public static PosAndDir GetNewBodyPos(PosAndDir pad)
{
PosAndDir newpad = new PosAndDir();
newpad.Dir = pad.Dir;
const int delta = 18;
switch (pad.Dir)
{
case 0:
newpad.X = pad.X - delta;
newpad.Y = pad.Y;
break;
case 1:
newpad.X = pad.X + delta;
newpad.Y = pad.Y;
break;
case 2:
newpad.Y = pad.Y + delta;
newpad.X = pad.X;
break;
case 3:
newpad.Y = pad.Y - delta;
newpad.X = pad.X;
break;
}
return(newpad);
}
/// <summary>
/// Allows the game to run logic such as updating the world,
/// checking for collisions, gathering input, and playing audio.
/// </summary>
/// <param name="gameTime">Provides a snapshot of timing values.</param>
protected override void Update(GameTime gameTime)
{
KeyboardState keyboardState = Keyboard.GetState();
if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed || Keyboard.GetState().IsKeyDown(Keys.Escape))
{
Exit();
}
GenerateFoodPosition();
PosAndDir oldSnakePosition = snake.snakePosition;
snake.Move();
snake.Turn(keyboardState);
if (snake.snakePosition.X > Window.ClientBounds.Width - snake.snakeTexture.Width - 1 || snake.snakePosition.X < 0 || snake.snakePosition.Y > Window.ClientBounds.Height - snake.snakeTexture.Height - 1 || snake.snakePosition.Y < 0)
{
snake.X = 4;
}
if (Collide())
{
Increase();
snake.snakeBody.Add(PosAndDir.Zero);
if (snake.BodySize > 1)
{
for (int i = snake.BodySize - 1; i > 0; i--)
{
snake.snakeBody[i] = SnakeParam.GetNewBodyPos(snake.snakeBody[i - 1]);
}
}
snake.snakeBody[0] = SnakeParam.GetNewBodyPos(oldSnakePosition);
foodPosition = Vector2.Zero;
}
else
{
if (snake.BodySize > 1)
{
for (int i = snake.BodySize - 1; i > 0; i--)
{
snake.snakeBody[i] = SnakeParam.GetNewBodyPos((snake.snakeBody[i - 1]));
}
}
if (snake.BodySize > 0)
{
snake.snakeBody[0] = SnakeParam.GetNewBodyPos(oldSnakePosition);
}
}
base.Update(gameTime);
}
public SnakeParam()
{
snakeBody = new List <PosAndDir>();
snakePosition = PosAndDir.Zero;
snakeBodyPosition = Vector2.Zero;
}
