Hi guys. I'm trying to render an Image in screen & to rotate it about Z-axis. I'm not allowed to use standard glRotate() from the OpenGL because it is not available in our portable device library.
I want to know how glRotate() works & i want to reflect it in my c program.

I've googled about this topic but I'm not able to grasp the idea of it clearly.So could someone please guide me to rotate image through some other transformations?
I'd be pleased if you suggest any sample codes/Tutorial Links.