port from perforce

hgplus/ShaderMinifier/tests/real/relief_tunnel.frag

@@ -0,0 +1,34 @@
+uniform vec2 resolution;
+uniform float time;
+uniform sampler2D tex0;
+uniform sampler2D tex1;
+uniform sampler2D tex2;
+uniform sampler2D tex3;
+
+void main(void)
+{
+    vec2 p = -1.0 + 2.0 * gl_FragCoord.xy / resolution.xy;
+    vec2 uv;
+
+    float r = sqrt( dot(p,p) );
+    float a = atan(p.y,p.x) + 0.5*sin(0.5*r-0.5*time);
+
+    float s = 0.5 + 0.5*cos(7.0*a);
+    s = smoothstep(0.0,1.0,s);
+    s = smoothstep(0.0,1.0,s);
+    s = smoothstep(0.0,1.0,s);
+    s = smoothstep(0.0,1.0,s);
+
+    uv.x = time + 1.0/( r + .2*s);
+    uv.y = 3.0*a/3.1416;
+
+    float w = (0.5 + 0.5*s)*r*r;
+
+    vec3 col = texture2D(tex0,uv).xyz;
+
+    float ao = 0.5 + 0.5*cos(7.0*a);
+    ao = smoothstep(0.0,0.4,ao)-smoothstep(0.4,0.7,ao);
+    ao = 1.0-0.5*ao*r;
+
+    gl_FragColor = vec4(col*w*ao,1.0);
+}