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