# coyote: CGPIXMAP

- coyote/Graphics
- [Source code]

Description

      Creates an invisible graphics window for IDL traditional commands (Plot, Contour,
      Surface, etc. or for Coyote Graphics routines, cgPlot, cgContour, cgSurf, etc.).
      In addition, the window contents can be saved as PostScript files or as raster image
      files. If ImageMagick is installed on your machine, the raster image files can be
      created in very high quality from PostScript files. This window is identical to
      cgWindow, except that it doesn't appear on the display unless you want it to.
      The program is designed to work with any IDL traditional graphics routine
      that is a procedure and includes no more than three positional parameters.
      Any number of keywords can be used to specify properties of the graphical
      output. Any number of graphics commands can be "added" the the cgWindow.
      Simply use the `AddCmd` keyword to add commands.
      If your program does not load its own color tables, the color tables in
      effect when cgWindow is first called are used to display the graphics
      commands.
      To create PostScript output from within cgWindow, your graphics program
      has to be written in such a way that it can work properly in the PostScript
      device. This means there are no Window commands, WSet commands, and the like
      that are not allowed in the PostScript device. Such commands are allowed in
      programs, of course, if they are "protected". Usually such protection looks
      like this::
         IF (!D.Flags AND 256) NE 0 THEN Window, ...
      The Coyote Graphics program `cgDisplay` is a good program for opening graphics
      "windows", because such PostScript protection is built into the program. In a PostScript
      device, cgDisplay produces a "window" with the same aspect ratio as the current
      display graphics window, which is an aid in producing PostScript output that
      looks like the same output in the display window.
      Much better looking raster files can be created from the cgWindow contents,
      if the raster files are created by converting PostScript files to the raster
      file. If the ImageMagick "convert" command can be found on your machine, you
      will have the option to create raster files using this method. I *highly*
      recommend doing so, as fonts and other plot annotation will be of much higher
      quality using this method.
      cgWindow has been designed to work with other Coyote Graphics routines: `cgPlot`,
      `cgContour`, `cgSurf`, and so on, although I expect it to work with any IDL
      traditional graphics routine, if the routine is well written.
      Default properties of the object can be controled with cgWindow_SetDefs and cgControl,
      as with cgWindow. Be sure to delete the pixmap object when you are done with it, by
      using (for example) cgDelete.

Categories

      Graphics

Author

      FANNING SOFTWARE CONSULTING::
         David W. Fanning
         1645 Sheely Drive
         Fort Collins, CO 80526 USA
         Phone: 970-221-0438
         E-mail: david@idlcoyote.com
         Coyote's Guide to IDL Programming: http://www.idlcoyote.com

Params

      command: in, required, type=string
         The graphics procedure command to be executed. This parameter
         must be a string and the the command must be a procedure. Examples
         are 'Surface', 'Contour', 'Plot', 'cgPlot', cgContour, etc.
      p1: in, optional, type=any
         The first positional parameter appropriate for the graphics command.
      p2: in, optional, type=any
         The second positional parameter appropriate for the graphics command.
      p3: in, optional, type=any
         The third positional parameter appropriate for the graphics command.
      p4: in, optional, type=any
         The fourth positional parameter appropriate for the graphics command.

Keywords

      addcmd: in, optional, type=boolean, default=0
         Set this keyword to add an additional graphics command to an cgWindow.
         The command is added to the last created cgWindow, unless the WinID
         keyword is used to select another cgWindow. Adding a command causes
         all the commands in the window to be immediately executed. If this is
         not behavior you desire, use the LOADCMD keyword instead. If CMDINDEX
         is used to select a command index, the new command is added before
         the command currently occuping that index in the command list.
      altps_Keywords: in, optional, type=string
         A structure containing alternative keyword names (as tags) and values for
         those keywords to be used when the current device is the PostScript device.
         See http://www.idlcoyote.com/cg_tips/kwexpressions.php and the examples
         below for details on how to use this keyword.
      altps_Params: in, optional, type=IntArr(3)
         A structure containing alternative parameter values to be used when
         the current device is the PostScript device. Structure names are restricted
         to the names "P1", "P2", "P3" and "P4" to correspond to the equivalent positional
         parameter. See http://www.idlcoyote.com/cg_tips/kwexpressions.php and the
         examples below for details on how to use this keyword.
      cmddelay: in, optional, type=float
         Ignored. Used only for compatibility with cgWindow.
      cmdindex: in, optional, type=integer
         This keyword is used to select which command in an cgWindow to act on
         when the AllCmd, DeleteCmd, LoadCmd and ReplaceCmd keywords are used.
         See the descriptions of these keywords for details on what happens when
         CmdIndex is missing.
      deletecmd: in, optional, type=boolean, default=0
         Set this keyword to delete a graphics command from an cgWindow.
         If CmdIndex is undefined the last command entered into the window is
         deleted. It is not possible to delete the last command in the window.
         Use WinID to identify the cgWindow you are interested in. If WinID
         is undefined, the last cgWindow created is used.
      executecmd: in, optional, type=boolean, default=0
         Set this keyword to immediate execute all the commands in an cgWindow.
         Normally, this is used after commands have been loaded with LOADCMD.
      group_leader: in, optional
         The identifier of a widget to serve as a group leader for this program.
         If the group leader is destroyed, this program is also destroyed. Used
         when calling this program from another widget program.
      listcmd: in, optional, type=boolean, default=0
         If this keyword is set, the commands currently in the cgWindow are
         listed. Use WinID to identify the cgWindow you are interested in.
         If WinID is undefined, the last cgWindow created is used.
      loadcmd: in, optional, type=boolean, default=0
         Set this keyword to add an additional graphics command to an cgWindow.
         The command is added to the last created cgWindow, unless the WinID
         keyword is used to select another cgWindow. Loaded commands are not
         automatically executed. Set the EXECUTECMD keyword at the end of loading
         to execute the loaded commands. If CMDINDEX is used to select a command
         index, the new command is loaded before the command currently occuping
         that index in the command list.
      method: in, optional, type=boolean, default=0
         Set this keyword if the command is an object method call rather than a
         procedure call. If this keyword is set, the first positional parameter, p1,
         must be present and must be a valid object reference.
      replacecmd: in, optional, type=boolean, default=0
         Set this keyword to replace a graphics command from an cgWindow.
         If CmdIndex is undefined, *all* commands in the window are replaced. Use
         WinID to identify the cgWindow you are interested in. If WinID is
         undefined, the last cgWindow created is used for the replacement.
      waspect: in, optional, type=float, default=normal
         Set this keyword to the aspect ratio you would like the window to have.
         The aspect ratio is calculated as (ysize/xsize). Must be a float value.
         If this keyword is set, the window will maintain this aspect ratio,
         even when it is resized.
      wbackground: in, optional, type=varies, default=!P.Background
         The background color of the window. Specifying a background color
         automatically sets the WErase keyword.
      wdestroyobjects: in, optional, type=boolean, default=0
         If this keyword is set, and any of the input parameters p1-p4 is an object,
         the object parameter will be destroyed when the window is destroyed.
      werase: in, optional, type=boolean, default=0
         Set this keyword to cause the window to be erased before graphics commands
         are drawn. This may need to be set, for example, to display images.
      winid: in, optional, type=integer
         Use this keyword to select the window cgWindow identifier (the number between
         the parentheses in the title bar of cgWindow). The AddCmd, ReplaceCmd, ListCmd,
         and DeleteCmd keywords will all apply to the commands in the last cgWindow
         created unless this keyword is used to select another cgWindow to apply the
         commands to.
      wmulti: in, optional, type=intarr(5)
          Set this keyword in exactly the same way you would set the !P.Multi keyword.
          It will allow you to display multi-plots in the cgWindow graphics window.
      wobject: out, optional, type=object
         cgWindow creates a FSC_CmdWindow object. This object reference is returned
         if this keyword is present.
      woxmargin: in, optional, type=float
         A two-element array indicating the left and right X outside margins for the
         graphical display. Used only when doing multiple plots with `WMulti`.
      woymargin: in, optional, type=float
         A two-element array indicating the bottom and top Y outside margins for the
         graphical display. Used only when doing multiple plots with `WMulti`.
      wxpos: in, optional, type=integer, default=5
         Ignored. Used only for compatibility with cgWindow.
      wypos: in, optional, type=integer, default=5
         Ignored. Used only for compatibility with cgWindow.
      wxsize: in, optional, type=integer, default=640
         The x size in device coordinates of the graphics window.
      wysize: in, optional, type=integer, default=5
         The y size in device coordinates of the the graphics window.
      wtitle: in, optional, type=string, default='Resizeable Graphics Window'
         Ignored. Used only for compatibility with cgWindow.

Examples

      Test code::
         data = cgDemoData(17)
         pixmap = cgPixmap()
         cgPlot, data, COLOR='red', /Window
         cgPlot, data, PSYM=2, /Overplot, COLOR='dodger blue', /AddCmd
         cgPlot, cgDemoData(17), color='olive', linestyle = 2, /Overplot, /AddCmd
         pixmap = cgPixmap(/ListCmd)
         pixmap = cgPixmap('cgPlot', data, COLOR='purple', /ReplaceCMD, CMDINDEX=0)
         pixmap -> Output, 'myplot.png'
      Example using different keyword parameters for the display and PostScript output::
         pixmap = cgPixmap('cgPlot', cgDemoData(1), $
               THICK=1.0, XTITLE='Distance (' + cgGreek('mu') + 'm)', $
               ALTPS_KEYWORDS={THICK:4.0, XTITLE:'Distance (' + cgGreek('mu', /PS) + 'm)'})
      Example using different positional parameters::
         pixmap = cgPixmap('cgText', 0.20, 0.85, /Normal, 'Line of Text', ALIGNMENT=0.0, $
               ALTPS_KEYWORDS={ALIGNMENT:1.0}, ALTPS_PARAMS={P1:0.88})
      Example copying pixmap contents to a normal IDL graphics window::
         Window
         pixmap -> Copy

Copyright

      Copyright (c) 2012, Fanning Software Consulting, Inc.

History

      Change History::
         Written, 7 February 2012, based on cgWindow, by David W. Fanning.
         Added WDESTROYOBJECTS keyword. 11 Nov 2012. DWF.