coyote: CGSET_TTFONT

Description
The purpose of this procedure is to allow the user to set the True-Type font in use
both at the IDL command line and in a PostScript file. Normally, True-Type fonts are
set with the Device command and the Set_Font and TT_Font keywords. However, if such a
command is issued at the IDL command line, it has no effect in the PostScript device.
The cgSet_TTFont command will set the True-Type font for both devices, thereby keeping 
them in sync with each other so that the expected output can be created both on the display 
and in a PostScript file.
Using this procedure also has an effect on Coyote Graphics routines by setting both the
PS_TT_FONT and PS_FONT keywords to cgWindow_SetDefs. This ensures that any Coyote Graphics
routine that creates a PostScript file will use the requested font upon producing PostScript
output. Revert to the default Helvetica font by either using the font name "Helvetica", 
or by simply calling the function without a font name parameter. If the ADDCMD keyword is 
used, the font change will apply ONLY to the current cgWindow (i.e., the PS_TT_FONT and PS_FONT 
keywords will be set for just the current cgWindow).
Categories
Utility
Params
font_name: in, optional, type=string, default="Helvetica"
     The name of a true-type font to use in producing graphical output.
Keywords
addcmd: in, optional, type=boolean, default=0
     Set this keyword to apply this True-Type font ONLY to the current cgWindow via
     the PS_TT_FONT and PS_FONT keywords of cgControl. An error will occur if there
     is no current cgWindow in existance.
Examples
Here is how to use this program to use the Times True-Type font::
    cgSet_TTFont, 'Times'
    cgPlot, cgDemoData(1), Title='This is Times Text', Output='cgplot.png'
or::
    cgSet_TTFont, 'Times'
    cgPS_Open, 'cgplot.ps', Font=1
    cgPlot, cgDemoData(1), Title='This is Times Text'
    cgPS_Close, /PNG
or, to set the font ONLY for the current cgWindow::
    cgPlot, cgDemoData(1), Title='This is Times Text', /Window
    cgSet_TTFont, 'Times', /AddCmd
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
History
Change History::
   Written, 21 May 2013 by David W. Fanning.
Copyright
Copyright (c) 2013, Fanning Software Consulting, Inc.