egui Android Demo

This is my attempt at getting latest version of the egui demo to work on Android.

Optimized for size the resulting egui-android-demo.aab is 2.4M.

Built using xbuild

Dependencies

xbuild requires additional tools that cannot be automatically installed with cargo install xbuild. Consider installing with a system package manager instead. For instance, pacman -Si xbuild for Arch Linux.

You can use x doctor to check which tools are detected by xbuild. Not all are required to build this project, but at least lld and llvm-readobj is needed.

Please check on how to install these tools with your preferred distribution's documentation.

Building

x build --arch arm64 --platform android

Running

x run --device <DEVICE>

Example

$ x devices
host                                              Linux               linux x64           Arch Linux 6.6.2-arch1-1
adb:d535946                                       OnePlus5T           android arm64       Android 10 (API 29)
$ x run --device adb:d535946 

wgpu dependency debugging

eframe does not enable necessary wgpu backends on Android by default so finicky overrides are done in Cargo.toml that only works if the dependency resolver deduplicates wpgu to a single dependency.

This can be checked with cargo tree like this:

$ cargo tree --target=aarch64-linux-android --edges features --invert wgpu
wgpu v27.0.1
├── wgpu feature "gles"
│   └── egui-android-demo v0.1.0 (/home/frehamma/Code/egui-android-demo)
│       └── egui-android-demo feature "default" (command-line)
├── wgpu feature "std"
│   ├── eframe v0.33.3
│   │   ├── eframe feature "android-native-activity"
│   │   │   └── egui-android-demo v0.1.0 (/home/frehamma/Code/egui-android-demo) (*)
│   │   ├── eframe feature "default_fonts"
│   │   │   └── egui-android-demo v0.1.0 (/home/frehamma/Code/egui-android-demo) (*)
│   │   └── eframe feature "wgpu"
│   │       └── egui-android-demo v0.1.0 (/home/frehamma/Code/egui-android-demo) (*)
│   └── egui-wgpu v0.33.3
│       └── egui-wgpu feature "winit"
│           └── eframe v0.33.3 (*)
│           └── egui-wgpu feature "winit" (*)
└── wgpu feature "wgsl"
    └── egui-wgpu v0.33.3 (*)

Failure case will look like this:

$ cargo tree --target=aarch64-linux-android --edges features --invert wgpu
error: There are multiple `wgpu` packages in your project, and the specification `wgpu` is ambiguous.
Please re-run this command with one of the following specifications:
  wgpu@27.0.1
  wgpu@28.0.0