friendica/php/PHPColors/Color.php

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2016-03-28 16:29:05 +02:00
<?php
/**
* Author: Arlo Carreon <http://arlocarreon.com>
* Info: http://mexitek.github.io/phpColors/
* License: http://arlo.mit-license.org/
*/
/**
* A color utility that helps manipulate HEX colors
*/
class Color {
private $_hex;
private $_hsl;
private $_rgb;
/**
* Auto darkens/lightens by 10% for sexily-subtle gradients.
* Set this to FALSE to adjust automatic shade to be between given color
* and black (for darken) or white (for lighten)
*/
const DEFAULT_ADJUST = 10;
/**
* Instantiates the class with a HEX value
* @param string $hex
* @throws Exception "Bad color format"
*/
function __construct( $hex ) {
// Strip # sign is present
$color = str_replace("#", "", $hex);
// Make sure it's 6 digits
if( strlen($color) === 3 ) {
$color = $color[0].$color[0].$color[1].$color[1].$color[2].$color[2];
} else if( strlen($color) != 6 ) {
throw new Exception("HEX color needs to be 6 or 3 digits long");
}
$this->_hsl = self::hexToHsl( $color );
$this->_hex = $color;
$this->_rgb = self::hexToRgb( $color );
}
// ====================
// = Public Interface =
// ====================
/**
* Given a HEX string returns a HSL array equivalent.
* @param string $color
* @return array HSL associative array
*/
public static function hexToHsl( $color ){
// Sanity check
$color = self::_checkHex($color);
// Convert HEX to DEC
$R = hexdec($color[0].$color[1]);
$G = hexdec($color[2].$color[3]);
$B = hexdec($color[4].$color[5]);
$HSL = array();
$var_R = ($R / 255);
$var_G = ($G / 255);
$var_B = ($B / 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;
$L = ($var_Max + $var_Min)/2;
if ($del_Max == 0)
{
$H = 0;
$S = 0;
}
else
{
if ( $L < 0.5 ) $S = $del_Max / ( $var_Max + $var_Min );
else $S = $del_Max / ( 2 - $var_Max - $var_Min );
$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 - $del_G;
else if ($var_G == $var_Max) $H = ( 1 / 3 ) + $del_R - $del_B;
else if ($var_B == $var_Max) $H = ( 2 / 3 ) + $del_G - $del_R;
if ($H<0) $H++;
if ($H>1) $H--;
}
$HSL['H'] = ($H*360);
$HSL['S'] = $S;
$HSL['L'] = $L;
return $HSL;
}
/**
* Given a HSL associative array returns the equivalent HEX string
* @param array $hsl
* @return string HEX string
* @throws Exception "Bad HSL Array"
*/
public static function hslToHex( $hsl = array() ){
// Make sure it's HSL
if(empty($hsl) || !isset($hsl["H"]) || !isset($hsl["S"]) || !isset($hsl["L"]) ) {
throw new Exception("Param was not an HSL array");
}
list($H,$S,$L) = array( $hsl['H']/360,$hsl['S'],$hsl['L'] );
if( $S == 0 ) {
$r = $L * 255;
$g = $L * 255;
$b = $L * 255;
} else {
if($L<0.5) {
$var_2 = $L*(1+$S);
} else {
$var_2 = ($L+$S) - ($S*$L);
}
$var_1 = 2 * $L - $var_2;
$r = round(255 * self::_huetorgb( $var_1, $var_2, $H + (1/3) ));
$g = round(255 * self::_huetorgb( $var_1, $var_2, $H ));
$b = round(255 * self::_huetorgb( $var_1, $var_2, $H - (1/3) ));
}
// Convert to hex
$r = dechex($r);
$g = dechex($g);
$b = dechex($b);
// Make sure we get 2 digits for decimals
$r = (strlen("".$r)===1) ? "0".$r:$r;
$g = (strlen("".$g)===1) ? "0".$g:$g;
$b = (strlen("".$b)===1) ? "0".$b:$b;
return $r.$g.$b;
}
/**
* Given a HEX string returns a RGB array equivalent.
* @param string $color
* @return array RGB associative array
*/
public static function hexToRgb( $color ){
// Sanity check
$color = self::_checkHex($color);
// Convert HEX to DEC
$R = hexdec($color[0].$color[1]);
$G = hexdec($color[2].$color[3]);
$B = hexdec($color[4].$color[5]);
$RGB['R'] = $R;
$RGB['G'] = $G;
$RGB['B'] = $B;
return $RGB;
}
/**
* Given an RGB associative array returns the equivalent HEX string
* @param array $rgb
* @return string RGB string
* @throws Exception "Bad RGB Array"
*/
public static function rgbToHex( $rgb = array() ){
// Make sure it's RGB
if(empty($rgb) || !isset($rgb["R"]) || !isset($rgb["G"]) || !isset($rgb["B"]) ) {
throw new Exception("Param was not an RGB array");
}
// https://github.com/mexitek/phpColors/issues/25#issuecomment-88354815
// Convert RGB to HEX
$hex[0] = str_pad(dechex($rgb['R']), 2, '0', STR_PAD_LEFT);
$hex[1] = str_pad(dechex($rgb['G']), 2, '0', STR_PAD_LEFT);
$hex[2] = str_pad(dechex($rgb['B']), 2, '0', STR_PAD_LEFT);
return implode( '', $hex );
}
/**
* Given a HEX value, returns a darker color. If no desired amount provided, then the color halfway between
* given HEX and black will be returned.
* @param int $amount
* @return string Darker HEX value
*/
public function darken( $amount = self::DEFAULT_ADJUST ){
// Darken
$darkerHSL = $this->_darken($this->_hsl, $amount);
// Return as HEX
return self::hslToHex($darkerHSL);
}
/**
* Given a HEX value, returns a lighter color. If no desired amount provided, then the color halfway between
* given HEX and white will be returned.
* @param int $amount
* @return string Lighter HEX value
*/
public function lighten( $amount = self::DEFAULT_ADJUST ){
// Lighten
$lighterHSL = $this->_lighten($this->_hsl, $amount);
// Return as HEX
return self::hslToHex($lighterHSL);
}
/**
* Given a HEX value, returns a mixed color. If no desired amount provided, then the color mixed by this ratio
* @param string $hex2 Secondary HEX value to mix with
* @param int $amount = -100..0..+100
* @return string mixed HEX value
*/
public function mix($hex2, $amount = 0){
$rgb2 = self::hexToRgb($hex2);
$mixed = $this->_mix($this->_rgb, $rgb2, $amount);
// Return as HEX
return self::rgbToHex($mixed);
}
/**
* Creates an array with two shades that can be used to make a gradient
* @param int $amount Optional percentage amount you want your contrast color
* @return array An array with a 'light' and 'dark' index
*/
public function makeGradient( $amount = self::DEFAULT_ADJUST ) {
// Decide which color needs to be made
if( $this->isLight() ) {
$lightColor = $this->_hex;
$darkColor = $this->darken($amount);
} else {
$lightColor = $this->lighten($amount);
$darkColor = $this->_hex;
}
// Return our gradient array
return array( "light" => $lightColor, "dark" => $darkColor );
}
/**
* Returns whether or not given color is considered "light"
* @param string|Boolean $color
* @param int $lighterThan
* @return boolean
*/
public function isLight( $color = FALSE, $lighterThan = 130 ){
// Get our color
$color = ($color) ? $color : $this->_hex;
// Calculate straight from rbg
$r = hexdec($color[0].$color[1]);
$g = hexdec($color[2].$color[3]);
$b = hexdec($color[4].$color[5]);
return (( $r*299 + $g*587 + $b*114 )/1000 > $lighterThan);
}
/**
* Returns whether or not a given color is considered "dark"
* @param string|Boolean $color
* @param int $darkerThan
* @return boolean
*/
public function isDark( $color = FALSE, $darkerThan = 130 ){
// Get our color
$color = ($color) ? $color:$this->_hex;
// Calculate straight from rbg
$r = hexdec($color[0].$color[1]);
$g = hexdec($color[2].$color[3]);
$b = hexdec($color[4].$color[5]);
return (( $r*299 + $g*587 + $b*114 )/1000 <= $darkerThan);
}
/**
* Returns the complimentary color
* @return string Complementary hex color
*
*/
public function complementary() {
// Get our HSL
$hsl = $this->_hsl;
// Adjust Hue 180 degrees
$hsl['H'] += ($hsl['H']>180) ? -180:180;
// Return the new value in HEX
return self::hslToHex($hsl);
}
/**
* Returns your color's HSL array
*/
public function getHsl() {
return $this->_hsl;
}
/**
* Returns your original color
*/
public function getHex() {
return $this->_hex;
}
/**
* Returns your color's RGB array
*/
public function getRgb() {
return $this->_rgb;
}
/**
* Returns the cross browser CSS3 gradient
* @param int $amount Optional: percentage amount to light/darken the gradient
* @param boolean $vintageBrowsers Optional: include vendor prefixes for browsers that almost died out already
* @param string $prefix Optional: prefix for every lines
* @param string $suffix Optional: suffix for every lines
* @link http://caniuse.com/css-gradients Resource for the browser support
* @return string CSS3 gradient for chrome, safari, firefox, opera and IE10
*/
public function getCssGradient( $amount = self::DEFAULT_ADJUST, $vintageBrowsers = FALSE, $suffix = "" , $prefix = "" ) {
// Get the recommended gradient
$g = $this->makeGradient($amount);
$css = "";
/* fallback/image non-cover color */
$css .= "{$prefix}background-color: #".$this->_hex.";{$suffix}";
/* IE Browsers */
$css .= "{$prefix}filter: progid:DXImageTransform.Microsoft.gradient(startColorstr='#".$g['light']."', endColorstr='#".$g['dark']."');{$suffix}";
/* Safari 4+, Chrome 1-9 */
if ( $vintageBrowsers ) {
$css .= "{$prefix}background-image: -webkit-gradient(linear, 0% 0%, 0% 100%, from(#".$g['light']."), to(#".$g['dark']."));{$suffix}";
}
/* Safari 5.1+, Mobile Safari, Chrome 10+ */
$css .= "{$prefix}background-image: -webkit-linear-gradient(top, #".$g['light'].", #".$g['dark'].");{$suffix}";
/* Firefox 3.6+ */
if ( $vintageBrowsers ) {
$css .= "{$prefix}background-image: -moz-linear-gradient(top, #".$g['light'].", #".$g['dark'].");{$suffix}";
}
/* Opera 11.10+ */
if ( $vintageBrowsers ) {
$css .= "{$prefix}background-image: -o-linear-gradient(top, #".$g['light'].", #".$g['dark'].");{$suffix}";
}
/* Unprefixed version (standards): FF 16+, IE10+, Chrome 26+, Safari 7+, Opera 12.1+ */
$css .= "{$prefix}background-image: linear-gradient(to bottom, #".$g['light'].", #".$g['dark'].");{$suffix}";
// Return our CSS
return $css;
}
// ===========================
// = Private Functions Below =
// ===========================
/**
* Darkens a given HSL array
* @param array $hsl
* @param int $amount
* @return array $hsl
*/
private function _darken( $hsl, $amount = self::DEFAULT_ADJUST){
// Check if we were provided a number
if( $amount ) {
$hsl['L'] = ($hsl['L'] * 100) - $amount;
$hsl['L'] = ($hsl['L'] < 0) ? 0:$hsl['L']/100;
} else {
// We need to find out how much to darken
$hsl['L'] = $hsl['L']/2 ;
}
return $hsl;
}
/**
* Lightens a given HSL array
* @param array $hsl
* @param int $amount
* @return array $hsl
*/
private function _lighten( $hsl, $amount = self::DEFAULT_ADJUST){
// Check if we were provided a number
if( $amount ) {
$hsl['L'] = ($hsl['L'] * 100) + $amount;
$hsl['L'] = ($hsl['L'] > 100) ? 1:$hsl['L']/100;
} else {
// We need to find out how much to lighten
$hsl['L'] += (1-$hsl['L'])/2;
}
return $hsl;
}
/**
* Mix 2 rgb colors and return an rgb color
* @param array $rgb1
* @param array $rgb2
* @param int $amount ranged -100..0..+100
* @return array $rgb
*
* ported from http://phpxref.pagelines.com/nav.html?includes/class.colors.php.source.html
*/
private function _mix($rgb1, $rgb2, $amount = 0) {
$r1 = ($amount + 100) / 100;
$r2 = 2 - $r1;
$rmix = (($rgb1['R'] * $r1) + ($rgb2['R'] * $r2)) / 2;
$gmix = (($rgb1['G'] * $r1) + ($rgb2['G'] * $r2)) / 2;
$bmix = (($rgb1['B'] * $r1) + ($rgb2['B'] * $r2)) / 2;
return array('R' => $rmix, 'G' => $gmix, 'B' => $bmix);
}
/**
* Given a Hue, returns corresponding RGB value
* @param int $v1
* @param int $v2
* @param int $vH
* @return int
*/
private static function _huetorgb( $v1,$v2,$vH ) {
if( $vH < 0 ) {
$vH += 1;
}
if( $vH > 1 ) {
$vH -= 1;
}
if( (6*$vH) < 1 ) {
return ($v1 + ($v2 - $v1) * 6 * $vH);
}
if( (2*$vH) < 1 ) {
return $v2;
}
if( (3*$vH) < 2 ) {
return ($v1 + ($v2-$v1) * ( (2/3)-$vH ) * 6);
}
return $v1;
}
/**
* You need to check if you were given a good hex string
* @param string $hex
* @return string Color
* @throws Exception "Bad color format"
*/
private static function _checkHex( $hex ) {
// Strip # sign is present
$color = str_replace("#", "", $hex);
// Make sure it's 6 digits
if( strlen($color) == 3 ) {
$color = $color[0].$color[0].$color[1].$color[1].$color[2].$color[2];
} else if( strlen($color) != 6 ) {
throw new Exception("HEX color needs to be 6 or 3 digits long");
}
return $color;
}
}