gyuha-wa-vect0r_Processing_old/2018/동아리/cannon/paper1/paper1.pde
// Drag (click and hold) your mouse across the
// image to change the value of the rectangle
int value = 0;
void draw() { 
  fill(value); 
  rect(25, 25, 50, 50);
}

void mouseDragged() { 
  value = value + 5;
    if (value > 255) {
      value = 0;  
    }
  }