Image::Base - phpMan

NAME
    Image::Base - base class for loading, manipulating and saving images.

SYNOPSIS
    This class should not be used directly. Known inheritors are Image::Xbm
    and Image::Xpm.

        use Image::Xpm ;

        my $i = Image::Xpm->new( -file => 'test.xpm' ) ;
        $i->line( 1, 1, 3, 7, 'red' ) ;
        $i->ellipse( 3, 3, 6, 7, '#ff00cc' ) ;
        $i->rectangle( 4, 2, 9, 8, 'blue' ) ;

    If you want to create your own algorithms to manipulate images in terms
    of (x,y,colour) then you could extend this class (without changing the
    file), like this:

        # Filename: mylibrary.pl
        package Image::Base ; # Switch to this class to build on it.

        sub mytransform {
            my $self  = shift ;
            my $class = ref( $self ) || $self ;

            # Perform your transformation here; might be drawing a line or filling
            # a rectangle or whatever... getting/setting pixels using $self->xy().
        }

        package main ; # Switch back to the default package.

    Now if you "require" mylibrary.pl after you've "use"d Image::Xpm or any
    other Image::Base inheriting classes then all these classes will inherit
    your "mytransform()" method.

DESCRIPTION
  new_from_image()
        my $bitmap = Image::Xbm->new( -file => 'bitmap.xbm' ) ;
        my $pixmap = $bitmap->new_from_image( 'Image::Xpm', -cpp => 1 ) ;
        $pixmap->save( 'pixmap.xpm' ) ;

    Note that the above will only work if you've installed Image::Xbm and
    Image::Xpm, but will work correctly for any image object that inherits
    from Image::Base and respects its API.

    You can use this method to transform an image to another image of the
    same type but with some different characteristics, e.g.

        my $p = Image::Xpm->new( -file => 'test1.xpm' ) ;
        my $q = $p->new_from_image( ref $p, -cpp => 2, -file => 'test2.xpm' ) ;
        $q->save ;

  line()
        $i->line( $x0, $y0, $x1, $y1, $colour ) ;

    Draw a line from point ($x0,$y0) to point ($x1,$y1) in colour $colour.

  ellipse()
        $i->ellipse( $x0, $y0, $x1, $y1, $colour ) ;

    Draw an oval enclosed by the rectangle whose top left is ($x0,$y0) and
    bottom right is ($x1,$y1) using a line colour of $colour.

  rectangle()
        $i->rectangle( $x0, $y0, $x1, $y1, $colour, $fill ) ;

    Draw a rectangle whose top left is ($x0,$y0) and bottom right is
    ($x1,$y1) using a line colour of $colour. If $fill is true then the
    rectangle will be filled.

  new()
    Virtual - must be overridden.

    Recommend that it at least supports "-file" (filename), "-width" and
    "-height".

  new_from_serialised()
    Not implemented. Recommended for inheritors. Should accept a string
    serialised using serialise() and return an object (reference).

  serialise()
    Not implemented. Recommended for inheritors. Should return a string
    representation (ideally compressed).

  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" get/set colours of the image itself.

  set()
    Virtual - must be overridden.

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

    See "xy" get/set colours of the image itself.

  xy()
    Virtual - must be overridden. Expected to provide the following
    functionality:

        $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.

    When called to set the colour the value returned is class specific; 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
        xy( $x, $y, $colour ) ;   # Return value is class specific

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

  load()
    Virtual - must be overridden. Expected to provide the following
    functionality:

        $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 "-file" attribute.

  save()
    Virtual - must be overridden. Expected to provide the following
    functionality:

        $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 "-file" attribute. The image is saved in xpm
    format.

CHANGES
    2000/05/05

    Added some basic drawing methods. Minor documentation changes.

    2000/05/04

    Created.

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

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

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