demo

shaders/tunnel.frag

@@ -0,0 +1,23 @@
+#version 100
+precision mediump float;
+uniform float u_time;
+uniform vec2 u_resolution;
+
+void main() {
+    vec2 p = (2.0 * gl_FragCoord.xy - u_resolution.xy) / u_resolution.y;
+    float a = atan(p.y, p.x);
+    float r = length(p);
+    vec2 uv = vec2(0.5 / r + 0.5 * u_time, a / 3.14159);
+    
+    // Simple checkerboard pattern
+    float f = sin(uv.x * 20.0) * sin(uv.y * 20.0);
+    vec3 col = vec3(f);
+    
+    // Fade to black in center
+    col *= r;
+    
+    // Add some color
+    col *= vec3(0.5 + 0.5 * sin(u_time), 0.5, 0.5 + 0.5 * cos(u_time));
+    
+    gl_FragColor = vec4(col, 1.0);
+}