port from perforce

hgplus/ShaderMinifier/tests/real/radial_blur.frag

@@ -0,0 +1,43 @@
+uniform vec2 resolution;
+uniform float time;
+uniform sampler2D tex0;
+uniform sampler2D tex1;
+uniform sampler2D tex2;
+uniform sampler2D tex3;
+
+vec3 deform( in vec2 p )
+{
+    vec2 uv;
+
+    vec2 q = vec2( sin(1.1*time+p.x),sin(1.2*time+p.y) );
+
+    float a = atan(q.y,q.x);
+    float r = sqrt(dot(q,q));
+
+    uv.x = sin(0.0+1.0*time)+p.x*sqrt(r*r+1.0);
+    uv.y = sin(0.6+1.1*time)+p.y*sqrt(r*r+1.0);
+
+    return texture2D(tex0,uv*.5).xyz;
+}
+
+void main(void)
+{
+    vec2 p = -1.0 + 2.0 * gl_FragCoord.xy / resolution.xy;
+    vec2 s = p;
+
+    vec3 total = vec3(0.0);
+    vec2 d = (vec2(0.0,0.0)-p)/40.0;
+    float w = 1.0;
+    for( int i=0; i<40; i++ )
+    {
+        vec3 res = deform(s);
+        res = smoothstep(0.1,1.0,res*res);
+        total += w*res;
+        w *= .99;
+        s += d;
+    }
+    total /= 40.0;
+    float r = 1.5/(1.0+dot(p,p));
+    gl_FragColor = vec4( total*r,1.0);
+}
+