enwandu-Project-07-Curves

curves

// Emmanuel Nwandu
// enwandu@andrew.cmu.edu
// Section D
// Project-07-Curves

function setup() {
    createCanvas(400, 400);
}

function draw() {
  background(0);
  translate(width/2, height/2);  // Center drawing on canvas
  drawEpitrochoid(); // Calls the function drawEpitrochoid
}

// Creates the geometry of the Epitrochoid curve
function drawEpitrochoid() {
    noFill();
    stroke(200, 0, 0);

    var points = 750;
    var x;
    var y;
    var h = constrain(mouseX, 0, 250)
    var a = 375;
    var b = a/constrain(mouseY, 0 , 250) //Constrains the width of geometry created
    // by the curves between the top and bottom edge of the canvas

    beginShape();
        for (var i=0; i < points; i++) {
            var t =map(i, 0, points, 0, TWO_PI);
            // Equation of epitrochoid applied to the x and y variables
            x = (a-b)*cos(t) + h*cos(((a-b)/b)*t)
            y = (a-b)*sin(t) + h*sin(((a-b)/b)*t)
            vertex(x, y);
        }
    endShape();
}

I ended up going for an Epitrochoid curve, but I bounced between that and the logarithmic spiral as an option. I played around with both, but ended up going for the Epitrochoid curve. I was initially confused about what parameters of the drawing would be controlled by what variables, but I played around with it for a while until I understood how my manipulation of the code influenced my drawing. I would suggest moving slowly across the canvas, in both x and y directions to see the full breadth of geometry generated by the code.

Source: http://mathworld.wolfram.com/Epitrochoid.html