Refreshing Window

I’m pretty new to VC++, MFC & also OpenGL. I’m working on a ray tracing project using VC++, with MFC & OpenGL. I realised that OpenGL will refresh the WHOLE window when there is any changes done on the graphics. May I know if there is anyway to refresh only the changed area??
Please guide. Thanks.


If you draw to the frontbuffer and don’t call glClear( GL_COLOR_BUFFER_BIT ) and don’t swap the buffers, the image won’t be cleared nor invalid.

[This message has been edited by Michael Steinberg (edited 02-25-2001).]