OpenGL Data Processing Process

When commands enter the process, you can use two methods to process them: one is to execute these commands immediately through the process; one way is to organize some of these commands into a "display list" and execute them after a while.

In the "valuer" stage in the process, it provides an effective method to generate approximate values of geometric and Curved Surfaces by assigning input values to polynomial commands. The next "operations on each vertex and the metaset" phase mainly deals with the geometric elements of OpenGL-points, line segments, and polygon. All these elements are described by vertices. Vertices can be converted and illuminated. Next, the elements are cut to the viewport to prepare for the next stage.

Grating generates a series of Frame Buffer addresses and corresponding two-dimensional values used to describe points, line segments, or polygon. These generated "fragments" will be sent to the last stage-"operations on each segment", which is the last operation before data is stored in the "frame buffer" in pixels. These operations include conditional update of the frame buffer based on the original depth value (used for the depth buffer operation) and input value in the frame buffer, it also includes fusion of input pixel colors and stored colors, shielding of pixel values, and other logical operations.

Data is input in the form of pixels rather than vertices. This data can be used to describe an image for texture ing. It will skip the first phase and be processed as pixels through the "pixel operation" phase. The processing of this phase will lead to two results: one is to be stored in the "texture storage" for use in the grating phase, and the other is to be directly raked. Fragments formed by the latter will be stored in the frame buffer, as if they are generated by geometric data.