustumcorner[2], r_refdef.view.frustum[3].normal);
 
+		// in a NORMAL view, forward cross left == up
+		// in a REFLECTED view, forward cross left == down
+		// so our cross products above need to be adjusted for a left handed coordinate system
+		CrossProduct(forward, left, v);
+		if(DotProduct(v, up) < 0)
+		{
+			VectorNegate(r_refdef.view.frustum[0].normal, r_refdef.view.frustum[0].normal);
+			VectorNegate(r_refdef.view.frustum[1].normal, r_refdef.view.frustum[1].normal);
+			VectorNegate(r_refdef.view.frustum[2].normal, r_refdef.view.frustum[2].normal);
+			VectorNegate(r_refdef.view.frustum[3].normal, r_refdef.view.frustum[3].normal);
+		}
+
 		// Leaving those out was a mistake, those were in the old code, and they
 		// fix a reproducable bug in this one: frustum culling got fucked up when viewmatrix was an identity matrix
 		// I couldn't reproduce it after adding those normalizations. --blub