Recording

These functions allow you to record a simulation for later playback. More...

Typedefs
typedef struct b2Recording	b2Recording
	Opaque handle for a recording buffer.

Functions
b2Recording *	b2CreateRecording (int byteCapacity)
	Create a recording buffer.
void	b2DestroyRecording (b2Recording *recording)
	Destroy a recording buffer and free its memory.
const uint8_t *	b2Recording_GetData (const b2Recording *recording)
	Get a pointer to the recorded bytes, for saving to a file or transmitting.
int	b2Recording_GetSize (const b2Recording *recording)
	Get the number of recorded bytes.
void	b2World_StartRecording (b2WorldId worldId, b2Recording *recording)
	Begin recording the world into recording.
void	b2World_StopRecording (b2WorldId worldId)
	Stop recording.
bool	b2Recording_SaveToFile (const b2Recording *recording, const char *path)
	Save a recording buffer to a file.
b2Recording *	b2CreateRecordingFromFile (const char *path)
	Load a recording from a file into a new recording buffer.

Detailed Description

These functions allow you to record a simulation for later playback.

Typedef Documentation

b2Recording

typedef struct b2Recording b2Recording

Opaque handle for a recording buffer.

Create one, hand it to b2World_StartRecording, then save its bytes and destroy it. The buffer grows as the world records into it.

Function Documentation

b2CreateRecording()

b2Recording * b2CreateRecording

(

int

byteCapacity

)

Create a recording buffer.

The buffer grows on demand. byteCapacity pre-sizes it to avoid reallocations during a known-length session. Pass 0 for a small default.

Returns

A recording handle, freed with b2DestroyRecording

b2CreateRecordingFromFile()

b2Recording * b2CreateRecordingFromFile

(

const char *

path

)

Load a recording from a file into a new recording buffer.

Convenience wrapper over your own file I/O. Destroy the result with b2DestroyRecording.

Returns

NULL if the file is missing or unreadable

b2Recording_GetData()

const uint8_t * b2Recording_GetData

(

const b2Recording *

recording

)

Get a pointer to the recorded bytes, for saving to a file or transmitting.

Valid until the next recording call or b2DestroyRecording.

b2Recording_SaveToFile()

bool b2Recording_SaveToFile	(	const b2Recording *	recording,
		const char *	path )

Save a recording buffer to a file.

Convenience wrapper over your own file I/O.

Returns

false if the file could not be written

b2World_StartRecording()

void b2World_StartRecording	(	b2WorldId	worldId,
		b2Recording *	recording )

Begin recording the world into recording.

Serializes a snapshot of the current world as the seed, then logs every mutating call. Call at a step boundary, before or after creating bodies. Start before the first step to capture the whole session. No effect if already recording or if the world is locked.

Parameters

worldId	The world to record
recording	A recording buffer from b2CreateRecording

b2World_StopRecording()

void b2World_StopRecording

(

b2WorldId

worldId

)

Stop recording.

The recording buffer keeps its bytes. Save and destroy it yourself.

Parameters

worldId

The world being recorded