pad_set_erase(A)

PAD_$SET_ERASE                    Domain/OS                     PAD_$SET_ERASE


NAME
     pad_$set_erase - set a pad's erase mode

SYNOPSIS (C)
     #include <apollo/base.h>
     #include <apollo/pad.h>

     void pad_$set_erase(
          stream_$id_t &stream_id,
          short &window_no,
          boolean &erase_mode,
          status_$t *status)

SYNOPSIS (Pascal)
     %include '/sys/ins/base.ins.pas';
     %include '/sys/ins/pad.ins.pas';

     procedure pad_$set_erase(
          in sid: stream_$id_t;
          in window_no: integer;
          in erase_mode: boolean;
          out sts: status_$t );

SYNOPSIS (FORTRAN)
     %include '/sys/ins/base.ins.ftn'
     %include '/sys/ins/pad.ins.ftn'

           integer*4 status,
           integer*2 stream_id, window_no
           logical*1 erase_mode

           call pad_$set_erase(stream_id, window_no, erase_mode, status)

DESCRIPTION
     Pad_$set_erase sets a pad's erase mode, which determines how  other pad_$
     routines redraw a graphics window after it has been partially obscured.

     The default erase mode is to erase all the visible graphics in a
     partially-hidden window as soon as any part of it is exposed, and then to
     redraw the entire window.

     stream_id
          The stream ID of the pad viewed by the window.

     window_no
          Specifies the window to be affected. window_no is an index into the
          window list returned by pad_$inq_windows. A window_no of 1 always
          refers to the first window created on the pad indicated by
          stream_id.

     erase_mode
          A boolean indicating whether the visible graphics in a partially
          obscured window should be erased when the window is exposed.

          If erase_mode is true, all of the visible graphics in the window are
          erased upon exposure of any obscured part of the window; the entire
          window is then refreshed.

          If erase_mode is false, exposing part of a window causes only the
          previously-obscured portion of the window to be redrawn;
          previously-exposed portions of the window remain unchanged. Setting
          a window's erase mode to false can result in a significant
          improvement in graphics refresh performance if the application sup-
          plies an intelligent refresh routine.

     status
          The completion status.

NOTES
     Applications should be careful to reset all windows' erase mode to the
     default setting, true, before exiting.
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