File: /var/www/html/elementsMachine/textStyles/Color.php
<?php
namespace GDText;
/**
* 8-bit RGB color representation.
* @package GDText
*/
class Color
{
/**
* @var int
*/
protected $red;
/**
* @var int
*/
protected $green;
/**
* @var int
*/
protected $blue;
/**
* @var int|null
*/
protected $alpha;
/**
* @param int $red Value of red component 0-255
* @param int $green Value of green component 0-255
* @param int $blue Value of blue component 0-255
* @param int $alpha A value between 0 and 127. 0 indicates completely opaque while 127 indicates completely transparent.
*/
public function __construct($red = 0, $green = 0, $blue = 0, $alpha = null)
{
$this->red = $red;
$this->green = $green;
$this->blue = $blue;
$this->alpha = $alpha;
}
/**
* Parses string to Color object representation.
* @param string $str String with color information, ex. #000000
* @return Color
* @todo Add parsing of CSS-like strings: rgb(), rgba(), hsl()
*/
public static function parseString($str)
{
$str = str_replace('#', '', $str);
if (strlen($str) == 6) {
$r = hexdec(substr($str, 0, 2));
$g = hexdec(substr($str, 2, 2));
$b = hexdec(substr($str, 4, 2));
} else if (strlen($str) == 3) {
$r = hexdec(str_repeat(substr($str, 0, 1), 2));
$g = hexdec(str_repeat(substr($str, 1, 1), 2));
$b = hexdec(str_repeat(substr($str, 2, 1), 2));
} else {
throw new \InvalidArgumentException('Unrecognized color.');
}
return new Color($r, $g, $b);
}
/**
* @param float $h Hue
* @param float $s Saturation
* @param float $l Light
* @return Color
*/
public static function fromHsl($h, $s, $l)
{
$fromFloat = function (array $rgb) {
foreach ($rgb as &$v) {
$v = (int)round($v * 255);
};
return new Color($rgb[0], $rgb[1], $rgb[2]);
};
// If saturation is 0, the given color is grey and only
// lightness is relevant.
if ($s == 0) {
return $fromFloat(array($l, $l, $l));
}
// Else calculate r, g, b according to hue.
// Check http://en.wikipedia.org/wiki/HSL_and_HSV#From_HSL for details
$chroma = (1 - abs(2 * $l - 1)) * $s;
$h_ = $h * 6;
$x = $chroma * (1 - abs((fmod($h_,2)) - 1)); // Note: fmod because % (modulo) returns int value!!
$m = $l - round($chroma/2, 10); // Bugfix for strange float behaviour (e.g. $l=0.17 and $s=1)
if ($h_ >= 0 && $h_ < 1) $rgb = array(($chroma + $m), ($x + $m), $m);
elseif ($h_ >= 1 && $h_ < 2) $rgb = array(($x + $m), ($chroma + $m), $m);
elseif ($h_ >= 2 && $h_ < 3) $rgb = array($m, ($chroma + $m), ($x + $m));
elseif ($h_ >= 3 && $h_ < 4) $rgb = array($m, ($x + $m), ($chroma + $m));
elseif ($h_ >= 4 && $h_ < 5) $rgb = array(($x + $m), $m, ($chroma + $m));
elseif ($h_ >= 5 && $h_ < 6) $rgb = array(($chroma + $m), $m, ($x + $m));
else throw new \InvalidArgumentException('Invalid hue, it should be a value between 0 and 1.');
return $fromFloat($rgb);
}
/**
* @param resource $image GD image resource
* @return int Returns the index of the specified color+alpha in the palette of the image,
* or index of allocated color if the color does not exist in the image's palette.
*/
public function getIndex($image)
{
$index = $this->hasAlphaChannel()
? imagecolorexactalpha(
$image, $this->red, $this->green, $this->blue, $this->alpha)
: imagecolorexact(
$image, $this->red, $this->green, $this->blue);
if ($index !== -1) {
return $index;
}
return $this->hasAlphaChannel()
? imagecolorallocatealpha(
$image, $this->red, $this->green, $this->blue, $this->alpha)
: imagecolorallocate(
$image, $this->red, $this->green, $this->blue);
}
/**
* @return bool TRUE when alpha channel is specified, FALSE otherwise
*/
public function hasAlphaChannel()
{
return $this->alpha !== null;
}
/**
* @return int[]
*/
public function toArray()
{
return array($this->red, $this->green, $this->blue);
}
}