[AS3] Planning Bytearrays

Yo, I’m trying to save an array of tiles to a bytearray in the best way possible (less filesize)
So I thought like, byte 1: length of the tile (in bytes), byte2=tiletype, byte3=x, byte4=y, byte5:movetoX, byte6:movetoY (because the tiles can be moveable and have infinite etc…
So I have to plan things before I start and idk if this would totally do it. Is there any useful algorithm of planning or a program or something that would make all this easier? (in the future too)
And do you have any tips regarding defining file syntax?

Thanks!

Your idea of how a bytearray works is slightly wrong, and I think I know why. It’s because the [ ] syntax can be very confusing.

Let’s say I wanted to store some color values in a bytearray.

mybytearray[0] = 0xFF55AA;
mybytearray[1] = 0x003377;

This code is faulty, because unlike a regular array, all of 0xFF55AA doesn’t fit into [0]. It actually spills over into [1] then [2] and so on. So if we tried to read what is inside [0] we would get the wrong result because we partially overwrote it with the second write to [1].

If I remember correctly, an Int takes 4 bytes to store. you would have to do this:

mybytearray[0] = 0xFF55AA;
mybytearray[4] = 0x003377;

There are some methods on the bytearray to simplify reading and writing, but they are slower than the direct [ ] access. But you could always use the easier thing first and swap it back later when you have a better grasp. You can find a list over all the methods here

Ah, yeah, bytes only have 8 bits… so I will use readInt and writeInt then. So this is what I’ve thought of so far.

b_1 = length
b_2 = number of positions (a position consists of time (to eventually get there), x and y)
3 and 3 bytes from b_3 to b_(b_2 * 3) = positions 
b_(b_2 * 3) to b_(b_1) = text parameter (string)

So here one b is one int. Is this the right way to think?

BTW is it possible to make a new temporary ByteArray for every tile I’m writing, and then push it to the main ByteArray without having to loop through all the bytes? Cause I don’t know how else I would write the length of the tile (in bytes) before the tile.

i.e. does it work with mainByteArray.writeObject(tempByteArray)?

Yes, there is a method called writeBytes which does pretty much that. Take stuff bytearray1 and write it to bytearray2