## Savegame Structure

- The Savegame is a TerranVirtualDisk archive that stores multiple files in the disk's root directory
- Savegame stores metadata, Worlds and Actors in the game
- A player gets one unique Savegame
- A player can have Multiple worlds
    - Worlds are identified using integer ranged 1 through 32767 (inclusive)
- Actor ID is unique within the scope of the Savegame
    - A World stores list of Actor IDs that resides in the world
  

### File Structure

Each file on the Savegame has following convention:

|Type|Filename|ID|
|---|---|---|
|Metadata|savegame|-1|
|Blocks Properties|blocks|-16|
|Items Properties|items|-17|
|Wires Properties|wires|-18|
|Materials Properties|materials|-19|
|Factions Properties|factions|-20|
|Other Properties used by modules|modprops|-1024|
|Worlds|world$n ($n is a world index)|$n|
|Actors|actor$n ($n is an Actor ID)|$n|

User formats can have ID of -2147483648..-65536

### Solving Problems

#### How do I determine which world to read in?

Load the player (always has the entry ID of 9545698) and the property "worldCurrentlyPlaying" should
contain an integer that is a world index. Only the actors that are instance of IngamePlayer will have
the property.


### Save File Examples

Following code is an example Savegame JSON files.

#### savegame.json
```
{
    savename: "Test World 1",
    genver: 4, /* generator version in integer */
    terrseed: "84088805e145b555",
    randseed: "19b25856e1c150ca834cffc8b59b23ad",
    weatseed: "e5e72beb4e3c6926d3dc9e3e2ef7833b",
    playerid: 9545698,
    creation_t: <creation time in real-world unix time>,
    lastplay_t: <last play time in real-world unix time>,
    playtime_t: <total play time in real-world unix time>,
    thumb: <Ascii85-encoded gzipped thumbnail image in TGA>,
    loadorder: <LoadOrder serialised>,
    worlds: [1,2,6,7]
}
```

#### world1.json

File is named as `"world"+world_index+".json"`.
The fields are auto-generated by GDX's JSON serialiser.

```
{
    worldName: "New World",
    worldIndex: 1,
    width: 9000,
    height: 2250,
    spawnX: 4500,
    spawnY: 248,
    creationTime: 1629857065,
    lastPlayTime: 1629857065,
    totalPlayTime: 0,
    layerTerrain: {
        h: <SHA-256 hash of 'b'>,
        b: <Ascii85-encoded gzipped terrain layerdata>,
        x: 9000,
        y: 2250
    },
    layerWall: {
        h: <SHA-256 hash of 'b'>,
        b: <Ascii85-encoded gzipped wall layerdata>,
        x: 9000,
        y: 2250
    },
    wallDamages:{},
    terrainDamages: {},
    fluidTypes: {}
    fluidFills: {},
    wirings: {},
    wiringGraph: {},
    gravitation: {y:9.8}
    globalLight: {
        r:0.8826928,
        g:0.8901961,
        b:0.9055425,
        a:0.93691504
    },
    averageTemperature: 288,
    generatorSeed: 0,
    worldTime: 27874,
    tileNumberToNameMap: {},
    extraFields: {},
    genver: 4
    comp: 1
}
```

#### actors.json

The fields are auto-generated by GDX's JSON serialiser.

```
[
    { /* actor serialised in JSON *
        class: "net.torvald.terrarum.modulebasegame.gameactors.IngamePlayer", /* depends on the actor */
        referenceID: 1342111743,
        actorValue: { /* actorValue serialised in JSON */ },
        hitbox: ...,
        ...
     },
    ...
]
```