NAME

       GD::Graph::colour - Colour manipulation routines for use with GD::Graph

SYNOPSIS

       use GD::Graph::colour qw(:colours :lists :files :convert);

DESCRIPTION

       The GD::Graph::colour package provides a few routines to work with colours. The
       functionality of this package is mainly defined by what is needed, now and historically,
       by the GD::Graph modules.

FUNCTIONS

   colour_list( number of colours )
       Returns a list of number of colours colour names known to the package.  Exported with the
       :lists tag.

   sorted_colour_list( number of colours )
       Returns a list of number of colours colour names known to the package, sorted by luminance
       or hue.  NB. Right now it always sorts by luminance. Will add an option in a later stage
       to decide sorting method at run time.  Exported with the :lists tag.

   _rgb( colour name )
       Returns a list of the RGB values of colour name. if the colour name is a string of the
       form that is acceptable to the hex2rgb sub, then the colour will be added to the list
       dynamically.  Exported with the :colours tag.

   _hue( R,G,B )
       Returns the hue of the colour with the specified RGB values.  Exported with the :colours
       tag.

   _luminance( R,G,B )
       Returns the luminance of the colour with the specified RGB values.  Exported with the
       :colours tag.

   add_colour(colourname => [$r, $g, $b]) or add_colour('#7fe310')
       Self-explanatory.  Exported with the :colours tag.

   rgb2hex($red, $green, $blue)
   hex2rgb('#7fe310')
       These functions translate a list of RGB values into a hexadecimal string, as is commonly
       used in HTML and the Image::Magick API, and vice versa.  Exported with the :convert tag.

   read_rgb( file name )
       Reads in colours from a rgb file as used by the X11 system.

       Doing something like:

           use GD::Graph::bars;
           use GD::Graph::colour;

           GD::Graph::colour::read_rgb("rgb.txt") or die "cannot read colours";

       Will allow you to use any colours defined in rgb.txt in your graph.  Exported with the
       :files tag.

PREDEFINED COLOUR NAMES

       white, lgray, gray, dgray, black, lblue, blue, dblue, gold, lyellow, yellow, dyellow,
       lgreen, green, dgreen, lred, red, dred, lpurple, purple, dpurple, lorange, orange, pink,
       dpink, marine, cyan, lbrown, dbrown.

AUTHOR

       Martien Verbruggen <mgjv@tradingpost.com.au>

   Copyright
       GIFgraph: Copyright (c) 1995-1999 Martien Verbruggen.  Chart::PNGgraph: Copyright (c) 1999
       Steve Bonds.  GD::Graph: Copyright (c) 1999 Martien Verbruggen.

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

SEE ALSO

       GD::Graph, GD::Graph::FAQ