CONVERT

     Given the coordinates of a point in one coordinate system, CONVERT
     returns the corresponding coordinates for the point in another
     coordinate system.  The converted coordinates are returned using the
     "to_x_integer" and "to_y_integer" parameters.

  Syntax

     CONVERT ({DECW_ROOT_WINDOW | SCREEN | window},
              {CHARACTERS | COORDINATES},
              from_x_integer, from_y_integer,
              {DECW_ROOT_WINDOW | SCREEN | window},
              {CHARACTERS | COORDINATES},
              to_x_integer, to_y_integer)

  Parameters

     DECW_ROOT_WINDOW     Specifies the coordinate system being used by the
                          root window of the screen on which DECTPU is
                          running.

     SCREEN               Specifies the coordinate system being used by the
                          DECwindows window associated with DECTPU's
                          top-level widget.

     window               Specifies the coordinate system being used by the
                          DECTPU window.

     CHARACTERS           Specifies a character-cell system for measuring
                          screen distance.  In a character-based system, the
                          point in the top row and the left-most column has
                          the coordinate (1,1).

     COORDINATES          Specifies a DECwindows-style coordinate system in
                          which coordinate units correspond to pixels.  The
                          pixel in the top row and the leftmost column has
                          the coordinates (0,0).

     from_x_integer and from_y_integer   Specify a a point in the coordinate
                                         system and units specified by the
                                         first two parameters.

     to_x_integer and to_y_integer       Receive the two integers specifying
                                         a point in the coordinate system
                                         and units specified by the fifth
                                         and sixth parameter.  The point
                                         specified by these integers
                                         corresponds to the point specified
                                         by the first four parameters.

  Example

     The following procedure converts a point's location from the current
     window's coordinate system (with the origin in the upper left-hand
     corner of the window) to the DECTPU screen's coordinate system (with
     the origin in the upper left-hand corner of the DECTPU screen).  If the
     current window is not the top window, CONVERT changes the value of the
     y-coordinate to reflect the difference in the DECTPU screen's
     coordinate system.

     PROCEDURE user_convert

     LOCAL source_x,
           source_y,
           dest_x,
           dest_y;

     source_x := 1;
     source_y := 1;
     dest_x := 0;
     dest_y := 0;

     CONVERT (CURRENT_WINDOW, COORDINATES, source_x, source_y, SCREEN,
              COORDINATES, dest_x, dest_y);

     ENDPROCEDURE;