/* built with Studio Sketchpad: 
 *   https://sketchpad.cc
 * 
 * observe the evolution of this sketch: 
 *   https://studio.sketchpad.cc/sp/pad/view/ro.IxnOnNXug-D/rev.1791
 * 
 * authors: 
 *   frederic.vernier
 *   

 * license (unless otherwise specified): 
 *   creative commons attribution-share alike 3.0 license.
 *   https://creativecommons.org/licenses/by-sa/3.0/ 
 */ 



float a = 0;

void setup() {
    size(700, 700); 
    smooth();
    strokeWeight(2);
    noLoop();
} 

void drawPoly(int x, int y, R, int v){
    float ANG = PI/3;
    colorMode(HSB);
    
  // dessine une courbe point par point
    stroke(v, 255, 128);
    for (int k=1; k<5; k++){
      strokeWeight(5-k);
      fill  (v, 128, 255-k*32);
      beginShape();
      vertex(x+R*cos(0), y+R*sin(0));
      for (int i=0; i<6; i++) {
        int x0 = x+R*cos(i*ANG);
        int y0 = y+R*sin(i*ANG);
        int x1 = x+R*cos((i+1)*ANG);
        int y1 = y+R*sin((i+1)*ANG);
        int dx = (y0-y1)/(2*k)*(1+cos(a));
        int dy = (x1-x0)/(2*k)*(1+cos(a));
        if (i%2==0)
          bezierVertex(1*(x0+x1)/2-dx, 1*(y0+y1)/2-dy, 
                       1*(x0+x1)/2-dx, 1*(y0+y1)/2-dy, x1, y1);
        else 
          bezierVertex(1*(x0+x1)/2+dx, 1*(y0+y1)/2+dy, 
                       1*(x0+x1)/2+dx, 1*(y0+y1)/2+dy, x1, y1);
      } 
     endShape(CLOSE);
     R=R/2;
    }
}

void draw()  {
  a= (a-PI/32)%TWO_PI;
  int R = 50
  background(255);
  for(int j=0; j<height/R/2+1; j++) {
    translate(0, R);
    pushMatrix();
    for (int i=0; i<width/R/2+2; i++) {
      if (i%2==0) translate(0, -R);
      int v = random(0, 255);
      v= (i%2+3-j%3)%3*75;
      drawPoly(0, 0, R, v);
      if (i%2==0) translate(0, R);
      translate(R*sqrt(3), 0);
    }
    popMatrix();
    translate(0, R);
  }
}

void mouseOver(){
  loop();
}

void mouseOut(){
  noLoop();
}