ocannoli-Intersections

 function setup() {
  createCanvas(400, 400);
}
var boolDoRefresh;
 
function setup() {
  createCanvas(400, 400);
  boolDoRefresh = true;
}
 
class Line {
  constructor(x1, y1, x2, y2){
    this.x1 = x1;
    this.y1 = y1;
    this.x2 = x2;
    this.y2 = y2;
 }
	drawLine(){
    line(this.x1,this.y1,this.x2,this.y2);
  }  	
}
 
function draw() {
  if (boolDoRefresh) {
    background(51);
    stroke(220);
    allLines=[];
    intersectionCircles=[];
    for (var k = 0; k < 12; k++) {
      var a = random(400);
      var b = random(400);
      var c = random(400);
      var d = random(400);
      var nLine= new Line(a,b,c,d);
      allLines.push(nLine);
      allLines[k].drawLine();
    }
    for(var i=0; i<allLines.length-1; i++){
      for(var j=1; j<allLines.length-2;j++){
      if(allLines[i]!=allLines[j])
      {
        var intersect= intersects(allLines[i].x1,allLines[i].y1,allLines[i].x2,allLines[i].y2,allLines[j].x1,allLines[j].y1,allLines[j].x2,allLines[j].y2);
      	if (intersect!==false){
          stroke(240,220,40); 
          fill(240,220,40);
          ellipse(intersect.x,intersect.y,10,10);
        }
           }
      }
    }
  }
  boolDoRefresh = false
}
//formula from Paul Bourke
function intersects(x1, y1, x2, y2, x3, y3, x4, y4) {
  if ((x1 === x2 && y1 === y2) || (x3 === x4 && y3 === y4)) {
		return false;
  }
  denominator = ((y4 - y3) * (x2 - x1) - (x4 - x3) * (y2 - y1));
	if (denominator === 0) {
		return false;
	}
  let ua = ((x4 - x3) * (y1 - y3) - (y4 - y3) * (x1 - x3)) / denominator;
	let ub = ((x2 - x1) * (y1 - y3) - (y2 - y1) * (x1 - x3)) / denominator;
  if (ua < 0 || ua > 1 || ub < 0 || ub > 1) {
		return false
	}
  let x = x1 + ua * (x2 - x1)
	let y = y1 + ua * (y2 - y1)
 
	return {x, y}
}
 
function mousePressed() {
  boolDoRefresh = true;
}