使用PHP生成颜色数组

Question

Is it possible to create an array of colors with PHP?

What I'm trying to do:

1. Select a start and end color
2. Choose an amount of "steps"
3. Create an array of those colors blending together (as a gradient) with that amount of steps.

Example:

Start color: White
End color: Black
Steps: 3

Result:

1. "white",
2. "gray",
3. "black"

Of course the colors would be in RGB/hex

Anyone with a solution on this?

Answer 1

 $greys=rainbow('000000','FFFFFF',3);

 function rainbow($start, $end, $steps)
 {
    $s=str_to_rgb($start);
    $e=str_to_rgb($end);
    $out=array();
    $r=(integer)($e['r'] - $s['r'])/$steps;
    $g=(integer)($e['g'] - $s['g'])/$steps;
    $b=(integer)($e['b'] - $s['b'])/$steps;
    for ($x=0; $x<$steps; $x++) {
       $out[]=rgb_to_str(
          $s['r']+(integer)($r * $x),
          $s['g']+(integer)($g * $x),
          $s['b']+(integer)($b * $x));
    }
    return $out;
 }
 function rgb_to_str($r, $g, $b)
 {
      return str_pad($r, 2, '0', STR_PAD_LEFT)
          .str_pad($g, 2, '0', STR_PAD_LEFT)
          .str_pad($b, 2, '0', STR_PAD_LEFT);
 }
 function str_to_rgb($str)
 {
    return array (
      'r'=>hexdec(substr($str, 0, 2)),
      'g'=>hexdec(substr($str, 3, 2)),
      'b'=>hexdec(substr($str, 5, 2))
    );
 }