CGPIXMAP

CGPIXMAP
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
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.

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.
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 (' + Greek('mu') + 'm)', $
ALTPS_KEYWORDS={THICK:4.0, XTITLE:'Distance (' + Greek('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

History

Change History::
Written, 7 February 2012, based on cgWindow, by David W. Fanning.