var CI2_ROOM_OFFSETS =
[
    [0x06, 0x08, 0x0A], // room 1
    [0x0C, 0x0E, 0x10], // room 2
    [0x00, 0x02], // room 3
];

var CI2_LAYER_OFFSETS =
{
    'layer1': snesAddressToOffset(0x05DB08),
    'layer2': snesAddressToOffset(0x0B5B1C),
    'sprite': snesAddressToOffset(0x0B5B1A),
};

function randomizeCI2(random, rom)
{
    for (var i = 0; i < CI2_ROOM_OFFSETS.length; ++i)
    {
        var roomset = CI2_ROOM_OFFSETS[i], backups = {};
        for (var j = 0; j < roomset.length; ++j)
        {
            var data = backups[roomset[j]] = {};
            for (var k in CI2_LAYER_OFFSETS) if (CI2_LAYER_OFFSETS.hasOwnProperty(k))
            {
                var start = CI2_LAYER_OFFSETS[k] + roomset[j];
                data[k] = rom.slice(start, start+2);
            }
        }

        var newrooms = roomset.slice(0).shuffle(random);
        for (var j = 0; j < roomset.length; ++j)
        {
            for (var k in CI2_LAYER_OFFSETS) if (CI2_LAYER_OFFSETS.hasOwnProperty(k))
                rom.set(backups[newrooms[j]][k], CI2_LAYER_OFFSETS[k] + roomset[j]);
        }
    }
}