[Main]
Name=GrayDBufSetActiveIdx
Type=Function
Subtype=Macro
Header Files=gray.h
Definition=void GrayDBufSetActiveIdx (short idx);
Real Definition=#define GrayDBufSetActiveIdx(i) ((void)(__gray_dbl_offset = ((i) ? 8 : 0)))
See Also=gray.h/GrayDBufSetActiveIdxSync, gray.h/GrayDBufToggle, gray.h/GrayDBufToggleSync, gray.h/GrayDBufGetActiveIdx, gray.h/GrayDBufGetHiddenIdx

[Description]
Sets the currently visible double buffer.

[Explanation]
GrayDBufSetActiveIdx sets the currently visible buffer to the one indexed by
<I>idx</I>, which should be either 0 or 1. Afterwards,
<A HREF="$$LINK(gray.h/GrayDBufGetActiveIdx)">GrayDBufGetActiveIdx</A> will return
<I>idx</I>, and
<A HREF="$$LINK(gray.h/GrayDBufGetHiddenIdx)">GrayDBufGetHiddenIdx</A> will return
the opposite. As the switch may happen during the time a plane is copied to
the screen, it may be desirable to use
<A HREF="$$LINK(gray.h/GrayDBufSetActiveIdxSync)">GrayDBufSetActiveIdxSync</A>
instead.
