From: terencehill <piuntn@gmail.com>
Date: Sun, 16 Jun 2024 15:09:18 +0000 (+0200)
Subject: Optimize Draw_CylindricLine: replace a normalize call with a cheaper division, avoid... 
X-Git-Url: https://git.rm.cloudns.org/?a=commitdiff_plain;h=23b9f7c450d34bd2f8edf2d0397540340bc59614;p=xonotic%2Fxonotic-data.pk3dir.git

Optimize Draw_CylindricLine: replace a normalize call with a cheaper division, avoid repeating a few operations
---

diff --git a/qcsrc/lib/draw.qh b/qcsrc/lib/draw.qh
index 82ae7c58d..0d0f9c38b 100644
--- a/qcsrc/lib/draw.qh
+++ b/qcsrc/lib/draw.qh
@@ -13,25 +13,23 @@
 		// I want to draw a quad...
 		// from and to are MIDPOINTS.
 
-		vector axis, thickdir, A, B, C, D;
-		float length_tex;
+		float len = vlen(to - from);
+		if (!len)
+			return;
 
-		axis = normalize(to - from);
-		length_tex = aspect * vlen(to - from) / thickness;
+		float length_tex = aspect * len / thickness;
+		vector axis = (to - from) / len; // same as axis = normalize(to - from) but cheaper
 
 		// direction is perpendicular to the view normal, and perpendicular to the axis
-		thickdir = normalize(cross(axis, vieworg - from));
+		vector thickdir = normalize(cross(axis, vieworg - from));
 
-		A = from - thickdir * (thickness / 2);
-		B = from + thickdir * (thickness / 2);
-		C = to + thickdir * (thickness / 2);
-		D = to - thickdir * (thickness / 2);
+		vector ofs = thickdir * (thickness / 2);
 
 		R_BeginPolygon(texture, drawflag, false);
-		R_PolygonVertex(A, '0 0 0' + shift * '1 0 0', rgb, theAlpha);
-		R_PolygonVertex(B, '0 1 0' + shift * '1 0 0', rgb, theAlpha);
-		R_PolygonVertex(C, '0 1 0' + (shift + length_tex) * '1 0 0', rgb, theAlpha);
-		R_PolygonVertex(D, '0 0 0' + (shift + length_tex) * '1 0 0', rgb, theAlpha);
+		R_PolygonVertex(from - ofs, '0 0 0' + shift * '1 0 0', rgb, theAlpha);
+		R_PolygonVertex(from + ofs, '0 1 0' + shift * '1 0 0', rgb, theAlpha);
+		R_PolygonVertex(to + ofs,   '0 1 0' + (shift + length_tex) * '1 0 0', rgb, theAlpha);
+		R_PolygonVertex(to - ofs,   '0 0 0' + (shift + length_tex) * '1 0 0', rgb, theAlpha);
 		R_EndPolygon();
 	}