BBCSDL Auto-starting snap for Raspberry Pi

snapcraft.yaml

name: bbcsdl
base: core20
version: "master"
summary: BBC BASIC for SDL 2.0
license: "Zlib"
description: |
  BBC BASIC for SDL 2.0 is a cross-platform implementation of the BBC BASIC
  programming language for Windows, Linux (x86), MacOS, Raspbian (Raspberry Pi),
  Android, iOS and Emscripten / WebAssembly. It is highly compatible with BBC
  BASIC for Windows and has the same language extensions, but uses SDL 2.0 as 
  an OS abstraction layer to achieve cross-platform compatibility.

grade: stable
confinement: strict

architectures:
  - build-on: armhf
    run-on: [ armhf, arm64 ]

layout:
  /usr/lib/$SNAPCRAFT_ARCH_TRIPLET/alsa-lib:
    bind: $SNAP/usr/lib/$SNAPCRAFT_ARCH_TRIPLET/alsa-lib
  /usr/share/alsa:
    bind: $SNAP/usr/share/alsa

parts:
  alsa-mixin:
    plugin: dump
    source: https://github.com/diddlesnaps/snapcraft-alsa.git
    source-subdir: snapcraft-assets
    build-packages:
      - libasound2-dev
    stage-packages:
      - libasound2
      - libasound2-plugins
      - yad
  glib-only:
    source: https://github.com/ubuntu/snapcraft-desktop-helpers.git
    source-subdir: glib-only
    plugin: make
    build-packages:
      - libglib2.0-dev
    stage-packages:
      - libglib2.0-bin
    override-prime: |
      snapcraftctl prime
      # force armhf
      sed -i 's/export SNAP_LAUNCHER/export ARCH="arm-linux-gnueabihf"\nexport SNAP_LAUNCHER/' bin/desktop-launch
      # do not try to update xdg links in home (HOME is SNAP_COMMON)
      sed -i '/# Create links for user-dirs.dirs/,+21 s/^/#/' bin/desktop-launch
  pi-libs:
    after: [alsa-mixin]
    source: https://github.com/raspberrypi/firmware.git
    source-depth: 1
    plugin: nil
    override-build: |
      mkdir -p $SNAPCRAFT_PART_INSTALL/usr
      cp -av hardfp/opt/vc/bin $SNAPCRAFT_PART_INSTALL/usr/
      cp -av hardfp/opt/vc/lib $SNAPCRAFT_PART_INSTALL/usr/
      cp -av hardfp/opt/vc/include $SNAPCRAFT_PART_INSTALL/usr/
      # we want to link against mesa, drop GLES and EGL includes
      rm -rf $SNAPCRAFT_PART_INSTALL/usr/include/*GL*
    prime:
      - -usr/include
  sdl2:
    after: [ pi-libs ]
    plugin: cmake
    source: https://github.com/spurious/SDL-mirror.git
    source-tag: release-2.0.14
    cmake-parameters:
      - -DCMAKE_PREFIX_PATH=${SNAPCRAFT_STAGE}/usr
      - -DCMAKE_INSTALL_PREFIX=/usr
      - -DVIDEO_OPENGL=OFF
      - -DVIDEO_OPENGLES=ON
      - -DVIDEO_X11=OFF
      - -DVIDEO_WAYLAND=OFF
      - -DVIDEO_KMSDRM=ON
      - -DVIDEO_RPI=OFF
      - -DESD=OFF
    build-packages:
      - libdrm-dev
      - libegl-dev
      - libgbm-dev
      - libgles-dev
      - libinput-dev
    build-environment:
      - CFLAGS: "-I${SNAPCRAFT_STAGE}/usr/include -I${SNAPCRAFT_STAGE}/usr/include/interface/vcos/pthreads -I${SNAPCRAFT_STAGE}/usr/include/interface/vm"
      - CXXFLAGS: "-I${SNAPCRAFT_STAGE}/usr/include -I${SNAPCRAFT_STAGE}/usr/include/interface/vcos/pthreads -I${SNAPCRAFT_STAGE}/usr/include/interface/vm"
    stage-packages:
      - libdrm2
      - libegl1
      - libgbm1
      - libgles2
  sdl2-ttf:
    after: [ sdl2 ]
    plugin: autotools
    source: https://www.libsdl.org/projects/SDL_ttf/release/SDL2_ttf-2.0.15.tar.gz
    build-packages:
      - libfreetype-dev
    autotools-configure-parameters:
      - --prefix=/usr
  sdl2-net:
    after: [ sdl2-ttf ]
    plugin: autotools
    source: https://www.libsdl.org/projects/SDL_net/release/SDL2_net-2.0.1.tar.gz
    autotools-configure-parameters:
      - --prefix=/usr
  bbcsdl:
    after: [sdl2-net]
    plugin: make
    source: https://github.com/rtrussell/BBCSDL.git
    build-packages:
      - nasm
    stage-packages:
      - libglu1-mesa
      - libgl1-mesa-glx
      - libgl1-mesa-dri
      - libc6
    override-build: |
      ARCHITECTURE=$(dpkg --print-architecture)
      if [ "${ARCHITECTURE}" = "amd64" ]; then
        cd bin/linux
      else 
        cd bin/raspi
        sed -i 's;-L/usr/lib/;-L$(SNAPCRAFT_STAGE)/usr/lib/;' makefile
        sed -i 's;-I ../../include;-I ../../include -I $(SNAPCRAFT_STAGE)/usr/include;' makefile
      fi
      make
      mkdir $SNAPCRAFT_PART_INSTALL/bin
      cp ./bbcsdl $SNAPCRAFT_PART_INSTALL/bin
      cp ./libstb.so $SNAPCRAFT_PART_INSTALL/lib
      cp -a ../../examples $SNAPCRAFT_PART_INSTALL/
apps: 
  bbcsdl:
    command: bin/desktop-launch $SNAP/bin/bbcsdl -fullscreen
    command-chain: ["snap/command-chain/alsa-launch"]
    daemon: simple
    environment:
      LD_LIBRARY_PATH: "$SNAP/usr/lib/$SNAPCRAFT_ARCH_TRIPLET/pulseaudio:$SNAP/usr/lib/arm-linux-gnueabihf/dri"
      ALWAYS_USE_PULSEAUDIO: '1'
      LIBGL_DRIVERS_PATH: "$SNAP/usr/lib/arm-linux-gnueabihf/dri"
      HOME: "$SNAP_COMMON"
    plugs:
      - pulseaudio
      - audio-playback
      - audio-record
      - hardware-observe
      - joystick
      - opengl
      - process-control
      - x11