lib/class-kirki-color.php
<?php
/**
* Color Calculations class for Kirki
* Initially built for the Shoestrap-3 theme and then tweaked for Kirki.
*
* @package Kirki
* @category Core
* @author Ari Stathopoulos (@aristath)
* @copyright Copyright (c) 2019, Ari Stathopoulos (@aristath)
* @license https://opensource.org/licenses/MIT
* @since 1.0
*/
// phpcs:ignoreFile
// Exit if accessed directly.
if ( ! defined( 'ABSPATH' ) ) {
exit;
}
/**
* Helper class for color manipulation.
*/
final class Kirki_Color extends ariColor {
/**
* A proxy for the sanitize_color method.
*
* @param string|array $color The color.
* @param bool $hash Whether we want to include a hash (#) at the beginning or not.
* @return string The sanitized hex color.
*/
public static function sanitize_hex( $color = '#FFFFFF', $hash = true ) {
if ( ! $hash ) {
return ltrim( self::sanitize_color( $color, 'hex' ), '#' );
}
return self::sanitize_color( $color, 'hex' );
}
/**
* A proxy the sanitize_color method.
*
* @static
* @access public
* @param string $color The color.
* @return string
*/
public static function sanitize_rgba( $color ) {
return self::sanitize_color( $color, 'rgba' );
}
/**
* Sanitize colors.
* Determine if the current value is a hex or an rgba color and call the appropriate method.
*
* @static
* @access public
* @since 0.8.5
* @param string|array $color The color.
* @param string $mode The mode to be used.
* @return string
*/
public static function sanitize_color( $color = '', $mode = 'auto' ) {
if ( is_string( $color ) && 'transparent' == trim( $color ) ) {
return 'transparent';
}
$obj = ariColor::newColor( $color );
if ( 'auto' == $mode ) {
$mode = $obj->mode;
}
return $obj->toCSS( $mode );
}
/**
* Gets the rgb value of a color.
*
* @static
* @access public
* @param string $color The color.
* @param boolean $implode Whether we want to implode the values or not.
* @return array|string
*/
public static function get_rgb( $color, $implode = false ) {
$obj = ariColor::newColor( $color );
if ( $implode ) {
return $obj->toCSS( 'rgb' );
}
return array( $obj->red, $obj->green, $obj->blue );
}
/**
* A proxy for the sanitize_color method.
*
* @static
* @access public
* @param string|array $color The color to convert.
* @return string The hex value of the color.
*/
public static function rgba2hex( $color ) {
return self::sanitize_color( $color, 'hex' );
}
/**
* Get the alpha channel from an rgba color.
*
* @static
* @access public
* @param string $color The rgba color formatted like rgba(r,g,b,a).
* @return int|float The alpha value of the color.
*/
public static function get_alpha_from_rgba( $color ) {
$obj = ariColor::newColor( $color );
return $obj->alpha;
}
/**
* Gets the rgba value of the $color.
*
* @static
* @access public
* @param string $color The hex value of a color.
* @param int|float $alpha Opacity level (0-1).
* @return string
*/
public static function get_rgba( $color = '#fff', $alpha = 1 ) {
$obj = ariColor::newColor( $color );
if ( 1 == $alpha ) {
return $obj->toCSS( 'rgba' );
}
// Make sure that opacity is properly formatted.
// Converts 1-100 values to 0-1.
if ( $alpha > 1 || $alpha < -1 ) {
// Divide by 100.
$alpha /= 100;
}
// Get absolute value.
$alpha = abs( $alpha );
// Max 1.
if ( 1 < $alpha ) {
$alpha = 1;
}
$new_obj = $obj->getNew( 'alpha', $alpha );
return $new_obj->toCSS( 'rgba' );
}
/**
* Strips the alpha value from an RGBA color string.
*
* @static
* @access public
* @param string $color The RGBA color string.
* @return string The corresponding RGB string.
*/
public static function rgba_to_rgb( $color ) {
$obj = ariColor::newColor( $color );
return $obj->toCSS( 'rgb' );
}
/**
* Gets the brightness of the $hex color.
*
* @static
* @access public
* @param string $hex The hex value of a color.
* @return int Value between 0 and 255.
*/
public static function get_brightness( $hex ) {
$hex = self::sanitize_hex( $hex, false );
// Returns brightness value from 0 to 255.
return intval( ( ( hexdec( substr( $hex, 0, 2 ) ) * 299 ) + ( hexdec( substr( $hex, 2, 2 ) ) * 587 ) + ( hexdec( substr( $hex, 4, 2 ) ) * 114 ) ) / 1000 );
}
/**
* Adjusts brightness of the $hex color.
*
* @static
* @access public
* @param string $hex The hex value of a color.
* @param integer $steps Should be between -255 and 255. Negative = darker, positive = lighter.
* @return string Returns hex color.
*/
public static function adjust_brightness( $hex, $steps ) {
$hex = self::sanitize_hex( $hex, false );
$steps = max( -255, min( 255, $steps ) );
// Adjust number of steps and keep it inside 0 to 255.
$red = max( 0, min( 255, hexdec( substr( $hex, 0, 2 ) ) + $steps ) );
$green = max( 0, min( 255, hexdec( substr( $hex, 2, 2 ) ) + $steps ) );
$blue = max( 0, min( 255, hexdec( substr( $hex, 4, 2 ) ) + $steps ) );
$red_hex = str_pad( dechex( $red ), 2, '0', STR_PAD_LEFT );
$green_hex = str_pad( dechex( $green ), 2, '0', STR_PAD_LEFT );
$blue_hex = str_pad( dechex( $blue ), 2, '0', STR_PAD_LEFT );
return self::sanitize_hex( $red_hex . $green_hex . $blue_hex );
}
/**
* Mixes 2 hex colors.
* The "percentage" variable is the percent of the first color.
* to be used it the mix. default is 50 (equal mix).
*
* @static
* @access public
* @param string|false $hex1 Color.
* @param string|false $hex2 Color.
* @param int $percentage A value between 0 and 100.
* @return string Returns hex color.
*/
public static function mix_colors( $hex1, $hex2, $percentage ) {
$hex1 = self::sanitize_hex( $hex1, false );
$hex2 = self::sanitize_hex( $hex2, false );
$red = ( $percentage * hexdec( substr( $hex1, 0, 2 ) ) + ( 100 - $percentage ) * hexdec( substr( $hex2, 0, 2 ) ) ) / 100;
$green = ( $percentage * hexdec( substr( $hex1, 2, 2 ) ) + ( 100 - $percentage ) * hexdec( substr( $hex2, 2, 2 ) ) ) / 100;
$blue = ( $percentage * hexdec( substr( $hex1, 4, 2 ) ) + ( 100 - $percentage ) * hexdec( substr( $hex2, 4, 2 ) ) ) / 100;
$red_hex = str_pad( dechex( $red ), 2, '0', STR_PAD_LEFT );
$green_hex = str_pad( dechex( $green ), 2, '0', STR_PAD_LEFT );
$blue_hex = str_pad( dechex( $blue ), 2, '0', STR_PAD_LEFT );
return self::sanitize_hex( $red_hex . $green_hex . $blue_hex );
}
/**
* Convert hex color to hsv.
*
* @static
* @access public
* @param string $hex The hex value of color 1.
* @return array Returns array( 'h', 's', 'v' ).
*/
public static function hex_to_hsv( $hex ) {
$rgb = (array) (array) self::get_rgb( self::sanitize_hex( $hex, false ) );
return self::rgb_to_hsv( $rgb );
}
/**
* Convert hex color to hsv.
*
* @static
* @access public
* @param string $color The rgb color to convert array( 'r', 'g', 'b' ).
* @return array Returns array( 'h', 's', 'v' ).
*/
public static function rgb_to_hsv( $color = array() ) {
$var_r = ( $color[0] / 255 );
$var_g = ( $color[1] / 255 );
$var_b = ( $color[2] / 255 );
$var_min = min( $var_r, $var_g, $var_b );
$var_max = max( $var_r, $var_g, $var_b );
$del_max = $var_max - $var_min;
$h = 0;
$s = 0;
$v = $var_max;
if ( 0 != $del_max ) {
$s = $del_max / $var_max;
$del_r = ( ( ( $var_max - $var_r ) / 6 ) + ( $del_max / 2 ) ) / $del_max;
$del_g = ( ( ( $var_max - $var_g ) / 6 ) + ( $del_max / 2 ) ) / $del_max;
$del_b = ( ( ( $var_max - $var_b ) / 6 ) + ( $del_max / 2 ) ) / $del_max;
if ( $var_r == $var_max ) {
$h = $del_b - $del_g;
} elseif ( $var_g == $var_max ) {
$h = ( 1 / 3 ) + $del_r - $del_b;
} elseif ( $var_b == $var_max ) {
$h = ( 2 / 3 ) + $del_g - $del_r;
}
if ( $h < 0 ) {
$h++;
}
if ( $h > 1 ) {
$h--;
}
}
return array(
'h' => round( $h, 2 ),
's' => round( $s, 2 ),
'v' => round( $v, 2 ),
);
}
/**
* This is a very simple algorithm that works by summing up the differences between the three color components red, green and blue.
* A value higher than 500 is recommended for good readability.
*
* @static
* @access public
* @param string $color_1 The 1st color.
* @param string $color_2 The 2nd color.
* @return string
*/
public static function color_difference( $color_1 = '#ffffff', $color_2 = '#000000' ) {
$color_1 = self::sanitize_hex( $color_1, false );
$color_2 = self::sanitize_hex( $color_2, false );
$color_1_rgb = self::get_rgb( $color_1 );
$color_2_rgb = self::get_rgb( $color_2 );
$r_diff = max( $color_1_rgb[0], $color_2_rgb[0] ) - min( $color_1_rgb[0], $color_2_rgb[0] );
$g_diff = max( $color_1_rgb[1], $color_2_rgb[1] ) - min( $color_1_rgb[1], $color_2_rgb[1] );
$b_diff = max( $color_1_rgb[2], $color_2_rgb[2] ) - min( $color_1_rgb[2], $color_2_rgb[2] );
$color_diff = $r_diff + $g_diff + $b_diff;
return $color_diff;
}
/**
* This function tries to compare the brightness of the colors.
* A return value of more than 125 is recommended.
* Combining it with the color_difference function above might make sense.
*
* @static
* @access public
* @param string $color_1 The 1st color.
* @param string $color_2 The 2nd color.
* @return string
*/
public static function brightness_difference( $color_1 = '#ffffff', $color_2 = '#000000' ) {
$color_1 = self::sanitize_hex( $color_1, false );
$color_2 = self::sanitize_hex( $color_2, false );
$color_1_rgb = self::get_rgb( $color_1 );
$color_2_rgb = self::get_rgb( $color_2 );
$br_1 = ( 299 * $color_1_rgb[0] + 587 * $color_1_rgb[1] + 114 * $color_1_rgb[2] ) / 1000;
$br_2 = ( 299 * $color_2_rgb[0] + 587 * $color_2_rgb[1] + 114 * $color_2_rgb[2] ) / 1000;
return intval( abs( $br_1 - $br_2 ) );
}
/**
* Uses the luminosity to calculate the difference between the given colors.
* The returned value should be bigger than 5 for best readability.
*
* @static
* @access public
* @param string $color_1 The 1st color.
* @param string $color_2 The 2nd color.
* @return string
*/
public static function lumosity_difference( $color_1 = '#ffffff', $color_2 = '#000000' ) {
$color_1 = self::sanitize_hex( $color_1, false );
$color_2 = self::sanitize_hex( $color_2, false );
$color_1_rgb = self::get_rgb( $color_1 );
$color_2_rgb = self::get_rgb( $color_2 );
$l1 = 0.2126 * pow( $color_1_rgb[0] / 255, 2.2 ) + 0.7152 * pow( $color_1_rgb[1] / 255, 2.2 ) + 0.0722 * pow( $color_1_rgb[2] / 255, 2.2 );
$l2 = 0.2126 * pow( $color_2_rgb[0] / 255, 2.2 ) + 0.7152 * pow( $color_2_rgb[1] / 255, 2.2 ) + 0.0722 * pow( $color_2_rgb[2] / 255, 2.2 );
$lum_diff = ( $l1 > $l2 ) ? ( $l1 + 0.05 ) / ( $l2 + 0.05 ) : ( $l2 + 0.05 ) / ( $l1 + 0.05 );
return round( $lum_diff, 2 );
}
}