Tk_GetPixels(3Tk)					     Tk_GetPixels(3Tk)

NAME    [Toc]    [Back]

     Tk_GetPixels, Tk_GetScreenMM - translate between strings and screen units

SYNOPSIS    [Toc]    [Back]

     #include <tk.h>

     int
     Tk_GetPixels(interp, tkwin, string, intPtr)

     int
     Tk_GetScreenMM(interp, tkwin, string, doublePtr)

ARGUMENTS    [Toc]    [Back]

     Tcl_Interp	  *interp    (in)      Interpreter to use for error reporting.

     Tk_Window	  tkwin	     (in)      Window whose screen geometry determines
				       the conversion between absolute units
				       and pixels.

     char	  *string    (in)      String that specifies a distance	on the
				       screen.

     int	  *intPtr    (out)     Pointer to location in which to store
				       converted distance in pixels.

     double	  *doublePtr (out)     Pointer to location in which to store
				       converted distance in millimeters.

DESCRIPTION    [Toc]    [Back]

     These two procedures take as argument a specification of distance on the
     screen (string) and compute the corresponding distance either in integer
     pixels or floating-point millimeters.  In either case, string specifies a
     screen distance as	a floating-point number	followed by one	of the
     following characters that indicates units:

     <none>
	  The number specifies a distance in pixels.

     c	  The number specifies a distance in centimeters on the	screen.

     i	  The number specifies a distance in inches on the screen.

     m	  The number specifies a distance in millimeters on the	screen.

     p	  The number specifies a distance in printer's points (1/72 inch) on
	  the screen.

     Tk_GetPixels converts string to the nearest even number of	pixels and
     stores that value at *intPtr.  Tk_GetScreenMM converts string to
     millimeters and stores the	double-precision floating-point	result at
     *doublePtr.



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Tk_GetPixels(3Tk)					     Tk_GetPixels(3Tk)



     Both procedures return TCL_OK under normal	circumstances.	If an error
     occurs (e.g. string contains a number followed by a character that	isn't
     one of the	ones above) then TCL_ERROR is returned and an error message is
     left in interp->result.

KEYWORDS    [Toc]    [Back]

     centimeters, convert, inches, millimeters,	pixels,	points,	screen units


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