PROJECT-07 (curves)

// SEAN CHEN
// 15-104 A

var nPoints = 100;
var tx = []; // keeping track of the x y of each hypotrochoid
var ty = [];
var rot = 0; // rot init
var size = []; // each size
var col = []; // each color

function setup() {
    createCanvas(480, 480);
    background(255);
}

function distance() { // distance from center to mouse
    var d = dist(width/2, height/2, mouseX, mouseY);
    return d;
}

function hypotrochoid(a, col) {
    push();
    fill(col);
    var x, y, a, b, t;
    b = a / int(map(distance(), 0, width/2, 1, a));
    stroke(0);
    rotate(radians(rot));
    beginShape();
    for (var i = 0; i < nPoints; i++) {
        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(random(3)+x, random(3)+y);
    }
    endShape(CLOSE);
    pop();
}

function draw() {
    background(255);
    rect(0, 0, 480, 480);
    push();
    translate(width/2, height/2); // initial hypotrochoid
    hypotrochoid(120, color(245,211,114));
    pop();
    for (var i = 0; i < tx.length; i++) { // added hypotrochoid
        push();
        translate(tx[i], ty[i]);
        hypotrochoid(size[i], col[i]);
        pop();
    }
    rot += 1;
    text("click to add!", 10, 20);
}

function mouseClicked() { // add new hypotrochoid
    tx.push(mouseX); // input new at mouseXY
    ty.push(mouseY);
    size.push(random(50, 200));
    col.push(color(random(255),211,114));
    if (tx.length > 12) { // delete after 12
        tx.shift();
        ty.shift();
        size.shift();
        col.shift();
    }
}