NAME

Graph::Drawing::Surface - 2D graph topology landscape

SYNOPSIS

This module does not need to be invoked explicitly, but rather, is called automatically by the parent.

Please see the Graph::Drawing subclass SYNOPSIS section documentation for usage.

DESCRIPTION

This module is a two dimensional graph topology landscape used by the parent to plot vertices, edges, axes and labels.

PUBLIC METHODS

new %ARGUMENTS

Create and return a new surface object.

image $OBJECT

An existing image object (currently a GD::Image object only), on which to draw the graph, may be provided.

Please see the eg/image program, for an example of this in action.

name $STRING

The file name (without the extension like ".png") to use when saving the image. This attribute is prepended to the format attribute to make the image filename.

This object attribute is not required, and can be set manually with the Graph::Drawing::Surface::write_image method.

format 'png' | 'gif' | ...

The graphic file format to use when saving and is dependent upon the support with which your graphic module (as specified the type attribute) is compiled.

This object attribute is appended (automatically) to the name attribute, as the "file extension", to make the image filename, if the name attribute is provided.

type $MODULE

Specify the graphics module to use. Currently, this is only GD. (Imager is next!)

size $PIXELS

The size of the (square) surface, in pixels.

If this is not set in the object construction, and there is a dataset, half the graph max weight will be used, otherwise zero (no visible image) is set as the default.

grade $PIXELS

The gradation interval.

layout ['circular' | 'rectangular']

The type of graph layout to use. Defaults to 'blank'.

show_grid 0 | 1

Show the grid, or not. Defaults to 0.

grid_labels 0 | 1

Show the grid labels or not. Defaults to 0.

* This functionality is pretty lame, right now. Labels are currently drawn in the middle of the chart, instead of on the outer edges.

show_axes 0 | 1

Show the chart axes. Defaults to 0.

show_arrows 0 | 1

Show edge arrows. Defaults to 1.

vertex_labels 0 | 1

Show vertex labels. Defaults to 1.

size

Return the size attribute.

write_image [$STRING]

Print the (binary) contents of the object's image attribute to a file, who's name, if not provided as an argument, is defined by the concatination of the object's name and format attributes.

PRIVATE METHODS

_debug @STUFF

Print the contents of the argument array with a newline appended.

draw_vertex $VERTEX

draw_edge $VERTEX1, $VERTEX2

draw_arrowhead $HEAD, $TAIL

SEE ALSO

Graph::Drawing

Graph::Drawing::Base

Graph::Drawing::Vertex

TO DO

Uhh...

AUTHOR

Gene Boggs <gene@cpan.org>

COPYRIGHT AND LICENSE

Copyright 2003 by Gene Boggs

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.