                                                                erase_obj 
Chapter 9 Input Modes

erase_obj

    Changes the input mode to erase the raster under user-defined vector
    objects.
     
         erase_obj [otype]

    Changes the input mode to erase the raster under vector objects.  The
    vector objects remain until the map is re-assembled.  Only the raster is
    changed.  When using this mode, a 3 pixel-wide path is erased under the
    vector object chosen.  The program searches within the specified search
    radius (header) when in this mode.  NOTE: The undo command will retrieve
    only the last 32 segments removed with erase_obj.  The recall command will
    retrieve any or all of the raster removed with erase_obj.  The disprstr_get
    command will replace the displayed (and modified) raster with an untouched
    version (since the last save command).
     
    THE DIFFERENCES BETWEEN erase_obj AND erase_seg ARE:

         1)   erase_obj requires assembly while erase_seg does not.
         2)   erase_obj will only erase under a vector object.
         3)   erase_obj will stop erasing a segment or polygon when the
              position of a vector node is reached, even when the node is no
              longer a junction or endpoint on the raster.   erase_seg will
              erase any raster data back to the first raster junction in both
              directions, no matter what.
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    Options/arguments:

         otype     Object type code, where:
                   0 = node
                   1 = segment
                   2 = polygon
         The default is the map_type = string in header)
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    Example(s):

    To erase the segment closest to the position defined by x=450 and y=678,
    enter:
     
         erase_obj 1
         continue 450 678
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    See also:

              del_objects, disprstr_get, erase_seg, header, recall, save, undo
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