Generate heat map colors through interpolation

Heat map colors

// declare start, mid, end colors
 
$c = array(
	array(0,0,0),
	array(128,128,128),
	array(255,255,255)
);
 
$loops = 127;
for ($t = 0; $t <= $loops; $t++)
{
	$e = $t / $loops;
 
	echo "(";
	echo intval((1 - $e) * $c[0][0] + $e * $c[1][0]) . ",";
	echo intval((1 - $e) * $c[0][1] + $e * $c[1][1]) . ",";
	echo intval((1 - $e) * $c[0][2] + $e * $c[1][2]);
	echo "),<br />";
}
 
$loops = 128;
for ($t = 0; $t <= $loops; $t++)
{
	$e = $t / $loops;
 
	if ($t > 0) // skip the mid color which is already in the array
	{
		echo "(";
		echo intval((1 - $e) * $c[1][0] + $e * $c[2][0]) . ",";
		echo intval((1 - $e) * $c[1][1] + $e * $c[2][1]) . ",";
		echo intval((1 - $e) * $c[1][2] + $e * $c[2][2]);
		echo "),<br />";
	}
}