rgngl · May 10, 2013 10:42 · May 10, 2013
diff --git a/whirl.glsl b/whirl.glsl
@@ -0,0 +1,31 @@
+#ifdef GL_ES
+precision mediump float;
+#endif
+
+uniform float time;
+uniform vec2 mouse;
+uniform vec2 resolution;
+
+void main( void ) {
+
+  vec2 posScale = vec2(resolution.y,resolution.x)/sqrt(resolution.x*resolution.y);
+	vec2 position = (( gl_FragCoord.xy / resolution.xy ) );
+
+	float sum = 0.;
+	float qsum = 0.;
+
+	for (float i = 0.; i < 15.; i++) {
+		float x2 = i*i*.3165+(sin(time/10.)*i*0.01)+.5;
+		float y2 = i*.161235+(cos(time/10.)*i*0.01)+.5;
+		vec2 p = (fract(position-vec2(x2,y2))-vec2(.5))/posScale;
+		float a = atan(p.y,p.x);
+		float r = length(p)*200.;
+		float e = exp(-r*.5);
+		sum += sin(r+a+time)*e;
+		qsum += e;
+	}
+
+	float color = sum/qsum;
+
+	gl_FragColor = vec4(sin(color+time)*.5 + .5, cos(color+time)*.5 + .5, -sin(color+time) * .1 + .7, 1.0 );
+}