weird: rothko succeeds now! yay

weird/rothko.glsl

@@ -6,7 +6,7 @@ uniform vec2 u_resolution;
 uniform vec2 u_mouse;
 uniform float u_time;
 
-float random (in vec2 st) { 
+float random (in vec2 st) {
     return fract(sin(dot(st.xy,
                          vec2(12.9898,78.233)))
                  * 43758.5453123);
@@ -27,8 +27,8 @@ float noise (in vec2 st) {
 
     vec2 u = f*f*(3.0-2.0*f);
 
-    return mix(a, b, u.x) + 
-            (c - a)* u.y * (1.0 - u.x) + 
+    return mix(a, b, u.x) +
+            (c - a)* u.y * (1.0 - u.x) +
             (d - b) * u.x * u.y;
 }
 
@@ -55,9 +55,15 @@ void main() {
     }
 
     st_.x /= 3.;
-    st_ *= 10.;
-    for (float i=0.;i<100.;i++) {
-        color += noise(st_*i)*0.03 * (random(st_*i) > 0.5 ? -1. : 1.);
+    int max = int(50.*abs(sin(u_time)))+100;
+    for (int i=0;i<150;i++) {
+        if (i>max) break;
+        vec2 target= st_*0.0001+float(i);
+        color += noise(target)* 0.03 * (random(target) > 0.5 ? -1. : 1.);
+    }
+
+    if (color.x == 0. && color.y == 0. && color.z == 0.) {
+        color = vec4(0.,0.,0.,1.);
     }
 
     gl_FragColor = vec4(color);