multiplayer.h

#include <modkit/multiplayer.h>36 functions · 15 structs · 7 enums · 30 typedefs · 9 macros

Optional server-authoritative RPC, input, and snapshot sessions.

Direction checks are routing policy. They do not authenticate a peer or authorize a gameplay action; handlers must validate both.

Functions

`mk_input_stream_desc_init`function

void mk_input_stream_desc_init(mk_input_stream_desc_t *desc)

Initialize an input-stream descriptor.

Parameter	Type	Description
`desc`	`mk_input_stream_desc_t *`	Descriptor to initialize.

`mk_multiplayer_capabilities`function

mk_multiplayer_capabilities_t mk_multiplayer_capabilities(mk_multiplayer_t multiplayer, const mk_peer_t *peer)

Query effective capabilities for a peer or session.

Parameter	Type	Description
`multiplayer`	`mk_multiplayer_t`	Session to query.
`peer`	`const mk_peer_t *`	Peer to inspect, or NULL for common host capabilities.

Returns ORed mk_multiplayer_capability bits.

`mk_multiplayer_connect`function

mk_result mk_multiplayer_connect(mk_multiplayer_t multiplayer, const char *host, uint16_t port, mk_peer_t **out_peer)

Connect a client session to a host and port.

Parameter	Type	Description
`multiplayer`	`mk_multiplayer_t`	Client session.
`host`	`const char *`	Remote hostname or address.
`port`	`uint16_t`	Remote port.
`out_peer`	`mk_peer_t **`	Optional destination for the peer.

Returns MK_SUCCESS when connection startup succeeds, otherwise an error.

`mk_multiplayer_connect_url`function

mk_result mk_multiplayer_connect_url(mk_multiplayer_t multiplayer, const char *url, mk_peer_t **out_peer)

Connect a client session using a transport URL.

Parameter	Type	Description
`multiplayer`	`mk_multiplayer_t`	Client session.
`url`	`const char *`	Remote transport URL.
`out_peer`	`mk_peer_t **`	Optional destination for the peer.

Returns MK_SUCCESS when connection startup succeeds, otherwise an error.

`mk_multiplayer_create`function

mk_result mk_multiplayer_create(const mk_multiplayer_desc_t *desc, mk_multiplayer_t *out_multiplayer)

Create a client or server session and all configured transport hosts.

Parameter	Type	Description
`desc`	`const mk_multiplayer_desc_t *`	Session configuration.
`out_multiplayer`	`mk_multiplayer_t *`	Receives the session handle.

Returns MK_SUCCESS or an error result.

`mk_multiplayer_desc_init`function

void mk_multiplayer_desc_init(mk_multiplayer_desc_t *desc)

Initialize a multiplayer session descriptor.

Parameter	Type	Description
`desc`	`mk_multiplayer_desc_t *`	Descriptor to initialize.

`mk_multiplayer_destroy`function

void mk_multiplayer_destroy(mk_multiplayer_t multiplayer)

Destroy a session, its hosts, peers, streams, and pending calls.

Parameter	Type	Description
`multiplayer`	`mk_multiplayer_t`	Session to destroy.

`mk_multiplayer_disconnect`function

mk_result mk_multiplayer_disconnect(mk_multiplayer_t multiplayer, mk_peer_t *peer, mk_disconnect_reason_t reason)

Disconnect one peer with an application-visible reason.

Parameter	Type	Description
`multiplayer`	`mk_multiplayer_t`	Owning session.
`peer`	`mk_peer_t *`	Peer to disconnect.
`reason`	`mk_disconnect_reason_t`	Disconnect reason.

Returns MK_SUCCESS or an error result.

`mk_multiplayer_effective_delivery`function

mk_delivery_t mk_multiplayer_effective_delivery(mk_multiplayer_t multiplayer, const mk_peer_t *peer, mk_delivery_t requested)

Resolve requested delivery against a peer's transport.

Parameter	Type	Description
`multiplayer`	`mk_multiplayer_t`	Session to query.
`peer`	`const mk_peer_t *`	Target peer.
`requested`	`mk_delivery_t`	Desired delivery mode.

Returns Effective delivery mode, strengthened when required.

`mk_multiplayer_get_stats`function

bool mk_multiplayer_get_stats(mk_multiplayer_t multiplayer, const mk_peer_t *peer, mk_multiplayer_stats_t *out_stats)

Read aggregate or per-peer counters.

Parameter	Type	Description
`multiplayer`	`mk_multiplayer_t`	Session to query.
`peer`	`const mk_peer_t *`	Peer to query, or NULL for aggregate counters.
`out_stats`	`mk_multiplayer_stats_t *`	Receives the counters.

Returns True when statistics were available.

`mk_multiplayer_host_desc_init`function

void mk_multiplayer_host_desc_init(mk_multiplayer_host_desc_t *desc)

Initialize one multiplayer endpoint descriptor.

Parameter	Type	Description
`desc`	`mk_multiplayer_host_desc_t *`	Descriptor to initialize.

`mk_multiplayer_max_unreliable_payload`function

size_t mk_multiplayer_max_unreliable_payload(mk_multiplayer_t multiplayer, const mk_peer_t *peer)

Get the effective unreliable application payload budget.

Parameter	Type	Description
`multiplayer`	`mk_multiplayer_t`	Session to query.
`peer`	`const mk_peer_t *`	Target peer, or NULL for the safe host minimum.

Returns Maximum payload bytes.

`mk_multiplayer_now_ms`function

uint64_t mk_multiplayer_now_ms(mk_multiplayer_t multiplayer)

Read the session's monotonic scheduling clock.

Parameter	Type	Description
`multiplayer`	`mk_multiplayer_t`	Session to query.

Returns Current time in milliseconds.

`mk_multiplayer_peer_count`function

uint32_t mk_multiplayer_peer_count(mk_multiplayer_t multiplayer)

Count peers currently owned by a session.

Parameter	Type	Description
`multiplayer`	`mk_multiplayer_t`	Session to query.

Returns Current peer count.

`mk_multiplayer_peer_first`function

mk_peer_t * mk_multiplayer_peer_first(mk_multiplayer_t multiplayer)

Begin iteration over session peers.

Parameter	Type	Description
`multiplayer`	`mk_multiplayer_t`	Session to query.

Returns First peer, or NULL when empty.

`mk_multiplayer_peer_next`function

mk_peer_t * mk_multiplayer_peer_next(mk_multiplayer_t multiplayer, mk_peer_t *peer)

Continue iteration over session peers.

Parameter	Type	Description
`multiplayer`	`mk_multiplayer_t`	Session to query.
`peer`	`mk_peer_t *`	Current peer.

Returns Next peer, or NULL at the end.

`mk_multiplayer_poll`function

uint32_t mk_multiplayer_poll(mk_multiplayer_t multiplayer, uint32_t timeout_ms, uint32_t max_events)

Service all owned hosts and dispatch events on the calling thread.

Parameter	Type	Description
`multiplayer`	`mk_multiplayer_t`	Session to poll.
`timeout_ms`	`uint32_t`	Maximum wall-clock wait; shared host I/O blocks at most once.
`max_events`	`uint32_t`	Maximum transport events to dispatch, or zero for the default.

Returns Number of dispatched transport events.

`mk_multiplayer_register_input`function

mk_result mk_multiplayer_register_input(mk_multiplayer_t multiplayer, const mk_input_stream_desc_t *desc)

Parameter	Type	Description
`multiplayer`	`mk_multiplayer_t`	Session to configure.
`desc`	`const mk_input_stream_desc_t *`	Stream description.

Returns MK_SUCCESS or an error result.

`mk_multiplayer_submit_input`function

mk_result mk_multiplayer_submit_input(mk_multiplayer_t multiplayer, mk_peer_t *peer, uint32_t stream_id, mk_multiplayer_encode_fn encode, void *user, uint32_t *out_sequence)

Encode and stage the newest client input for a stream.

Parameter	Type	Description
`multiplayer`	`mk_multiplayer_t`	Owning client session.
`peer`	`mk_peer_t *`	Server peer.
`stream_id`	`uint32_t`	Registered stream ID.
`encode`	`mk_multiplayer_encode_fn`	Payload encoder.
`user`	`void *`	Encoder context.
`out_sequence`	`uint32_t *`	Optional destination for the assigned sequence.

Returns MK_SUCCESS or an error result.

`mk_rpc_call`function

mk_result mk_rpc_call(mk_multiplayer_t multiplayer, mk_peer_t *peer, uint32_t method_id, mk_multiplayer_encode_fn encode, void *encode_user, uint32_t timeout_ms, mk_rpc_completion_fn completion, void *completion_user, mk_rpc_call_t *out_call)

Start an RPC request and register its completion callback.

Parameter	Type	Description
`multiplayer`	`mk_multiplayer_t`	Owning session.
`peer`	`mk_peer_t *`	Recipient peer.
`method_id`	`uint32_t`	Registered method ID.
`encode`	`mk_multiplayer_encode_fn`	Optional payload encoder.
`encode_user`	`void *`	Encoder context.
`timeout_ms`	`uint32_t`	Wall-clock timeout, or zero for the session default.
`completion`	`mk_rpc_completion_fn`	Terminal completion callback.
`completion_user`	`void *`	Completion context.
`out_call`	`mk_rpc_call_t *`	Optional destination for the call handle.

Returns MK_SUCCESS or an error result.

`mk_rpc_cancel`function

mk_result mk_rpc_cancel(mk_multiplayer_t multiplayer, mk_rpc_call_t call)

Cancel a pending outgoing RPC request.

Parameter	Type	Description
`multiplayer`	`mk_multiplayer_t`	Owning session.
`call`	`mk_rpc_call_t`	Pending call handle.

Returns MK_SUCCESS or an error result.

`mk_rpc_method_desc_init`function

void mk_rpc_method_desc_init(mk_rpc_method_desc_t *desc)

Initialize an RPC method descriptor.

Parameter	Type	Description
`desc`	`mk_rpc_method_desc_t *`	Descriptor to initialize.

`mk_rpc_notify`function

mk_result mk_rpc_notify(mk_multiplayer_t multiplayer, mk_peer_t *peer, uint32_t method_id, mk_multiplayer_encode_fn encode, void *encode_user)

Send a one-way RPC notification to one peer.

Parameter	Type	Description
`multiplayer`	`mk_multiplayer_t`	Owning session.
`peer`	`mk_peer_t *`	Recipient peer.
`method_id`	`uint32_t`	Registered method ID.
`encode`	`mk_multiplayer_encode_fn`	Optional payload encoder.
`encode_user`	`void *`	Encoder context.

Returns MK_SUCCESS or an error result.

`mk_rpc_notify_all`function

mk_result mk_rpc_notify_all(mk_multiplayer_t multiplayer, uint32_t method_id, mk_multiplayer_encode_fn encode, void *encode_user)

Send one shared RPC notification to every peer.

Parameter	Type	Description
`multiplayer`	`mk_multiplayer_t`	Owning session.
`method_id`	`uint32_t`	Registered method ID.
`encode`	`mk_multiplayer_encode_fn`	Optional payload encoder.
`encode_user`	`void *`	Encoder context.

Returns MK_SUCCESS or an error result.

`mk_rpc_notify_all_except`function

mk_result mk_rpc_notify_all_except(mk_multiplayer_t multiplayer, mk_peer_t *except, uint32_t method_id, mk_multiplayer_encode_fn encode, void *encode_user)

Send one shared RPC notification to every peer except one.

Parameter	Type	Description
`multiplayer`	`mk_multiplayer_t`	Owning session.
`except`	`mk_peer_t *`	Peer to exclude.
`method_id`	`uint32_t`	Registered method ID.
`encode`	`mk_multiplayer_encode_fn`	Optional payload encoder.
`encode_user`	`void *`	Encoder context.

Returns MK_SUCCESS or an error result.

`mk_rpc_register`function

mk_result mk_rpc_register(mk_multiplayer_t multiplayer, const mk_rpc_method_desc_t *desc)

Parameter	Type	Description
`multiplayer`	`mk_multiplayer_t`	Session to configure.
`desc`	`const mk_rpc_method_desc_t *`	Method description.

Returns MK_SUCCESS or an error result.

`mk_rpc_reply_defer`function

mk_result mk_rpc_reply_defer(mk_multiplayer_t multiplayer, mk_rpc_reply_t reply)

Retain an incoming reply handle for asynchronous completion.

Parameter	Type	Description
`multiplayer`	`mk_multiplayer_t`	Owning session.
`reply`	`mk_rpc_reply_t`	Live reply handle.

Returns MK_SUCCESS or an error result.

`mk_rpc_reply_error`function

mk_result mk_rpc_reply_error(mk_multiplayer_t multiplayer, mk_rpc_reply_t reply, uint32_t error_code, const char *message)

Complete an incoming RPC request with an application error.

Parameter	Type	Description
`multiplayer`	`mk_multiplayer_t`	Owning session.
`reply`	`mk_rpc_reply_t`	Live reply handle.
`error_code`	`uint32_t`	Application error code.
`message`	`const char *`	UTF-8 error message.

Returns MK_SUCCESS or an error result.

`mk_rpc_reply_send`function

mk_result mk_rpc_reply_send(mk_multiplayer_t multiplayer, mk_rpc_reply_t reply, mk_multiplayer_encode_fn encode, void *encode_user)

Complete an incoming RPC request with a success payload.

Parameter	Type	Description
`multiplayer`	`mk_multiplayer_t`	Owning session.
`reply`	`mk_rpc_reply_t`	Live reply handle.
`encode`	`mk_multiplayer_encode_fn`	Optional reply encoder.
`encode_user`	`void *`	Encoder context.

Returns MK_SUCCESS or an error result.

`mk_snapshot_frame_ack`function

bool mk_snapshot_frame_ack(const mk_snapshot_frame_view_t *frame, uint32_t input_stream_id, uint32_t *out_sequence)

Find an input acknowledgement in a snapshot frame.

Parameter	Type	Description
`frame`	`const mk_snapshot_frame_view_t *`	Snapshot frame to query.
`input_stream_id`	`uint32_t`	Input stream ID.
`out_sequence`	`uint32_t *`	Receives the acknowledged sequence.

Returns True when an acknowledgement exists.

`mk_snapshot_register`function

mk_result mk_snapshot_register(mk_multiplayer_t multiplayer, const mk_snapshot_stream_desc_t *desc)

Parameter	Type	Description
`multiplayer`	`mk_multiplayer_t`	Session to configure.
`desc`	`const mk_snapshot_stream_desc_t *`	Stream description.

Returns MK_SUCCESS or an error result.

`mk_snapshot_sample`function

bool mk_snapshot_sample(mk_multiplayer_t multiplayer, mk_peer_t *peer, uint32_t stream_id, uint64_t client_now_ms, mk_snapshot_sample_t *out_sample)

Sample buffered frames at synchronized server time minus interpolation delay.

Parameter	Type	Description
`multiplayer`	`mk_multiplayer_t`	Owning session.
`peer`	`mk_peer_t *`	Source server peer.
`stream_id`	`uint32_t`	Registered stream ID.
`client_now_ms`	`uint64_t`	Current local monotonic time.
`out_sample`	`mk_snapshot_sample_t *`	Receives borrowed frame views and sampling mode.

Returns True when a sample is available.

`mk_snapshot_send`function

mk_result mk_snapshot_send(mk_multiplayer_t multiplayer, mk_peer_t *peer, uint32_t stream_id, uint32_t tick, mk_multiplayer_encode_fn encode, void *user)

Encode and stage one recipient-specific authoritative snapshot.

Parameter	Type	Description
`multiplayer`	`mk_multiplayer_t`	Owning session.
`peer`	`mk_peer_t *`	Recipient peer.
`stream_id`	`uint32_t`	Registered stream ID.
`tick`	`uint32_t`	Authoritative simulation tick.
`encode`	`mk_multiplayer_encode_fn`	Payload encoder.
`user`	`void *`	Encoder context.

Returns MK_SUCCESS or an error result.

`mk_snapshot_send_all`function

mk_result mk_snapshot_send_all(mk_multiplayer_t multiplayer, uint32_t stream_id, uint32_t tick, const void *payload, size_t payload_size, mk_snapshot_send_report_t *out_report)

Stage one shared snapshot payload for every peer.

Parameter	Type	Description
`multiplayer`	`mk_multiplayer_t`	Owning session.
`stream_id`	`uint32_t`	Registered stream ID.
`tick`	`uint32_t`	Authoritative simulation tick.
`payload`	`const void *`	Shared state bytes.
`payload_size`	`size_t`	State byte count.
`out_report`	`mk_snapshot_send_report_t *`	Optional destination for outcome counts.

Returns MK_SUCCESS or an error result.

`mk_snapshot_send_all_encoded`function

mk_result mk_snapshot_send_all_encoded(mk_multiplayer_t multiplayer, uint32_t stream_id, uint32_t tick, mk_multiplayer_peer_encode_fn encode, void *user, mk_snapshot_send_report_t *out_report)

Encode and stage a recipient-specific snapshot for every peer.

Parameter	Type	Description
`multiplayer`	`mk_multiplayer_t`	Owning session.
`stream_id`	`uint32_t`	Registered stream ID.
`tick`	`uint32_t`	Authoritative simulation tick.
`encode`	`mk_multiplayer_peer_encode_fn`	Per-peer encoder.
`user`	`void *`	Encoder context.
`out_report`	`mk_snapshot_send_report_t *`	Optional destination for outcome counts.

Returns MK_SUCCESS or an error result.

`mk_snapshot_stream_desc_init`function

void mk_snapshot_stream_desc_init(mk_snapshot_stream_desc_t *desc)

Initialize a snapshot-stream descriptor.

Parameter	Type	Description
`desc`	`mk_snapshot_stream_desc_t *`	Descriptor to initialize.

Structs

`mk_input_stream_desc`struct

Registration and validation policy for a client input stream.

Field	Type	Description
`struct_size`	`uint32_t`	Structure size in bytes.
`struct_version`	`uint32_t`	MK_INPUT_STREAM_DESC_VERSION.
`id`	`uint32_t`	Stable application stream ID.
`version`	`uint16_t`	Application payload version.
`max_payload_bytes`	`uint32_t`	Maximum encoded input bytes.
`handler`	`mk_input_handler_fn`	Server-side input handler.
`user`	`void *`	Context passed to handler.

`mk_multiplayer_desc`struct

Session endpoints, timing, capacities, budgets, and callbacks.

Field	Type	Description
`struct_size`	`uint32_t`	Structure size in bytes.
`struct_version`	`uint32_t`	MK_MULTIPLAYER_DESC_VERSION.
`role`	`mk_host_role_t`	Client or server session role.
`hosts`	`const mk_multiplayer_host_desc_t *`	Transport endpoints copied during creation.
`host_count`	`uint32_t`	Number of endpoint descriptors.
`app_protocol_id`	`uint32_t`	Application protocol identifier.
`tick_rate_hz`	`uint32_t`	Authoritative simulation tick rate.
`snapshot_rate_hz`	`uint32_t`	Snapshot send rate, clamped to tick_rate_hz.
`interpolation_delay_ms`	`uint32_t`	Default client interpolation delay.
`max_extrapolation_ms`	`uint32_t`	Default maximum extrapolation window.
`rpc_timeout_ms`	`uint32_t`	Default request timeout in milliseconds.
`clock_sync_interval_ms`	`uint32_t`	Clock synchronization cadence.
`max_rpc_methods`	`uint32_t`	Registered RPC method capacity.
`max_snapshot_streams`	`uint32_t`	Registered snapshot-stream capacity.
`max_input_streams`	`uint32_t`	Registered input-stream capacity.
`max_pending_calls`	`uint32_t`	Concurrent outgoing request capacity.
`max_deferred_replies`	`uint32_t`	Concurrent deferred-reply capacity.
`event_staging_bytes`	`uint32_t`	Storage preserving callback payloads during poll.
`max_reliable_payload_bytes`	`uint32_t`	Maximum reliable application payload.
`max_reliable_queued_bytes_per_peer`	`uint32_t`	Reliable send-queue budget per peer.
`max_snapshot_bytes_per_second_per_peer`	`uint32_t`	Snapshot bandwidth budget per peer.
`now_ms_fn`	`mk_multiplayer_now_ms_fn`	Optional monotonic clock override.
`now_ms_user`	`void *`	Context passed to now_ms_fn.
`event_fn`	`mk_multiplayer_event_fn`	Optional session event callback.
`event_user`	`void *`	Context passed to event_fn.

`mk_multiplayer_event`struct

Data delivered to the session event callback.

Field	Type	Description
`type`	`mk_multiplayer_event_type_t`	Event kind.
`peer`	`mk_peer_t *`	Peer associated with the event.
`transport`	`mk_transport_t`	Peer's effective transport.
`endpoint_index`	`uint32_t`	Index in mk_multiplayer_desc_t.hosts.
`disconnect_reason`	`mk_disconnect_reason_t`	Reason for a disconnect event.
`protocol_error`	`mk_multiplayer_protocol_error_t`	Detail for a protocol-error event.

`mk_multiplayer_host_desc`struct

One transport endpoint owned by a multiplayer session.

Field	Type	Description
`struct_size`	`uint32_t`	Structure size in bytes.
`struct_version`	`uint32_t`	MK_MULTIPLAYER_HOST_DESC_VERSION.
`transport`	`mk_transport_t`	UDP, TCP, or WebSocket transport.
`bind_address`	`const char *`	Server bind address, or client local address.
`port`	`uint16_t`	Local listening or binding port.
`max_peers`	`uint32_t`	Maximum peers accepted by this endpoint.

`mk_multiplayer_stats`struct

Aggregate session or per-peer multiplayer counters.

Field	Type	Description
`bytes_sent`	`uint64_t`	Application and protocol bytes sent.
`bytes_received`	`uint64_t`	Application and protocol bytes received.
`rpc_sent`	`uint64_t`	RPC messages sent.
`rpc_received`	`uint64_t`	RPC messages received.
`rpc_timeouts`	`uint64_t`	Requests completed by timeout.
`rpc_rejected`	`uint64_t`	RPC messages rejected by validation.
`protocol_errors`	`uint64_t`	Protocol violations observed.
`snapshots_sent`	`uint64_t`	Snapshot frames sent.
`snapshots_received`	`uint64_t`	Snapshot frames accepted.
`coalesced_snapshots`	`uint64_t`	Staged snapshots replaced before send.
`budget_deferred_snapshots`	`uint64_t`	Snapshots deferred by bandwidth limits.
`stale_snapshots`	`uint64_t`	Stale snapshots discarded.
`inputs_sent`	`uint64_t`	Input frames sent.
`inputs_received`	`uint64_t`	Input frames accepted.
`stale_inputs`	`uint64_t`	Duplicate or stale inputs discarded.
`staged_event_bytes`	`uint64_t`	Event payload bytes copied during poll.
`staging_pressure`	`uint64_t`	Events that exceeded preferred staging pressure.
`clock_offset_ms`	`int64_t`	Estimated server-minus-client clock offset.
`clock_jitter_ms`	`uint32_t`	Estimated clock synchronization jitter.
`snapshot_buffered`	`uint32_t`	Snapshot frames currently buffered.

`mk_rpc_call`struct

Generational handle for an outgoing RPC request.

Field	Type	Description
`id`	`uint32_t`	Packed call slot and generation.

`mk_rpc_context`struct

Routing metadata supplied to an RPC handler.

Field	Type	Description
`peer`	`mk_peer_t *`	Peer that sent the invocation.
`method_id`	`uint32_t`	Registered method ID.
`version`	`uint16_t`	Registered payload version.
`kind`	`mk_rpc_kind_t`	Notification or request.

`mk_rpc_method_desc`struct

Registration, routing, delivery, and validation policy for an RPC method.

Field	Type	Description
`struct_size`	`uint32_t`	Structure size in bytes.
`struct_version`	`uint32_t`	MK_RPC_METHOD_DESC_VERSION.
`id`	`uint32_t`	Stable application method ID.
`version`	`uint16_t`	Application payload version.
`kind`	`mk_rpc_kind_t`	Notification or request/reply method.
`direction`	`mk_rpc_direction_t`	Allowed routing direction.
`delivery`	`mk_delivery_t`	Requested transport delivery behavior.
`max_payload_bytes`	`uint32_t`	Maximum encoded invocation payload.
`handler`	`mk_rpc_handler_fn`	Receiving endpoint handler.
`user`	`void *`	Context passed to handler.

`mk_rpc_reply`struct

Generational handle for replying to an incoming RPC request.

Field	Type	Description
`id`	`uint32_t`	Packed reply slot and generation.

`mk_rpc_result`struct

Result passed to an outgoing RPC completion callback.

Field	Type	Description
`status`	`mk_rpc_status_t`	Terminal request status.
`error_code`	`uint32_t`	Remote application error code.
`error_message`	`mk_string_view_t`	Borrowed remote error message.
`payload`	`mk_reader_t *`	Reader over a successful reply payload.

`mk_snapshot_ack`struct

Acknowledged client input sequence carried by a snapshot.

Field	Type	Description
`input_stream_id`	`uint32_t`	Stable input-stream ID.
`sequence`	`uint32_t`	Newest authoritative sequence processed.

`mk_snapshot_frame_view`struct

Borrowed view of one received authoritative snapshot frame.

Field	Type	Description
`tick`	`uint32_t`	Wrap-safe authoritative simulation tick.
`server_time_ms`	`uint64_t`	Synchronized server timestamp.
`data`	`const void *`	Opaque application state bytes.
`size`	`size_t`	State payload size in bytes.
`acknowledgements`	`const mk_snapshot_ack_t *`	Per-input-stream acknowledgements.
`acknowledgement_count`	`uint32_t`	Number of acknowledgement entries.

`mk_snapshot_sample`struct

Pair of frames and interpolation state selected for rendering.

Field	Type	Description
`older`	`mk_snapshot_frame_view_t`	Older frame view.
`newer`	`mk_snapshot_frame_view_t`	Newer frame view.
`alpha`	`float`	Interpolation or extrapolation factor.
`mode`	`mk_snapshot_sample_mode_t`	How the returned frames should be sampled.

`mk_snapshot_send_report`struct

Outcome counts for a snapshot broadcast operation.

Field	Type	Description
`considered`	`uint32_t`	Connected peers considered.
`staged`	`uint32_t`	New snapshots staged for sending.
`replaced`	`uint32_t`	Older unsent snapshots replaced.
`failed`	`uint32_t`	Peers for which encoding or staging failed.

`mk_snapshot_stream_desc`struct

Registration and buffering policy for one authoritative snapshot stream.

Field	Type	Description
`struct_size`	`uint32_t`	Structure size in bytes.
`struct_version`	`uint32_t`	MK_SNAPSHOT_STREAM_DESC_VERSION.
`id`	`uint32_t`	Stable application stream ID.
`version`	`uint16_t`	Application payload version.
`max_payload_bytes`	`uint32_t`	Maximum encoded state bytes.
`history_size`	`uint32_t`	Retained frames per peer.
`interpolation_delay_ms`	`uint32_t`	Stream interpolation delay override.
`max_extrapolation_ms`	`uint32_t`	Stream extrapolation limit override.

Enums

`mk_multiplayer_capability`enum

Capability bits reported for a connected multiplayer peer.

Value	Description
`MK_MULTIPLAYER_CAP_RELIABLE`	Reliable delivery is available.
`MK_MULTIPLAYER_CAP_UNRELIABLE`	Native unreliable delivery is available.
`MK_MULTIPLAYER_CAP_UNRELIABLE_SEQUENCED`	Native sequenced-unreliable delivery is available.
`MK_MULTIPLAYER_CAP_RPC`	RPC methods are supported.
`MK_MULTIPLAYER_CAP_SNAPSHOTS`	Snapshot streams are supported.
`MK_MULTIPLAYER_CAP_INPUT`	Input streams are supported.

`mk_multiplayer_event_type`enum

Session lifecycle and protocol event type.

Value	Description
`MK_MULTIPLAYER_EVENT_CONNECTED`	A peer completed the transport handshake.
`MK_MULTIPLAYER_EVENT_DISCONNECTED`	A peer disconnected and is being retired.
`MK_MULTIPLAYER_EVENT_PROTOCOL_ERROR`	Incoming data violated the multiplayer protocol.

`mk_multiplayer_protocol_error`enum

Detailed reason for a multiplayer protocol error.

Value	Description
`MK_MULTIPLAYER_PROTOCOL_MALFORMED`	Message framing or payload was malformed.
`MK_MULTIPLAYER_PROTOCOL_UNKNOWN_MESSAGE`	Message type is not recognized.
`MK_MULTIPLAYER_PROTOCOL_UNKNOWN_STREAM`	Stream ID is not registered.
`MK_MULTIPLAYER_PROTOCOL_UNKNOWN_RPC`	RPC method ID is not registered.
`MK_MULTIPLAYER_PROTOCOL_WRONG_DIRECTION`	Message violated declared routing direction.
`MK_MULTIPLAYER_PROTOCOL_VERSION_MISMATCH`	Registered method or stream version differs.
`MK_MULTIPLAYER_PROTOCOL_PAYLOAD_TOO_LARGE`	Payload exceeds its declared limit.

`mk_rpc_direction`enum

Permitted routing direction for an RPC method.

Value	Description
`MK_RPC_CLIENT_TO_SERVER`	Only clients may invoke the server handler.
`MK_RPC_SERVER_TO_CLIENT`	Only the server may invoke client handlers.
`MK_RPC_BIDIRECTIONAL`	Either endpoint may invoke the method.

`mk_rpc_kind`enum

Whether an RPC method is a notification or request/reply call.

Value	Description
`MK_RPC_NOTIFICATION`	One-way message with no completion.
`MK_RPC_REQUEST`	Request that must complete with a result or timeout.

`mk_rpc_status`enum

Terminal status delivered for an outgoing RPC request.

Value	Description
`MK_RPC_STATUS_SUCCESS`	Remote handler returned a payload successfully.
`MK_RPC_STATUS_REMOTE_ERROR`	Remote handler returned an application error.
`MK_RPC_STATUS_TIMEOUT`	Wall-clock timeout elapsed.
`MK_RPC_STATUS_CANCELLED`	Local caller cancelled the request.
`MK_RPC_STATUS_DISCONNECTED`	Peer disconnected before completion.
`MK_RPC_STATUS_PROTOCOL_ERROR`	Reply violated the registered protocol.

`mk_snapshot_sample_mode`enum

Sampling behavior selected for synchronized snapshot playback.

Value	Description
`MK_SNAPSHOT_SAMPLE_INTERPOLATE`	Blend between an older and newer frame.
`MK_SNAPSHOT_SAMPLE_HOLD`	Hold the nearest available frame.
`MK_SNAPSHOT_SAMPLE_EXTRAPOLATE`	Predict forward from the newest frame.

Typedefs

`mk_input_handler_fn`typedef

typedef bool(*) mk_input_handler_fn(mk_multiplayer_t multiplayer, mk_peer_t *peer, uint32_t stream_id, uint32_t sequence, mk_reader_t *payload, void *user)

Handle one accepted client input payload on the server.

Returns True when the payload was accepted.

`mk_input_stream_desc_t`typedef

typedef struct mk_input_stream_desc mk_input_stream_desc_t

Registration and validation policy for a client input stream.

`mk_multiplayer_capabilities_t`typedef

typedef uint32_t mk_multiplayer_capabilities_t

Bitmask of delivery and subsystem capabilities available for a peer.

`mk_multiplayer_desc_t`typedef

typedef struct mk_multiplayer_desc mk_multiplayer_desc_t

Session endpoints, timing, capacities, budgets, and callbacks.

`mk_multiplayer_encode_fn`typedef

typedef bool(*) mk_multiplayer_encode_fn(mk_writer_t *writer, void *user)

Encode a payload into a bounded writer.

Returns True when encoding succeeds.

`mk_multiplayer_event_fn`typedef

typedef void(*) mk_multiplayer_event_fn(mk_multiplayer_t multiplayer, const mk_multiplayer_event_t *event, void *user)

Receive a session lifecycle or protocol event.

`mk_multiplayer_event_t`typedef

typedef struct mk_multiplayer_event mk_multiplayer_event_t

Data delivered to the session event callback.

`mk_multiplayer_event_type_t`typedef

typedef enum mk_multiplayer_event_type mk_multiplayer_event_type_t

Session lifecycle and protocol event type.

`mk_multiplayer_host_desc_t`typedef

typedef struct mk_multiplayer_host_desc mk_multiplayer_host_desc_t

One transport endpoint owned by a multiplayer session.

`mk_multiplayer_now_ms_fn`typedef

typedef uint64_t(*) mk_multiplayer_now_ms_fn(void *user)

Return a monotonic wall-clock time in milliseconds.

Returns Monotonic milliseconds.

`mk_multiplayer_peer_encode_fn`typedef

typedef bool(*) mk_multiplayer_peer_encode_fn(mk_writer_t *writer, mk_peer_t *peer, void *user)

Encode a recipient-specific payload.

Returns True when encoding succeeds.

`mk_multiplayer_protocol_error_t`typedef

typedef enum mk_multiplayer_protocol_error mk_multiplayer_protocol_error_t

Detailed reason for a multiplayer protocol error.

`mk_multiplayer_stats_t`typedef

typedef struct mk_multiplayer_stats mk_multiplayer_stats_t

Aggregate session or per-peer multiplayer counters.

`mk_multiplayer_t`typedef

typedef struct mk_multiplayer* mk_multiplayer_t

Opaque multiplayer session handle.

`mk_rpc_call_t`typedef

typedef struct mk_rpc_call mk_rpc_call_t

Generational handle for an outgoing RPC request.

`mk_rpc_completion_fn`typedef

typedef void(*) mk_rpc_completion_fn(mk_multiplayer_t multiplayer, mk_rpc_call_t call, const mk_rpc_result_t *result, void *user)

Receive terminal completion of an outgoing RPC request.

`mk_rpc_context_t`typedef

typedef struct mk_rpc_context mk_rpc_context_t

Routing metadata supplied to an RPC handler.

`mk_rpc_direction_t`typedef

typedef enum mk_rpc_direction mk_rpc_direction_t

Permitted routing direction for an RPC method.

`mk_rpc_handler_fn`typedef

typedef void(*) mk_rpc_handler_fn(mk_multiplayer_t multiplayer, const mk_rpc_context_t *context, mk_reader_t *payload, mk_rpc_reply_t reply, void *user)

Handle an incoming RPC invocation.

`mk_rpc_kind_t`typedef

typedef enum mk_rpc_kind mk_rpc_kind_t

Whether an RPC method is a notification or request/reply call.

`mk_rpc_method_desc_t`typedef

typedef struct mk_rpc_method_desc mk_rpc_method_desc_t

Registration, routing, delivery, and validation policy for an RPC method.

`mk_rpc_reply_t`typedef

typedef struct mk_rpc_reply mk_rpc_reply_t

Generational handle for replying to an incoming RPC request.

`mk_rpc_result_t`typedef

typedef struct mk_rpc_result mk_rpc_result_t

Result passed to an outgoing RPC completion callback.

`mk_rpc_status_t`typedef

typedef enum mk_rpc_status mk_rpc_status_t

Terminal status delivered for an outgoing RPC request.

`mk_snapshot_ack_t`typedef

typedef struct mk_snapshot_ack mk_snapshot_ack_t

Acknowledged client input sequence carried by a snapshot.

`mk_snapshot_frame_view_t`typedef

typedef struct mk_snapshot_frame_view mk_snapshot_frame_view_t

Borrowed view of one received authoritative snapshot frame.

`mk_snapshot_sample_mode_t`typedef

typedef enum mk_snapshot_sample_mode mk_snapshot_sample_mode_t

Sampling behavior selected for synchronized snapshot playback.

`mk_snapshot_sample_t`typedef

typedef struct mk_snapshot_sample mk_snapshot_sample_t

Pair of frames and interpolation state selected for rendering.

`mk_snapshot_send_report_t`typedef

typedef struct mk_snapshot_send_report mk_snapshot_send_report_t

Outcome counts for a snapshot broadcast operation.

`mk_snapshot_stream_desc_t`typedef

typedef struct mk_snapshot_stream_desc mk_snapshot_stream_desc_t

Registration and buffering policy for one authoritative snapshot stream.

Macros

`MK_INPUT_STREAM_DESC_VERSION`define

MK_INPUT_STREAM_DESC_VERSION

ABI version for mk_input_stream_desc_t.

`MK_MULTIPLAYER_DESC_VERSION`define

MK_MULTIPLAYER_DESC_VERSION

ABI version for mk_multiplayer_desc_t.

`MK_MULTIPLAYER_HOST_DESC_VERSION`define

MK_MULTIPLAYER_HOST_DESC_VERSION

ABI version for mk_multiplayer_host_desc_t.

`MK_MULTIPLAYER_INVALID`define

MK_MULTIPLAYER_INVALID

Invalid multiplayer session handle.

`MK_MULTIPLAYER_WIRE_VERSION`define

MK_MULTIPLAYER_WIRE_VERSION

Multiplayer message-format version folded into the peer protocol ID.

`MK_RPC_CALL_INVALID`define

MK_RPC_CALL_INVALID

Invalid outgoing RPC call handle.

`MK_RPC_METHOD_DESC_VERSION`define

MK_RPC_METHOD_DESC_VERSION

ABI version for mk_rpc_method_desc_t.

`MK_RPC_REPLY_INVALID`define

MK_RPC_REPLY_INVALID

Invalid incoming RPC reply handle.

`MK_SNAPSHOT_STREAM_DESC_VERSION`define

MK_SNAPSHOT_STREAM_DESC_VERSION

ABI version for mk_snapshot_stream_desc_t.

multiplayer.h

Functions

mk_input_stream_desc_initfunction

mk_multiplayer_capabilitiesfunction

mk_multiplayer_connectfunction

mk_multiplayer_connect_urlfunction

mk_multiplayer_createfunction

mk_multiplayer_desc_initfunction

mk_multiplayer_destroyfunction

mk_multiplayer_disconnectfunction

mk_multiplayer_effective_deliveryfunction

mk_multiplayer_get_statsfunction

mk_multiplayer_host_desc_initfunction

mk_multiplayer_max_unreliable_payloadfunction

mk_multiplayer_now_msfunction

mk_multiplayer_peer_countfunction

mk_multiplayer_peer_firstfunction

mk_multiplayer_peer_nextfunction

mk_multiplayer_pollfunction

mk_multiplayer_register_inputfunction

mk_multiplayer_submit_inputfunction

mk_rpc_callfunction

mk_rpc_cancelfunction

mk_rpc_method_desc_initfunction

mk_rpc_notifyfunction

mk_rpc_notify_allfunction

mk_rpc_notify_all_exceptfunction

mk_rpc_registerfunction

mk_rpc_reply_deferfunction

mk_rpc_reply_errorfunction

mk_rpc_reply_sendfunction

mk_snapshot_frame_ackfunction

mk_snapshot_registerfunction

mk_snapshot_samplefunction

mk_snapshot_sendfunction

mk_snapshot_send_allfunction

mk_snapshot_send_all_encodedfunction

mk_snapshot_stream_desc_initfunction

Structs

mk_input_stream_descstruct

mk_multiplayer_descstruct

mk_multiplayer_eventstruct

mk_multiplayer_host_descstruct

mk_multiplayer_statsstruct

mk_rpc_callstruct

mk_rpc_contextstruct

mk_rpc_method_descstruct

mk_rpc_replystruct

mk_rpc_resultstruct

mk_snapshot_ackstruct

mk_snapshot_frame_viewstruct

mk_snapshot_samplestruct

mk_snapshot_send_reportstruct

mk_snapshot_stream_descstruct

Enums

mk_multiplayer_capabilityenum

mk_multiplayer_event_typeenum

mk_multiplayer_protocol_errorenum

mk_rpc_directionenum

mk_rpc_kindenum

mk_rpc_statusenum

mk_snapshot_sample_modeenum

Typedefs

mk_input_handler_fntypedef

mk_input_stream_desc_ttypedef

mk_multiplayer_capabilities_ttypedef

mk_multiplayer_desc_ttypedef

mk_multiplayer_encode_fntypedef

mk_multiplayer_event_fntypedef

mk_multiplayer_event_ttypedef

mk_multiplayer_event_type_ttypedef

mk_multiplayer_host_desc_ttypedef

mk_multiplayer_now_ms_fntypedef

mk_multiplayer_peer_encode_fntypedef

mk_multiplayer_protocol_error_ttypedef

mk_multiplayer_stats_ttypedef

mk_multiplayer_ttypedef

mk_rpc_call_ttypedef

mk_rpc_completion_fntypedef

mk_rpc_context_ttypedef

`mk_input_stream_desc_init`function

`mk_multiplayer_capabilities`function

`mk_multiplayer_connect`function

`mk_multiplayer_connect_url`function

`mk_multiplayer_create`function

`mk_multiplayer_desc_init`function

`mk_multiplayer_destroy`function

`mk_multiplayer_disconnect`function

`mk_multiplayer_effective_delivery`function

`mk_multiplayer_get_stats`function

`mk_multiplayer_host_desc_init`function

`mk_multiplayer_max_unreliable_payload`function

`mk_multiplayer_now_ms`function

`mk_multiplayer_peer_count`function

`mk_multiplayer_peer_first`function

`mk_multiplayer_peer_next`function

`mk_multiplayer_poll`function

`mk_multiplayer_register_input`function

`mk_multiplayer_submit_input`function

`mk_rpc_call`function

`mk_rpc_cancel`function

`mk_rpc_method_desc_init`function

`mk_rpc_notify`function

`mk_rpc_notify_all`function

`mk_rpc_notify_all_except`function

`mk_rpc_register`function

`mk_rpc_reply_defer`function

`mk_rpc_reply_error`function

`mk_rpc_reply_send`function

`mk_snapshot_frame_ack`function

`mk_snapshot_register`function

`mk_snapshot_sample`function

`mk_snapshot_send`function

`mk_snapshot_send_all`function

`mk_snapshot_send_all_encoded`function

`mk_snapshot_stream_desc_init`function

`mk_input_stream_desc`struct

`mk_multiplayer_desc`struct

`mk_multiplayer_event`struct

`mk_multiplayer_host_desc`struct

`mk_multiplayer_stats`struct

`mk_rpc_call`struct

`mk_rpc_context`struct

`mk_rpc_method_desc`struct

`mk_rpc_reply`struct

`mk_rpc_result`struct

`mk_snapshot_ack`struct

`mk_snapshot_frame_view`struct

`mk_snapshot_sample`struct

`mk_snapshot_send_report`struct

`mk_snapshot_stream_desc`struct

`mk_multiplayer_capability`enum

`mk_multiplayer_event_type`enum

`mk_multiplayer_protocol_error`enum

`mk_rpc_direction`enum

`mk_rpc_kind`enum

`mk_rpc_status`enum

`mk_snapshot_sample_mode`enum

`mk_input_handler_fn`typedef

`mk_input_stream_desc_t`typedef

`mk_multiplayer_capabilities_t`typedef

`mk_multiplayer_desc_t`typedef

`mk_multiplayer_encode_fn`typedef

`mk_multiplayer_event_fn`typedef

`mk_multiplayer_event_t`typedef

`mk_multiplayer_event_type_t`typedef

`mk_multiplayer_host_desc_t`typedef

`mk_multiplayer_now_ms_fn`typedef

`mk_multiplayer_peer_encode_fn`typedef

`mk_multiplayer_protocol_error_t`typedef

`mk_multiplayer_stats_t`typedef

`mk_multiplayer_t`typedef

`mk_rpc_call_t`typedef

`mk_rpc_completion_fn`typedef

`mk_rpc_context_t`typedef

`mk_rpc_direction_t`typedef

`mk_rpc_handler_fn`typedef

`mk_rpc_kind_t`typedef

`mk_rpc_method_desc_t`typedef

`mk_rpc_reply_t`typedef