huh

experiments/perlin/circles.frag

@@ -0,0 +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;
+  float s = u_time/2.;
+  float color = sin(s)*cos(s)/s*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(s/md),cos(s/md)))), .3,(.1*abs(sin(s/md))));
+    md *=2.;
+  }
+  color *= abs(pnoise(st+(10000.*cos(s)),st*sin(s)));
+   
+  gl_FragColor = vec4(cosPalette(color), alpha);
+}

experiments/perlin/main.frag

@@ -7,14 +7,6 @@ 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; }
 
@@ -105,25 +97,47 @@ float pnoise(vec2 P, vec2 rep)
   return 2.3 * n_xy;
 }
 
+
+const vec3 uAColor = vec3(.821,.328,.242);
+const vec3 uBColor = vec3(.659,.481,.896);
+const vec3 uCColor = vec3(.612,.340,.296);
+const vec3 uDColor = vec3(2.82,3.026,-.273);
+
+//get colors from http://dev.thi.ng/gradients/
+vec3 cosPalette(float t) { return uAColor + uBColor*cos(6.28318*(uCColor*t+uDColor)); }
+
 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.; }
+float triSDF(vec2 st) {
+  st = (st*2.-1.)*2.;
+  return max(abs(st.x)*.866025+st.y*.5,-st.y*.5);
+}
+vec2 rotate(vec2 st, float a) {
+  st = mat2(cos(a),-sin(a),sin(a),cos(a))*(st-.5);
+  return st+.5;
+}
 
 void main() {
   vec2 st = gl_FragCoord.xy/u_resolution;
-  float color = sin(u_time)*cos(u_time)/u_time*st.x;
+  st.x *= u_resolution.x/u_resolution.y;
+  st = st -.5;
+  st *= 2.;
+ // vec3 color = vec3(0.0,0.0,0.0);
+  float color = 0.;
+  float d = length(st);
   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));
+  float s = u_time*8.;
+  float f_amount = 4.;
+  vec2 f_st = fract(st*f_amount);
+  f_st = rotate(f_st,dot(st,st)+(s*d));
 
-  gl_FragColor = vec4(cosPalette(color), alpha);
+  float t = triSDF(f_st);
+  //color += stroke(t, .5,.1);
+  color += stroke(t, .8,.2);
+  color *= pnoise(st*s, f_st*s)+.5;
+  
+  gl_FragColor = vec4(vec3(color), alpha);
 }