pokeemerald-multiplatform

An experimental Windows, Linux, and Android port of the Pokemon Emerald decompilation.

The project runs the decompiled game code directly. It is not a bundled GBA emulator and does not include a commercial ROM.

Platform Status

Platform	Status	Output
Windows	Working through the SDL2 backend	pokeemerald.exe
Linux	Working native 32-bit SDL2 build	pokeemerald
Android	Working experimental ARMv7 SDL2 build	android/app/build/outputs/apk/debug/app-debug.apk
GBA ROM	Upstream target	pokeemerald.gba

Port Changes

• Repaired the portable MP2K/M4A music player and sound mixer build.
• Added SDL2 float audio output at 42060 Hz.
• Sanitized invalid floating-point samples independently in the M4A and CGB audio paths, eliminating loud buzzing without discarding valid audio.
• Added output headroom and clipping protection.
• Fixed structure and pointer conversions required by the portable audio engine.
• Fixed portable BIOS, DMA, flash-save, trainer-card, and sound-related compilation errors.
• Added working save-file access through pokeemerald.sav.
• Added a Wine launcher for the Windows build.
• Added native 32-bit Linux compilation and SDL2 linkage.
• Added aspect-ratio-preserving 3:2 rendering with independently scaled background artwork and a transparent frame.
• Added persistent display settings with automatic support for additional numbered background images.
• Added an experimental Android SDL2/Gradle project and an ARMv7 cross-compilation pipeline.
• Added Android rendering, frame pacing, audio output, writable save storage, and lifecycle handling.
• Added an Android-native labeled multitouch overlay and SDL game-controller input.
• Added launcher icons on Android and an embedded multi-resolution icon on Windows.
• Added an experimental 2.5D voxel renderer engine for Pokémon maps (--voxel).

Controls

GBA control	Keyboard
A	Z
B	X
Start	Enter
Select	Backslash
L	A
R	S
D-pad	Arrow keys
Fast-forward	Space
Pause	Ctrl+P
Soft reset	Ctrl+R

Windows XInput controllers are supported by the SDL2 backend. Android supports SDL-compatible gamepads, including D-pad and left analog-stick movement. Native Linux currently uses keyboard input.

Windows Build

The Windows target uses the 32-bit MinGW toolchain, SDL2, and ImageMagick. ImageMagick converts the PNG border assets to alpha-preserving BMP files supported by the Windows SDL2 build:

make -f Makefile_pc -j4

Place SDL2.dll beside pokeemerald.exe. On Linux, the Windows build can be launched through Wine with:

./launch.sh

Linux Build

The game data contains 32-bit pointers, so the native Linux target must currently be built as a 32-bit executable. Install a multilib C toolchain plus 32-bit SDL2 and SDL2_image development files, then run:

make -f Makefile_pc linux -j4
./pokeemerald

Linux objects are kept separately under build/linux, so they do not interfere with the Windows build.

The resulting executable is pokeemerald in the repository root.

Display Settings

The in-game Options menu includes a DISPLAY page. Settings apply immediately and are written to pokeemerald.cfg; Android stores the same config in the app's private storage.

Desktop builds support fullscreen, window size, integer scaling, VSync, border frame visibility, background selection, and volume. Android supports border frame visibility, background selection, and volume.

Border Artwork

Windows, Linux, and Android use the same border assets from the repository root:

• Border.png is the transparent frame fitted around the centered 3:2 gameplay viewport.
• BG.png is the default background and scales independently to fill the complete output.
• BG1.png, BG2.png, and subsequent sequentially numbered files add selectable backgrounds after the default BG entry.

The background selector order is BG, BG 1, BG 2, and so on, followed by OFF for a plain black background. Numbered files must be contiguous; for example, BG2.png is only detected when BG1.png is also present.

Backgrounds and the frame should use a 1280x720 canvas. Keep the frame opening centered at the same location and dimensions as Border.png so it remains aligned at different output aspect ratios.

Saving

Save data is read from and written to:

pokeemerald.sav

Keep this file if you clean or move the build.

Voxel Engine (Experimental)

This repository includes an experimental 2.5D voxel renderer. Instead of drawing flat 2D tilemaps, the engine extrapolates Pokémon map collision and metadata into a 3D environment with seamless map connections, structure grouping, and dynamic camera cutaways.

To run the game in voxel mode on Linux, pass the --voxel flag:

./pokeemerald --voxel

To enable a free-roaming 3D First-Person camera instead of the fixed isometric follow-camera, press F7 in-game while in voxel mode. Use W/A/S/D to move and Space/Shift to ascend/descend.

Android Build

The Android project targets API 36 and armeabi-v7a. The 32-bit ABI is required by the game's current pointer layout. Android SDK 36, NDK 26.3.11579264, CMake 3.22.1, and a compatible JDK are required.

Initialize SDL2 and apply the Android lifecycle patch once after cloning:

git submodule update --init --recursive
git -C android/SDL2 apply ../patches/sdl2-android-lifecycle.patch

Set JAVA_HOME and ANDROID_HOME, then build with SDL2's Gradle wrapper:

android/SDL2/android-project/gradlew -p android :app:assembleDebug

Install the debug APK on a connected device with:

adb install -r android/app/build/outputs/apk/debug/app-debug.apk

Android saves are stored in the app's writable private storage. Windows and Linux continue to use pokeemerald.sav in the working directory.

Android includes a labeled multitouch overlay for the D-pad, A, B, Start, Select, L, and R.

Upstream Project

This repository is based on the Pokémon Emerald decompilation. The upstream project builds the following ROM:

• pokeemerald.gba
• SHA-1: f3ae088181bf583e55daf962a92bb46f4f1d07b7

See INSTALL.md for the original decompilation setup and pret.github.io for other pret projects.

Legal

Pokémon and Pokémon Emerald are trademarks of Nintendo, Creatures Inc., and GAME FREAK inc. This is an unofficial fan project and is not affiliated with or endorsed by those companies.

The scoped license in LICENSE applies only to original multiplatform-port modifications contributed through this fork. It does not relicense upstream code, third-party components, or copyrighted game assets.