The remaining OpenGL commands are those that may be put into display lists. Multiple occurrences of these commands are grouped together into a single X extension request ( GLXRender). This is diagrammed in Figure 2.
The grouping minimizes dispatching within the X server. The library packs as many OpenGL commands as possible into a single X request (without exceeding the maximum size limit). No OpenGL command may be split across multiple GLXRender requests.
For long OpenGL commands (those longer than a maximum X request size), a series of GLXRenderLarge commands are issued. The structure of the OpenGL command within GLXRenderLarge is the same as for GLXRender.
Note that it is legal to have a glBegin in one request, followed by glVertex commands, and eventually the matching glEnd in a subsequent request. A command is not the same as a OpenGL primitive.