public void MoveSnake()
{
// Remove the last part of the snake, in preparation of the new part added below
while (snakeParts.Count >= snakeLength)
{
mw.GameArea.Children.Remove(snakeParts[0].UiElement);
snakeParts.RemoveAt(0);
}
// Next up, we'll add a new element to the snake, which will be the (new) head
// Therefore, we mark all existing parts as non-head (body) elements and then
// we make sure that they use the body brush
foreach (SnakePart snakePart in snakeParts)
{
(snakePart.UiElement as Rectangle).Fill = snakeBodyBrush;
snakePart.IsHead = false;
}
// Determine in which direction to expand the snake, based on the current direction
SnakePart snakeHead = snakeParts[snakeParts.Count - 1];
double nextX = snakeHead.Position.X;
double nextY = snakeHead.Position.Y;
switch (snakeDirection)
{
case MainWindow.SnakeDirection.Left:
nextX -= vm.SnakeSquareSize;
break;
case MainWindow.SnakeDirection.Right:
nextX += vm.SnakeSquareSize;
break;
case MainWindow.SnakeDirection.Up:
nextY -= vm.SnakeSquareSize;
break;
case MainWindow.SnakeDirection.Down:
nextY += vm.SnakeSquareSize;
break;
}
// Now add the new head part to our list of snake parts...
snakeParts.Add(new SnakePart(mw, vm)
{
Position = new Point(nextX, nextY),
IsHead = true
});
//... and then have it drawn!
DrawSnake();
DoCollisionCheck();
}
private void DoCollisionCheck()
{
SnakePart snakeHead = snakeParts[snakeParts.Count - 1];
if ((snakeHead.Position.X == Canvas.GetLeft(snakeFood)) && (snakeHead.Position.Y == Canvas.GetTop(snakeFood)))
{
EatSnakeFood();
return;
}
if ((snakeHead.Position.Y < 0) || (snakeHead.Position.Y >= mw.GameArea.ActualHeight) ||
(snakeHead.Position.X < 0) || (snakeHead.Position.X >= mw.GameArea.ActualWidth))
{
EndGame();
}
foreach (SnakePart snakeBodyPart in snakeParts.Take(snakeParts.Count - 1))
{
if ((snakeHead.Position.X == snakeBodyPart.Position.X) && (snakeHead.Position.Y == snakeBodyPart.Position.Y))
{
EndGame();
}
}
}
public MainViewModel(MainWindow mainWindow)
{
mw = mainWindow;
snakePart = new SnakePart(mw, this);
}