Binary serialization API

Introduction

Godot has a 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.

Full Objects vs Object instance IDs

If a variable is serialized with full_objects = true, then any Objects contained in the variable will be serialized and included in the result. This is recursive.

If full_objects = false, then only the instance IDs will be serialized for any Objects contained in the variable.

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;

Type

Value

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

int32 array

22

int64 array

23

float32 array

24

float64 array

25

string array

26

vector2 array

27

vector3 array

28

color array

29

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

Type

Description

4

4

Integer

0 for False, 1 for True

2: int

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

Offset

Len

Type

Description

4

4

Integer

32-bit signed integer

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

Offset

Len

Type

Description

4

8

Integer

64-bit signed integer

3: float

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

Offset

Len

Type

Description

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:

Offset

Len

Type

Description

4

8

Float

IEEE 754 double-precision float

4: String

Offset

Len

Type

Description

4

4

Integer

String length (in bytes)

8

X

Bytes

UTF-8 encoded string

This field is padded to 4 bytes.

5: Vector2

Offset

Len

Type

Description

4

4

Float

X coordinate

8

4

Float

Y coordinate

6: Rect2

Offset

Len

Type

Description

4

4

Float

X coordinate

8

4

Float

Y coordinate

12

4

Float

X size

16

4

Float

Y size

7: Vector3

Offset

Len

Type

Description

4

4

Float

X coordinate

8

4

Float

Y coordinate

12

4

Float

Z coordinate

8: Transform2D

Offset

Len

Type

Description

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

Type

Description

4

4

Float

Normal X

8

4

Float

Normal Y

12

4

Float

Normal Z

16

4

Float

Distance

10: Quat

Offset

Len

Type

Description

4

4

Float

Imaginary X

8

4

Float

Imaginary Y

12

4

Float

Imaginary Z

16

4

Float

Real W

11: AABB

Offset

Len

Type

Description

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

Type

Description

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

Type

Description

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

Type

Description

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

Type

Description

4

4

Integer

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

For old format:

Offset

Len

Type

Description

8

X

Bytes

UTF-8 encoded string

Padded to 4 bytes.

For new format:

Offset

Len

Type

Description

4

4

Integer

Sub-name count

8

4

Integer

Flags (absolute: val&1 != 0 )

For each Name and Sub-Name

Offset

Len

Type

Description

X+0

4

Integer

String length

X+4

X

Bytes

UTF-8 encoded string

Every name string is padded to 4 bytes.

16: RID (unsupported)

17: Object

An Object could be serialized in three different ways: as a null value, with full_objects = false, or with full_objects = true.

A null value

Offset

Len

Type

Description

4

4

Integer

Zero (32-bit signed integer)

full_objects disabled

Offset

Len

Type

Description

4

8

Integer

The Object instance ID (64-bit signed integer)

full_objects enabled

Offset

Len

Type

Description

4

4

Integer

Class name (String length)

8

X

Bytes

Class name (UTF-8 encoded string)

X+8

4

Integer

The number of properties that are serialized

For each property:

Offset

Len

Type

Description

Y

4

Integer

Property name (String length)

Y+4

Z

Bytes

Property name (UTF-8 encoded string)

Y+4+Z

W

<variable>

Property value, using this same format

Note

Not all properties are included. Only properties that are configured with the PROPERTY_USAGE_STORAGE flag set will be serialized. You can add a new usage flag to a property by overriding the _get_property_list method in your class. You can also check how property usage is configured by calling Object._get_property_list See PropertyUsageFlags for the possible usage flags.

18: Dictionary

Offset

Len

Type

Description

4

4

Integer

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

Type

Description

4

4

Integer

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: PackedByteArray

Offset

Len

Type

Description

4

4

Integer

Array length (Bytes)

8..8+length

1

Byte

Byte (0..255)

The array data is padded to 4 bytes.

21: PackedInt32Array

Offset

Len

Type

Description

4

4

Integer

Array length (Integers)

8..8+length*4

4

Integer

32-bit signed integer

22: PackedInt64Array

Offset

Len

Type

Description

4

8

Integer

Array length (Integers)

8..8+length*8

8

Integer

64-bit signed integer

23: PackedFloat32Array

Offset

Len

Type

Description

4

4

Integer

Array length (Floats)

8..8+length*4

4

Integer

32-bit IEEE 754 single-precision float

24: PackedFloat64Array

Offset

Len

Type

Description

4

4

Integer

Array length (Floats)

8..8+length*8

8

Integer

64-bit IEEE 754 double-precision float

25: PackedStringArray

Offset

Len

Type

Description

4

4

Integer

Array length (Strings)

For each String:

Offset

Len

Type

Description

X+0

4

Integer

String length

X+4

X

Bytes

UTF-8 encoded string

Every string is padded to 4 bytes.

26: PackedVector2Array

Offset

Len

Type

Description

4

4

Integer

Array length

8..8+length*8

4

Float

X coordinate

8..12+length*8

4

Float

Y coordinate

27: PackedVector3Array

Offset

Len

Type

Description

4

4

Integer

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

28: PackedColorArray

Offset

Len

Type

Description

4

4

Integer

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)