Project 07: Composition with Curves

// Jiyeon Chun
// Section C
// jiyeonch@andrew.cmu.edu 
// Project-07-Project

var nPoints = 100;

function setup() {
    createCanvas(400, 400);
    background(242, 140, 86);
    frameRate(20);
}

function draw() {
    push(); 
    //make origin the center of canvas
    translate(width/2, height/2);
    drawEpicycloidCurve();
    pop();

}

function drawEpicycloidCurve() {
    //Epicycloid:
    //https://mathworld.wolfram.com/Epicycloid.html
    var x;
    var y;

    var a = mouseX / 5;
    var b = a / int(mouseY / 25);

    stroke(255);
    strokeWeight(.5);
    noFill();
    beginShape();
    for (var i=0; i<nPoints; i++) {
        var t = map(i, 0, nPoints, 0, TWO_PI);

        x = (a+b)*cos(t)-b*cos(((a+b)/b)*t);
        y = (a+b)*sin(t)-b*sin(((a+b)/b)*t);
        vertex(x,y);
    }
    endShape(CLOSE);

}

function mousePressed() { //press mouse to clear canvas and restart
    background(242, 140, 86);
}