Tk_GetPixels(3Tk)Tk_GetPixels(3Tk)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 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.
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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
centimeters, convert, inches, millimeters, pixels, points, screen units
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