Controlling the snake in a snake game with the mouse

Question

I am trying to implement a snake game in C# using the WPF forms. Well I know to implement the snake game, where the snake is controlled by the keyboard. But how would I do it, if I wanted to control the snake using a mouse rather than a keyboard?

Answer 1

On your gamefield element add a MouseMove event handler, in this handler add:

var pos = Mouse.GetPosition(e.MouseDevice.DirectlyOver);
worm.Target = new Vector(pos.X, pos.Y);

And in an appropriate spot in the worm class (such as an update method, or called from the Target/Position setters):

var delta = new Vector(Target.X - Position.X, Target.Y - Position.Y);
if (Math.Abs(delta.Y) > Math.Abs(delta.X))
{
    if (delta.Y < 0)
        this.Direction = Direction.Up;
    else
        this.Direction = Direction.Down;
}
else
{
    if (delta.X < 0)
        this.Direction = Direction.Left;
    else
        this.Direction = Direction.Right;
}

With this logic it would try to close in the longest orthogonal distance (x or y) first, and then go zigzag to the cursor when the distance is the same in both x and y, other options would be to use a line drawing algorithm to make it go more smoothly towards the cursor.

There is a few other things to consider as well, such as what do we do if the worm reaches the mouse, does it stop, or do we allow it to first pass the cursor and then double back thus hitting itself?