So, I decided to start a 2D platform game for Windows using only the ANSI character set but the problem is, I am not sure how to do collision detection. Does anybody know how to do this? I have to be able to check the player's position and velocity in relation to a four-sided polygon (a square). Also, there is gravity also affecting the player (and later to implement: enemies).

Would anybody how to accomplish this, or even point me to right direction as to where I can get some help? I have searched the Internet (what feels like forever) and found nothing basic and relevant.

Additional:
Hah! I think I found a great site, and in C++! (FINALLY! ) [link]