Translating between cartesian and screen coordinates

Question

For my game I need functions to translate between two coordinate systems. Well it\'s mainly math question but what I need is the C++ code to do it and a bit of explanation h

Answer 1

You need to know the width and height of the screen.

Then you can do:

cartX =   screenX - (width / 2);
cartY = -(screenY - (height / 2));

And:

screenX =  cartX + (width / 2);
screenY = -cartY + (height / 2);