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.IX Title "Graph::colour 3"
.TH Graph::colour 3 2024-07-13 "perl v5.38.2" "User Contributed Perl Documentation"
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.SH NAME
GD::Graph::colour \- Colour manipulation routines for use with GD::Graph
.SH SYNOPSIS
.IX Header "SYNOPSIS"
use GD::Graph::colour qw(:colours :lists :files :convert);
.SH DESCRIPTION
.IX Header "DESCRIPTION"
The \fBGD::Graph::colour\fR 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.
.SH FUNCTIONS
.IX Header "FUNCTIONS"
.SS "colour_list( \fInumber of colours\fP )"
.IX Subsection "colour_list( number of colours )"
Returns a list of \fInumber of colours\fR colour names known to the package.
Exported with the :lists tag.
.SS "sorted_colour_list( \fInumber of colours\fP )"
.IX Subsection "sorted_colour_list( number of colours )"
Returns a list of \fInumber of colours\fR colour names known to the package, 
sorted by luminance or hue.
\&\fBNB.\fR 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.
.SS "_rgb( \fIcolour name\fP )"
.IX Subsection "_rgb( colour name )"
Returns a list of the RGB values of \fIcolour name\fR. 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.
.SS "_hue( \fIR,G,B\fP )"
.IX Subsection "_hue( R,G,B )"
Returns the hue of the colour with the specified RGB values.
Exported with the :colours tag.
.SS "_luminance( \fIR,G,B\fP )"
.IX Subsection "_luminance( R,G,B )"
Returns the luminance of the colour with the specified RGB values.
Exported with the :colours tag.
.ie n .SS "add_colour(colourname => [$r, $g, $b]) or add_colour('#7fe310')"
.el .SS "add_colour(colourname => [$r, \f(CW$g\fP, \f(CW$b\fP]) or add_colour('#7fe310')"
.IX Subsection "add_colour(colourname => [$r, $g, $b]) or add_colour('#7fe310')"
Self-explanatory.
Exported with the :colours tag.
.ie n .SS "rgb2hex($red, $green, $blue)"
.el .SS "rgb2hex($red, \f(CW$green\fP, \f(CW$blue\fP)"
.IX Subsection "rgb2hex($red, $green, $blue)"
.SS hex2rgb('#7fe310')
.IX Subsection "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.
.SS "read_rgb( \fIfile name\fP )"
.IX Subsection "read_rgb( file name )"
Reads in colours from a rgb file as used by the X11 system.
.PP
Doing something like:
.PP
.Vb 2
\&    use GD::Graph::bars;
\&    use GD::Graph::colour;
\&
\&    GD::Graph::colour::read_rgb("rgb.txt") or die "cannot read colours";
.Ve
.PP
Will allow you to use any colours defined in rgb.txt in your graph.
Exported with the :files tag.
.SH "PREDEFINED COLOUR NAMES"
.IX Header "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.
.SH AUTHOR
.IX Header "AUTHOR"
Martien Verbruggen <mgjv@tradingpost.com.au>
.SS Copyright
.IX Subsection "Copyright"
GIFgraph: Copyright (c) 1995\-1999 Martien Verbruggen.
Chart::PNGgraph: Copyright (c) 1999 Steve Bonds.
GD::Graph: Copyright (c) 1999 Martien Verbruggen.
.PP
All rights reserved. This package is free software; you can redistribute
it and/or modify it under the same terms as Perl itself.
.SH "SEE ALSO"
.IX Header "SEE ALSO"
GD::Graph, 
GD::Graph::FAQ