3-Gear Spirograph

//spirograph

//5/25/15

//draws with three circles and not just two

​

float R = 275;// radius of big circle

float r = 203;//radius of circle 2

float r3 = 151;//radius of circle 3

float theta = 0;

float p = .8;//proportion of little circle

​

void setup(){

  size(600,600);

  background(0);

​

}

​

void draw(){

  //background(0);

  fill(255,0);//transparent

  translate(width/2,height/2); //to center of big circle

  stroke(255,0);

  ellipse(0,0,2*R,2*R); //draw big circle

  rotate(theta); //rotate to angle of circle2

  translate(R - r,0); //go to center of circle2

  ellipse(0,0,2*r,2*r); //draw little circle

  float phi = -R/r*theta;//angle of rotation of circle 2

  rotate(phi); //rotate phi

  fill(255,0);

  translate(r - r3,0); //go to center of circle 3

  float angle3 = -r/r3*phi;//angle of rotation of circle 3

  rotate(angle3);

  line(0,0,p*r3,0);//draw using just this! cool.

  translate(p*r3,0);

  fill(255,0,0);

  ellipse(0,0,2,2);//or point(...

  theta += 0.01;

  }