private void input() {
        if (Keyboard.isKeyDown(Keyboard.KEY_W) || Keyboard.isKeyDown(Keyboard.KEY_UP)) {
            platform.setDY(-SPEED);
        }
        else if (Keyboard.isKeyDown(Keyboard.KEY_S) || Keyboard.isKeyDown(Keyboard.KEY_DOWN)) {
            platform.setDY(SPEED);
        }
        else if (Keyboard.isKeyDown(Keyboard.KEY_A) || Keyboard.isKeyDown(Keyboard.KEY_LEFT)) {
            platform.setDX(-SPEED);
        }
        else if (Keyboard.isKeyDown(Keyboard.KEY_D) || Keyboard.isKeyDown(Keyboard.KEY_RIGHT)) {
            platform.setDX(SPEED);
        }
    }