SASD Protocols

Tests of many syncronization methods with TCP:

Protocols

• Timewarp + LocalLag
• Perceptive Consistency
• Trailing State Syncronization
• Dead Reckoning

Build instructions

Requirements:

• cmake >= 3.0
• SDL2 (Graphics library)

Tested on linux and macOS.

First, compile netutils library:

# Inside the project root directory execute
cd src/netutils
mkdir build
cd build
cmake ..
make
make install

Then, compile tests:

# Inside the project root directory execute
mkdir build
cd build
cmake ..
make
make install # Copies useful start scripts to build directory

If succesful, the following binary files will be generated:

• server: Broadcast server. Simulates p2p multicast with a TCP connection.
• dr_server: Centralized server. Simulates game state updates and sends them back to all connected clients. Used for the dead reckoning protocol.
• game_timewarp: Timewarp client implementation.
• game_fasteventordering: Perceptive consistency client implementation.
• game_deadreckoning: Dead reckoning client implementation.

How to run

Timewarp test:

As a p2p protocol, it need an instance of server running before any client is connected. To ensure consistency in tests, it is preferable to start all game_timewarp clients simultaneously.

To run predefined tests, from build directory execute:

# In a terminal
./server
# In another terminal
sh tw_start.sh

Perceptive consistency test:

As a p2p protocol, it need an instance of server running before any client is connected. To ensure consistency in tests, it is preferable to start all game_fasteventordering clients simultaneously.

Note that game_fasteventordering needs to know how many clients there will be connected, so it receives a single argument to acknoledge it at runtime.

To run predefined tests, from build directory execute:

# In a terminal
./server
# In another terminal
sh feo_start.sh

Dead reckoning test:

This protocol needs its server executed at the same time as the clients since it also simulates new states. To ensure consitency, all game_deadreckoning clients and dr_server must be started simultaneously.

To run predefined tests, from build directory execute:

sh dr_start.sh

Simulated lag

Lag can be simulated by modifying the following parameters:

Timewarp:

In the beginning of the file src/game_timewarp.c, a "lag matrix" is defined. Each cell indicates the lag from client row to client column.

Perceptive consistency:

In the beginning of the file src/game_fasteventordering.c, a "lag matrix" is defined. Each cell indicates the lag from client row to client column.

Dead reckoning:

In the beginning of the file src/game_deadreckoning.c, there are 2 "lag arrays":

• input_lags indicate the simulated delay for the incoming states from the server.
• local_lags indicate the delay between the event summoning frame and its execution frame (before it has reached the server and back).

Document compilation instructions

Required packages:

• texlive-fourier