/*
  keys:
  UP: more recursion
  DOWN: less recursion
*/

int aMax = 200;
int steps = 9;

void setup(){
  size(700, 700);
}

void draw(){
  background(255);
  stroke(0);
  noFill();
  noLoop();
  rTriangle(width/2, height/2, aMax, 0);
}

void rTriangle(float x, float y, float a, int step){
  if(step >= steps) return;
  float h = sqrt(3)/2*a;
  triangle(x-a/2, y-h/2, x+a/2, y-h/2, x, y+h/2);
  float hNew = sqrt(3)/2*a/2;
  // top
  rTriangle(x, y-h/2-hNew/2, a/2, step+1);
  // left
  rTriangle(x-a/2, y+hNew/2, a/2, step+1);
  // right
  rTriangle(x+a/2, y+hNew/2, a/2, step+1);
}

void keyPressed(){
  if(keyCode == UP) steps++;
  else if(keyCode == DOWN) steps--;
  redraw();
}