my $tile = $tiles[$rx][$ry][$bz][type];
if (!defined $tile || $$tile != $type_data[$tile_index])
{
    $changed = 1;
    $$tile = $type_data[$tile_index];
}

##</code><code>##

use strict;
use warnings;
use Benchmark qw(cmpthese);

use constant type => 0;

cmpthese (-1, {
    Original     => 'org (0, 0, 0)',
    Grandfathers => 'gf (0, 0, 0)',
	Tillys       => 'tilly (0, 0, 0)',
    justers      => 'juster (0, 0, 0)'
});



sub org {
    my ($bz, $bx, $by) = @_;
    my $changed;
    my @tiles;
    my @type_data;
    
    for my $y (0 .. 15) {
        for my $x (0 .. 15) {
            # this calculates the tile index we are currently at,
            # using the x and y coords in this block
            my $tile_index = $y + ($x * 16);
    
            # this calculates the real x and y values of this tile
            my $rx = ($bx * 16) + $x;
            my $ry = ($by * 16) + $y;
    
            # insert type data into the internal map array and
            # note that there was change in this block if applicable
            if (!defined $tiles[$rx][$ry][$bz][type]
                || $tiles[$rx][$ry][$bz][type] != $type_data[$tile_index])
            {
                $changed = 1;
                $tiles[$rx][$ry][$bz][type] = $type_data[$tile_index];
            }
        }
    }
}

sub gf {
    my ($bz, $bx, $by) = @_;
    my $changed;
    my @tiles;
    my @type_data;
    my $bxScaled = $bx * 16;
    my $byScaled = $by * 16;
    
    for my $x (0 .. 15) {
        my $xScaled = 16 * $x;
        
        for my $y (0 .. 15) {
            # this calculates the tile index we are currently at,
            # using the x and y coords in this block
            my $tile_index = $y + $xScaled;
    
            # this calculates the real x and y values of this tile
            my $rx = $bxScaled + $x;
            my $ry = $byScaled + $y;
    
            # insert type data into the internal map array and
            # note that there was change in this block if applicable
            my $tile = $tiles[$rx][$ry][$bz][type];
            if (!defined $tile || $$tile != $type_data[$tile_index])
            {
                $changed = 1;
                $$tile = $type_data[$tile_index];
            }
        }
    }
}

sub tilly {
    my ($bz, $bx, $by) = @_;
    my $changed;
    my @tiles;
    my @type_data;
	my $bxScaled = $bx * 16;
	my $byScaled = $by * 16;

	for my $x (0 .. 15)
	{
		my $xScaled = 16 * $x;

		# These calculations were factored out of the inner loop
		my $rx = $bxScaled + $x;
		my $tiles_for_rx = $tiles[$rx];

		for my $y (0 .. 15)
		{
			# this calculates the tile index we are currently at,
			# using the x and y coords in this block
			my $tile_index = $y + $xScaled;

			# this calculates the real y value of this tile
			my $ry = $byScaled + $y;

			# insert type data into the internal map array and
			# note that there was change in this block if applicable
			my $tile = $tiles_for_rx->[$ry][$bz][type];
			if (!defined $tile || $$tile != $type_data[$tile_index])
			{
				$changed = 1;
				$$tile = $type_data[$tile_index];
			}
		}
	}
}

sub juster {
    my ($bz, $bx, $by) = @_;
    my $changed;
    my @tiles;
    my @type_data;
    my $bxScaledBase = $bx * 16;
    my $byScaledBase = $by * 16;

	# seemed to help a bit!
	my $tile_index=0;

	# this didn't help much
	my (@bxScaled, @byScaled);
	for (0..15) {
		push @byScaled, $byScaledBase+$_;
		push @bxScaled, $bxScaledBase+$_;
	}

	for my $x (0 .. 15)
	{
		my $xScaled = 16 * $x;

		# These calculations were factored out of the inner loop

		my $rx = $bxScaled[$x];
		my $tiles_for_rx = $tiles[$rx];

		for my $y (0 .. 15)
		{
			# this calculates the real y value of this tile
			my $ry = $byScaled[$y];

			# insert type data into the internal map array and
			# note that there was change in this block if applicable
			my $tile = $tiles_for_rx->[$ry][$bz][type];

			if (!defined $tile || $$tile != $type_data[$tile_index])
			{
				$changed = 1;
				$$tile = $type_data[$tile_index];
			}

# I think this works properly, but ruins the benchmark unless
# applied to gf's and tillys.

#  			if (!exists $tiles_for_rx->[$ry][$bz][type] ||
#			    $tiles_for_rx->[$ry][$bz][type] != $type_data[$tile_index])
#  			{
#  				$changed = 1;
#  				$tiles_for_rx->[$ry][$bz][type] = $type_data[$tile_index];
#  			}


 			++$tile_index;
		}
	}
}

##</code><code>##

(1 2 3)
(4 5 6) ===> ( 1 2 3 4 5 6 7 8 9 )
(7 8 9) how to do in three dimensions, I dunno...