=head1 NAME

Image::Xpm - Load, create, manipulate and save xpm image files.

=head1 SYNOPSIS

    use Image::Xpm;

    my $j = Image::Xpm->new(-file, 'Camel.xpm');

    my $i = Image::Xpm->new(-width => 10, -height => 16);

    my $h = $i->new; # Copy of $i

    $i->xy(5, 8, 'red');       # Set a colour (& add to palette if necessary)
    print $i->xy(9, 3);        # Get a colour

    $i->xy(120, 130, '#1256DD');
    $i->xy(120, 130, $i->rgb2colour(66, 0x4D, 31));

    $i->vec(24, '#808080');    # Set a colour using a vector offset
    print $i->vec(24);         # Get a colour using a vector offset

    print $i->get(-width);     # Get and set object attributes
    $i->set(-height, 15);

    $i->load('test.xpm');
    $i->save;

    # Changing just the palette
    $i->add_colours(qw(red green blue #123456 #C0C0C0));
    $i->del_colour('blue');

=head1 DESCRIPTION

This class module provides basic load, manipulate and save functionality for
the xpm file format. It inherits from C<Image::Base> which provides additional
manipulation functionality, e.g. C<new_from_image()>. See the C<Image::Base>
pod for information on adding your own functionality to all the Image::Base
derived classes.

=head2 new()

    my $i = Image::Xpm->new(-file => 'test.xpm');
    my $j = Image::Xpm->new(-width => 12, -height => 18);
    my $k = $i->new;

We can create a new xpm image by reading in a file, or by creating an image
from scratch (all the pixels are white by default), or by copying an image
object that we created earlier.

If we set C<-file> then all the other arguments are ignored (since they're
taken from the file). If we don't specify a file, C<-width> and C<-height> are
mandatory and C<-cpp> will default to 1 unless specified otherwise.

=over

=item C<-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 C<load>ing and C<save>ing, though it
can be overridden when you load or save.

=item C<-width>

The width of the image; taken from the file or set when the object is created;
read-only.

=item C<-height>

The height of the image; taken from the file or set when the object is created;
read-only.

=item C<-cpp>

Characters per pixel. Commonly 1 or 2, default is 1 for images created by the
module; read-only.

See the example for how to change an image's cpp.

=item C<-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.

=item C<-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.

=item C<-ncolours>

The number of unique colours in the palette. The image may not be using all
of them; read-only.

=item C<-cindex>

An hash whose keys are colour names, e.g. '#123456' or 'blue' and whose values
are the palette names, e.g. ' ', '#', etc; read-only. If you want to add more
colours to the image itself simply write pixels with the new colours using
C<xy>; if you want to add more colours to the palette without necessarily
using them in the image use C<add_colours>.

=item C<-palette>

A hash whose keys are the palette names, e.g. ' ', '#', etc. and whose values
are hashes of colour type x colour name pairs, e.g. C<c =E<gt> red>, etc;
read-only. If you want to add more colours to the image itself simply write
pixels with the new colours using C<xy>; if you want to add more colours to
the palette without necessarily using them in the image use C<add_colours>.

=item C<-pixels>

A string of palette names which constitutes the data for the image itself;
read-only.

=item C<-extname>

The name of the extension text if any; commonly XPMEXT; read-only.

=item C<-extlines>

The lines of text of any extensions; read-only.

=item C<-comments>

An array (possibly empty) of comment lines that were in a file that was read
in; they will be written out although we make no guarantee regarding their
placement; read-only.

=back

=head2 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 C<xy> and C<vec> to get/set colours of the image itself.

=head2 set()

    $i->set(-hotx => 120, -hoty => 32);

Set any of the object's attributes. Multiple attributes may be set in a single
call; some attributes are read-only.

See C<xy> and C<vec> to get/set colours of the image itself.

=head2 xy()

    $i->xy(4, 11, '#123454');    # Set the colour at point 4,11
    my $v = $i->xy(9, 17);       # Get the colour at point 9,17

Get/set colours using x, y coordinates; coordinates start at 0. If the colour
does not exist in the palette it will be added automatically.

When called to set the colour the value returned is characters used for that
colour in the palette; when called to get the colour the value returned is the
colour name, e.g. 'blue' or '#f0f0f0', etc, e.g.

    $colour = xy($x, $y);            # e.g. #123456 
    $cc     = xy($x, $y, $colour);   # e.g. !

We don't normally pick up the return value when setting the colour.

=head2 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. The offset of a pixel
is ((y * width * cpp) + (x * cpp)).

The sort of return value depends on whether we are reading (getting) or
writing (setting) the colour - see C<xy> for an explanation.

=head2 rgb2colour() and rgb2color()
    
    $i->rgb2colour(0xff, 0x40, 0x80);    # Returns #ff4080
    Image::Xpm->rgb2colour(10, 20, 30);  # Returns #0a141e

Convenience class or object methods which accept three integers and return a
colour name string.

=head2 load()

    $i->load;
    $i->load('test.xpm');

Load the image whose name is given, or if none is given load the image whose
name is in the C<-file> attribute.

=head2 save()

    $i->save;
    $i->save('test.xpm');

Save the image using the name given, or if none is given save the image using
the name in the C<-file> attribute. The image is saved in xpm format.

=head2 add_colours() and add_colors()

    $i->add_colours(qw(#C0C0DD red blue #123456));

These are for adding colours to the palette; you don't need to use them to set
a pixel's colour - use C<xy> for that.

Add one or more colour names either as hex strings or as literal colour names.
These are always added as type 'c' colours; duplicates are ignored.

NB If you just want to set some pixels in colours that may not be in the
palette, simply do so using C<xy> since new colours are added automatically.

=head2 del_colour() and del_color()

    $i->del_colour('green');

Delete a colour from the palette; returns undef if the colour isn't in the
palette, false (0) if the colour is in the palette but also in the image, or
true (1) if the colour has been deleted (i.e. it was in the palette but not in
use in the image).

=head1 EXAMPLE

=head2 Changing the -cpp of an image:

    my $i = Image::Xpm(-file => 'test1.xpm'); # test1.xpm has cpp == 1
    my $j = $i->new_from_image('Image::xpm', -cpp => 2);
    $j->save('test2.xpm');

    # Could have written 2nd line above as:
    my $j = $i->new_from_image(ref $i, -cpp => 2);

=head1 CHANGES

2000/11/09

Added Jerrad Pierce's patch to allow load() to accept filehandles or strings;
will document in next release.


2000/10/19

Fixed bugs in xy() and vec() reported by Pat Gunn.


2000/05/25

Fixed a bug in the test file; fixed a bug in save() which affected xpm
extensions.


2000/05/04

Fixed bugs in xy(), vec(), save() and load(). 
Improved the test program.


2000/05/03 

Created. 

=head1 AUTHOR

Mark Summerfield. I can be contacted as <summer@perlpress.com> -
please include the word 'xpm' in the subject line.

=head1 COPYRIGHT

Copyright (c) Mark Summerfield 2000. All Rights Reserved.

This module may be used/distributed/modified under the GPL. 

=cut