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.

The lowest value two bytes are used to determine the type, while the highest value two bytes contain flags:

base_type = val & 0xFFFF;
flags = val >> 16;

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

Scostamento

Len

Tipo

Descrizione

4

4

Numero intero

0 per False, 1 per True

2: int

If no flags are set (flags == 0), the integer is sent as a 32 bit integer:

Scostamento

Len

Tipo

Descrizione

4

4

Numero intero

32-bit signed integer

If flag ENCODE_FLAG_64 is set (flags & 1 == 1), the integer is sent as a 64-bit integer:

Scostamento

Len

Tipo

Descrizione

4

8

Numero intero

64-bit signed integer

3: float

If no flags are set (flags == 0), the float is sent as a 32 bit single precision:

Scostamento

Len

Tipo

Descrizione

4

4

Float

IEEE 754 single-precision float

If flag ENCODE_FLAG_64 is set (flags & 1 == 1), the float is sent as a 64-bit double precision number:

Scostamento

Len

Tipo

Descrizione

4

8

Float

IEEE 754 double-precision float

4: String

Scostamento

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

Scostamento

Len

Tipo

Descrizione

4

4

Float

X coordinate

8

4

Float

Y coordinate

6: Rect2

Scostamento

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

Scostamento

Len

Tipo

Descrizione

4

4

Float

X coordinate

8

4

Float

Y coordinate

12

4

Float

Z coordinate

8: Transform2D

Scostamento

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

Scostamento

Len

Tipo

Descrizione

4

4

Float

Normal X

8

4

Float

Normal Y

12

4

Float

Normal Z

16

4

Float

Distance

10: Quat

Scostamento

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

Scostamento

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

Scostamento

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

Scostamento

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

Scostamento

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

Scostamento

Len

Tipo

Descrizione

4

4

Numero intero

String length, or new format (val&0x80000000!=0 and NameCount=val&0x7FFFFFFF)

For old format:

Scostamento

Len

Tipo

Descrizione

8

X

Bytes

UTF-8 encoded string

Padded to 4 bytes.

For new format:

Scostamento

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

Scostamento

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 (non supportato)

17: Object (unsupported)

18: Dictionary

Scostamento

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

Scostamento

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

Scostamento

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

Scostamento

Len

Tipo

Descrizione

4

4

Numero intero

Array length (Integers)

8..8+length*4

4

Numero intero

32-bit signed integer

22: PoolRealArray

Scostamento

Len

Tipo

Descrizione

4

4

Numero intero

Array length (Floats)

8..8+length*4

4

Numero intero

32-bits IEEE 754 float

23: PoolStringArray

Scostamento

Len

Tipo

Descrizione

4

4

Numero intero

Array length (Strings)

For each String:

Scostamento

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

Scostamento

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

Scostamento

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

Scostamento

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)