% @(#)createdisp.hlq	19.2 (ESO-IPG) 05/22/03 11:18:13 
%++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
%.COPYRIGHT  (c)  1990 European Southern Observatory
%.IDENT      createdisp.hlq
%.AUTHOR     KB, IPG/ESO
%.KEYWORDS   MIDAS, help files, CREATE/DISPLAY
%.PURPOSE    On-line help file for the command: CREATE/DISPLAY
%.VERSION    1.0  30-OCT-1990 : Creation, KB
%----------------------------------------------------------------
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SECTION./DISP
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CREATE/DISPLAY			        	22-MAY-2003  KB
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CREATE/DISPLAY [dspid] [dspinfo] [meminfo] [specs] [gsize] [Xstation]
	create a display window
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Purpose: 
          Create a display window (using XWindow).
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Subject:
          Image Display
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Syntax: 
          CREATE/DISPLAY [dspid] [dspinfo] [meminfo] [specs] [gsize]
                         [Xstation]
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          dspid = single digit display identification number in [0,9] for
              a "main" display window, or single character in [a,z] for a
              shadow display window; defaulted to 0
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          dspinfo = xdim,ydim,xoff,yoff for main display window,
\\
              size in x,y, offset in x,y (lower left corner is 0,0);
              or `shadow,refid' for a "shadow" window, where `refid' is the 
              id of the display window to be shadowed;
              defaulted to 512,512,630,330  (i.e. assuming a "main" window)
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          meminfo = nomem,xm,ym;
              no. of image memories (channels), defaulted to 2 for dsp_id 0,
              to 1 for all others, (max no. of channels = 12);
              memory size in x, y - defaulted to size of display window;
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          specs = alpha_flag,backcolr_no
              alph_flag = Y(es) or N(o), for using an alpha_memory or not,
              backcolr_no = no. of color for background pixel, as used in
                          the DRAW/... commands (cf. Note: below);
              defaulted to Y,1 (1 = black)
\ap\pa
          gsize = no. of graphic line segments saved;
              this parameter is important for the refreshing of the window,
              because only as many line segments can be redrawn as are
              saved internally;
              default is 30000 for dsp_id 0, 10000 for all others
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          Xstation = name of Xworkstation/Xterminal screen (in X11 syntax)
              on which the display window should be created,
              ojo: the `Xstation' and the local display have to be in the
              same visual mode, i.e. either both are set up for TrueColor
              or both are set up for PseudoColor mode!
              defaulted to `default' which indicates the local screen
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See also:
          DELETE/DISPLAY, RESET/DISPLAY, INITIALIZE/DISPLAY, CREATE/GRAPHICS
          ASSIGN/DISPLAY, COPY/DISPLAY, MODIFY/DISPLAY, DRAW/RECT (for colors)
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Note:  
             Shadow displays "shadow" (repeat) all operations on the referenced
          "main" display window. They are useful for showing the contents of
          your display window elsewhere in the network. There may be more
          than one shadow display window for a given reference window.
           displays take all input parameters from the referenced
          "main" display window, except `Xstation'. Consequently, the
          parameters `meminfo', `alph_flag' and `gsize' are not used.
          The display size is taken from the reference display, but the offset 
          of the shadow display can be specified via `shadow,refid,offx,offy'
          instead of `shadow,refid'.
             An overlay/graphics memory is always available and will have
          the highest channel no.
          The parameter 'gsize' has no influence on the drawing of lines,
          it's only important for the refreshing of the window.
          When creating a display window, this display becomes the `active'
          display which all display related commands will act on.
             To navigate among different displays use the command 
          ASSIGN/DISPLAY which will change the currently `active' display.
          You have to have access rights and somebody must be logged in if
          you want to use a different Xstation than the one you're sitting at.
          Keyword DAZDEVR(10) will hold the display id (if "main" display).
	     The no.s for background colour are:
	  (2) - white, (3) - red, (4) - green, (5) - blue,
	  (6) - yellow, (7) - magenta, (8) - cyan, everything else -> black
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Examples:
\ex
          CREATE/DISP 3 400,200,120,320 2 
            Create a display (id = 3) of size 400*200 pixels with
            two image memories, which will be referred to later on as
            channel 0 and 1, the overlay channel will be channel 2.
            Also use alphanumerics window and default fonts.
\xe\ex
          CREATE/DISPLAY P5=75000
            Create a display (id = 0) of size 512*512 pixels with
            two image memories, which will be referred to later on as
            channel 0 and 1, the overlay channel will be channel 2.
            Also use alphanumerics window and default fonts.
\\
            We plan to use the overlay channel of the display as a plot device
            later on, so we reserve space for 75000 line segments to be saved.
\xe\ex
          CREATE/DISPLAY 1 400,400,0,0 ? yes,2
            Create display window with a white background.
\xe\ex
          CREATE/DISPLAY p6=ws4:0.0
            Create display window on Xstation which has the name `ws4'.
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          CREATE/DISPLAY a shadow,0 p6=xt65:0.0
            Create shadow display window of display with id 0 on X11-terminal
            with name `xt65'.
            All operations on display window 0 like e.g. image loading, cursor
            movements, etc. are repeated on the shadow display.
\xe\sxe
