GameBoyEmulator

Game Boy Emulator made in C++.

MIT License

Stars
4
View Code on GitHub
Ecosystems: C++

GameBoyEmulator

Description

Game Boy Emulator developed in C++ using SDL2. You can compile the program using CMake. Games like Pokémon aren't working due to the lack of MBC3/MBC5 cartridges implementation.

SDL2 website: https://www.libsdl.org

Note C++ version 17 SDL2 version 2.0.14.

Features

The Emulator features :

  • Save-state
  • Screenshots
  • Different color modes
  • Audio
  • Xbox/PlayStation controller

Images

Tetris Super Mario Land 2
tetrisTitleScreen marioLand2TitleScreen
Kirby's Dream Land The Legend of Zelda Link's Awakening
kirbyDreamLandTitleScreen zeldaTitleScreen

Video

https://user-images.githubusercontent.com/59691442/150530024-ac2dceee-1162-4894-bc44-334bbad2544f.mp4

Quickstart

To use the emulator it depends on your system. Please follow the steps in section Windows or Linux.

All the releases can be found in the link below: Source code and releases

You can download the emulator by clicking on one of the Windows or Linux images, depending on your operating system.

Windows

Once download make sure you have the sdl2.dll file next to the emulator .exe file, you can start the emulator by doing a drag and drop of a rom to the .exe file, it will automatically start the game. You can also start the emulator by typing the following command in your terminal.

./GameBoyEmulator.exe <romPath>

Linux

Once download you'll need to install the SDL2 library by typing one of the following commands :

sudo apt-get install libsdl2-dev

or

sudo apt-get install libsdl2-2.0-0

Warning Depending on your Linux distribution the command to install SDL2 may change.

Once it's done, you can start the emulator by doing a drag and drop of a rom on the emulator file, or you can type the following command:

./GameBoyEmulator.exe <romPath>

Compilation

Emulator is supported under Linux and Windows. The source code provide a CMakeList.txt file to compile the emulator.

You can download CMake here: https://cmake.org

Linux's users need to install the developer version of SDL2 to compile the Emulator. To install it types the following command in your terminal:

sudo apt-get install libsdl2-dev

Emulator controls

Emulator interface

  • F10 : Switch Game Boy's color mode (GreenScale or Grayscale)

  • F11 : Switch between Fullscreen and windowed mode

  • Escape button/click cross to exit emulation

  • O : Create a screenshot of the game in the folder next to tha app (screenshots/)

  • P : Pause emulation

  • U : Increase emulator audio volume

  • J : Decrease emulator audio volume

  • B : create save-state

  • N : load save-state

  • Tab : restart game/emulator

Use save states

To use a save-state press the B button on your keyboard, it will create a bmp image file named with the name of the game and the extension .gb.state.bmp. To load it, just press the N on your keyboard to load it when the game is playing.

The save-state is a screenshot of the game, allowing you to know where you're going to resume the game if you use it.

Screenshots feature

The emulator allow you to do screenshot of the game everytime. You can create one by pushing the IMP key on your keyboard. The screenshots will be saved in the folder next to the Emulator screenshots/<gameName>.

Emulator game controls

You can play games with your keyboard and also with Xbox or Playstation controller.

The controller must be connected before you start the emulator. The selected controller will Rumble for you to know which controller has been selected (for PlayStation user the controller's led will be green).

Console buttons Emulator buttons Xbox Controller Playstation Controller
A D B O
B S A X
Start Enter start options
Select Space select share
← ← arrow/joystick arrow/joystick
→ → arrow/joystick arrow/joystick
↓ ↓ arrow/joystick arrow/joystick
↑ ↑ arrow/joystick arrow/joystick

Ini file

When you download/start the emulator you will get a GameBoyEmulator.ini file. This file allows you to change some parameters about the emulator.

Ini file setting Description
startBios load or not bios
biosPath set boot-rom path
width window width
height window height
colorMode change color mode (from 0 to 3)

You can modify each of these parameters manually. To disable the bios load, put the value 0 in

Original .ini file:

startBios='0'
biosPath='./dmg_boot.bin'
width='640'
height='576'
colorMode='0'

Emulation color modes

Zelda Link's Awakening in grayscale Zelda Link's Awakening in green-scale
zelda_grayscale zelda_green-scale

GitHub Actions

The repository has a GitHub Actions file to verify the good behaviour of the project before merging/pushing to the main branch with a wrong code.

Documentations

CMake: https://cmake.org

SDL wiki: https://wiki.libsdl.org

Video overview of the Game Boy, to understand the fundamental: https://www.youtube.com/watch?v=HyzD8pNlpwI

The main documentation about the console: https://archive.org/details/GameBoyProgManVer1.1/mode/2up https://gbdev.io/pandocs/Specifications.html

The boot-rom: https://gbdev.gg8.se/wiki/articles/Gameboy_Bootstrap_ROM

Opcodes map: https://www.pastraiser.com/cpu/gameboy/gameboy_opcodes.html

Rom/Ram banking: http://www.codeslinger.co.uk/pages/projects/gameboy/beginning.html

PPU: https://hacktixme.ga/GBEDG/ppu/

Audio and sound: https://xiph.org/video/vid1.shtml

SPU: https://nightshade256.github.io/2021/03/27/gb-sound-emulation.html https://emudev.de https://www.youtube.com/watch?v=a52p6ji1WZs

Test roms I used to debug my emulator: https://gbdev.gg8.se/files/roms/blargg-gb-tests/ https://github.com/mattcurrie/dmg-acid2

Other docs (mostly about emulation in general): https://emudev.org http://emulator101.com/

Contributors

Quentin MOREL :

Badges
Extracted from project README
CMake GitHub contributors