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tt-rss/include/colors.php

120 lines
3.6 KiB
PHP

<?php
### RGB >> HSL
function _color_rgb2hsl($rgb) {
$r = $rgb[0]; $g = $rgb[1]; $b = $rgb[2];
$min = min($r, min($g, $b)); $max = max($r, max($g, $b));
$delta = $max - $min; $l = ($min + $max) / 2; $s = 0;
if ($l > 0 && $l < 1) {
$s = $delta / ($l < 0.5 ? (2 * $l) : (2 - 2 * $l));
}
$h = 0;
if ($delta > 0) {
if ($max == $r && $max != $g) $h += ($g - $b) / $delta;
if ($max == $g && $max != $b) $h += (2 + ($b - $r) / $delta);
if ($max == $b && $max != $r) $h += (4 + ($r - $g) / $delta);
$h /= 6;
} return array($h, $s, $l);
}
### HSL >> RGB
function _color_hsl2rgb($hsl) {
$h = $hsl[0]; $s = $hsl[1]; $l = $hsl[2];
$m2 = ($l <= 0.5) ? $l * ($s + 1) : $l + $s - $l*$s;
$m1 = $l * 2 - $m2;
return array(_color_hue2rgb($m1, $m2, $h + 0.33333),
_color_hue2rgb($m1, $m2, $h),
_color_hue2rgb($m1, $m2, $h - 0.33333));
}
### Helper function for _color_hsl2rgb().
function _color_hue2rgb($m1, $m2, $h) {
$h = ($h < 0) ? $h + 1 : (($h > 1) ? $h - 1 : $h);
if ($h * 6 < 1) return $m1 + ($m2 - $m1) * $h * 6;
if ($h * 2 < 1) return $m2;
if ($h * 3 < 2) return $m1 + ($m2 - $m1) * (0.66666 - $h) * 6;
return $m1;
}
### Convert a hex color into an RGB triplet.
function _color_unpack($hex, $normalize = false) {
if (strlen($hex) == 4) {
$hex = $hex[1] . $hex[1] . $hex[2] . $hex[2] . $hex[3] . $hex[3];
} $c = hexdec($hex);
for ($i = 16; $i >= 0; $i -= 8) {
$out[] = (($c >> $i) & 0xFF) / ($normalize ? 255 : 1);
} return $out;
}
### Convert an RGB triplet to a hex color.
function _color_pack($rgb, $normalize = false) {
foreach ($rgb as $k => $v) {
$out |= (($v * ($normalize ? 255 : 1)) << (16 - $k * 8));
}return '#'. str_pad(dechex($out), 6, 0, STR_PAD_LEFT);
}
function rgb2hsl($arr) {
$r = $arr[0];
$g = $arr[1];
$b = $arr[2];
$var_R = ($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;
$v = $var_Max;
if ($del_Max == 0) {
$h = 0;
$s = 0;
} else {
$s = $del_Max / $var_Max;
$del_R = ( ( ( $max - $var_R ) / 6 ) + ( $del_Max / 2 ) ) / $del_Max;
$del_G = ( ( ( $max - $var_G ) / 6 ) + ( $del_Max / 2 ) ) / $del_Max;
$del_B = ( ( ( $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) $h--;
}
return array($h, $s, $v);
}
function hsl2rgb($arr) {
$h = $arr[0];
$s = $arr[1];
$v = $arr[2];
if($s == 0) {
$r = $g = $B = $v * 255;
} else {
$var_H = $h * 6;
$var_i = floor( $var_H );
$var_1 = $v * ( 1 - $s );
$var_2 = $v * ( 1 - $s * ( $var_H - $var_i ) );
$var_3 = $v * ( 1 - $s * (1 - ( $var_H - $var_i ) ) );
if ($var_i == 0) { $var_R = $v ; $var_G = $var_3 ; $var_B = $var_1 ; }
else if ($var_i == 1) { $var_R = $var_2 ; $var_G = $v ; $var_B = $var_1 ; }
else if ($var_i == 2) { $var_R = $var_1 ; $var_G = $v ; $var_B = $var_3 ; }
else if ($var_i == 3) { $var_R = $var_1 ; $var_G = $var_2 ; $var_B = $v ; }
else if ($var_i == 4) { $var_R = $var_3 ; $var_G = $var_1 ; $var_B = $v ; }
else { $var_R = $v ; $var_G = $var_1 ; $var_B = $var_2 ; }
$r = $var_R * 255;
$g = $var_G * 255;
$B = $var_B * 255;
}
return array($r, $g, $B);
}
?>