You can draw three types of triangles in OpenGL: separate triangles, triangle strips, and triangle fans.
OpenGL has no equivalent for the IRIS GL swaptmesh function. You can achieve the same effect using a combination of triangles, triangle strips, and triangle fans.
The following table lists the IRIS GL functions for drawing triangles and their equivalent OpenGL functions.
| IRIS GL Function | Equivalent glBegin Parameter | Meaning |
|---|---|---|
| — | GL_TRIANGLES | Triples of vertices interpreted as triangles. |
| bgntmesh endtmesh |
GL_TRIANGLE_STRIP | Linked strips of triangles. |
| — | GL_TRIANGLE_FAN | Linked fans of triangles. |