HP Workstation zx2000 OpenGL 1.1 Reference for HP-UX 11.x - Page 304

N gluNurbsCallback gluNurbsCallback gluNurbsCallback: define a callback for a NURBS object. C Specification void gluNurbsCallback( GLUnurbs* nurb, GLenum which, GLvoid (*CallBackFunc)() Parameters nurb which CallBackFunc Specifies the NURBS object (created with gluNewNurbsRenderer). Specifies the callback being defined. The only valid value is GLU_ERROR. Specifies the function that the callback calls. Description gluNurbsCallback is used to define a callback to be used by a NURBS object. If the specified callback is already defined, then it is replaced. If CallBackFunc is NULL, then any existing callback is erased. The one legal callback is GLU_ERROR: GLU_ERROR The error function is called when an error is encountered. Its single argument is of type GLenum, and it indicates the specific error that occurred. There are 37 errors unique to NURBS named GLU_NURBS_ERROR1 through GLU_NURBS_ERROR37. Character strings describing these errors can be retrieved with gluErrorString. See Also gluErrorString, gluNewNurbsRenderer 304 Chapter 12