/*
 *  Simple "graphing calculator" to sketch the parametric curve:
 *    x = t * cos(t)
 *    y = t * sin(t)
 *  albeit, recentered in the middle of the canvas
 */

float theta = 0.0;

void setup() {
  size(600, 400);
  noFill();
}

void draw() {
  background(255);
  beginShape();
  for (float t=0; t < width; t += 0.01) {
    float x = 0.5*width + t * cos(t+theta);
    float y = 0.5*height + t * sin(t+theta);
    vertex(x, y);
  }
  theta += mouseX * TWO_PI/width;
  endShape();
}