# coyote: CGERASE

- coyote/Graphics
- [Source code]

Description

      Provides a device-independent and color-model-independent way to erase a graphics
      window with a particular color.

Categories

      Graphics

Params

      background_color: in, optional, type=string/integer/long, default='white'
           The color to use in erasing the graphics window. Default is "white."
           Color names are those used with cgColor.

Keywords

      color: in, optional, type=string/integer/long, default='white'
          An alternative way to specify the color to use in erasing the graphics window.
          Color names are those used with cgColor. This parameter is used in
          preference to the background_color parameter.
      layout: in, optional, type=intarr(3)
          This keyword specifies a grid with a graphics window and determines where the
          graphic should appear. The syntax of LAYOUT is three numbers: [ncolumns, nrows, location].
          The grid is determined by the number of columns (ncolumns) by the number of
          rows (nrows). The location of the graphic is determined by the third number. The
          grid numbering starts in the upper left (1) and goes sequentually by column and then
          by row. If this keyword is used, only this portion of the window is erased.
      window: in, optional, type=boolean, default=0
          Set this keyword to erase the current cgWindow application. "Erasing" in
          this case means removing all the current commands.

Examples

      Used to "erase" various things::
         IDL> cgErase
         IDL> cgErase, 'gray'
         IDL> cgErase, COLOR='charcoal'
         IDL> cgPlot, cgDemoData(1), /Window
         IDL> cgErase, /Window
         IDL> cgPlot, cgDemoData(17), Layout=[2,2,1]
         IDL> cgPlot, cgDemoData(17), Layout=[2,2,4]
         IDL> cgErase, Layout=[2,2,1]

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, 12 November 2010. DWF.
         Modified so that input variables are not changed. 18 Nov 2010. DWF.
         Got my color selection algorithm right. COLOR keyword takes precedence
           over the parameter. 18 Nov 2010. DWF.
         Modified to erase in decomposed color, if possible.
         In some cases, I was turning BYTE values to strings without converting to
             INTEGERS first. 30 Dec 2010. DWF.
         Added WINDOW keyword. 26 Jan 2011. DWF.
         Added LAYOUT keyword. 1 Feb 2011. DWF.
         Modified error handler to restore the entry decomposition state if there is an error. 17 March 2011. DWF

Copyright

      Copyright (c) 2010, Fanning Software Consulting, Inc.