From: Rudolf Polzer <divverent@alientrap.org>
Date: Wed, 29 Dec 2010 16:36:09 +0000 (+0100)
Subject: Author: rambetter
X-Git-Tag: xonotic-v0.5.0~80
X-Git-Url: http://de.git.xonotic.org/?p=xonotic%2Fnetradiant.git;a=commitdiff_plain;h=7daa362c91eb88948d107dbec1daf2a4139350f6;ds=sidebyside

Author: rambetter
New Revision: 376
Undoing revision 375 because it did not offer measured accuracy improvements
in the q3map2 math calculations.
---

diff --git a/regression_tests/q3map2/disappearing_sliver2/README.txt b/regression_tests/q3map2/disappearing_sliver2/README.txt
index c0d4eaa6..55f9b51d 100644
--- a/regression_tests/q3map2/disappearing_sliver2/README.txt
+++ b/regression_tests/q3map2/disappearing_sliver2/README.txt
@@ -66,3 +66,18 @@ is this:
 
 As you can see, all points but one have an increase in accuracy.  This is
 still not accurate enough in my opinion, but is a step in the right direction.
+
+
+MORE NOTES:
+===========
+
+I attempted to improve upon revision 371 by streamlining the code in
+BaseWindingForPlane() some more.  Those attempts were committed as r375.
+After revision 375:
+
+  (6784.09375000 16241.01757812 -1722.04687500)
+  (6144.00000000 16082.99414062 -1443.00390625)
+  (6144.00000000 16122.00000000 -1424.00097656)
+
+Revision 375 has since been reverted (undone) because of the loss in
+accuracy.
diff --git a/tools/quake3/common/polylib.c b/tools/quake3/common/polylib.c
index 7d5b8a83..b62d12ff 100644
--- a/tools/quake3/common/polylib.c
+++ b/tools/quake3/common/polylib.c
@@ -253,9 +253,13 @@ winding_t *BaseWindingForPlane (vec3_t normal, vec_t dist)
 			vright[2] = normal[1];
 			break;
 	}
-	// NOTE: vright is NOT a unit vector at this point.
-	VectorSetLength(vright, MAX_WORLD_COORD * 2, vright);
 	CrossProduct(normal, vright, vup);
+
+	// IMPORTANT NOTE: vright and vup are NOT unit vectors at this point.
+	// However, normal, vup, and vright are pairwise perpendicular.
+
+	VectorSetLength(vup, MAX_WORLD_COORD * 2, vup);
+	VectorSetLength(vright, MAX_WORLD_COORD * 2, vright);
 	VectorScale(normal, dist, org);
 
 	w = AllocWinding(4);