getColorRange.php

<?php

  $begin = '75B4CA';
  $end = '98F29F';
  

  print_r(getRangeColors($begin, $end, 96));

    function getRangeColors($begin, $end, $theNumSteps){


        $theColorBegin = hexdec($begin);
        $theColorEnd = hexdec($end);

        $theColorBegin = (($theColorBegin >= 0x000000) && ($theColorBegin <= 0xffffff)) ? $theColorBegin : 0x000000;
        $theColorEnd = (($theColorEnd >= 0x000000) && ($theColorEnd <= 0xffffff)) ? $theColorEnd : 0xffffff;
        $theNumSteps = (($theNumSteps > 0) && ($theNumSteps < 256)) ? $theNumSteps : 16;

        $theR0 = ($theColorBegin & 0xff0000) >> 16;
        $theG0 = ($theColorBegin & 0x00ff00) >> 8;
        $theB0 = ($theColorBegin & 0x0000ff) >> 0;

        $theR1 = ($theColorEnd & 0xff0000) >> 16;
        $theG1 = ($theColorEnd & 0x00ff00) >> 8;
        $theB1 = ($theColorEnd & 0x0000ff) >> 0;


          $result = [];

          for ($i = 0; $i <= $theNumSteps; $i++) {
            $theR = interpolate($theR0, $theR1, $i, $theNumSteps);
            $theG = interpolate($theG0, $theG1, $i, $theNumSteps);
            $theB = interpolate($theB0, $theB1, $i, $theNumSteps);

            $theVal = ((($theR << 8) | $theG) << 8) | $theB;

            $theTDARTag = sprintf("#%06X", $theVal);
            $result[] = $theTDARTag;

          }


          return $result;        


    }

    function interpolate($pBegin, $pEnd, $pStep, $pMax) {

      if ($pBegin < $pEnd) {

        return (($pEnd - $pBegin) * ($pStep / $pMax)) + $pBegin;

      } else {

        return (($pBegin - $pEnd) * (1 - ($pStep / $pMax))) + $pEnd;

      }

  }


?>