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authorBrian Paul <brian.paul@tungstengraphics.com>2008-08-16 09:36:46 -0600
committerBrian Paul <brian.paul@tungstengraphics.com>2008-08-16 09:36:46 -0600
commitc0dd9122fdedd4bcab5bc0b3bbb490e6b62fac83 (patch)
treeac114b79c5790b10c0a8904ca79dfea5480c5617 /progs/glsl/shadowtex.frag
parentce00d232f3c01c71fb659568e9b58da1f24b2519 (diff)
remove .txt suffix from shader source files
Diffstat (limited to 'progs/glsl/shadowtex.frag')
-rw-r--r--progs/glsl/shadowtex.frag21
1 files changed, 21 insertions, 0 deletions
diff --git a/progs/glsl/shadowtex.frag b/progs/glsl/shadowtex.frag
new file mode 100644
index 0000000000..a6a80da47f
--- /dev/null
+++ b/progs/glsl/shadowtex.frag
@@ -0,0 +1,21 @@
+// Fragment shader for 2D texture with shadow attenuation
+// Brian Paul
+
+
+uniform sampler2D tex2d;
+uniform vec3 lightPos;
+
+void main()
+{
+ // XXX should compute this from lightPos
+ vec2 shadowCenter = vec2(-0.25, -0.25);
+
+ // d = distance from center
+ float d = distance(gl_TexCoord[0].xy, shadowCenter);
+
+ // attenuate and clamp
+ d = clamp(d * d * d, 0.0, 2.0);
+
+ // modulate texture by d for shadow effect
+ gl_FragColor = d * texture2D(tex2d, gl_TexCoord[0].xy, 0.0);
+}