dees was echt fun om te gebruiken. kmoe zeker de andere noise fn's es

testen

experiments/perlin/dumb.frag

@@ -0,0 +1,17 @@
+#ifdef GL_ES
+precision mediump float;
+#endif
+
+uniform vec2 u_resolution;
+uniform vec2 u_mouse;
+uniform float u_time;
+
+#define PI 3.14159265359
+
+
+
+void main() {
+  vec2 st = gl_FragCoord.xy/u_resolution;
+  vec3 color = vec3(0.0,0.0,0.0)
+  gl_FragColor = vec4(color, 1.0);
+}

experiments/perlin/main.frag

@@ -1,17 +1,129 @@
 #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(.0,.5,.5);
+const vec3 uBColor = vec3(.0,.5,.5);
+const vec3 uCColor = vec3(0.,.5,.333);
+const vec3 uDColor = vec3(.0,.5,.667);
 
+//get colors from http://dev.thi.ng/gradients/
+vec3 cosPalette(float t) { return uAColor + uBColor*cos(6.28318*(uCColor*t+uDColor)); }
+
+//2d perlin noise fn via stegu/webgl-noise
+vec4 mod289(vec4 x) { return x - floor(x * (1.0 / 289.0)) * 289.0; }
+
+vec4 permute(vec4 x) { return mod289(((x*34.0)+10.0)*x);}
+
+vec4 taylorInvSqrt(vec4 r){ return 1.79284291400159 - 0.85373472095314 * r; }
+
+vec2 fade(vec2 t) { return t*t*t*(t*(t*6.0-15.0)+10.0); }
+
+// Classic Perlin noise
+float cnoise(vec2 P)
+{
+  vec4 Pi = floor(P.xyxy) + vec4(0.0, 0.0, 1.0, 1.0);
+  vec4 Pf = fract(P.xyxy) - vec4(0.0, 0.0, 1.0, 1.0);
+  Pi = mod289(Pi); // To avoid truncation effects in permutation
+  vec4 ix = Pi.xzxz;
+  vec4 iy = Pi.yyww;
+  vec4 fx = Pf.xzxz;
+  vec4 fy = Pf.yyww;
+
+  vec4 i = permute(permute(ix) + iy);
+
+  vec4 gx = fract(i * (1.0 / 41.0)) * 2.0 - 1.0 ;
+  vec4 gy = abs(gx) - 0.5 ;
+  vec4 tx = floor(gx + 0.5);
+  gx = gx - tx;
+
+  vec2 g00 = vec2(gx.x,gy.x);
+  vec2 g10 = vec2(gx.y,gy.y);
+  vec2 g01 = vec2(gx.z,gy.z);
+  vec2 g11 = vec2(gx.w,gy.w);
+
+  vec4 norm = taylorInvSqrt(vec4(dot(g00, g00), dot(g01, g01), dot(g10, g10), dot(g11, g11)));
+  g00 *= norm.x;  
+  g01 *= norm.y;  
+  g10 *= norm.z;  
+  g11 *= norm.w;  
+
+  float n00 = dot(g00, vec2(fx.x, fy.x));
+  float n10 = dot(g10, vec2(fx.y, fy.y));
+  float n01 = dot(g01, vec2(fx.z, fy.z));
+  float n11 = dot(g11, vec2(fx.w, fy.w));
+
+  vec2 fade_xy = fade(Pf.xy);
+  vec2 n_x = mix(vec2(n00, n01), vec2(n10, n11), fade_xy.x);
+  float n_xy = mix(n_x.x, n_x.y, fade_xy.y);
+  return 2.3 * n_xy;
+}
+
+// Classic Perlin noise, periodic variant
+float pnoise(vec2 P, vec2 rep)
+{
+  vec4 Pi = floor(P.xyxy) + vec4(0.0, 0.0, 1.0, 1.0);
+  vec4 Pf = fract(P.xyxy) - vec4(0.0, 0.0, 1.0, 1.0);
+  Pi = mod(Pi, rep.xyxy); // To create noise with explicit period
+  Pi = mod289(Pi);        // To avoid truncation effects in permutation
+  vec4 ix = Pi.xzxz;
+  vec4 iy = Pi.yyww;
+  vec4 fx = Pf.xzxz;
+  vec4 fy = Pf.yyww;
+
+  vec4 i = permute(permute(ix) + iy);
+
+  vec4 gx = fract(i * (1.0 / 41.0)) * 2.0 - 1.0 ;
+  vec4 gy = abs(gx) - 0.5 ;
+  vec4 tx = floor(gx + 0.5);
+  gx = gx - tx;
+
+  vec2 g00 = vec2(gx.x,gy.x);
+  vec2 g10 = vec2(gx.y,gy.y);
+  vec2 g01 = vec2(gx.z,gy.z);
+  vec2 g11 = vec2(gx.w,gy.w);
+
+  vec4 norm = taylorInvSqrt(vec4(dot(g00, g00), dot(g01, g01), dot(g10, g10), dot(g11, g11)));
+  g00 *= norm.x;  
+  g01 *= norm.y;  
+  g10 *= norm.z;  
+  g11 *= norm.w;  
+
+  float n00 = dot(g00, vec2(fx.x, fy.x));
+  float n10 = dot(g10, vec2(fx.y, fy.y));
+  float n01 = dot(g01, vec2(fx.z, fy.z));
+  float n11 = dot(g11, vec2(fx.w, fy.w));
+
+  vec2 fade_xy = fade(Pf.xy);
+  vec2 n_x = mix(vec2(n00, n01), vec2(n10, n11), fade_xy.x);
+  float n_xy = mix(n_x.x, n_x.y, fade_xy.y);
+  return 2.3 * n_xy;
+}
+
+float stroke(in float x_coor, float s, float width){
+  float d = step(s,x_coor+width*.5)-step(s,x_coor-width*.5);
+  return clamp(d, 0.,1.);
+}
+
+float circleSDF(vec2 st) { return length(st-.5)*2.; }
 
 void main() {
   vec2 st = gl_FragCoord.xy/u_resolution;
-  vec3 color = vec3(0.0,0.0,0.0)
-  gl_FragColor = vec4(color, 1.0);
+  float color = sin(u_time)*cos(u_time)/u_time*st.x;
+  float alpha = 1.0;
+  vec2 off = vec2(.2);
+  float md = sin(u_time);
+  int it = 8;
+  for (int i = 0; i<it; i++) {
+    color += stroke(circleSDF(st+(off*vec2(sin(u_time/md),cos(u_time/md)))), .3,(.1*abs(sin(u_time/md))));
+    md *=2.;
+  }
+  color *= pnoise(st+(10000.*cos(u_time)),st*sin(u_time));
+   
+  gl_FragColor = vec4(cosPalette(color), alpha);
 }