random examples

10/iching-02.frag

@@ -0,0 +1,80 @@
+// Author @patriciogv ( patriciogonzalezvivo.com ) - 2015
+
+#ifdef GL_ES
+precision mediump float;
+#endif
+
+#define PI 3.14159265359
+#define TWO_PI 6.28318530718
+
+uniform vec2 u_resolution;
+uniform float u_time;
+
+float shape(vec2 st, float N){
+    st = st*2.-1.;
+    float a = atan(st.x,st.y)+PI;
+    float r = TWO_PI/N;
+    return abs(cos(floor(.5+a/r)*r-a)*length(st));
+}
+
+float box(vec2 st, vec2 size){
+    return shape(st*size,4.);
+}
+
+float rect(vec2 _st, vec2 _size){
+    _size = vec2(0.5)-_size*0.5;
+    vec2 uv = smoothstep(_size,_size+vec2(1e-4),_st);
+    uv *= smoothstep(_size,_size+vec2(1e-4),vec2(1.0)-_st);
+    return uv.x*uv.y;
+}
+
+float hex(vec2 st, float a, float b, float c, float d, float e, float f){
+    st = st*vec2(2.,6.);
+
+    vec2 fpos = fract(st);
+    vec2 ipos = floor(st);
+
+    if (ipos.x == 1.0) fpos.x = 1.-fpos.x;
+    if (ipos.y < 1.0){
+        return mix(box(fpos, vec2(0.84,1.)),box(fpos-vec2(0.03,0.),vec2(1.)),a);
+    } else if (ipos.y < 2.0){
+        return mix(box(fpos, vec2(0.84,1.)),box(fpos-vec2(0.03,0.),vec2(1.)),b);
+    } else if (ipos.y < 3.0){
+        return mix(box(fpos, vec2(0.84,1.)),box(fpos-vec2(0.03,0.),vec2(1.)),c);
+    } else if (ipos.y < 4.0){
+        return mix(box(fpos, vec2(0.84,1.)),box(fpos-vec2(0.03,0.),vec2(1.)),d);
+    } else if (ipos.y < 5.0){
+        return mix(box(fpos, vec2(0.84,1.)),box(fpos-vec2(0.03,0.),vec2(1.)),e);
+    } else if (ipos.y < 6.0){
+        return mix(box(fpos, vec2(0.84,1.)),box(fpos-vec2(0.03,0.),vec2(1.)),f);
+    }
+    return 0.0;
+}
+
+float hex(vec2 st, float N){
+    float b[6];
+    float remain = floor(mod(N,64.));
+    for(int i = 0; i < 6; i++){
+        b[i] = 0.0;
+        b[i] = step(1.0,mod(remain,2.));
+        remain = ceil(remain/2.);
+    }
+    return hex(st,b[0],b[1],b[2],b[3],b[4],b[5]);
+}
+
+float random (in vec2 _st) { return fract(sin(dot(_st.xy, vec2(12.9898,78.233)))* 43758.5453123);}
+
+void main(){
+    vec2 st = gl_FragCoord.xy/u_resolution.xy;
+    st.y *= u_resolution.y/u_resolution.x;
+
+    st *= 10.0;
+    vec2 fpos = fract(st);
+    vec2 ipos = floor(st);
+    
+    float t = u_time*5.0;
+    float df = 1.0;
+    df = hex(fpos,ipos.x+ipos.y+t*random(ipos))+(1.0-rect(fpos,vec2(0.7)));
+
+    gl_FragColor = vec4(mix(vec3(0.),vec3(1.),step(0.7,df)),1.0);
+}

examples/README.md

@@ -5,12 +5,16 @@ The following is a list of examples present in this book.
 ### Chapters examples
 
 * Getting started
+
     * [Hello World](../02/)
         - ["Hello World!"](../edit.html#02/hello_world.frag)
+
     * [Uniforms](../03/)
         - [u_time](../edit.html#03/time.frag)
         - [gl_FragCoord](../edit.html#03/space.frag)
+
 * Algorithmic drawing
+
     * [Shaping functions](../05/)
         - [Linear Interpolation](../edit.html#05/linear.frag)
         - [Exponential Interpolation](../edit.html#05/expo.frag)
@@ -32,12 +36,12 @@ The following is a list of examples present in this book.
     * [Shapes](../07/)
         - Rectangle: [making](../edit.html#07/rect-making.frag), [function](../edit.html#07/rect.frag) and [distance-field](../edit.html#07/rect-df.frag)
         - Circle: [making](../edit.html#07/circle-making.frag) and [function](../edit.html#07/circle.frag)
-        - [Batman (distance field)](../edit.html#07/batman.frag)
-        - [Line (distance field)](../edit.html#07/line.frag)
+        - [Batman](../edit.html#07/batman.frag)
+        - [Line](../edit.html#07/line.frag)
         - [Cross](../edit.html#07/cross.frag)
         - [Polar](../edit.html#07/polar.frag)
-        - [Polar (distance field)](../edit.html#07/shapes.frag)
-        - [Arrow (distance field)](../edit.html#07/arrow.frag)
+        - [Polar](../edit.html#07/shapes.frag)
+        - [Arrow](../edit.html#07/arrow.frag)
 
     * [Matrix](../08/)
         - [cross](../edit.html#08/cross.frag)
@@ -61,16 +65,25 @@ The following is a list of examples present in this book.
         - [Deco](../edit.html#09/deco.frag)
         - [I Ching](../edit.html#09/iching-01.frag)
 
+
+* Generative designs
+
     * [Random](../10/)
         - [1D Random](../edit.html#10/1d-random.frag)
         - [2D Random](../edit.html#10/2d-random.frag)
         - [Random Mosaic](../edit.html#10/2d-random-mosaic.frag)
         - [Random Dots](../edit.html#10/2d-random-dots.frag)
         - [Random Truchet](../edit.html#10/2d-random-truchet.frag)
-        - Ikeda's style: [test pattern](../edit.html#10/ikeda-00.frag), [data path](../edit.html#10/ikeda-03.frag) and [data defrag](../edit.html#10/ikeda-04.frag).
+        - Ikeda's style: [test pattern](../edit.html#10/ikeda-00.frag), [wave](../edit.html#10/ikeda-01.frag),[test pattern](../edit.html#10/ikeda-02.frag), [data path](../edit.html#10/ikeda-03.frag) and [data defrag](../edit.html#10/ikeda-04.frag).
+        - [Matrix](../edit.html#10/matrix.frag)
+        - [Digits](../edit.html#10/ikeda-digits.frag)
+        - [Random Grid](../edit.html#10/ikeda-simple-grid.frag)
+        - [Random Numbered Grid](../edit.html#10/ikeda-numered-grid.frag)
+        - [Random I Ching](../edit.html#10/iching-02.frag)
         
 ### Advance
 
 * [Moon](../edit.html#examples/moon.frag&examples/images/moon-texture.jpg)
 * [Matrix](../edit.html#08/matrix.frag)
 * [I Ching](../edit.html#09/iching.frag)
+* Ikeda's series: [test pattern](../edit.html#10/ikeda-00.frag), [data path](../edit.html#10/ikeda-03.frag) and [data defrag](../edit.html#10/ikeda-04.frag), [digits](../edit.html#10/ikeda-digits.frag), [radar](../edit.html#10/ikeda-simple-grid.frag), [numered grid](../edit.html#10/ikeda-numered-grid.frag)