Help with understanding a Javascript program that deals with using trigonometry and transformations

Question

var numPlanets = 4;

var arms = 11;

var speed = 0.015;

var tick = 0;

translate(200,200);

var draw = function() {

background(0, 0, 0);

tick += speed;

for (var s = 10; s < arms * 20; s += 20) {

pushMatrix();

for (var p = 0; p < numPlanets; p++) {

fill(255, 0, 60 * p + 20);

ellipse(0, 0, 30 / p, 30 / p);

translate(sin(tick * p + s) * (8 / (p * 0.1)), cos(tick * p + s) * (8 / (p * 0.1)));

}

popMatrix();

}

};

I learned a bit about push-popMatrix() and transformation methods like translate() and rotate(), but I still can't understand how this program works. How does Line 14 allow the ellipses drawn spin relative to each other and how are the variables and trig methods used to dictate the translation?

Answer 1

the sine and cosine functions are always between -1 and 1...

that is why the behavior repeats