NAME
        CoerceMode -- calculate viewport mode coercion (v39)

   SYNOPSIS
        ID = CoerceMode(RealViewPort, MonitorID, Flags);
        d0              a0            d0         d1

        ULONG CoerceMode(struct viewport *, ulong, ulong);

   FUNCTION
        To determine the best mode in the MonitorID to coerce RealViewPort to,
        given the restrictions set in Flags.

   INPUTS
        RealViewPort - viewport to coerce
        MonitorID    - Montor number to coerce to (ie a mode masked with
                       MONITOR_ID_MASK).
        Flags        - PRESERVE_COLORS - keep the number of bitplanes
                       in the viewport.
                       AVOID_FLICKER - do not coerce to an interlace mode

   RESULTS
        ID      - ID of the best mode to coerce to, or INVALID_ID if could not
                  coerce (see NOTES).

   NOTES
        This function takes into account the compatibility of the Monitor
        being coerced to, and the viewport that is being coerced.
        Incompatibilities will cause a result of INVALID_ID.

   EXAMPLE
        newmode = CoerceMode(vp, VGA_MONITOR_ID, PRESERVE_COLORS);

   SEE ALSO
        <graphics/coerce.h> <graphics/displayinfo.h>