PHP中的十六進制顏色百分比

Question

我想將百分比轉換爲十六進制顏色。 HSV顏色度如何工作...
我正在使用PHP。

IE: 
    0% : RED  (#FF0000) 
    8% : ORANGE (#FF7F00) 
17% : YELLOW (#FFFF00) 
25% : LIMEGREEN (#7FFF00) 
... : ... 
83% : MAGENTA (#FF00FF) 
92% : ROSE  (#FF007F) 
100% : RED  (#FF0000) 

Answer 1

這個小片段似乎做你想要達到的

http://bytes.com/topic/php/insights/890539-how-produce-first-pair-rgb-hex-color-value-percent-value

function percent2Color($value,$brightness = 255, $max = 100,$min = 0, $thirdColorHex = '00') 
{  
    // Calculate first and second color (Inverse relationship) 
    $first = (1-($value/$max))*$brightness; 
    $second = ($value/$max)*$brightness; 

    // Find the influence of the middle color (yellow if 1st and 2nd are red and green) 
    $diff = abs($first-$second);  
    $influence = ($brightness-$diff)/2;  
    $first = intval($first + $influence); 
    $second = intval($second + $influence); 

    // Convert to HEX, format and return 
    $firstHex = str_pad(dechex($first),2,0,STR_PAD_LEFT);  
    $secondHex = str_pad(dechex($second),2,0,STR_PAD_LEFT); 

    return $firstHex . $secondHex . $thirdColorHex ; 

    // alternatives: 
    // return $thirdColorHex . $firstHex . $secondHex; 
    // return $firstHex . $thirdColorHex . $secondHex; 

} 

Answer 2

嘗試的比例轉換爲HSV（除以100的比例，以獲得色調和剛剛成立的飽和度和價值，像1的任意常數），然後使用這個問題，將其轉換成RGB形式：PHP HSV to RGB formula comprehension

Answer 3

ŧ他不是我的代碼，我不記得我在哪裏找到它。我一直在使用它幾年，它對我來說非常合適。這可能是你尋找的東西（或者它的一部分）。

<?php 
class colour 
{ 
    protected $R = 0; //Red 
    protected $G = 0; //Green 
    protected $B = 0; //Blue 
    protected $H = 0; //Hue 
    protected $S = 0; //Saturation 
    protected $L = 0; //Luminance 
    protected $hex = 0; 
    protected $web; 
    protected $complement; 

    public function __construct($r, $g = false, $b = false) 
    { 
    //set up array of web colour names 
    $this->web = array(
     'black' => '#000000', 
     'green' => '#008000', 
      'silver' => '#C0C0C0', 
     'lime' => '#00FF00', 
     'gray' => '#808080', 
     'olive' => '#808000', 
     'white' => '#FFFFFF', 
     'yellow' => '#FFFF00', 
     'maroon' => '#800000', 
     'navy' => '#000080', 
     'red'  => '#FF0000', 
     'blue' => '#0000FF', 
     'purple' => '#800080', 
     'teal' => '#008080', 
     'fuchsia' => '#FF00FF' 
    ); 
    //accept either R,G,B or hex colour 
    //If hex, convert to RGB 
    //RGB? 
    if($r && $g && $b){ 
     //yes then save 
     $this->R = $r; 
     $this->G = $g; 
     $this->B = $b; 
    } elseif(isset($this->web[strtolower($r)])){ 
     //named colour? 
     $this->hex = $this->web[strtolower($r)]; 
     $this->convertToRGB($this->hex); 
    } else { 
     //no - so convert 
     if($r[0] != '#') $r = '#' . $r; 
     $this->hex = $r; 
     $this->convertToRGB($r); 
    } 
    $this->rgbTohsl(); 
    //$this->complement = $this->getComplement(); 
    } 

    public function getLighter($factor) 
    { 
    //return colour lightened by %$factor in hex 
    //$factor can be negative to give a darker colour 
    if($factor > 1 || $factor < -1) $factor = $factor/100; 
    $r = (string)round($this->R+((255 - $this->R) * $factor)); 
    $g = (string)round($this->G+((255 - $this->G) * $factor)); 
    $b = (string)round($this->B+((255 - $this->B) * $factor)); 

    if($r > 255)$r = 255; 
    if($r < 0)$r = 0; 
    if($g > 255)$g = 255; 
    if($g < 0)$g = 0; 
    if($b > 255)$b = 255; 
    if($b < 0)$b = 0; 
    var_dump($r, $g, $b); 
    return $this->convertToHex($r, $g, $b); 
    } 

    public function opposite() 
    { 
    $r = $this->R; 
    $g = $this->G; 
    $b = $this->B; 

    $r = 255 - $r; 
    $g = 255 - $g; 
    $b = 255 - $b; 

    return $this->convertToHex($r, $g, $b); 

    } 

    public function getRGB() 
    { 
    //returns an array (r, g, b) 

    $rgb = array('r' => $this->R, 
        'g' => $this->G, 
        'b' => $this->B); 
    return $rgb; 
    } 

    public function getHex() 
    { 
    if($this->hex) return $this->hex; 
    $hex = '#' . dechex($this->R) . dechex($this->G) . dechex($this->B); 
    return $hex; 
    } 

    public static function namedToHex($name) 
    { 
    //return hex value of named colour 
    $web = array(
     'black' => '#000000', 
     'green' => '#008000', 
      'silver' => '#C0C0C0', 
     'lime' => '#00FF00', 
     'gray' => '#808080', 
     'olive' => '#808000', 
     'white' => '#FFFFFF', 
     'yellow' => '#FFFF00', 
     'maroon' => '#800000', 
     'navy' => '#000080', 
     'red'  => '#FF0000', 
     'blue' => '#0000FF', 
     'purple' => '#800080', 
     'teal' => '#008080', 
     'fuchsia' => '#FF00FF' 
    ); 
    if(isset($web[strtolower($name)])){ 
     return $web[strtolower($name)]; 
    } 
    return false; 
    } 

    public static function contrast(colour $fg, colour $bg){ 
    //calculate and return contrast between $fg and $bg 
    $cont = 1; 
    $fglum = $fg->luminance(); 
    $bglum = $bg->luminance(); 

    if($fglum > $bglum) $cont = ($fglum + 0.05)/($bglum + 0.05); 
    if($bglum > $fglum) $cont = ($bglum + 0.05)/($fglum + 0.05); 

    return $cont; 

    } 

    public static function colourDiff(colour $colour1, colour $colour2) 
    { 
    //returns the colour difference between two colours 
    $rgb1 = $colour1->getRGB(); 
    $rgb2 = $colour2->getRGB(); 

    $r1 = $rgb1['r']; 
    $r2 = $rgb2['r']; 

    $g1 = $rgb1['g']; 
    $g2 = $rgb2['g']; 

    $b1 = $rgb1['b']; 
    $b2 = $rgb2['b']; 

    $diff = max($r1, $r2) - min($r1, $r2); 
    $diff += max($g1, $g2) - min($g1, $g2); 
    $diff += max($b1, $b2) - min($b1, $b2); 

    return $diff; 
    } 

    public function brightness() 
    { 
    return (($this->R * 299) + ($this->G * 587) + ($this->B * 114))/1000; 
    } 

    public function luminance() 
    { 
    //returns luminence of coulour 
    $r = $this->lumCheck($this->R/255); 
    $g = $this->lumCheck($this->G/255); 
    $b = $this->lumCheck($this->B/255); 

    $lum = (0.2126 * $r) + (0.7152 * $g) + (0.0722 * $b); 
    return $lum; 
    } 

    protected function lumCheck($col) 
    { 
    if($col <= 0.03298){ 
     return $col/12.92; 
    } else { 
     return pow((($col + 0.055)/1.055), 2.4); 
    } 
    } 

    protected function convertToRGB($color) 
    { 
    $color = (string)$color; 
    if($color[0] == '#'){ 
     $color = substr($color, 1); 
    } 
    if(strlen($color) == 6){ 
     list($r, $g, $b) = array($color[0].$color[1], 
           $color[2].$color[3], 
           $color[4].$color[5]); 
    } 
    elseif(strlen($color) == 3){ 
     list($r, $g, $b) = array($color[0].$color[0], $color[1].$color[1], $color[2].$color[2]); 
    } 
    else{ 
     return false; 
    } 

    $r = hexdec($r); $g = hexdec($g); $b = hexdec($b); 

    $this->R = (int)$r; 
    $this->G = (int)$g; 
    $this->B = (int)$b; 
    } 

    protected function convertToHex($r, $g, $b) 
    { 
    $r = dechex($r); 
    if(strlen($r) == 1)$r = '0' . $r; 

    $g = dechex($g); 
    if(strlen($g) == 1)$g = '0' . $g; 

    $b = dechex($b); 
    if(strlen($b) == 1)$b = '0' . $b; 

    $hex = '#' . $r . $g . $b; 
    return $hex; 
    } 

    protected function rgbTohsl() 
    { 
    $r = ($this->R/255);      //RGB from 0 to 255 
    $g = ($this->G/255); 
    $b = ($this->B/255); 

    $var_Min = min($r, $g, $b); //Min. value of RGB 
    $var_Max = max($r, $g, $b); //Max. value of RGB 
    $del_Max = $var_Max - $var_Min; //Delta RGB value 

    $l = ($var_Max + $var_Min)/2; 
    $this->L = $l; 

    if ($del_Max == 0){   //This is a gray, no chroma... 
     $this->H = 0;        //HSL results from 0 to 1 
     $this->S = 0; 
    } else {         //Chromatic data... 
     if ($l < 0.5) { 
     $this->S = $del_Max/($var_Max + $var_Min); 
     } else { 
     $this->S = $del_Max/(2 - $var_Max - $var_Min); 

     $del_R = ((($var_Max - $r)/6) + ($del_Max/2))/$del_Max; 
     $del_G = ((($var_Max - $g)/6) + ($del_Max/2))/$del_Max; 
     $del_B = ((($var_Max - $b)/6) + ($del_Max/2))/$del_Max; 

     if($r == $var_Max){ 
      $h = $del_B - $del_G; 
     } elseif($g == $var_Max){ 
      $h = (1/3) + $del_R - $del_B; 
     } elseif($b == $var_Max) { 
      $h = (2/3) + $del_G - $del_R; 
     } 

     if ($h < 0) $h += 1; 
     if ($h > 1) $h -= 1; 
     $this->H = $h; 
     } 
    } 
    } 

    protected function hslTorgb($h, $s, $l) 
    { 
    if ($s == 0){      //HSL from 0 to 1 
     $r = $l * 255;      //RGB results from 0 to 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 = 255 * $this->hueToRGB($var_1, $var_2, $h + (1/3)); 
     $g = 255 * $this->hueToRGB($var_1, $var_2, $h); 
     $b = 255 * $this->hueToRGB($var_1, $var_2, $h - (1/3)); 
    } 
    return array('r'=>$r,'g'=>$g,'b'=>$b); 
    } 

    protected 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); 
    } 

    public function getComplement() 
    { 
    $h = $this->H + 180; 
    if($h > 360)$h -= 360; 
    $rgb = $this->hslTorgb($h, $this->S, $this->L); 
    return $this->convertToHex($rgb['r'], $rgb['g'], $rgb['b']); 
    } 
}