p3d_fork_ffi_interface/README.md

p3d

3D object shape recognition tools for WASM, which not only has the same functionality to pass3d, but also it's compatible to Substrate. Now, it's used as a part of 3Dpass network Node.

How to update library in threedpass

• Make your changes.
• Check the lib name is calc see the source, the exported functions have bindable types. Also make sure to annotate your exported functions with #[no_mangle] and pub extern so the function names can be matched from Dart. See working bindable function example.
• Compile the library. There is a makefile copied from brickpop's example. So follow his instruction.
  • Make sure that the Android NDK is installed
  • You might also need LLVM from the SDK manager
  • Ensure that the env variable $ANDROID_NDK_HOME points to the NDK base folder
  • It may look like /Users/brickpop/Library/Android/sdk/ndk-bundle on MacOS
  • And look like /home/brickpop/dev/android/ndk-bundle on Linux
  • On the rust folder:
  • Run make to see the available actions
  • Run make init to install the Rust targets
  • Run make all to build the libraries and the .h file
  • Update the name of your library in Cargo.toml
  • You'll need to update the symlinks to target the new file names. See iOS and Android below. Generated artifacts:
  • Android libraries
  • target/aarch64-linux-android/release/libexample.so
  • target/armv7-linux-androideabi/release/libexample.so
  • target/i686-linux-android/release/libexample.so
  • target/x86_64-linux-android/release/libexample.so
  • iOS library
  • target/universal/release/libexample.a
  • Bindings header
  • target/bindings.h
• Place artifacts to the threedpass project. Follow this structure in threedpass/packages/calc/android: src └── main └── jniLibs ├── arm64-v8a │ └── libexample.so -> p3d/target/aarch64-linux-android/release/libexample.so ├── armeabi-v7a │ └── libexample.so@ -> p3d/target/armv7-linux-androideabi/release/libexample.so ├── x86 │ └── libexample.so@ -> p3d/target/i686-linux-android/release/libexample.so └── x86_64 └── libexample.so@ -> p3d/target/x86_64-linux-android/release/libexample.so
• Update the ios folder. Place p3d/target/aarch64-apple-ios/release/libcalc.a into threedpass/packages/calc/ios
• If you have changed the interface, follow next steps also. Otherwise you can compile the app and check the functionality.
  • Copy p3d/target/bindings.h to threedpass/rust/target/bindings.h.
  • Generate bindings. Check the ffigen section in threedpass/packages/calc/pubspec.yaml. To use ffigen install llvm
    

On MacOS:

  brew install llvm

On Linux:

  sudo apt-get install -y clang libclang-dev

Write path to llvm for your system in pubspec.yaml.

  llvm-path:
    - /usr/local/opt/llvm/bin # For MacOS. Set path for your system

And generate lib/generated/bindings.dart:

  flutter pub run ffigen

• Setup on iOS. Append the p3d/target/bindings.h to threedpass/packages/calc/ios/Classes/CalcPlugin.h. In ios/Classes/SwiftCalcPlugin.swift call your functions, so the compiler won't remove them.
• Use bindings and write Dart code you need.

Thank you for contribution!