From: Steinar H. Gunderson <sgunderson@bigfoot.com>
Date: Tue, 31 Jul 2018 15:06:19 +0000 (+0200)
Subject: Speed up hole filling by ~10%.
X-Git-Tag: 1.8.0~76^2~158
X-Git-Url: https://git.sesse.net/?a=commitdiff_plain;h=9a9e773dbc1229c9120b09538464e19fcd3d7702;p=nageru

Speed up hole filling by ~10%.
---

diff --git a/hole_fill.vert b/hole_fill.vert
index ea1302a..276a61c 100644
--- a/hole_fill.vert
+++ b/hole_fill.vert
@@ -8,13 +8,17 @@ uniform vec2 sample_offset;
 
 void main()
 {
+	// Moving the position is equivalent to moving the texture coordinate,
+	// but cheaper -- as it means some of the fullscreen quad can be clipped away.
+	vec2 adjusted_pos = position - sample_offset;
+
 	// The result of glOrtho(0.0, 1.0, 0.0, 1.0, 0.0, 1.0) is:
 	//
 	//   2.000  0.000  0.000 -1.000
 	//   0.000  2.000  0.000 -1.000
 	//   0.000  0.000 -2.000 -1.000
 	//   0.000  0.000  0.000  1.000
-	gl_Position = vec4(2.0 * position.x - 1.0, 2.0 * position.y - 1.0, 2.0f * (z - 0.5f), 1.0);
+	gl_Position = vec4(2.0 * adjusted_pos.x - 1.0, 2.0 * adjusted_pos.y - 1.0, 2.0f * (z - 0.5f), 1.0);
 
-	tc = position + sample_offset;
+	tc = position;
 }