Manual Reference Pages - CONVERT::COLOR::RGB (3)
"Convert::Color::RGB" - a color value represented as red/green/blue
my $red = Convert::Color::RGB->new( 1, 0, 0 );
# Can also parse strings
my $pink = Convert::Color::RGB->new( 1,0.7,0.7 );
my $cyan = Convert::Color->new( rgb:0,1,1 );
Objects in this class represent a color in RGB space, as a set of three
floating-point values in the range 0 to 1.
For representations using 8- or 16-bit integers, see Convert::Color::RGB8
CW$color = Convert::Color::RGB->new( CW$red, CW$green, CW$blue )
Returns a new object to represent the set of values given. These values should
be floating-point numbers between 0 and 1. Values outside of this range will
CW$color = Convert::Color::RGB->new( CW$string )
Parses $string for values, and construct a new object similar to the above
three-argument form. The string should be in the form
containing the three floating-point values in decimal notation.
CW$r = CW$color->red
CW$g = CW$color->green
CW$b = CW$color->blue
Accessors for the three components of the color.
( CW$red, CW$green, CW$blue ) = CW$color->rgb
Returns the individual red, green and blue color components of the color
CW$mix = CW$color->alpha_blend( CW$other, [ CW$alpha ] )
Return a new color which is a blended combination of the two passed into it.
The optional $alpha parameter defines the mix ratio between the two colors,
defaulting to 0.5 if not defined. Values closer to 0 will blend more of
$color, closer to 1 will blend more of $other.
CW$measure = CW$color->dst_rgb( CW$other )
Return a measure of the distance between the two colors. This is the
unweighted Euclidean distance of the three color components. Two identical
colors will have a measure of 0, pure black and pure white have a distance of
1, and all others will lie somewhere inbetween.
CW$measure = CW$color->dst_rgb_cheap( CW$other )
Return a measure of the distance between the two colors. This is the sum of
the squares of the differences of each of the color components. This is part
of the value used to calculate dst_rgb, but since it involves no square
root it will be cheaper to calculate, for use in cases where only the relative
values matter, such as when picking the best match out of a set of colors.
It ranges between 0 for identical colours and 3 for the distance between pure
black and pure white.
The alpha_blend method can be used to generate a smooth gradient between
my $blue = Convert::Color->new("vga:blue");
my $cyan = Convert::Color->new("vga:cyan");
say $blue->alpha_blend( $cyan, $_/10 )->as_rgb8->hex for 0 .. 10
Paul Evans <firstname.lastname@example.org>
|perl v5.20.3 ||CONVERT::COLOR::RGB (3) ||2014-06-01 |
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