[doc] cross compile LMN-3-DAW with docker

[iamdey]

Following the documentation to build the DAW from source for the raspberry-pi, I wanted an easy way to do it thanks to docker. So I share my snippets.

Pre-requisite

You don't need to install anything except docker
(I'm not sure this would work on a windows host)

You have to clone the LMN-3-DAW repository: https://github.com/FundamentalFrequency/LMN-3-DAW?tab=readme-ov-file#cloning-the-repository

Snippets

cd <LMN-3-DAW directory>

# BUILD x86_64
docker run -v $PWD:/source stonepreston/juce-x86_64-compiler:latest /bin/bash -c '
  cd /source
  cmake -B build -DCMAKE_CXX_COMPILER=clang++ -DCMAKE_C_COMPILER=clang -DCMAKE_BUILD_TYPE=Release -DCMAKE_CXX_FLAGS=-fuse-ld=lld
  cmake --build build -j8
  '

# BUILD arm
docker run -v $PWD:/source stonepreston/juce-arm-linux-cross-compiler:latest /bin/bash -c '
  cd /source
  cmake -B build -DCMAKE_BUILD_TYPE=Release -DPACKAGE_TESTS=OFF -DCMAKE_TOOLCHAIN_FILE=/toolchain/toolchain.cmake
  cmake --build build -j8
  '


# TEST x86_64
docker run -v $PWD:/source stonepreston/juce-x86_64-compiler:latest /bin/bash -c '
  cd /source
  cmake -B build -DCMAKE_CXX_COMPILER=clang++ -DCMAKE_C_COMPILER=clang -DCMAKE_BUILD_TYPE=Release
  cmake --build build --target Tests -j8
  ./build/Tests/Tests_artefacts/Release/Tests
  '

[iamdey]

Recently I've migrated the code to C++ 20 and the initial images don't work anymore.

I've made a new repo that makes easier to rebuild a sysroot compatible with every common arch for raspberry and PC: arm/aarch/x86_64

https://github.com/iamdey/LMN-3-DAW-docker-compiler

Following the repo you'll also find published images on docker's hub: https://hub.docker.com/r/iamdey/lmn-3-daw-docker-compiler

So to compile LMN-3_DAW for aarch for example, you can simply this command on a linux PC (may be it can work on other systems but not tested yet):

(Docker must be installed & working)

cd LMN-3-DAW
docker run --rm -v $PWD:/source iamdey/lmn-3-daw-docker-compiler:arm64 /bin/bash -c '
  cd /source
  cmake -B build -DCMAKE_BUILD_TYPE=Debug -DPACKAGE_TESTS=OFF -DCMAKE_TOOLCHAIN_FILE=/toolchain/toolchain.cmake
  cmake --build build -j8
  '