756 lines
17 KiB
PHP
756 lines
17 KiB
PHP
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<?php
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/**
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* Color utility and conversion
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*
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* Represents a color value, and converts between RGB/HSV/XYZ/Lab/HSL
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*
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* Example:
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* $color = new Jetpack_Color(0xFFFFFF);
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*
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* @author Harold Asbridge <hasbridge@gmail.com>
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* @author Matt Wiebe <wiebe@automattic.com>
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* @license http://www.opensource.org/licenses/MIT
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*/
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class Jetpack_Color {
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/**
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* @var int
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*/
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protected $color = 0;
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/**
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* Initialize object
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*
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* @param string|array $color A color of the type $type
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* @param string $type The type of color we will construct from.
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* One of hex (default), rgb, hsl, int
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*/
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public function __construct( $color = null, $type = 'hex' ) {
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if ( $color ) {
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switch ( $type ) {
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case 'hex':
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$this->fromHex( $color );
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break;
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case 'rgb':
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if ( is_array( $color ) && count( $color ) == 3 ) {
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list( $r, $g, $b ) = array_values( $color );
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$this->fromRgbInt( $r, $g, $b );
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}
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break;
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case 'hsl':
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if ( is_array( $color ) && count( $color ) == 3 ) {
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list( $h, $s, $l ) = array_values( $color );
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$this->fromHsl( $h, $s, $l );
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}
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break;
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case 'int':
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$this->fromInt( $color );
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break;
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default:
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// there is no default.
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break;
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}
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}
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}
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/**
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* Init color from hex value
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*
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* @param string $hexValue
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*
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* @return Jetpack_Color
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*/
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public function fromHex($hexValue) {
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$hexValue = str_replace( '#', '', $hexValue );
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// handle short hex codes like #fff
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if ( 3 === strlen( $hexValue ) ) {
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$short = $hexValue;
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$i = 0;
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$hexValue = '';
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while ( $i < 3 ) {
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$chunk = substr($short, $i, 1 );
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$hexValue .= $chunk . $chunk;
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$i++;
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}
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}
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$intValue = hexdec( $hexValue );
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if ( $intValue < 0 || $intValue > 16777215 ) {
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throw new RangeException( $hexValue . " out of valid color code range" );
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}
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$this->color = $intValue;
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return $this;
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}
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/**
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* Init color from integer RGB values
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*
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* @param int $red
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* @param int $green
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* @param int $blue
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*
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* @return Jetpack_Color
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*/
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public function fromRgbInt($red, $green, $blue)
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{
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if ( $red < 0 || $red > 255 )
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throw new RangeException( "Red value " . $red . " out of valid color code range" );
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if ( $green < 0 || $green > 255 )
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throw new RangeException( "Green value " . $green . " out of valid color code range" );
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if ( $blue < 0 || $blue > 255 )
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throw new RangeException( "Blue value " . $blue . " out of valid color code range" );
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$this->color = (int)(($red << 16) + ($green << 8) + $blue);
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return $this;
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}
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/**
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* Init color from hex RGB values
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*
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* @param string $red
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* @param string $green
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* @param string $blue
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*
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* @return Jetpack_Color
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*/
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public function fromRgbHex($red, $green, $blue)
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{
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return $this->fromRgbInt(hexdec($red), hexdec($green), hexdec($blue));
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}
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/**
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* Converts an HSL color value to RGB. Conversion formula
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* adapted from http://en.wikipedia.org/wiki/HSL_color_space.
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* @param int $h Hue. [0-360]
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* @param in $s Saturation [0, 100]
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* @param int $l Lightness [0, 100]
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*/
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public function fromHsl( $h, $s, $l ) {
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$h /= 360; $s /= 100; $l /= 100;
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if ( $s == 0 ) {
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$r = $g = $b = $l; // achromatic
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}
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else {
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$q = $l < 0.5 ? $l * ( 1 + $s ) : $l + $s - $l * $s;
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$p = 2 * $l - $q;
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$r = $this->hue2rgb( $p, $q, $h + 1/3 );
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$g = $this->hue2rgb( $p, $q, $h );
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$b = $this->hue2rgb( $p, $q, $h - 1/3 );
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}
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return $this->fromRgbInt( $r * 255, $g * 255, $b * 255 );
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}
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/**
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* Helper function for Jetpack_Color::fromHsl()
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*/
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private function hue2rgb( $p, $q, $t ) {
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if ( $t < 0 ) $t += 1;
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if ( $t > 1 ) $t -= 1;
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if ( $t < 1/6 ) return $p + ( $q - $p ) * 6 * $t;
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if ( $t < 1/2 ) return $q;
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if ( $t < 2/3 ) return $p + ( $q - $p ) * ( 2/3 - $t ) * 6;
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return $p;
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}
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/**
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* Init color from integer value
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*
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* @param int $intValue
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*
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* @return Jetpack_Color
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*/
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public function fromInt($intValue)
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{
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if ( $intValue < 0 || $intValue > 16777215 )
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throw new RangeException( $intValue . " out of valid color code range" );
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$this->color = $intValue;
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return $this;
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}
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/**
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* Convert color to hex
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*
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* @return string
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*/
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public function toHex()
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{
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return str_pad(dechex($this->color), 6, '0', STR_PAD_LEFT);
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}
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/**
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* Convert color to RGB array (integer values)
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*
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* @return array
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*/
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public function toRgbInt()
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{
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return array(
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'red' => (int)(255 & ($this->color >> 16)),
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'green' => (int)(255 & ($this->color >> 8)),
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'blue' => (int)(255 & ($this->color))
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);
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}
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/**
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* Convert color to RGB array (hex values)
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*
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* @return array
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*/
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public function toRgbHex()
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{
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$r = array();
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foreach ($this->toRgbInt() as $item) {
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$r[] = dechex($item);
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}
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return $r;
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}
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/**
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* Get Hue/Saturation/Value for the current color
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* (float values, slow but accurate)
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*
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* @return array
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*/
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public function toHsvFloat()
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{
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$rgb = $this->toRgbInt();
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$rgbMin = min($rgb);
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$rgbMax = max($rgb);
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$hsv = array(
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'hue' => 0,
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'sat' => 0,
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'val' => $rgbMax
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);
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// If v is 0, color is black
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if ($hsv['val'] == 0) {
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return $hsv;
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}
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// Normalize RGB values to 1
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$rgb['red'] /= $hsv['val'];
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$rgb['green'] /= $hsv['val'];
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$rgb['blue'] /= $hsv['val'];
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$rgbMin = min($rgb);
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$rgbMax = max($rgb);
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// Calculate saturation
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$hsv['sat'] = $rgbMax - $rgbMin;
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if ($hsv['sat'] == 0) {
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$hsv['hue'] = 0;
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return $hsv;
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}
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// Normalize saturation to 1
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$rgb['red'] = ($rgb['red'] - $rgbMin) / ($rgbMax - $rgbMin);
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$rgb['green'] = ($rgb['green'] - $rgbMin) / ($rgbMax - $rgbMin);
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$rgb['blue'] = ($rgb['blue'] - $rgbMin) / ($rgbMax - $rgbMin);
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$rgbMin = min($rgb);
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$rgbMax = max($rgb);
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// Calculate hue
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if ($rgbMax == $rgb['red']) {
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$hsv['hue'] = 0.0 + 60 * ($rgb['green'] - $rgb['blue']);
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if ($hsv['hue'] < 0) {
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$hsv['hue'] += 360;
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}
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} else if ($rgbMax == $rgb['green']) {
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$hsv['hue'] = 120 + (60 * ($rgb['blue'] - $rgb['red']));
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} else {
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$hsv['hue'] = 240 + (60 * ($rgb['red'] - $rgb['green']));
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}
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return $hsv;
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}
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/**
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* Get HSV values for color
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* (integer values from 0-255, fast but less accurate)
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*
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* @return int
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*/
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public function toHsvInt()
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{
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$rgb = $this->toRgbInt();
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$rgbMin = min($rgb);
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$rgbMax = max($rgb);
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$hsv = array(
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'hue' => 0,
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'sat' => 0,
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'val' => $rgbMax
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);
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// If value is 0, color is black
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if ($hsv['val'] == 0) {
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return $hsv;
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}
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// Calculate saturation
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$hsv['sat'] = round(255 * ($rgbMax - $rgbMin) / $hsv['val']);
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if ($hsv['sat'] == 0) {
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$hsv['hue'] = 0;
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return $hsv;
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}
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// Calculate hue
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if ($rgbMax == $rgb['red']) {
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$hsv['hue'] = round(0 + 43 * ($rgb['green'] - $rgb['blue']) / ($rgbMax - $rgbMin));
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} else if ($rgbMax == $rgb['green']) {
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$hsv['hue'] = round(85 + 43 * ($rgb['blue'] - $rgb['red']) / ($rgbMax - $rgbMin));
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} else {
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$hsv['hue'] = round(171 + 43 * ($rgb['red'] - $rgb['green']) / ($rgbMax - $rgbMin));
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}
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if ($hsv['hue'] < 0) {
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$hsv['hue'] += 255;
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}
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return $hsv;
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}
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/**
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* Converts an RGB color value to HSL. Conversion formula
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* adapted from http://en.wikipedia.org/wiki/HSL_color_space.
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* Assumes r, g, and b are contained in the set [0, 255] and
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* returns h in [0, 360], s in [0, 100], l in [0, 100]
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*
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* @return Array The HSL representation
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*/
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public function toHsl() {
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list( $r, $g, $b ) = array_values( $this->toRgbInt() );
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$r /= 255; $g /= 255; $b /= 255;
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$max = max( $r, $g, $b );
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$min = min( $r, $g, $b );
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$h = $s = $l = ( $max + $min ) / 2;
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#var_dump( array( compact('max', 'min', 'r', 'g', 'b')) );
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if ( $max == $min ) {
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$h = $s = 0; // achromatic
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}
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else {
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$d = $max - $min;
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$s = $l > 0.5 ? $d / ( 2 - $max - $min ) : $d / ( $max + $min );
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switch ( $max ) {
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case $r:
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$h = ( $g - $b ) / $d + ( $g < $b ? 6 : 0 );
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break;
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case $g:
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$h = ( $b - $r ) / $d + 2;
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break;
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case $b:
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$h = ( $r - $g ) / $d + 4;
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break;
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}
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$h /= 6;
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}
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$h = (int) round( $h * 360 );
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$s = (int) round( $s * 100 );
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$l = (int) round( $l * 100 );
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return compact( 'h', 's', 'l' );
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}
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public function toCSS( $type = 'hex', $alpha = 1 ) {
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switch ( $type ) {
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case 'hex':
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return $this->toString();
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break;
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case 'rgb':
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case 'rgba':
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list( $r, $g, $b ) = array_values( $this->toRgbInt() );
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if ( is_numeric( $alpha ) && $alpha < 1 ) {
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return "rgba( {$r}, {$g}, {$b}, $alpha )";
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}
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else {
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return "rgb( {$r}, {$g}, {$b} )";
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}
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break;
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case 'hsl':
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case 'hsla':
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list( $h, $s, $l ) = array_values( $this->toHsl() );
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if ( is_numeric( $alpha ) && $alpha < 1 ) {
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return "hsla( {$h}, {$s}, {$l}, $alpha )";
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}
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else {
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return "hsl( {$h}, {$s}, {$l} )";
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}
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break;
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default:
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return $this->toString();
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break;
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}
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}
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/**
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* Get current color in XYZ format
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*
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* @return array
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*/
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public function toXyz()
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{
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$rgb = $this->toRgbInt();
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// Normalize RGB values to 1
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$rgb_new = array();
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foreach ($rgb as $item) {
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$rgb_new[] = $item / 255;
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}
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$rgb = $rgb_new;
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$rgb_new = array();
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foreach ($rgb as $item) {
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if ($item > 0.04045) {
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$item = pow((($item + 0.055) / 1.055), 2.4);
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} else {
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$item = $item / 12.92;
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}
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$rgb_new[] = $item * 100;
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}
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$rgb = $rgb_new;
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// Observer. = 2°, Illuminant = D65
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$xyz = array(
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'x' => ($rgb['red'] * 0.4124) + ($rgb['green'] * 0.3576) + ($rgb['blue'] * 0.1805),
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'y' => ($rgb['red'] * 0.2126) + ($rgb['green'] * 0.7152) + ($rgb['blue'] * 0.0722),
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'z' => ($rgb['red'] * 0.0193) + ($rgb['green'] * 0.1192) + ($rgb['blue'] * 0.9505)
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);
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return $xyz;
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}
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/**
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* Get color CIE-Lab values
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*
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* @return array
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*/
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public function toLabCie()
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{
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$xyz = $this->toXyz();
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//Ovserver = 2*, Iluminant=D65
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$xyz['x'] /= 95.047;
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$xyz['y'] /= 100;
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$xyz['z'] /= 108.883;
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$xyz_new = array();
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foreach ($xyz as $item) {
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if ($item > 0.008856) {
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$xyz_new[] = pow($item, 1/3);
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|
} else {
|
||
|
$xyz_new[] = (7.787 * $item) + (16 / 116);
|
||
|
}
|
||
|
}
|
||
|
$xyz = $xyz_new;
|
||
|
|
||
|
$lab = array(
|
||
|
'l' => (116 * $xyz['y']) - 16,
|
||
|
'a' => 500 * ($xyz['x'] - $xyz['y']),
|
||
|
'b' => 200 * ($xyz['y'] - $xyz['z'])
|
||
|
);
|
||
|
|
||
|
return $lab;
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* Convert color to integer
|
||
|
*
|
||
|
* @return int
|
||
|
*/
|
||
|
public function toInt()
|
||
|
{
|
||
|
return $this->color;
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* Alias of toString()
|
||
|
*
|
||
|
* @return string
|
||
|
*/
|
||
|
public function __toString()
|
||
|
{
|
||
|
return $this->toString();
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* Get color as string
|
||
|
*
|
||
|
* @return string
|
||
|
*/
|
||
|
public function toString()
|
||
|
{
|
||
|
$str = $this->toHex();
|
||
|
return strtoupper("#{$str}");
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* Get the distance between this color and the given color
|
||
|
*
|
||
|
* @param Jetpack_Color $color
|
||
|
*
|
||
|
* @return int
|
||
|
*/
|
||
|
public function getDistanceRgbFrom(Jetpack_Color $color)
|
||
|
{
|
||
|
$rgb1 = $this->toRgbInt();
|
||
|
$rgb2 = $color->toRgbInt();
|
||
|
|
||
|
$rDiff = abs($rgb1['red'] - $rgb2['red']);
|
||
|
$gDiff = abs($rgb1['green'] - $rgb2['green']);
|
||
|
$bDiff = abs($rgb1['blue'] - $rgb2['blue']);
|
||
|
|
||
|
// Sum of RGB differences
|
||
|
$diff = $rDiff + $gDiff + $bDiff;
|
||
|
return $diff;
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* Get distance from the given color using the Delta E method
|
||
|
*
|
||
|
* @param Jetpack_Color $color
|
||
|
*
|
||
|
* @return float
|
||
|
*/
|
||
|
public function getDistanceLabFrom(Jetpack_Color $color)
|
||
|
{
|
||
|
$lab1 = $this->toLabCie();
|
||
|
$lab2 = $color->toLabCie();
|
||
|
|
||
|
$lDiff = abs($lab2['l'] - $lab1['l']);
|
||
|
$aDiff = abs($lab2['a'] - $lab1['a']);
|
||
|
$bDiff = abs($lab2['b'] - $lab1['b']);
|
||
|
|
||
|
$delta = sqrt($lDiff + $aDiff + $bDiff);
|
||
|
|
||
|
return $delta;
|
||
|
}
|
||
|
|
||
|
public function toLuminosity() {
|
||
|
$lum = array();
|
||
|
foreach( $this->toRgbInt() as $slot => $value ) {
|
||
|
$chan = $value / 255;
|
||
|
$lum[ $slot ] = ( $chan <= 0.03928 ) ? $chan / 12.92 : pow( ( ( $chan + 0.055 ) / 1.055 ), 2.4 );
|
||
|
}
|
||
|
return 0.2126 * $lum['red'] + 0.7152 * $lum['green'] + 0.0722 * $lum['blue'];
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* Get distance between colors using luminance.
|
||
|
* Should be more than 5 for readable contrast
|
||
|
*
|
||
|
* @param Jetpack_Color $color Another color
|
||
|
* @return float
|
||
|
*/
|
||
|
public function getDistanceLuminosityFrom( Jetpack_Color $color ) {
|
||
|
$L1 = $this->toLuminosity();
|
||
|
$L2 = $color->toLuminosity();
|
||
|
if ( $L1 > $L2 ) {
|
||
|
return ( $L1 + 0.05 ) / ( $L2 + 0.05 );
|
||
|
}
|
||
|
else{
|
||
|
return ( $L2 + 0.05 ) / ( $L1 + 0.05 );
|
||
|
}
|
||
|
}
|
||
|
|
||
|
public function getMaxContrastColor() {
|
||
|
$withBlack = $this->getDistanceLuminosityFrom( new Jetpack_Color( '#000') );
|
||
|
$withWhite = $this->getDistanceLuminosityFrom( new Jetpack_Color( '#fff') );
|
||
|
$color = new Jetpack_Color;
|
||
|
$hex = ( $withBlack >= $withWhite ) ? '#000000' : '#ffffff';
|
||
|
return $color->fromHex( $hex );
|
||
|
}
|
||
|
|
||
|
public function getGrayscaleContrastingColor( $contrast = false ) {
|
||
|
if ( ! $contrast ) {
|
||
|
return $this->getMaxContrastColor();
|
||
|
}
|
||
|
// don't allow less than 5
|
||
|
$target_contrast = ( $contrast < 5 ) ? 5 : $contrast;
|
||
|
$color = $this->getMaxContrastColor();
|
||
|
$contrast = $color->getDistanceLuminosityFrom( $this );
|
||
|
|
||
|
// if current max contrast is less than the target contrast, we had wishful thinking.
|
||
|
if ( $contrast <= $target_contrast ) {
|
||
|
return $color;
|
||
|
}
|
||
|
|
||
|
$incr = ( '#000000' === $color->toString() ) ? 1 : -1;
|
||
|
while ( $contrast > $target_contrast ) {
|
||
|
$color = $color->incrementLightness( $incr );
|
||
|
$contrast = $color->getDistanceLuminosityFrom( $this );
|
||
|
}
|
||
|
|
||
|
return $color;
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* Gets a readable contrasting color. $this is assumed to be the text and $color the background color.
|
||
|
* @param object $bg_color A Color object that will be compared against $this
|
||
|
* @param integer $min_contrast The minimum contrast to achieve, if possible.
|
||
|
* @return object A Color object, an increased contrast $this compared against $bg_color
|
||
|
*/
|
||
|
public function getReadableContrastingColor( $bg_color = false, $min_contrast = 5 ) {
|
||
|
if ( ! $bg_color || ! is_a( $bg_color, 'Jetpack_Color' ) ) {
|
||
|
return $this;
|
||
|
}
|
||
|
// you shouldn't use less than 5, but you might want to.
|
||
|
$target_contrast = $min_contrast;
|
||
|
// working things
|
||
|
$contrast = $bg_color->getDistanceLuminosityFrom( $this );
|
||
|
$max_contrast_color = $bg_color->getMaxContrastColor();
|
||
|
$max_contrast = $max_contrast_color->getDistanceLuminosityFrom( $bg_color );
|
||
|
|
||
|
// if current max contrast is less than the target contrast, we had wishful thinking.
|
||
|
// still, go max
|
||
|
if ( $max_contrast <= $target_contrast ) {
|
||
|
return $max_contrast_color;
|
||
|
}
|
||
|
// or, we might already have sufficient contrast
|
||
|
if ( $contrast >= $target_contrast ) {
|
||
|
return $this;
|
||
|
}
|
||
|
|
||
|
$incr = ( 0 === $max_contrast_color->toInt() ) ? -1 : 1;
|
||
|
while ( $contrast < $target_contrast ) {
|
||
|
$this->incrementLightness( $incr );
|
||
|
$contrast = $bg_color->getDistanceLuminosityFrom( $this );
|
||
|
// infininite loop prevention: you never know.
|
||
|
if ( $this->color === 0 || $this->color === 16777215 ) {
|
||
|
break;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
return $this;
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* Detect if color is grayscale
|
||
|
*
|
||
|
* @param int @threshold
|
||
|
*
|
||
|
* @return bool
|
||
|
*/
|
||
|
public function isGrayscale($threshold = 16)
|
||
|
{
|
||
|
$rgb = $this->toRgbInt();
|
||
|
|
||
|
// Get min and max rgb values, then difference between them
|
||
|
$rgbMin = min($rgb);
|
||
|
$rgbMax = max($rgb);
|
||
|
$diff = $rgbMax - $rgbMin;
|
||
|
|
||
|
return $diff < $threshold;
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* Get the closest matching color from the given array of colors
|
||
|
*
|
||
|
* @param array $colors array of integers or Jetpack_Color objects
|
||
|
*
|
||
|
* @return mixed the array key of the matched color
|
||
|
*/
|
||
|
public function getClosestMatch(array $colors)
|
||
|
{
|
||
|
$matchDist = 10000;
|
||
|
$matchKey = null;
|
||
|
foreach($colors as $key => $color) {
|
||
|
if (false === ($color instanceof Jetpack_Color)) {
|
||
|
$c = new Jetpack_Color($color);
|
||
|
}
|
||
|
$dist = $this->getDistanceLabFrom($c);
|
||
|
if ($dist < $matchDist) {
|
||
|
$matchDist = $dist;
|
||
|
$matchKey = $key;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
return $matchKey;
|
||
|
}
|
||
|
|
||
|
/* TRANSFORMS */
|
||
|
|
||
|
public function darken( $amount = 5 ) {
|
||
|
return $this->incrementLightness( - $amount );
|
||
|
}
|
||
|
|
||
|
public function lighten( $amount = 5 ) {
|
||
|
return $this->incrementLightness( $amount );
|
||
|
}
|
||
|
|
||
|
public function incrementLightness( $amount ) {
|
||
|
$hsl = $this->toHsl();
|
||
|
extract( $hsl );
|
||
|
$l += $amount;
|
||
|
if ( $l < 0 ) $l = 0;
|
||
|
if ( $l > 100 ) $l = 100;
|
||
|
return $this->fromHsl( $h, $s, $l );
|
||
|
}
|
||
|
|
||
|
public function saturate( $amount = 15 ) {
|
||
|
return $this->incrementSaturation( $amount );
|
||
|
}
|
||
|
|
||
|
public function desaturate( $amount = 15 ) {
|
||
|
return $this->incrementSaturation( - $amount );
|
||
|
}
|
||
|
|
||
|
public function incrementSaturation( $amount ) {
|
||
|
$hsl = $this->toHsl();
|
||
|
extract( $hsl );
|
||
|
$s += $amount;
|
||
|
if ( $s < 0 ) $s = 0;
|
||
|
if ( $s > 100 ) $s = 100;
|
||
|
return $this->fromHsl( $h, $s, $l );
|
||
|
}
|
||
|
|
||
|
public function toGrayscale() {
|
||
|
$hsl = $this->toHsl();
|
||
|
extract( $hsl );
|
||
|
$s = 0;
|
||
|
return $this->fromHsl( $h, $s, $l );
|
||
|
}
|
||
|
|
||
|
public function getComplement() {
|
||
|
return $this->incrementHue( 180 );
|
||
|
}
|
||
|
|
||
|
public function getSplitComplement( $step = 1 ) {
|
||
|
$incr = 180 + ( $step * 30 );
|
||
|
return $this->incrementHue( $incr );
|
||
|
}
|
||
|
|
||
|
public function getAnalog( $step = 1 ) {
|
||
|
$incr = $step * 30;
|
||
|
return $this->incrementHue( $incr );
|
||
|
}
|
||
|
|
||
|
public function getTetrad( $step = 1 ) {
|
||
|
$incr = $step * 60;
|
||
|
return $this->incrementHue( $incr );
|
||
|
}
|
||
|
|
||
|
public function getTriad( $step = 1 ) {
|
||
|
$incr = $step * 120;
|
||
|
return $this->incrementHue( $incr );
|
||
|
}
|
||
|
|
||
|
public function incrementHue( $amount ) {
|
||
|
$hsl = $this->toHsl();
|
||
|
extract( $hsl );
|
||
|
$h = ( $h + $amount ) % 360;
|
||
|
if ( $h < 0 ) $h = 360 - $h;
|
||
|
return $this->fromHsl( $h, $s, $l );
|
||
|
}
|
||
|
|
||
|
} // class Jetpack_Color
|