Road Rumble

CI compiles both binaries but does not run them.

▶ Watch the trailer on YouTube

A four-player top-down racing game written in C with SDL2, where a dedicated server relays car state between clients over UDP.

Built as a team project at KTH. All four players share one fixed screen — there is no split-screen and no scrolling camera; the whole track fits in the window.

What works

Racing

• Four cars on a tile-based track, three laps, first to finish wins.
• Car-to-car collision (positional push-apart with speed damping) and car-to-world collision against barrels, crates, and off-track tiles.
• Lap counting on finish-line crossing, with a laps/3 HUD and a winner screen that resets the round.
• Drift mechanic with tyre trails that persist behind the car.
• Boost: drive over the boost tile on lap 2 to unlock a single 5-second burst at double acceleration, triggered with Right Shift, drawn as an animated flame. Both drift and boost are replicated to the other players.
• Animated traffic-light countdown with three sound cues, started by the server once every player has joined.

Networking

• Dedicated server binary, separate from the client, on UDP port 55000 via SDL_net.
• Four player slots, address-based registration, "server full" rejection, and a five-second inactivity timeout.
• Round-trip ping measured once per second and drawn in the corner, colour-coded by latency.

Interface

• Menus for Start, Multiplayer, and Options, in two complete themes: classic and dark.
• Options: theme toggle, WASD/arrow-key remapping, five-step music and SFX sliders, mute.
• Multiplayer menu with text-entry fields for the server IP and player ID.
• Diagnostic mode (--test) that checks the renderer, the font, and SDL_net initialisation before starting.

Download

Prebuilt zips for Linux, macOS, and Windows are attached to each GitHub release. The Windows zip bundles the SDL2 DLLs; on Linux and macOS you still need the SDL2 libraries from Requirements below.

Requirements

• A C compiler (GCC) and make
• SDL2 plus SDL2_image, SDL2_ttf, SDL2_net, SDL2_mixer

# Debian / Ubuntu
sudo apt install build-essential libsdl2-dev libsdl2-image-dev \
                 libsdl2-ttf-dev libsdl2-net-dev libsdl2-mixer-dev

# macOS
brew install sdl2 sdl2_image sdl2_ttf sdl2_net sdl2_mixer

On Windows, build under MSYS2/MinGW64. Makefile.win expects the SDL2 headers and libraries at C:/msys64/mingw64; edit INCLUDEDIR and LIBDIR if your installation lives elsewhere.

Building

make

The top-level Makefile detects the platform and includes Makefile.linux, Makefile.win, or Makefile.mac. It produces two binaries in the repository root: Game (the client, Game.exe on Windows) and server.

Makefile.mac builds only the client. To get a server on macOS, build it by hand:

gcc -Iinclude -o server source/server_main.c source/server.c \
    -lSDL2main -lSDL2 -lSDL2_net -lm

Running

A race needs exactly four clients — see Known gaps. Start the server first, then four clients with IDs 1 through 4.

./server                          # terminal 1
./Game --ip 127.0.0.1 --id 1      # terminal 2
./Game --ip 127.0.0.1 --id 2      # terminal 3
./Game --ip 127.0.0.1 --id 3      # terminal 4
./Game --ip 127.0.0.1 --id 4      # terminal 5

Run the binaries from the repository root — asset paths are relative to the working directory.

Flag	Meaning
--ip <address>	Server address. Port is always 55000.
--id <1-4>	Player slot. Each client needs a different one.
--test	Run the startup diagnostics, then continue into the game.
--debug	Verbose logging.

Controls

Key	Action
W A S D or arrow keys	Drive (switch the scheme in Options)
Right Shift	Boost, once unlocked on lap 2
Esc	First press leaves fullscreen, second press quits

The client redirects its own stdout and stderr to testlog.txt, so nothing prints to the terminal. Read that file when diagnosing a failure.

Known gaps

These are real and currently unfixed. They are tracked as issues.

• A race needs exactly four players, not "up to four". The server sends the start signal only when all four slots are active, and nothing moves until it arrives. Single-player and two- or three-player sessions put you on the track with a car that never responds to input.
• Three buttons are invisible in the dark theme. Their textures are declared and drawn but never loaded, so the back and enter buttons render as nothing while the dark theme is active.

Team

Ibrahim Awad, Ahmed El Yasini, Ali Al Roudini, Ousama Sayeh Kebiche, Hamza Osman, Malik Zihaoui.

Managed with SCRUM in Taiga.

License

MIT