glutCreateMenu - creates a new pop-up menu.

glutCreateMenu
	glutCreateMenu(func) -> menu

int glutCreateMenu(void (*func)(int value));

func      The  callback  function  for  the  menu  that is
          called when  a  menu  entry  from  the  menu  is
          selected.  The  value  passed to the callback is
          determined by the value for  the  selected  menu
          entry.

glutCreateMenu  creates  a  new  pop-up menu and returns a
unique small integer identifier. The  range  of  allocated
identifiers  starts  at  one. The menu identifier range is
separate from the window identifier range. Implicitly, the
current  menu  is set to the newly created menu. This menu
identifier can be used when calling glutSetMenu.

When the menu callback is called because a menu  entry  is
selected for the menu, the current menu will be implicitly
set to the menu with the selected entry before  the  call-
back is made.

Here is a quick example of how to create a GLUT popup menu
with two submenus and attach it to the right button of the
current window:

  int submenu1, submenu2;

  submenu1 = glutCreateMenu(selectMessage);
  glutAddMenuEntry("abc", 1);
  glutAddMenuEntry("ABC", 2);
  submenu2 = glutCreateMenu(selectColor);
  glutAddMenuEntry("Green", 1);
  glutAddMenuEntry("Red", 2);
  glutAddMenuEntry("White", 3);
  glutCreateMenu(selectFont);
  glutAddMenuEntry("9 by 15", 0);
  glutAddMenuEntry("Times Roman 10", 1);
  glutAddMenuEntry("Times Roman 24", 2);
  glutAddSubMenu("Messages", submenu1);
  glutAddSubMenu("Color", submenu2);
  glutAttachMenu(GLUT_RIGHT_BUTTON);

If  available,  GLUT  for X will take advantage of overlay
planes for implementing pop-up menus. The use  of  overlay
planes  can  eliminate display callbacks when pop-up menus
are deactivated. The SERVER_OVERLAY_VISUALS convention  is

used to determine if overlay visuals are available.

glutCreateWindow,  glutDestroyMenu,  glutSetMenu,  glutAt-
tachMenu

Mark J. Kilgard (mjk@nvidia.com)