Binary serialization API

Introduzione

Godot has a simple serialization API based on Variant. It's used for converting data types to an array of bytes efficiently. This API is used in the functions get_var and store_var of File as well as the packet APIs for PacketPeer. This format is not used for binary scenes and resources.

Packet specification

The packet is designed to be always padded to 4 bytes. All values are little-endian-encoded. All packets have a 4-byte header representing an integer, specifying the type of data:

Tipo Valore
0 null
1 bool
2 integer
3 float
4 string
5 vector2
6 rect2
7 vector3
8 transform2d
9 plane
10 quat
11 aabb
12 basis
13 transform
14 color
15 node path
16 rid
17 object
18 dictionary
19 array
20 raw array
21 int array
22 real array
23 string array
24 vector2 array
25 vector3 array
26 color array
27 max

Following this is the actual packet contents, which varies for each type of packet. Note that this assumes Godot is compiled with single-precision floats, which is the default. If Godot was compiled with double-precision floats, the length of "Float" fields within data structures should be 8, and the offset should be (offset - 4) * 2 + 4. The "float" type itself always uses double precision.

0: null

1: bool

Offset Len Tipo Descrizione
4 4 Numero intero 0 for False, 1 for True

2: int

Offset Len Tipo Descrizione
4 8 Numero intero 64-bit signed integer

3: float

Offset Len Tipo Descrizione
4 4 Float IEE 754 32-Bits Float

4: String

Offset Len Tipo Descrizione
4 4 Numero intero String length (in bytes)
8 X Bytes UTF-8 encoded string

This field is padded to 4 bytes.

5: Vector2

Offset Len Tipo Descrizione
4 4 Float X coordinate
8 4 Float Y coordinate

6: Rect2

Offset Len Tipo Descrizione
4 4 Float X coordinate
8 4 Float Y coordinate
12 4 Float X size
16 4 Float Y size

7: Vector3

Offset Len Tipo Descrizione
4 4 Float X coordinate
8 4 Float Y coordinate
12 4 Float Z coordinate

8: Transform2D

Offset Len Tipo Descrizione
4 4 Float The X component of the X column vector, accessed via [0][0]
8 4 Float The Y component of the X column vector, accessed via [0][1]
12 4 Float The X component of the Y column vector, accessed via [1][0]
16 4 Float The Y component of the Y column vector, accessed via [1][1]
20 4 Float The X component of the origin vector, accessed via [2][0]
24 4 Float The Y component of the origin vector, accessed via [2][1]

9: Plane

Offset Len Tipo Descrizione
4 4 Float Normal X
8 4 Float Normal Y
12 4 Float Normal Z
16 4 Float Distance

10: Quat

Offset Len Tipo Descrizione
4 4 Float Imaginary X
8 4 Float Imaginary Y
12 4 Float Imaginary Z
16 4 Float Real W

11: AABB

Offset Len Tipo Descrizione
4 4 Float X coordinate
8 4 Float Y coordinate
12 4 Float Z coordinate
16 4 Float X size
20 4 Float Y size
24 4 Float Z size

12: Basis

Offset Len Tipo Descrizione
4 4 Float The X component of the X column vector, accessed via [0][0]
8 4 Float The Y component of the X column vector, accessed via [0][1]
12 4 Float The Z component of the X column vector, accessed via [0][2]
16 4 Float The X component of the Y column vector, accessed via [1][0]
20 4 Float The Y component of the Y column vector, accessed via [1][1]
24 4 Float The Z component of the Y column vector, accessed via [1][2]
28 4 Float The X component of the Z column vector, accessed via [2][0]
32 4 Float The Y component of the Z column vector, accessed via [2][1]
36 4 Float The Z component of the Z column vector, accessed via [2][2]

13: Transform

Offset Len Tipo Descrizione
4 4 Float The X component of the X column vector, accessed via [0][0]
8 4 Float The Y component of the X column vector, accessed via [0][1]
12 4 Float The Z component of the X column vector, accessed via [0][2]
16 4 Float The X component of the Y column vector, accessed via [1][0]
20 4 Float The Y component of the Y column vector, accessed via [1][1]
24 4 Float The Z component of the Y column vector, accessed via [1][2]
28 4 Float The X component of the Z column vector, accessed via [2][0]
32 4 Float The Y component of the Z column vector, accessed via [2][1]
36 4 Float The Z component of the Z column vector, accessed via [2][2]
40 4 Float The X component of the origin vector, accessed via [3][0]
44 4 Float The Y component of the origin vector, accessed via [3][1]
48 4 Float The Z component of the origin vector, accessed via [3][2]

14: Color

Offset Len Tipo Descrizione
4 4 Float Red (typically 0..1, can be above 1 for overbright colors)
8 4 Float Green (typically 0..1, can be above 1 for overbright colors)
12 4 Float Blue (typically 0..1, can be above 1 for overbright colors)
16 4 Float Alpha (0..1)

15: NodePath

Offset Len Tipo Descrizione
4 4 Numero intero String length, or new format (val&0x80000000!=0 and NameCount=val&0x7FFFFFFF)

For old format:

Offset Len Tipo Descrizione
8 X Bytes UTF-8 encoded string

Padded to 4 bytes.

For new format:

Offset Len Tipo Descrizione
4 4 Numero intero Sub-name count
8 4 Numero intero Flags (absolute: val&1 != 0 )

For each Name and Sub-Name

Offset Len Tipo Descrizione
X+0 4 Numero intero String length
X+4 X Bytes UTF-8 encoded string

Every name string is padded to 4 bytes.

16: RID (unsupported)

17: Object (unsupported)

18: Dictionary

Offset Len Tipo Descrizione
4 4 Numero intero val&0x7FFFFFFF = elements, val&0x80000000 = shared (bool)

Then what follows is, for amount of "elements", pairs of key and value, one after the other, using this same format.

19: Array

Offset Len Tipo Descrizione
4 4 Numero intero val&0x7FFFFFFF = elements, val&0x80000000 = shared (bool)

Then what follows is, for amount of "elements", values one after the other, using this same format.

20: PoolByteArray

Offset Len Tipo Descrizione
4 4 Numero intero Array length (Bytes)
8..8+length 1 Byte Byte (0..255)

The array data is padded to 4 bytes.

21: PoolIntArray

Offset Len Tipo Descrizione
4 4 Numero intero Array length (Integers)
8..8+length*4 4 Numero intero 32-bit signed integer

22: PoolRealArray

Offset Len Tipo Descrizione
4 4 Numero intero Array length (Floats)
8..8+length*4 4 Numero intero 32-bits IEEE 754 float

23: PoolStringArray

Offset Len Tipo Descrizione
4 4 Numero intero Array length (Strings)

For each String:

Offset Len Tipo Descrizione
X+0 4 Numero intero String length
X+4 X Bytes UTF-8 encoded string

Every string is padded to 4 bytes.

24: PoolVector2Array

Offset Len Tipo Descrizione
4 4 Numero intero Array length
8..8+length*8 4 Float X coordinate
8..12+length*8 4 Float Y coordinate

25: PoolVector3Array

Offset Len Tipo Descrizione
4 4 Numero intero Array length
8..8+length*12 4 Float X coordinate
8..12+length*12 4 Float Y coordinate
8..16+length*12 4 Float Z coordinate

26: PoolColorArray

Offset Len Tipo Descrizione
4 4 Numero intero Array length
8..8+length*16 4 Float Red (typically 0..1, can be above 1 for overbright colors)
8..12+length*16 4 Float Green (typically 0..1, can be above 1 for overbright colors)
8..16+length*16 4 Float Blue (typically 0..1, can be above 1 for overbright colors)
8..20+length*16 4 Float Alpha (0..1)