'\"
'\" Copyright (c) 1994 The Regents of the University of California.
'\" Copyright (c) 1994-1995 Sun Microsystems, Inc.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" @(#) bitmap.n 1.7 95/08/12 17:35:01
'\" 
.so STk-man.macros
.TH bitmap n 3.1 STk "Tk Built-In Commands"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
bitmap \- Images that display two colors
.SH SYNOPSIS
(\fBimage 'create 'bitmap \fR?\fIname\fR? ?\fIoptions\fR?)
.BE

.SH DESCRIPTION
.PP
A bitmap is an image whose pixels can display either of two colors
or be transparent.
A bitmap image is defined by four things:  a background color,
a foreground color, and two bitmaps, called the \fIsource\fR
and the \fImask\fR.
Each of the bitmaps specifies 0/1 values for a rectangular
array of pixels, and the two bitmaps must have the same
dimensions.
For pixels where the mask is zero, the image displays nothing,
producing a transparent effect.
For other pixels, the image displays the foreground color if
the source data is one and the background color if the source
data is zero.

.SH "CREATING BITMAPS"
.PP
Like all images, bitmaps are created using the \fBimage create\fR
procedure.
Bitmaps support the following \fIoptions\fR:
.TP
\fB:background \fIcolor\fR
Specifies a background color for the image in any of the standard
ways accepted by Tk.  If this option is set to an empty string
then the background pixels will be transparent.  This effect
is achieved by using the source bitmap as the mask bitmap, ignoring
any \fB:maskdata\fR or \fB:maskfile\fR options.
.TP
\fB:data \fIstring\fR
Specifies the contents of the source bitmap as a string.
The string must adhere to X11 bitmap format (e.g., as generated
by the \fBbitmap\fR program).
If both the \fB:data\fR and \fB:file\fR options are specified,
the \fB:data\fR option takes precedence.
.TP
\fB:file \fIname\fR
\fIname\fR gives the name of a file whose contents define the
source bitmap.
The file must adhere to X11 bitmap format (e.g., as generated
by the \fBbitmap\fR program).
.TP
\fB:foreground \fIcolor\fR
Specifies a foreground color for the image in any of the standard
ways accepted by Tk.
.TP
\fB:maskdata \fIstring\fR
Specifies the contents of the mask as a string.
The string must adhere to X11 bitmap format (e.g., as generated
by the \fBbitmap\fR program).
If both the \fB:maskdata\fR and \fB:maskfile\fR options are specified,
the \fB:maskdata\fR option takes precedence.
.TP
\fB:maskfile \fIname\fR
\fIname\fR gives the name of a file whose contents define the
mask.
The file must adhere to X11 bitmap format (e.g., as generated
by the \fBbitmap\fR program).

.SH "IMAGE PROCEDURE"
.PP
When a bitmap image is created, Tk also creates a new procedure
whose name is the same as the image.
This procedure may be used to invoke various operations
on the image.
It has the following general form:
.CS
(\fIimageName option \fR?\fIarg arg ...\fR?)
.CE
\fIOption\fR and the \fIarg\fRs
determine the exact behavior of the procedure.  The following
procedures are possible for bitmap images:
.TP
(\fIimageName \fBcget\fR \fIoption\fR)
Returns the current value of the configuration option given
by \fIoption\fR.
\fIOption\fR may have any of the values accepted by the
\fBimage create bitmap\fR procedure.
.TP
(\fIimageName \fBconfigure\fR ?\fIoption\fR? ?\fIvalue option value ...\fR?)
Query or modify the configuration options for the image.
If no \fIoption\fR is specified, returns a list describing all of
the available options for \fIimageName\fR (see \fBTk_ConfigureInfo\fR for
information on the format of this list).  If \fIoption\fR is specified
with no \fIvalue\fR, then the procedure returns a list describing the
one named option (this list will be identical to the corresponding
sublist of the value returned if no \fIoption\fR is specified).  If
one or more \fIoption\-value\fR pairs are specified, then the procedure
modifies the given option(s) to have the given value(s);  in
this case the procedure returns an empty string.
\fIOption\fR may have any of the values accepted by the
\fBimage create bitmap\fR procedure.

.SH SEE ALSO
make-image, image, jpeg, photo, pixmap