API Hooking

http://zfx.info/viewtopic.php?f=4&t=2625

http://www.ownedcore.com/forums/world-of-warcraft/world-of-warcraft-bots-programs/wow-memory-editing/299810-c-tutorial-how-become-endscene-hooker.html
http://spazzarama.com/2010/03/29/screen-capture-with-direct3d-api-hooks/
http://spazzarama.com/2011/03/14/c-screen-capture-and-overlays-for-direct3d-9-10-and-11-using-api-hooks/