seg4.pde

int step = 0;
int segmentCount = 70;
int startStep = 0;//offset the start position, not necessary but more interesting while drawing.
float pointDiameter = 0.25;
float plotRadius = 5;
float radiusIncrement = 6;
 
void setup(){
  size(500, 500);
  background(255);
  noStroke();
}
 
void draw(){
  step++;
   
  float theta = (step + startStep) * TWO_PI / segmentCount;
  float x = width/2 + cos(theta) * plotRadius;
  float y = height/2 + sin(theta) * plotRadius;
     
  float colorComponentA = map(x, 0, width, 100, 255);
  float colorComponentB = map(y, 0, width, 200, 255);
  fill(colorComponentA, (colorComponentA + colorComponentB)/2, colorComponentB);
   
  ellipse(x, y, pointDiameter, pointDiameter);
    
  if(step == segmentCount){
    step = 0;
    startStep++;
     
    plotRadius += radiusIncrement;
    segmentCount += 2;
     
    //Control how the the plot points grow:
    if(pointDiameter < 6 && plotRadius > 25){
      pointDiameter+=0.25;
    } 
  }
   
  if(plotRadius >= width/2 - width/10){
    noLoop();
    println("fin");
  }
}