ray casting

would you help me giving the source program of
ray casting? Email to me! thank you

Try a google for ‘ray casting’ or ‘ray tracing’, and follow the links. There’s a ton of documentation/source out there.

Which ray casting do you really want?
ray casting = ray tracing (common misnomer)
ray casting = volume rendering
ray casting = 2.5d engine (Doom/Doom2)