Messages

To receive messages from the server, you must first register your client. This is done by opening a mapped file with the server name of the game instance you want to connect to. To register, send a C_REGISTER message. If a client is already registered, the server will respond with kClientAlreadyRegistered error code. If the registration was successful, the error code will be 0. To deregister, send a C_DEREGISTER message.

Synchronous server calls

While being registered, TMInterface will call the client on events such as a simulation step, a race step, checkpoint state change and more. Each call is completely synchronous - no game code is being executed while waiting for the client to process the request. A server call is simply a message with a special type prefixed with S_. Available calls that need to be handled are:

• S_SHUTDOWN - process server shutting down
• S_ON_RUN_STEP - process race physics step
• S_ON_SIM_BEGIN - process a start of new simulation
• S_ON_SIM_STEP - process a single physics simulation tick
• S_ON_SIM_END - process the end of a simulation
• S_ON_CHECKPOINT_COUNT_CHANGED - process current checkpoint count change
• S_ON_LAPS_COUNT_CHANGED - process current laps count change

For a description of each call refer to the header file. After processing the call, the client has to respond back with a message of type C_PROCESSED_CALL, and with the which field set to the call ID it responds to. The server will clear the buffer after receiving a response.

If the client fails to respond within the timeout window (default 2000ms), the server will automatically deregister the client and will continue to run. This timeout can be configured by sending a message of type C_SET_TIMEOUT after registering or in one of the server calls.