Henon 1 p5js

DimX=800
DimY=800
Zoom=0.7
Angle=1.11
function setup() {
  createCanvas(DimX, DimY);
}

function draw() {
  background(220);

  a=Angle
  y=0
  sn=sin(a)
  cs=cos(a)
  xi=-1.2
  xf=1.2
  yi=-1.2
  yf=1.2
  sx=(xf-xi)/(DimX*Zoom)
  sy=(yf-yi)/(DimY*Zoom)
  cl=0
  for(xc=xi; xc<xf;  xc=xc+sx){
      y=xc
      x=xc
      i=1
      while(i <= 1000) {
          if (x > 1.0E+15)
              break;
          yx = y-x*x
          xx=x*cs-yx*sn
          y=x*sn+yx*cs
          x=xx
          px=int((DimX/2)+x/sx)
          py=int((DimY/2)-y/sy)
          if (px>0 && px<=DimX && py>0 && py<=DimY){
              stroke(cl%256, cl%128, cl%64)
              point(px, py)
          }
          i=i+1
      }
      cl=cl+1
  }

}