у меня пара вопросов про opengl) что такое callback pointer в cl, что такое SYSTEM-AREA-POINTER, как они обьявляются?
glutDisplayFunc(void (*func)(void)) is the first and most important event callback function you will see. Whenever GLUT determines the contents of the window need to be redisplayed, the callback function registered by glutDisplayFunc() is executed. Therefore, you should put all the routines you need to redraw the scene in the display callback function.
>> (glut:display-func #'display)
The value #<FUNCTION DISPLAY> is not of type SYSTEM-AREA-POINTER.
[Condition of type TYPE-ERROR]
0: (CL-GLUT:DISPLAY-FUNC #<FUNCTION DISPLAY>)
Locals:
SB-DEBUG::ARG-0 = #<FUNCTION DISPLAY>