Bipolar Coordinates - OpenProcessing

mySketch.js
xxxxxxxxxx
 
function setup() {
  createCanvas(1112, 834);
  colorMode(HSB, 255);
  time = 0.01
}
​
function draw() {
  translate(width/2, height/2)
  scale(1, -1)
  blendMode(BLEND)
  background(255)
  stroke(0)
  strokeWeight(2)
  noStroke()
  blendMode(DIFFERENCE)
  n = 200
  l = 200
  k = 10
  h = 10
  a = 100
  
  point(-a, 0)
  point(a, 0)
  
  for(j = 0; j < k; j++){
  fill(j*23, 255, 255)
  step = fract((j+time)/k)*k-k/2
  beginShape()
  for(i = -l; i <= l; i++){
  sigma = i/l*PI
  tau = step
  x = a * sinh(tau)/(cosh(tau)-cos(sigma))
  y = a * sin(sigma)/(cosh(tau)-cos(sigma))
  vertex(x, y)
  }
  endShape(CLOSE)
  }
  
  
  for(j=0; j<h; j++){
  fill(j*23, 255, 255)
  step = fract((j+time)/h)*PI-PI/2
  beginShape()
  for(i = -n; i <= n; i++){
  sigma = PI/2+step
  tau = -i/n*3
  x = a * sinh(tau)/(cosh(tau)-cos(sigma))
  y = a * sin(sigma)/(cosh(tau)-cos(sigma))
  vertex(x, y)
  }
    
  for(i = -n; i <= n; i++){
  sigma = -PI/2+step
  tau = i/n*3
​
  x = a * sinh(tau)/(cosh(tau)-cos(sigma))
  y = a * sin(sigma)/(cosh(tau)-cos(sigma))
  vertex(x, y)
  }
    
  endShape(CLOSE)
  }
  
  time += 0.02
}
​
​
function sinh(x){
  return((exp(x)-exp(-x))/2)
}
​
function cosh(x){
  return((exp(x)+exp(-x))/2)
}
​
//save JPG
let lapse = 0;    // mouse timer
function mousePressed(){
  // prevents mouse press from registering twice
  if (millis() - lapse > 400){
    save("img_" + month() + '-' + day() + '_' + hour() + '-' + minute() + '-' + second() + ".jpg");
    lapse = millis();
  }
}