A graphics pipeline allows us to draw anything on screen. It controls the parameters of all programmable and fixed stages of the pipeline realized by the graphics hardware. A simplified diagram of a graphics pipeline is presented in the following image. White blocks represent programmable stages, gray ones are the fixed parts of the pipeline:

Programmable stages consist of vertex, tessellation control and evaluation, and geometry and fragment shaders, of which only the vertex stage is obligatory. The rest are optional and enabling them depends on the parameters specified during the pipeline creation. As an example, if rasterization ...