PHP HSV to RGB formula comprehension

Question

I can convert RGB values to HSV with the following code...

 $r = $r/255;
 $g = $g/255;
 $b = $b/255;

 $h = 0;
 $s = 0;
 $v         


        

Answer 1

Found this post too late, my alternate take on it:

hsv2rgb function PHP

hue: 0-360, sat: 0-100, val: 0-100

  function hsv2rgb($hue,$sat,$val) {;
    $rgb = array(0,0,0);
    //calc rgb for 100% SV, go +1 for BR-range
    for($i=0;$i<4;$i++) {
      if (abs($hue - $i*120)<120) {
        $distance = max(60,abs($hue - $i*120));
        $rgb[$i % 3] = 1 - (($distance-60) / 60);
      }
    }
    //desaturate by increasing lower levels
    $max = max($rgb);
    $factor = 255 * ($val/100);
    for($i=0;$i<3;$i++) {
      //use distance between 0 and max (1) and multiply with value
      $rgb[$i] = round(($rgb[$i] + ($max - $rgb[$i]) * (1 - $sat/100)) * $factor);
    }
    $rgb['html'] = sprintf('#%02X%02X%02X', $rgb[0], $rgb[1], $rgb[2]);
    return $rgb;
  }