LSystem lsystem;
int iterations = 1;
float step;
void setup(){
  size(400, 400);
  lsystem = new LSystem("F", "F[+F]F[-F]F");
  lsystem.iterate(iterations);
  fitStep();
  smooth();
}
void draw(){
  background(255);
  lsystem.draw(0, height / 2, step, HALF_PI);
}
void fitStep(){
  int pushed = 0;
  int scaling = 0;
  for(int i = 0; i < lsystem.tree.length(); i++){
    switch(lsystem.tree.charAt(i)){
      case 'F':
      if(pushed == 0)
      scaling++;
      break;
      case '[':
      pushed++;
      break;
      case ']':
      pushed--;
      break;
    }
  }
  step = (float)width / scaling;
}
void mousePressed(){
  iterations = constrain(iterations+1, 0, 5);
  lsystem.iterate(iterations);
  fitStep();
}