Personally, I'm more of a fan of binary formats with sections (like Windows PE, just much simpler). They are also easier to parse (but that's just my opinion.... I did work with XML enough to give me headaches, checking whether getElementByName has returned a single value or a list of values... ugh). So, if I were you, I'd make it something like this:
".MMF\0" // magic value at the start, null-terminated string. stands for My Map Format :)
char header_length // useful when parsing. char is a byte, of course, an unsigned one
char version // version of the map file. (you don't really need ints here, because you probably won't be needing more than 255 versions for example, but you can also use them)
char* map_name // null terminated string describing the name of the level/map
char* author_name // if you are going to have a map editor for the general public, it would be nice to credit the person who made the map
int width // it's probably wise to plan ahead and expect an int here when you're parsing the file
int height
".layer\0" // we begin another subsection
char header_length
char type // type of the layer. for example, you can put 1 there if you want this to be a layer describing different tiles/block in a Terraria like game
".data\0" // yet another subsection. this will hold the data for the tiles
// in a hypothetical terraria 2d game, you would lay down tiles from
// the top-right corner (0,0) and then begin writing row after row
// write(1,0); write(2,0); write(3,0); ... then write(0,1); write(1,1);
// write(2,1); write(3,1); and so on..
char t1 // tile at (0,0). for example, value 0 is empty, or passable tile
char t2 // tile at (1,0). this might be a dirt block - value 1
char t3 // tile at (2,0). a rock, perhaps? value 3
(...)
char tn // tile at (width-1, height-1) or the bottom-left tile
".layer\0" // another layer.
char header_length
char type // let this on be of value 2, and let it describe portals.
// putting portals in a game makes it instantly 20% cooler
".data\0"
char t1 // 0, no portal here at tile (0,0)
char t2 // still nothing
char t3 // nope, try again
(...)
char t47 // at some location, you made a red portal. let's put 1 here so we can read it in our engine
(...)
char t86 // looke here, another 1! you can exit here from location corresponding to t47
(...)
char t99 // value 2. hm, a green portal?
(...)
char tn // bottom-left tile, at (width-1, height-1)
".layer\0" // another layer
char header_length
char type // value 3, player&enemies spawn points
char something // you don't have to have header len fixed. you can add stuff later
// and because you were smart enough to put header length
// older versions can know where the stuff of interest lays
// i.e. version one of the parser can read only the type of layer
// in version two, you add more meta-data and the old parser
// just skips it, and goes straight to the .data section
".data\0"
char t1 // zero
char t2 // zero
char t3 // zero
(...)
char t42 // a 1 - maybe the player spawn point. 5 tiles to the right
// there's a red portal
(...)
char t77 // a 2: some enemy spawn point
(...)
char tn // last tile
,
Advantages:
- Looks cool.
- Makes you think you know something about programming, doing stuff the old fashion way.
- You can manually write your levels in a hex editor:
- Generally faster than INIs and XMLs, both from writing and reading perspective
- It's a long stream of byte data, really. No need to spend time on making it look pretty, indentation wise (like what you'd want to do with XML).
- It's easy to add stuff in the headers. If a piece of data comes at the bottom of the header, old versions of parsers can be instructed to avoid it and jump to the part of the file they understand.
Disadvantages:
- You have to take good care of data placement.
- Data fields must be ordered.
- You must know their type in parser - like I said, it's just a long stream of bytes.
- Moving data by one location (for example, you forget to write the type of the layer; the parser expects a byte there and it finds the value of '.' - that's not good) messes up the entire data array from that point onward.
- Harder to jump right into - there is no API, no function like getLayerWidth() - you have to implement all of that yourself.
- There's potentially a lot of wasted space. Take the third layer for example. It will certainly be packed with a lot of zeros. This can be circumvented though if you use some sort of compression. But again, that's messing with low-level stuff yet again...
But the best thing in this approach in my opinion is - you get to do it all by yourself. Lots of trial-and-errors, but at the end, you end up learning a lot.
