space_invaders_arcade_emulator

Description

Space Invaders arcade game emulator made in Rust with SDL2 and SDL2_mixer.

Complete Emulator of the Intel 8080, the app is implemented to run the Space Invaders Arcade game.

Everything is working including the Space Invaders Easter Egg.

You can also play it in the browser, I ported the code to WebGL, you can find the code here.

🚀🚀 Play in the browser here. 🚀🚀

Features

Full emulation
Sound
Two-players mode
Window resizing without deformation

Images

Title screen	Game screen

Taito Cop Easter Egg	Score advance table with Invaders

Videos

https://user-images.githubusercontent.com/59691442/183045566-0a3df947-06e7-4c46-9fc6-9d2b8f7d9a46.mp4

Quick start

To download the emulator, you can click one of the icons below depending on your operating system, or you can click the release section of the GitHub page.

For each version when you unzip the downloaded release, you will get the executable and two folder, one named game_roms where you must put the game's roms:

invaders.h
invaders.g
invaders.e
invaders.f

Depending on you operating system you will need to install some libs, they are installed differently depending on your system, please follow one of the section below Windows or Linux or MacOs.

Windows

For Windows users you don't need to install the libs, you just need to be carefully that you have the SDL2.dll and SDL2_mixer.dll next to the space_invaders_arcade_emulator.exe or the emulator won't start.

Once everything is set up by you can start the emulator by double-clicking the executable of typing the following command next to it:

.\space_invaders_arcade_emulator.exe

Linux

For Linux users, you need to install the SDL2 lib, to do so type one of the following commands:

sudo apt-get install libsdl2-2.0-0 libsdl2-mixer-2.0-0

or if you're a developer and want to compile the Emulator, please install this version of SDL2:

sudo apt-get install libsdl2-dev libsdl2-mixer-dev

Then you can start by double-clicking the executable of typing the following command next to it:

./space_invaders_arcade_emulator

MacOs

For macOS users you will need to install Brew, please follow the instruction in the link below: https://brew.sh

Once it is installed, you can type the following command to install SDL2.

brew install sdl2
brew install sdl2_mixer

You also need to add SDL2 to the paths by typing:

export LIBRARY_PATH="$LIBRARY_PATH:$(brew --prefix)/lib"

Then you can start by double-clicking the executable of typing the following command next to it:

./space_invaders_arcade_emulator

Controls

You can use the keyboard to play the game.

Arcade buttons	Emulator/Keyboard
Insert coin	C
Shoot	↑
←	←
→	→
Start 1	1
Start 2	2

The original game is mapped with some inputs that allow the constructor to choose the difficulty. I Mapped those inputs to the keyboard. This allows you to increase the numer of lives and change the extra ship necessity points.

Before pressing start with player 1 or 2, you can choose the number of life you want to have for a game party.

Emulator/Keyboard	Emulator buttons
O	Show additional info in demo
K	1 more life
L	2 more lives
M	extra ship at 1000 points instead of 1500 points

Note If you don't keep pressed K or L before pressing start and starting a new game you will have 3 lives. In the same way, you can enable the extra ship to came at 1000 points instead of 1500, but you just need to press the button one time (a confirmation will be displayed in the console).

Code architecture

The Emulator is divided into 4 parts:

main (starter)
si_arcade (console emulation)
my_sdl2 (video, audio and inputs si_arcade interpreter)
binary_lib (a set of binary functions to manipulate data)

The sound is implemented using .wav files, they are loaded in the si_aracade part of the program and totally interpreted in the my_sdl2 part.

Compilation

First thing you need is to install cargo and rust. You can find them by following the instructions in the link below: https://www.rust-lang.org/tools/install

You also need to download the following audio files:

0.wav
1.wav
2.wav
3.wav
4.wav
5.wav
6.wav
7.wav
8.wav

The wav files wan be downloaded in the links below: https://samples.mameworld.info https://www.classicgaming.cc/classics/space-invaders/sounds

They all must be put in the game_audios folder.

Warning Be carefully when downloading the .wav files, some files pay have the wrong name.

Depending on your OS, you will need to follow specific steps to compile the app. Please refer to the sections below Windows, Linux and macOs.

Windows

~~Windows users need to install SDL2 for your OS. The setup instruction can be followed in the link below:~~ https://github.com/Rust-SDL2/rust-sdl2

I set up a static SDL2 Linking so Windows user just need to download the project and everything will be set up for SDL2. I used the instructions in the link below to set up the dynamic linking: https://github.com/Rust-SDL2/rust-sdl2#user-content-windows-with-build-script

Linux

Linux Users need to install the SDL2 libs (SDL2 and SDL2_mixer). To do so, type in your bash system the following commands.

If you want to compile the program, install the developer version with the command below:

sudo apt-get install libsdl2-dev libsdl2-mixer-dev

MacOs

For macOS users you will need to install Brew, please follow the instruction in the link below: https://brew.sh

Once it is installed, you can type the following command to install SDL2.

brew install sdl2
brew install sdl2_mixer

You also need to add SDL2 to the paths by typing:

export LIBRARY_PATH="$LIBRARY_PATH:$(brew --prefix)/lib"

With Rust and SDL2 libs installed, you can now compile the project in two-way, debug or release. To compile go to the project root folder and type one of the two following commands below (If you want to use the emulator please compile using the second command).

cargo build

cargo build --release

The compiled app will be in the folder target/debug or target/release depending on the compilation you did.

Rust tests

You can test the good behaviour of the project by typing the commands onf of the following command. It will start the unit test of the CPU.

It will start a test rom for the Intel 8080 CPU. You can find it in the link below: https://altairclone.com/downloads/cpu_tests/

cargo test

cargo test --release

Currently, the CPU is passing the following tests:

cpudiag.bin
TST8080.COM
8080PRE.COM
CPUTEST.COM
8080EXER.COM
8080EXM.COM

The tests are named:

cpu_test_rom_cpudiag
cpu_test_rom_tst8080
cpu_test_rom_8080pre
cpu_test_rom_cputest
cpu_test_rom_8080exer
cpu_test_rom_8080exm

You can start them individuality by typing:

cargo test <test_name>

cargo test <test_name> --release

Example: If you want to start the cpu_test_rom_tst8080 test.

cargo test cpu_test_rom_tst8080

cargo test cpu_test_rom_tst8080 --release

To show the CPU test logs, you can use the --show-output flag.

cargo test --release -- --show-output

You can also debug disassembly by uncommenting the two following lines in the cpu.rs file in the test module.

// let mut f = File::create("test_roms/my_output.log").expect("Cannot create debug log file");

// write_debug_to_file(&mut cpu_debug, &mut f, cycles_counter);

This will output the complete disassembly of the CPU in the test_roms/my_output.log file.

Note Depending on the test the output is different. Refer to this project for more explanation about how they work. https://github.com/superzazu/8080 http://www.emulator101.com/full-8080-emulation.html

The last test (cpu_test_rom_8080exm) can take a lot of time in debug mode, you should test it in release mode, use the command below:
cargo test cpu_test_rom_8080exm --release