ssnepenthe / color-utils
A PHP library for performing SASS-like color manipulations.
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Requires
- php: >=7.0
Requires (Dev)
- phploc/phploc: ^3.0
- phpmd/phpmd: ^2.6
- phpunit/phpunit: ^6.0
- psy/psysh: ^0.8
- squizlabs/php_codesniffer: ^2.8
- vimeo/psalm: ^0.3
This package is auto-updated.
Last update: 2024-11-11 04:15:43 UTC
README
This package is intended to provide a variety of SASS-like color manipulation functions.
Requirements
Composer, PHP 7.0 or later.
Installation
Install using Composer:
composer require ssnepenthe/color-utils
Usage
All functions listed are within the SSNepenthe\ColorUtils
namespace.
Color Representation
Create Color objects using the color
function:
color(array $color)
$color
is an array of $channel => $value
pairs. Valid channels are red, green, blue, hue, saturation, lightness and alpha.
color(['red' => 255, 'green' => 0, 'blue' => 51])
color(['hue' => 348, 'saturation' => 100, 'lightness' => 50, 'alpha' => 0.7])
color(string $color)
$color
is a string representation of a color in one of the following formats:
- Hex notation:
'#f03'
or'#ff0033'
- Keyword notation:
'white'
(list of valid keywords on MDN) - Functional hsl(a) notation:
'hsl(348, 100%, 50%)
or'hsla(348, 100%, 50%, 0.7)'
- Functional rgb(a) notation:
'rgb(255, 0, 51)'
or'rgba(255, 0, 51, 0.7)'
color(int $red, int $green, int $blue, [float $alpha])
0 - 255 range for each of $red
, $green
and $blue
, 0 - 1 for $alpha
.
color(255, 0, 51)
color(255, 0, 51, 0.7)
color(float $hue, float $saturation, float $lightness, [float $alpha])
0 - 360 range for $hue
, 0 - 100 for each of $saturation
and $lightness
, 0 - 1 for $alpha
.
color(348.0, 100.0, 50.0)
color(348.0, 100.0, 50.0, 0.7)
Regarding the previous two examples:
The values 255, 0 and 51 could technically represent RGB values as well as HSL values. In cases like this, RGB takes precedence over HSL.
If you need finer control, use the following functions:
hsl(float $hue, float $saturation, float $lightness)
hsla(float $hue, float $saturation, float $lightness, float $alpha)
rgb(int $red, int $green, int $blue)
rgba(int $red, int $green, int $blue, float $alpha)
Lastly, the hsla
and rgba
functions can also be used to adjust the transparency of an existing color:
$hsl = hsl(348, 100, 50); echo $hsl; // 'hsl(348, 100%, 50%)' $hsla = hsla($hsl, 0.7); echo $hsla; // 'hsla(348, 100%, 50%, 0.7)'
Color Components
Individual color components are accessible using the following functions (which each accept any $color
argument recognized by the color
function, including a complete color object):
alpha($color)
Get the alpha channel of a color.
alpha('#f03'); // 1.0
blue($color)
Get the blue channel of a color.
blue('#f03'); // 51
brightness($color)
Calculates color brightness on a scale from 0 (black) to 255 (white).
brightness('#f03') // 82.059
green($color)
Get the green channel of a color.
green('#f03'); // 0
hue($color)
Get the hue channel of a color.
hue('#f03'); // 348.0
is_bright($color)
Accepts an optional $threshold
float as the last parameter with a default of 127.5. Checks brightness($color) >= $threshold
.
is_bright('#f03'); // false
is_bright('#f03', 82); // true
is_light($color)
Accepts an optional $threshold
float as the last parameter with a default of 50.0. Checks lightness($color) >= $threshold
.
is_light('#f03'); // true
is_light('#f03', 55); // false
lightness($color)
Get the lightness channel of a color.
lightness('#f03'); // 50.0
looks_bright($color)
Accepts an optional $threshold
float as the last parameter with a default of 127.5. Checks perceived_brightness($color) >= $threshold
.
looks_bright('#f03'); // true
looks_bright('#f03', 141.0); // false
name($color)
Get the name (keyword) representation of a color. Returns an empty string if none is found.
name('#f03'); // ''
name('#00f'); // 'blue'
opacity($color)
Alias of alpha($color)
.
perceived_brightness($color)
Calculates the perceived brightness of a color on a scale from 0 (black) to 255 (white).
perceived_brightness('#f03'); // 140.49551
red($color)
Get the red channel of a color.
red('#f03'); // 255
relative_luminance($color)
Calculates the relative luminance of a color on a scale from 0 (black) to 1 (white).
relative_luminance('#f03'); // 0.21499
saturation($color)
Get the saturation channel of a color.
saturation('#f03'); // 100.0
Color Calculations
The following functions calculate differences between two given colors:
brightness_difference(Color $color1, Color $color2)
Calculates brightness difference on a scale from 0 to 255.
brightness_difference(color('red'), color('green')) // 1.109
color_difference(Color $color1, Color $color2)
Calculates color difference on a scale from 0 to 765.
color_difference(color('red'), color('green')) // 383
constrast_ratio(Color $color1, Color $color2)
Calculates the contrast ratio between two colors on a scale from 1 to 21.
contrast_ratio(color('red'), color('green')) // 1.28486
Color Transformations
Colors can be transformed using the following functions (all accept any $color
argument recognized by the color
function):
adjust_color($color, array $channels)
Creates a new color by increasing/decreasing one or more channel values of $color
. This can change red, green, blue, hue, saturation, lightness and alpha channels. $channels
are specified as an array of $channel => $amount
pairs.
(string) adjust_color('rgb(50, 100, 150)', ['green' => 50, 'blue' => -50]); // 'rgb(50, 150, 100)'
change_color($color, array $channels)
Creates a new color by changing one or more channel values of $color
. This can change red, green, blue, hue, saturation, lightness and alpha channels. $channels
are specified as an array of $channel => $amount
pairs.
(string) change_color('rgb(50, 100, 150)', ['green' => 50, 'blue' => 25]); // 'rgb(50, 50, 25)'
invert($color)
Creates a new color by inverting (subtracting from 255) the red, green and blue channels of $color
. Alpha is left unchanged.
(string) invert('rgb(50, 100, 150)'); // 'rgb(205, 155, 105)'
mix(Color $color1, Color $color2, int $weight = 50)
Creates a new color by averaging the red, green and blue channels from $color1
and $color2
, with $color1
optionally weighted by $weight
%. Alpha is also considered. Uses the same algorithm as SASS.
(string) mix(color('rgb(50, 100, 150)'), color('rgb(100, 100, 100)')); // 'rgb(75, 100, 125)
(string) mix(color('rgb(50, 100, 150)'), color('rgb(100, 100, 100)'), 25); // 'rgb(88, 100, 113)
(string) mix(color('rgb(50, 100, 150)'), color('rgb(100, 100, 100)'), 75); // 'rgb(63, 100, 138)
scale_color($color, array $channels)
Creates a new color by scaling one or more channel values of $color
. This can change red, green, blue, hue, saturation, lightness and alpha channels. $channels
are specified as an array of $channel => $percent
pairs, and each channel value is scaled by $percent
% of the max possible adjustment.
In the example below, green is 100 and we want to scale positively by 50%. The maximum allowed value is 255 which means the maximum possible adjustment is 155. The new green value then becomes 100 + (155 * 0.5).
Likewise, blue is 150 and we want to scale negatively by 50%. The minimum allowed value is 0 which means the maximum possible adjustment is -150. The new blue value then becomes 150 + (-150 * 0.5).
(string) scale_color('rgb(50, 100, 150)', ['green' => 50, 'blue' => -50]); // 'rgb(50, 178, 75)'
adjust_hue($color, float $degrees)
Alias of adjust_color($color, ['hue' => $degrees])
.
complement($color)
Alias of adjust_color($color, ['hue' => 180])
.
darken($color, float $amount)
Alias of adjust_color($color, ['lightness' => -1 * $amount])
.
desaturate($color, float $amount)
Alias of adjust_color($color, ['saturation' => -1 * $amount])
.
fade_in($color, float $amount)
Alias of opacify($color, $amount)
.
fade_out($color, float $amount)
Alias of transparentize($color, $amount)
.
grayscale($color)
Alias of change_color($color, ['saturation' => 0])
.
lighten($color, float $amount)
Alias of adjust_color($color, ['lightness' => $amount])
.
opacify($color, float $amount)
Alias of adjust_color($color, ['alpha' => $amount])
.
saturate($color, float $amount)
Alias of adjust_color($color, ['saturation' => $amount])
.
shade($color, int $weight = 50)
Alias of mix(color('black'), color($color), $weight)
.
tint($color, int $weight = 50)
Alias of mix(color('white'), color($color), $weight)
.
transparentize($color, float $amount)
Alias of adjust_color($color, ['alpha' => -1 * $amount])
.