int bailout = 8;
float segmentLength = 100;
float theta = PI/3;
float scaleFactor = 0.75;

void setup() {
  size(512, 512);
}

void draw() {
  
  background(255);
  stroke(64);
  translate(width/2, height-64);
  renderSegment(0);
  
  scaleFactor = mouseY/(float)height;
  theta = PI/3 * (mouseX/(float)width);
  
}

void renderSegment(int depth) {
  
  if (depth >= bailout) {
    return;
  }
  
  line(0, 0, 0, -segmentLength);
  
  pushMatrix();
  translate(0, -segmentLength);
  rotate(-theta);
  scale(scaleFactor);
  renderSegment(depth+1);
  popMatrix();
  
  pushMatrix();
  translate(0, -segmentLength);
  rotate(theta);
  scale(scaleFactor);
  renderSegment(depth+1);
  popMatrix();
  
  return;

}