| _circ | Circle primitive structure: |
| _Coord | Primitive vertex coordinate structure |
| _prm | Primitive data structure: The primitives are stored in memory in a circular doubly-linked list, with a pointer to the head of the list |
| _quad | Quadrilateral primitive structure: |
| Edge | Polygon edge |
| NscPnt | 3D point in normalized screen coordinates |
| Pixel | Pixel point |
| pnt3d | Definition of a 3D point and vector |
| Vector | 3D vector |
1.2.18