oracular (3) Graphics::Toolkit::Color::Values.3pm.gz

NAME

       Graphics::Toolkit::Color::Value - single color related high level methods

SYNOPSIS

       Readonly object that holds values of a color. It provides methods to get the values back in different
       formats, to measure difference to other colors or to create value objects of related colors.

           use Graphics::Toolkit::Color::Value;

           my $blue = Graphics::Toolkit::Color::Value->new( 'hsl(220,50,60)' );
           my @rgb = $blue->get();
           my $purple = $blue->set({red => 220});

DESCRIPTION

       The object that holds the normalized values of the original color definition (getter argument) and the
       normalized RGB tripled, if the color was not defined in RGB values. This way we omit conversion and
       rounding errors as much as possible.

       This package is a mediation layer between Graphics::Toolkit::Color::Space::Hub below, where its just
       about number crunching of value vectors and the user API above in Graphics::Toolkit::Color, where it's
       mainly about producing sets of colors and handling the arguments. This module is not meant to be used as
       an public API since it has much less comfort than Graphics::Toolkit::Color.

METHODS

   new
       The constructor takes only one required argument, a scalar that completely and numerically defines a
       color. Inside color definitions are color space names case insensitive. Some possible formats are

           [ 1, 2, 3 ]                  # RGB triplet
           [ HSL => 220, 100, 3 ]       # named HSL vector
           { h => 220, s =>100, l => 3} # char hash
           { cyan => 1, magenta => 0.5, yellow => 0} # hash
           'hwb: 20, 60, 30'            # string
           'hwb(20,60,30)'              # css_string
           '#2211FF'                    # rgb hex string

   get
       Universal getter method -almost reverse function to new: It can return the colors values in all supported
       color spaces (first argument) (see: "COLOR-SPACES" in Graphics::Toolkit::Color::Space::Hub) and all
       mentioned formats above (second argument). Additionally a third arguments can convert the numerical
       values into different ranges.  The default name space is RGB, default format is a list and every color
       space has its default range.

           my @rgb = $val_object->get();
           my @cmyk = $val_object->get('CMYK', 'list', 255);
           my $YIQ = $val_object->get('YIQ', 'string');

   set
       Constructs a new "Graphics::Toolkit::Color::Value" object by absolutely changing some values of the
       current object and keeping others. (add changes some values relatively.) The only and required argument
       is a HASH reference which has keys that match only one of the supported color spaces (see: "COLOR-SPACES"
       in Graphics::Toolkit::Color::Space::Hub).  Values outside of the defined limits will be clamped to an
       acceptable value (or rotated in case of circular dimensions).

           my $more_blend_color = $val_object->set( {saturation => 40} );
           my $bright_color = $val_object->set( {saturation => 2240} ); #saturation will be 100

   add
       This method takes also a HASH reference as input and also produces a related color object as previous
       set. Only difference is: the hash values will be added to the current. If they go outside of the defined
       limits, they will be clamped (or rotated in case of circular dimensions).

           my $darker_color = $val_object->set( {lightness => -10} );

   blend
       Creates a color value object by mixing two colors.  First and only required argument is the second color
       value object.  Second argument is the mixing ratio. Zero would result in the original color and one to
       the second color. Default value is 0.5 (1:1 mix). Values outside the 0..1 rande are possible and values
       will be clamped if they leave the defined bounds of the required color space.

       Third optional argument is the name of the color space the mix will be calculated in - it defaults to
       'HSL'.

           my $green = Graphics::Toolkit::Color::Values->new( '#00ff00' );
           my $cyan = $blue->blend( $green, 0.6, 'YIQ' );

   distance
       Computes a real number which designates the (Euclidean) distance between two points in a color space
       (a.k.a. colors).

       The first and only required argument is the second color as an Graphics::Toolkit::Color::Value object.
       Second and optional argument is the name of the color space, where the distance is calculated in (default
       is 'HSL'). Third argument is the metric, which currently is just the subset of dimension in the chosen
       space that should be observed.  One can also mention the shortcut name of a dimension several times to
       increase their weight in the calculation. Fourth optional argument are the numeric ranges of the
       dimensions. If none are given, the method only uses normalised (range: 0..1) values.

           my $blue = Graphics::Toolkit::Color::Values->new( '#0000ff' );
           my $green = Graphics::Toolkit::Color::Values->new( '#00ff00' );
           my $d = $blue->distance( $green, 'HSV', 's', 255); # 0 : both have same saturation

SEE ALSO

       •   Convert::Color

COPYRIGHT & LICENSE

       Copyright 2023 Herbert Breunung.

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

AUTHOR

       Herbert Breunung, <lichtkind@cpan.org>