nog wa werk nodig :(

experiments/holo/holo.frag

@@ -0,0 +1,53 @@
+#ifdef GL_ES
+precision mediump float;
+#endif
+uniform vec2 u_resolution;
+uniform vec2 u_mouse;
+uniform float u_time;
+
+#define PI 3.14159265359
+
+const vec3 uAColor = vec3(.5);
+const vec3 uBColor = vec3(.5);
+const vec3 uCColor = vec3(1.);
+const vec3 uDColor = vec3(.3,.2,.2);
+
+//get colors from http://dev.thi.ng/gradients/
+vec3 cosPalette(float t) {
+  return uAColor + uBColor*cos(6.28318*(uCColor*t+uDColor));
+}
+
+float circleSDF(vec2 st) {
+  return length(st-.5)*2.;
+}
+
+float fill(float x, float size) {
+  return 1.-step(size, x);
+}
+
+void main() {
+  vec2 st = gl_FragCoord.xy/u_resolution;
+  float col = 0.0;
+  vec2 l = vec2(.5,.5)-(u_mouse/u_resolution);
+  l = l*.1;
+  float alpha = 1.0;
+  float dots = 17.;
+  float dotsize = .7;
+  vec2 off = vec2(.1,.1);
+  float movemod = sin(u_time)/2.+1.;
+  for (int i = 0; i < 4; i++) {
+    vec2 off1 = off * vec2(-1,1);
+    vec2 off2 = off * vec2(1,-1);
+    vec2 off3 = off * vec2(1,1);
+    vec2 off4 = off * vec2(-1,-1);
+    col += fill(circleSDF(fract(st*dots)+off1+l+movemod),dotsize)/4.;
+    col += fill(circleSDF(fract(st*dots)+off2+l),dotsize)/4.;
+    col += fill(circleSDF(fract(st*dots)+off3+l),dotsize)/4.;
+    col += fill(circleSDF(fract(st*dots)+off4+l),dotsize)/4.;
+    //col += fill(circleSDF(fract(st*dots + l*.9+off)*.3), dotsize);
+    off += vec2(.1,.1);
+  }
+  vec3 color = cosPalette(col);
+
+  gl_FragColor = vec4(color, alpha);
+}