OpenGL Procedure Calls

In order to facilitate maximum performance, the OpenGL library uses a unique procedure calling convention. This convention is currently supported only by the HP C and C compilers which are available in conjunction with the Workstation ACE for HP-UX 10.20 (July 1997) OpenGL developers package.

If you get a large number of "Undefined pragma" messages (for example, Undefined pragma "HP_PLT_CALL" ignored) when compiling an OpenGL application, you are most likely using a compiler that does not support this new calling convention. To get an appropriate HP C or C compiler, you will need to contact your local HP Sales Representative.

You must also include the gl.h header file supplied with HP's implementation of OpenGL in any source code that makes OpenGL calls. If you have unresolved OpenGL symbols (for example, "Unsatisfied symbol glVertex3f") when linking your application, make sure that the correct gl.h file is being included in all your source files. Any gl.h files from other vendors or other sources will not work with HP's implementation of OpenGL.