From cd87aeae00e17e49e258d4d0db6524d808ba7d3f Mon Sep 17 00:00:00 2001
From: Zack Rusin <zack@tungstengraphics.com>
Date: Tue, 20 May 2008 18:49:40 -0400
Subject: add a simple but nice example of convolution filters in glsl

shows basics of image processing with glsl
---
 progs/glsl/convolution.frag | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)
 create mode 100644 progs/glsl/convolution.frag

(limited to 'progs/glsl/convolution.frag')

diff --git a/progs/glsl/convolution.frag b/progs/glsl/convolution.frag
new file mode 100644
index 0000000000..e49b8acf54
--- /dev/null
+++ b/progs/glsl/convolution.frag
@@ -0,0 +1,21 @@
+
+const int KernelSize = 9;
+
+//texture offsets
+uniform vec2 Offset[KernelSize];
+//convolution kernel
+uniform vec4 KernelValue[KernelSize];
+uniform sampler2D srcTex;
+uniform vec4 ScaleFactor;
+uniform vec4 BaseColor;
+
+void main(void)
+{
+    int i;
+    vec4 sum = vec4(0.0);
+    for (i = 0; i < KernelSize; ++i) {
+        vec4 tmp = texture2D(srcTex, gl_TexCoord[0].st + Offset[i]);
+        sum += tmp * KernelValue[i];
+    }
+    gl_FragColor = sum * ScaleFactor + BaseColor;
+}
-- 
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