From: Steinar H. Gunderson <sgunderson@bigfoot.com>
Date: Sat, 26 Jul 2014 23:17:12 +0000 (+0200)
Subject: Correct the number of blur taps read.
X-Git-Tag: 1.1.2~1
X-Git-Url: https://git.sesse.net/?p=movit;a=commitdiff_plain;h=47b4160062cdaa53b7d49d7f99ce2c686f02cff8

Correct the number of blur taps read.

We read about twice as many as we should have; the others were
probably just set to 0.0, which has no effect but still burns
arithmetic, unless your driver happens to optimize very aggressively
for this (which I don't think anyone does anymore).

Found by Christophe Thommeret.
---

diff --git a/blur_effect.frag b/blur_effect.frag
index afe9f2e..df0aa46 100644
--- a/blur_effect.frag
+++ b/blur_effect.frag
@@ -4,11 +4,11 @@
 
 #define NUM_TAPS 16
 
-uniform vec2 PREFIX(samples)[NUM_TAPS + 1];
+uniform vec2 PREFIX(samples)[NUM_TAPS / 2 + 1];
 
 vec4 FUNCNAME(vec2 tc) {
 	vec4 sum = vec4(PREFIX(samples)[0].y) * INPUT(tc);
-	for (int i = 1; i < NUM_TAPS + 1; ++i) {
+	for (int i = 1; i < NUM_TAPS / 2 + 1; ++i) {
 		vec2 sample = PREFIX(samples)[i];
 		vec2 sample1_tc = tc, sample2_tc = tc;
 #if DIRECTION_VERTICAL