Provided by: libimage-base-bundle-perl_1.0.7-3_all 
NAME
Image::Xbm - Load, create, manipulate and save xbm image files.
SYNOPSIS
use Image::Xbm ;
my $j = Image::Xbm->new( -file, 'balArrow.xbm' ) ;
my $i = Image::Xbm->new( -width => 10, -height => 16 ) ;
my $h = $i->new ; # Copy of $i
my $p = Image::Xbm->new_from_string( "###\n#-#\n###" ) ;
my $q = $p->new_from_string( "H##", "#-#", "###" ) ;
my $s = $q->serialse ; # Compresses a little too.
my $t = Image::Xbm->new_from_serialsed( $s ) ;
$i->xybit( 5, 8, 1 ) ; # Set a bit
print '1' if $i->xybit( 9, 3 ) ; # Get a bit
print $i->xy( 4, 5 ) ; # Will print black or white
$i->vec( 24, 0 ) ; # Set a bit using a vector offset
print '1' if $i->vec( 24 ) ; # Get a bit using a vector offset
print $i->get( -width ) ; # Get and set object and class attributes
$i->set( -height, 15 ) ;
$i->load( 'test.xbm' ) ;
$i->save ;
print "equal\n" if $i->is_equal( $j ) ;
print $j->as_string ;
#####-
###---
###---
#--#--
#---#-
-----#
print $j->as_binstring ;
1111101110001110001001001000100000010000
View an xbm file from the command line:
% perl -MImage::Xbm -e'print Image::Xbm->new(-file,shift)->as_string' file
Create an xbm file from the command line:
% perl -MImage::Xbm -e'Image::Xbm->new_from_string("###\n#-#\n-#-")->save("test.xbm")'
DESCRIPTION
This class module provides basic load, manipulate and save functionality for the xbm file
format. It inherits from "Image::Base" which provides additional manipulation
functionality, e.g. "new_from_image()". See the "Image::Base" pod for information on
adding your own functionality to all the "Image::Base" derived classes.
new()
my $i = Image::Xbm->new( -file => 'test.xbm' ) ;
my $j = Image::Xbm->new( -width => 12, -height => 18 ) ;
my $k = $i->new ;
We can create a new xbm image by reading in a file, or by creating an image from scratch
(all the bits are unset by default), or by copying an image object that we created
earlier.
If we set "-file" then all the other arguments are ignored (since they're taken from the
file). If we don't specify a file, "-width" and "-height" are mandatory.
"-file"
The name of the file to read when creating the image. May contain a full path. This
is also the default name used for "load"ing and "save"ing, though it can be overridden
when you load or save.
"-width"
The width of the image; taken from the file or set when the object is created; read-
only.
"-height"
The height of the image; taken from the file or set when the object is created; read-
only.
"-hotx"
The x-coord of the image's hotspot; taken from the file or set when the object is
created. Set to -1 if there is no hotspot.
"-hoty"
The y-coord of the image's hotspot; taken from the file or set when the object is
created. Set to -1 if there is no hotspot.
"-bits"
The bit vector that stores the image; read-only.
new_from_string()
my $p = Image::Xbm->new_from_string( "###\n#-#\n###" ) ;
my $q = $p->new_from_string( "H##", "#-#", "###" ) ;
my $r = $p->new_from_string( $p->as_string ) ;
Create a new bitmap from a string or from an array or list of strings. If you want to use
different characters you can:
Image::Xbm->set( -setch => 'X', -unsetch => ' ' ) ;
my $s = $p->new_from_string( "XXX", "X X", "XhX" ) ;
You can also specify a hotspot by making one of the characters a 'H' (set bit hotspot) or
'h' (unset bit hotspot) -- you can use different characters by setting "-sethotch" and
"-unsethotch" respectively.
new_from_serialised()
my $i = Image::Xbm->new_from_serialised( $s ) ;
Creates an image from a string created with the "serialse()" method. Since such strings
are a little more compressed than xbm files or Image::Xbm objects they might be useful if
storing a lot of bitmaps, or for transferring bitmaps over comms links.
serialise()
my $s = $i->serialise ;
Creates a string version of the image which can be completed recreated using the
"new_from_serialised" method.
get()
my $width = $i->get( -width ) ;
my( $hotx, $hoty ) = $i->get( -hotx, -hoty ) ;
Get any of the object's attributes. Multiple attributes may be requested in a single call.
See "xy" and "vec" to get/set bits of the image itself.
set()
$i->set( -hotx => 120, -hoty => 32 ) ;
Set any of the object's attributes. Multiple attributes may be set in a single call.
Except for "-setch" and "-unsetch" all attributes are object attributes; some attributes
are read-only.
See "xy" and "vec" to get/set bits of the image itself.
class attributes
Image::Xbm->set( -setch => 'X' ) ;
$i->set( -setch => '@', -unsetch => '*' ) ;
"-setch"
The character to print set bits as when using "as_string", default is '#'. This is a
class attribute accessible from the class or an object via "get" and "set".
"-unsetch"
The character to print set bits as when using "as_string", default is '-'. This is a
class attribute accessible from the class or an object via "get" and "set".
"-sethotch"
The character to print set bits as when using "as_string", default is 'H'. This is a
class attribute accessible from the class or an object via "get" and "set".
"-unsethotch"
The character to print set bits as when using "as_string", default is 'h'. This is a
class attribute accessible from the class or an object via "get" and "set".
xybit()
$i->xy( 4, 11, 1 ) ; # Set the bit at point 4,11
my $v = $i->xy( 9, 17 ) ; # Get the bit at point 9,17
Get/set bits using x, y coordinates; coordinates start at 0.
xy()
$i->xy( 4, 11, 'black' ) ; # Set the bit from a colour at point 4,11
my $v = $i->xy( 9, 17 ) ; # Get the bit as a colour at point 9,17
Get/set bits using colours using x, y coordinates; coordinates start at 0.
If set with a colour of 'black' or a numeric value > 0 or a string not matching /^#0+$/
then the bit will be set, otherwise it will be cleared.
If you get a colour you will always get 'black' or 'white'.
vec()
$i->vec( 43, 0 ) ; # Unset the bit at offset 43
my $v = $i->vec( 87 ) ; # Get the bit at offset 87
Get/set bits using vector offsets; offsets start at 0.
load()
$i->load ;
$i->load( 'test.xbm' ) ;
Load the image whose name is given, or if none is given load the image whose name is in
the "-file" attribute.
save()
$i->save ;
$i->save( 'test.xbm' ) ;
Save the image using the name given, or if none is given save the image using the name in
the "-file" attribute. The image is saved in xbm format, e.g.
#define test_width 6
#define test_height 6
static unsigned char test_bits[] = {
0x1f, 0x07, 0x07, 0x09, 0x11, 0x20 } ;
is_equal()
print "equal\n" if $i->is_equal( $j ) ;
Returns true (1) if the images are equal, false (0) otherwise. Note that hotspots and
filenames are ignored, so we compare width, height and the actual bits only.
as_string()
print $i->as_string ;
Returns the image as a string, e.g.
#####-
###---
###---
#--#--
#---#-
-----#
The characters used may be changed by "set"ting the "-setch" and "-unsetch" characters. If
you give "as_string" a parameter it will print out the hotspot if present using
"-sethotch" or "-unsethotch" as appropriate, e.g.
print $n->as_string( 1 ) ;
H##
#-#
###
as_binstring()
print $i->as_binstring ;
Returns the image as a string of 0's and 1's, e.g.
1111101110001110001001001000100000010000
CHANGES
2000/11/09
Added Jerrad Pierce's patch to allow load() to accept filehandles or strings; will
document in next release.
2000/05/05
Added new_from_serialised() and serialise() methods.
2000/05/04
Made xy() compatible with Image::Base, use xybit() for the earlier functionality.
2000/05/01
Improved speed of vec(), xy() and as_string().
Tried use integer to improve speed but according to Benchmark it made the code slower so I
dropped it; interestingly perl 5.6.0 was around 25% slower than perl 5.004 with and
without use integer.
2000/04/30
Created.
AUTHOR
Mark Summerfield. I can be contacted as <summer@perlpress.com> - please include the word
'xbm' in the subject line.
COPYRIGHT
Copyright (c) Mark Summerfield 2000. All Rights Reserved.
This module may be used/distributed/modified under the LGPL.