Prevent points from overflowing view area if width > height in mouse signals example

[0xekez]

Before changes the mouse input example would overflow the display area if the width was > the height (notice how the top line goes below its bottom axis in the image).

After the changes they get scaled correctly.

[limzykenneth]

I believe the overflow is intentional here and should not be scaled. Please open an issue if you like to discuss this example further. Thanks!