// number of points on the spiral
var N = 240;
var maxRadius = 290;
background(0, 0, 0);
// determines the inital spiral configuration
var angleChange = 90;
var opacity = 400;
var draw = function() {

    //stroke(redValue, greenValue, blueValue);
    
    // coordinates of the current point
    var x = 200;
    var y = 200;

    // coordinates of the previous point
    var lastX = 200;
    var lastY = 200;

    for (var i = 0; i < N; i += 1) {
        opacity -= random(0, 0.001);
        // calculate position of current point
        var theta = angleChange * i;
        var radius = maxRadius * (i / N);
        x = 200 + radius * sin(theta);
        y = 200 + radius * cos(theta);
        
     
        // draw a line from the last point to the current point
        line(lastX, lastY, x, y);
        
        // update the previous point to be the current point
        lastX = x;
        lastY = y;
        var redx = 250 * sin(theta) + 200;
        var greenx = 100 * cos(theta) + 112;
        var bluex = 1 + 150 * sin(theta);
        stroke(redx, greenx, bluex, opacity);
        strokeWeight(2);
    }
    
    // increment angleChange to rotate the spiral
    angleChange += 0.01;
};