kerjos-Intersections

Here’s my Intersections project!

If you can’t see that, maybe you can see this GIF:

Here’s my code!

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function setup() { 
  createCanvas(500, 500);
	noLoop();
	angleMode(DEGREES);
}
 
 
function mouseClicked() {
	data = generateRandomLines();
	linesArray = data[0];
	intersectionPoints = calcIntersections(linesArray);
	draw(linesArray,intersectionPoints);
}
 
//Math Functions
 
function generateRandomLines() {
	numLines = 12;
	length = 200;
	linesArray = [];
	radius = 20;
	for (i=0; i<numLines; i++) {
			linesArray[i] = calcLinePoints(length);
	}
	intersectionPoints = calcIntersections(linesArray);
	return [linesArray, intersectionPoints]
}
 
function calcLinePoints(length) {
	x1 = random(width);
	y1 = random(height);
	theta = random(360);
	x2 = x1 + (length * cos(theta));
	y2 = y1 + (length * sin(theta));
	if ((x2 > width) || (x2 < 0)) {
		x2 = x1 - (length * cos(theta));
	}
	if ((y2 > height) || (y2 < 0)) {
		y2 = y1 - (length * sin(theta));
	}
	return [x1,y1,x2,y2];
}
 
function calcIntersections(linesArray){
//Paul Bourke's April 1989 work, Intersection point of two line segments in 2 dimensions,
//I credit for the math behind the algorithm below:
	numLines = linesArray.length;
	intersectionPoints = [];
	for (i=0; i<(numLines); i++) {
		line1 = linesArray[i];
		x1 = line1[0];
		y1 = line1[1];
		x2 = line1[2];
		y2 = line1[3];
		for (j=0; j<i; j++) {
			line2 = linesArray[j];
			//if (line2 == line1) { continue }
			x3 = line2[0];
			y3 = line2[1];
			x4 = line2[2];
			y4 = line2[3];
			uANumer = ((x4 - x3)*(y1 - y3)) - ((y4 - y3)*(x1 - x3));
			uBNumer = ((x2 - x1)*(y1 - y3)) - ((y2 - y1)*(x1 - x3));
			Denom = ((y4 - y3)*(x2 - x1)) - ((x4 - x3)*(y2 - y1));
			uA = uANumer/Denom;
			uB = uBNumer/Denom;
			if ((uA > 1) || (uA < 0) || (uB > 1) || (uB < 0)) {continue}
			xIntersect = x1 + (uA * (x2-x1));
			yIntersect = y1 + (uA * (y2-y1));
			intersectionPoints.push([xIntersect,yIntersect]);
		}
	}
	return intersectionPoints
}
 
//Drawing Functions
 
function draw(linesArray,intersectionPoints) { 
	background(255,224,224);
	drawCircles(intersectionPoints);
	drawLines(linesArray);
}
 
function drawCircles(centersArray) {
	for (i=0; i<centersArray.length; i++) {
			drawCircle(centersArray[i],radius);
	}
}
 
function drawLines(linesArray) {
	numLines = linesArray.length;
	for (i=0; i<numLines; i++) {
			linePoints = linesArray[i];
			drawLine(linePoints);
	}
}
 
function drawLine(linePoints) {
	stroke(0);
	x1 = linePoints[0];
	y1 = linePoints[1];
	x2 = linePoints[2];
	y2 = linePoints[3];
	line(x1,y1,x2,y2);
}
 
function drawCircle(center,radius) {
	noStroke();
	fill(245,105,122);
	cx = center[0];
	cy = center[1];
	ellipse(cx,cy,radius,radius);
}