### Prerequisites

The building of all five executables can be done on an x86 Linux system, but the runtime MUST be prepared and copied from the target systems.

### Preparation

Download and unzip the JDKs to ~/Documents/openjdk/* for the appropriate operating systems first! JDKs can be downloaded on https://jdk.java.net/archive/.

The filenames must be:

| Target OS/Arch      | filename           |
|---------------------|--------------------|
| Linux AMD64         | jdk-21.0.2-x86     |
| Linux Aarch64       | jdk-21.0.2-arm     |
| Windows AMD64       | jdk-21.0.2-windows |
| macOS Apple Silicon | jdk-21.0.2.jdk-arm |
| macOS Intel         | jdk-21.0.2.jdk-x86 |

Then, on the terminal, run following commands:

```
jlink --module-path ~/Documents/openjdk/jdk-21.0.2-x86/jmods:mods  --add-modules java.base,java.desktop,java.net.http,jdk.crypto.ec,java.logging,java.scripting,jdk.unsupported --output ~/Documents/Terrarum/out/runtime-linux-x86 --no-header-files --no-man-pages --strip-debug --compress=2
jlink --module-path ~/Documents/openjdk/jdk-21.0.2-arm/jmods:mods  --add-modules java.base,java.desktop,java.net.http,jdk.crypto.ec,java.logging,java.scripting,jdk.unsupported --output ~/Documents/Terrarum/out/runtime-linux-arm --no-header-files --no-man-pages --strip-debug --compress=2
jlink --module-path ~/Documents/openjdk/jdk-21.0.2-windows/jmods:mods  --add-modules java.base,java.desktop,java.net.http,jdk.crypto.ec,java.logging,java.scripting,jdk.unsupported --output ~/Documents/Terrarum/out/runtime-windows-x86 --no-header-files --no-man-pages --strip-debug --compress=2
jlink --module-path ~/Documents/openjdk/jdk-21.0.2.jdk-arm/Contents/Home/jmods:mods  --add-modules java.base,java.desktop,java.net.http,jdk.crypto.ec,java.logging,java.scripting,jdk.unsupported --output ~/Documents/Terrarum/out/runtime-osx-arm --no-header-files --no-man-pages --strip-debug --compress=2
jlink --module-path ~/Documents/openjdk/jdk-21.0.2.jdk-x86/Contents/Home/jmods:mods  --add-modules java.base,java.desktop,java.net.http,jdk.crypto.ec,java.logging,java.scripting,jdk.unsupported --output ~/Documents/Terrarum/out/runtime-osx-x86 --no-header-files --no-man-pages --strip-debug --compress=2
```

This process assumes that the game does NOT use the Java 9+ modules and every single required libraries are fat-jar'd (their contents extracted right into the Jar)

The Linux Aarch64 runtime must be prepared on the actual ARM Linux session.

Copy the runtimes to your workstation, rename the `bin/java` into `bin/Terrarum`, then `chmod -R +x` all of them.

### Packaging

Create an output directory if there is none (project root/buildapp/out)

Before running the packaging script make sure:

1. The required runtime must exist on `(project root)/out/runtime-<linux|osx|windows>-<arm|x86>` directory
2. The build scripts are on a subdirectory of the project directory

To build, **cd into the "(project root)/buildapp/", then execute the appropriate Make job**.

The packaged application can be found on `(project root)/buildapp/out/`

### OSX .icns creation

Details: https://gist.github.com/jamieweavis/b4c394607641e1280d447deed5fc85fc
0. Do this on a real macOS
1. Create a folder `icon.iconset`, then cp the .png file as `icon_512x512.png`
2. On Terminal, `iconutil -c icns icon.iconset`

It might be possible to create .icns on Linux, haven't tried though. https://dentrassi.de/2014/02/25/creating-mac-os-x-icons-icns-on-linux/

### Windows .ico creation

0. Open up the icon (png) file using GIMP
1. Export As... -> *.ico, make sure to select either of 24 bpp (1 bit alpha) or 32 bpp (8 bit alpha)


### Notes to Terrarum Programmers

By self-containing everything in one file, it is not possible to modify the base game easily. Modloading scheme must be extended to load from mutable directory such as `%APPDATA%/Terrarum/mods`.
[Building-the-App.md](../Terrarum.wiki/Building-the-App.md)