Tk_GetPixels(3) Tk Library Procedures Tk_GetPixels(3)_________________________________________________________________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.
_________________________________________________________________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
Tk 1
Tk_GetPixels(3) Tk Library Procedures Tk_GetPixels(3)
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->result.
KEYWORDS
centimeters, convert, inches, millimeters, pixels, points,
screen units
Tk 2
