NAME      
        GetScreenDrawInfo -- Get pointer to rendering information. (V36)

   SYNOPSIS
        DrInfo = GetScreenDrawInfo( screen )
        D0                          A0

        struct drawinfo *getscreendrawinfo( struct screen * );

   FUNCTION
        Returns a pointer to a drawinfo structure derived from the
        screen passed.  This data structure is READ ONLY.  The field
        dri_Version identifies which version of struct drawinfo you
        are given a pointer to.

   INPUTS
        screen        - pointer to a valid, open screen.

   RESULT
        DrInfo - pointer to a system-allocated drawinfo structure,
        as defined in intuition/screens.h.

   NOTES
        Some information in the drawinfo structure may in the future
        be calculated the first time this function is called for a
        particular screen.

        You must call freescreendrawinfo() when you are done using the
        returned pointer.

        This function does not prevent a screen from closing.  Apply it
        only to the screens you opened yourself, or apply a protocol
        such as lockpubscreen().

        WARNING: Until further notice, the pointer returned does not
        remain valid after the screen is closed.

        This function and freescreendrawinfo() don't really do much now,
        but they provide an upward compatibility path.  That means that
        if you misuse them today, they probably won't cause a problem,
        although they may someday later.  So, please be very careful
        only to use the drawinfo structure between calls to
        GetScreenDrawInfo() and freescreendrawinfo(), and be sure
        that you don't forget freescreendrawinfo().

   BUGS
        Does not reflect to changes in screen modes, depth, or pens.

   SEE ALSO
        freescreendrawinfo(), lockpubscreen(), intuition/screens.h