var_dump( build_suffix_image(".MP3"));
function build_suffix_image($suffix, $background = null)
{
$suffix = mb_substr(strtoupper($suffix), 0, 4);
$total = unpack('L', hash('adler32', $suffix, true))[1];
$hue = $total % 360;
list($r, $g, $b) = hsv2rgb($hue / 360, 0.3, 0.9);
$background = $background ? $background : "rgb({$r},{$g},{$b})";
$icon = <<<EOT
<svg version="1.1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" x="0px" y="0px" viewBox="0 0 512 512" style="enable-background:new 0 0 512 512;" xml:space="preserve">
<path style="fill:#E2E5E7;" d="M128,0c-17.6,0-32,14.4-32,32v448c0,17.6,14.4,32,32,32h320c17.6,0,32-14.4,32-32V128L352,0H128z"/>
<path style="fill:#B0B7BD;" d="M384,128h96L352,0v96C352,113.6,366.4,128,384,128z"/>
<polygon style="fill:#CAD1D8;" points="480,224 384,128 480,128 "/>
<path style="fill:{$background};" d="M416,416c0,8.8-7.2,16-16,16H48c-8.8,0-16-7.2-16-16V256c0-8.8,7.2-16,16-16h352c8.8,0,16,7.2,16,16 V416z"/>
<path style="fill:#CAD1D8;" d="M400,432H96v16h304c8.8,0,16-7.2,16-16v-16C416,424.8,408.8,432,400,432z"/>
<g><text><tspan x="220" y="380" font-size="124" font-family="Verdana, Helvetica, Arial, sans-serif" fill="white" text-anchor="middle">{$suffix}</tspan></text></g>
</svg>
EOT;
return $icon;
}
function hsv2rgb($h, $s, $v)
{
$r = $g = $b = 0;
$i = floor($h * 6);
$f = $h * 6 - $i;
$p = $v * (1 - $s);
$q = $v * (1 - $f * $s);
$t = $v * (1 - (1 - $f) * $s);
switch ($i % 6) {
case 0:
$r = $v;
$g = $t;
$b = $p;
break;
case 1:
$r = $q;
$g = $v;
$b = $p;
break;
case 2:
$r = $p;
$g = $v;
$b = $t;
break;
case 3:
$r = $p;
$g = $q;
$b = $v;
break;
case 4:
$r = $t;
$g = $p;
$b = $v;
break;
case 5:
$r = $v;
$g = $p;
$b = $q;
break;
}
return [
floor($r * 255),
floor($g * 255),
floor($b * 255)
];
}
