//a radius of outer circle
//b radius of inner circle
float a, b, h; // h distace of point from center of inner circle
float x, y;
float gradient, incr;

void setup(){
  size(800,600);
  background(0,0,100);
  stroke(255);
  noFill();
  strokeWeight(0.11);
  smooth();
  incr = 5;
  gradient = 255./incr;
//  println("gradient = "+gradient);
  frameRate(24);
  a = 10; //radius of outer circle
  b = 10; 
  h = 150;
}

void draw(){
  getMouseData();
}
 

void getMouseData(){
  if((keyPressed == true && key == 65535)||(mousePressed==true)){
    h = mouseX*0.5;
    drawStop();
  } else {
    a = mouseX*0.1;
    b = mouseY*0.2;
    drawFree();
  }
}

void drawFree(){
  background(0,0,100);
  translate(width/2,height/2);
  float p = 0;
  for(int g=255; g>1; g--){
    p = g*incr;
    beginShape();
    stroke(p, g, x, mouseX+100);  // colors need help
    for(int t=g; t<incr+g; t++){
      x = ((a-b)*cos(t))+ h*cos((a-b/b)*t);
      y = ((a-b)*sin(t))+ h*sin((a-b/b)*t);
      curveVertex(x,y);
    }
    endShape();
  }
}

void drawStop(){
  translate(width/2,height/2);
  float p = 0;
  for(int g=255; g>1; g--){
    p = g*incr;
    beginShape();
    stroke(p, g,mouseX-mouseY,x);  // colors need help
    for(int t=g; t<incr+g; t++){
      x = ((a-b)*cos(t))+ h*cos((a-b/b)*t);
      y = ((a-b)*sin(t))+ h*sin((a-b/b)*t);
      curveVertex(x,y);
    }
    endShape();
  }
}