Add an ArrayList to another ArrayList

[quark]

@vincentstrebelle

public void draw(){
 world.makeVegetalPassif(20, 20);
 world.render(); 
}

The draw method is executed ~60fps so the first line world.makeVegetalPassif(20, 20); is also executed 60 times a second. So you are adding 1200 Grass2 and 1200 Mushroom a second there will not be suitable positions for all but the findSuitablePosition method allows 100ms per attempt, a maximum of 4 minutes per frame!