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308 13. Programming 3D Graphics in Real Time
Figure 13.2. The OpenGL processing pipeline: geometric 3D data in the form of ver-
tex data and image data in the form of pixels pass through a series of steps until they
appear as the output rendered image in the frame buffer at the end of the pipeline.
each other. It shows that the output from the frame buffers can be fed back
to the host computer’s main memory if desired. There are two key places
where the 3D geometric data and pixel image interact: in the rasterizer they
are mixed together so that you could, for example, play a movie in an inset
area of the window or make a Windows window a ppear ...