tormol / space_tennis

A 3D pong game

Space tennis

A 3D pong game written in Rust using the Piston game engine.

How to play / Game mechanics

The goal of the game is to block the ball from leaving the square tube at your side, and make the computer-controlled oponent unable to do so at his end.
The ball bounces of walls without changing speed, but will take up a percentage of the velocity of the racket when it hits it.
A new round is started when somebody misses, and the loser starts with the ball attached to his racket.
Move your racket with the mouse or arrow keys, and click any mouse button or press space or enter to start the round when you have the ball.
Clicking or pressing enter or space when the ball is moving will pause or un-pause the game.

Compiling

You need the Rust compiler and package manager, which can be downloaded from rust-lang.org. Then run these commands:

git clone https://github.com/tormol/space_tennis
cd space_tennis
cargo build --release
cargo run --release

Hot Reloading Mode

To speed up the edit-compile-run cycle, most of the game logic can be compiled as a dynamic library which is recompiled and reloaded when the source is changed.

This is enabled by the dyn feature:

cargo run --features dyn

The dynamic library has minimal dependencies, and compiles in 1,5 seconds on my A10-4600M laptop, whereas the main program takes 4,3 seconds. (Both examples are after minimal code changes.)

The compile times could be improved further by not going though cargo each time, but build plans are an unstable cargo feature so that would be brittle.

I originally reloaded the executable, which would've made this trivial to reuse for other games as all the game-specific code was there and the game engine and reloading stuff was in a dynamic library. But newer versions of glibc or libdl doesn't allow loading executables as dynamic libraries, so I had to switch it around.
Exporting symbols from an executable also required passing "-C link-args=-Wl,-export-dynamic" via RUSTFLAGS, which would cause all dependencies to be compiled again on the first reload if you forgot to set it for the original cargo build or cargo run.

License

Copyright 2018 Torbjørn Birch Moltu. Licensed under the GNU General Public License, as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.