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-rw-r--r--doc/GetPixels.371
1 files changed, 53 insertions, 18 deletions
diff --git a/doc/GetPixels.3 b/doc/GetPixels.3
index 6c271a7..3df2985 100644
--- a/doc/GetPixels.3
+++ b/doc/GetPixels.3
@@ -1,24 +1,34 @@
'\"
'\" Copyright (c) 1990 The Regents of the University of California.
-'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
+'\" Copyright (c) 1994-1998 Sun Microsystems, Inc.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\"
-'\" RCS: @(#) $Id: GetPixels.3,v 1.2 1998/09/14 18:22:50 stanton Exp $
+'\" RCS: @(#) $Id: GetPixels.3,v 1.3 1999/04/16 01:51:08 stanton Exp $
'\"
.so man.macros
-.TH Tk_GetPixels 3 "" Tk "Tk Library Procedures"
+.TH Tk_GetPixelsFromObj 3 8.1 Tk "Tk Library Procedures"
.BS
.SH NAME
-Tk_GetPixels, Tk_GetScreenMM \- translate between strings and screen units
+Tk_GetPixelsFromObj, Tk_GetPixels, Tk_GetMMFromObj, Tk_GetScreenMM \- translate between strings and screen units
.SH SYNOPSIS
.nf
\fB#include <tk.h>\fR
.sp
+.VS 8.1
+int
+\fBTk_GetPixelsFromObj(\fIinterp, tkwin, objPtr, intPtr\fB)\fR
+.VE
+.sp
int
\fBTk_GetPixels(\fIinterp, tkwin, string, intPtr\fB)\fR
.sp
+.VS 8.1
+int
+\fBTk_GetMMFromObj(\fIinterp, tkwin, objPtr, doublePtr\fB)\fR
+.VE
+.sp
int
\fBTk_GetScreenMM(\fIinterp, tkwin, string, doublePtr\fB)\fR
.SH ARGUMENTS
@@ -27,9 +37,15 @@ int
Interpreter to use for error reporting.
.AP Tk_Window tkwin in
Window whose screen geometry determines the conversion between absolute
-units and pixels.
+units and pixels.
+.VS 8.1 br
+.AP Tcl_Obj *objPtr in/out
+String value specifies a distance on the screen;
+internal rep will be modified to cache converted distance.
.AP char *string in
-String that specifies a distance on the screen.
+Same as \fIobjPtr\fR except specification of distance is passed as
+a string.
+.VE
.AP int *intPtr out
Pointer to location in which to store converted distance in pixels.
.AP double *doublePtr out
@@ -38,10 +54,16 @@ Pointer to location in which to store converted distance in millimeters.
.SH DESCRIPTION
.PP
-These two procedures take as argument a specification of distance on
-the screen (\fIstring\fR) and compute the corresponding distance
-either in integer pixels or floating-point millimeters.
-In either case, \fIstring\fR specifies a screen distance as a
+These procedures take as argument a specification of distance on
+.VS 8.1
+the screen (\fIobjPtr\fR or \fIstring\fR) and compute the
+.VE
+corresponding distance either in integer pixels or floating-point millimeters.
+In either case,
+.VS 8.1
+\fIobjPtr\fR or \fIstring\fR
+.VE
+specifies a screen distance as a
floating-point number followed by one of the following characters
that indicates units:
.TP
@@ -61,16 +83,29 @@ The number specifies a distance in millimeters on the screen.
The number specifies a distance in printer's points (1/72 inch)
on the screen.
.PP
-\fBTk_GetPixels\fR converts \fIstring\fR to the nearest even
-number of pixels and stores that value at \fI*intPtr\fR.
-\fBTk_GetScreenMM\fR converts \fIstring\fR to millimeters and
-stores the double-precision floating-point result at \fI*doublePtr\fR.
-.PP
-Both procedures return \fBTCL_OK\fR under normal circumstances.
-If an error occurs (e.g. \fIstring\fR contains a number followed
+.VS 8.1
+\fBTk_GetPixelsFromObj\fR converts the value of \fIobjPtr\fR to the
+nearest even number of pixels and stores that value at \fI*intPtr\fR.
+It returns \fBTCL_OK\fR under normal circumstances.
+If an error occurs (e.g. \fIobjPtr\fR contains a number followed
by a character that isn't one of the ones above) then
\fBTCL_ERROR\fR is returned and an error message is left
-in \fIinterp->result\fR.
+in \fIinterp\fR's result if \fIinterp\fR isn't NULL.
+\fBTk_GetPixelsFromObj\fR caches information about the return
+value in \fIobjPtr\fR, which speeds up future calls to
+\fBTk_GetPixelsFromObj\fR with the same \fIobjPtr\fR.
+.PP
+\fBTk_GetPixels\fR is identical to \fBTk_GetPixelsFromObj\fR except
+that the screen distance is specified with a string instead
+of an object. This prevents \fBTk_GetPixels\fR from caching the
+return value, so \fBTk_GetAnchor\fR is less efficient than
+\fBTk_GetPixelsFromObj\fR.
+.PP
+\fBTk_GetMMFromObj\fR and \fBTk_GetScreenMM\fR are similar to
+\fBTk_GetPixelsFromObj\fR and \fBTk_GetPixels\fR (respectively) except
+that they convert the screen distance to millimeters and
+store a double-precision floating-point result at \fI*doublePtr\fR.
+.VE
.SH KEYWORDS
centimeters, convert, inches, millimeters, pixels, points, screen units