Tk_GetPixels(3)

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NAME
       Tk_GetPixels,  Tk_GetScreenMM  - translate between strings
       and screen units

SYNOPSIS
       #include <<tk.h>>

       int
       Tk_GetPixels(interp, tkwin, string, intPtr)

       int
       Tk_GetScreenMM(interp, tkwin, string, doublePtr)

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

       Tk_Window    tkwin      (in)      Window    whose   screen
                                         geometry determines  the
                                         conversion between abso-
                                         lute 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.
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DESCRIPTION
       These  two  procedures take as argument a specification of
       distance on the screen (string)  and  compute  the  corre-
       sponding  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-pre-
       cision floating-point result at *doublePtr.

       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-&gt;result.

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