Make the simulator generic and safe as a subproject

.clang-format

@@ -1,5 +1,6 @@
 ---
 Language:        Cpp
+BasedOnStyle:    LLVM
 AccessModifierOffset: -4
 AlignAfterOpenBracket: BlockIndent
 AlignConsecutiveBitFields:
@@ -26,20 +27,25 @@ IncludeCategories:
     SortPriority:    1
   - Regex:           '^".*"'
     SortPriority:    2
-IncludeIsMainRegex: '$'
+# No include is treated as the main header, so that sorting preserves the existing
+# grouping instead of promoting the header matching the source file name
+IncludeIsMainRegex: 'NO_MAIN_INCLUDE'
 IndentCaseLabels: true
 IndentExternBlock: NoIndent
 IndentPPDirectives: BeforeHash
 IndentRequiresClause: false
 IndentWidth:     4
 IndentWrappedFunctionNames: true
+InsertNewlineAtEOF: true
 KeepEmptyLinesAtTheStartOfBlocks: false
+LineEnding:      LF
 PackConstructorInitializers: NextLine
 PointerAlignment: Left
 SeparateDefinitionBlocks: Always
 ShortNamespaceLines: 0
-SortIncludes:    Never
+SortIncludes:    CaseSensitive
 SpaceInEmptyBlock: true
 SpacesBeforeTrailingComments: 2
+Standard:        Latest
 TabWidth:        4
 ...

.clang-tidy

@@ -1,4 +1,13 @@
 ---
+# llvm-include-order enforces LLVM's own ordering, which contradicts the project's
+# .clang-format rules; clang-format is the single authority on include order here.
+#
+# The trailing group disables checks for constructs this project cannot contain. They match
+# nothing, so they only cost time scanning the standard library and the Cube headers:
+#   string_view, coroutines, Objective-C, GoogleTest, the LLVM internal APIs, std::bind,
+#   iostreams, std::auto_ptr and std::random_shuffle (both removed in C++17), and printf.
+# It also drops clang-analyzer-core.FixedAddressDereference, which every memory mapped
+# peripheral access looks like by construction.
 Checks:
   -*,
   bugprone-*,
@@ -14,8 +23,8 @@ Checks:
   google-*,
   llvm-*,
   -llvm-header-guard,
+  -llvm-include-order,
   misc-*,
-  -misc-include-cleaner,
   -misc-use-anonymous-namespace,
   modernize-*,
   -modernize-use-nodiscard,
@@ -25,6 +34,19 @@ Checks:
   -readability-duplicate-include,
   -readability-magic-numbers,
   -readability-math-missing-parentheses,
+  -bugprone-stringview-nullptr,
+  -cppcoreguidelines-no-suspend-with-lock,
+  -google-objc-*,
+  -google-upgrade-googletest-case,
+  -llvm-prefer-isa-or-dyn-cast-in-conditionals,
+  -llvm-prefer-register-over-unsigned,
+  -llvm-twine-local,
+  -modernize-avoid-bind,
+  -modernize-deprecated-ios-base-aliases,
+  -modernize-replace-auto-ptr,
+  -modernize-replace-random-shuffle,
+  -modernize-use-std-print,
+  -clang-analyzer-core.FixedAddressDereference,
 HeaderFileExtensions:
   - ''
   - h
@@ -36,9 +58,17 @@ ImplementationFileExtensions:
   - cc
   - cpp
   - cxx
-HeaderFilterRegex: ''
-FormatStyle: none
+HeaderFilterRegex: '(include|config)/.*\.(hpp|tpp)$'
+ExcludeHeaderFilterRegex: '(_deps|external)/'
+FormatStyle: file
 CheckOptions:
+  # The vendor HAL module headers are not standalone; they require stm32<family>xx_hal.h to have
+  # pulled in stm32<family>xx_hal_def.h first, so include-cleaner must not suggest or remove them.
+  # This is why micras_hal includes the generated main.h, which reaches the right one for the
+  # family it was generated for, instead of naming a module header of its own. main.h is on the
+  # list for the same reason: every symbol behind it resolves to a header already listed here, so
+  # nothing is credited to main.h and it would otherwise be reported as unused.
+  misc-include-cleaner.IgnoreHeaders: 'stm32.*;core_cm.*;cmsis.*;system_stm32.*;lsm6dsv.*;main\.h'
   readability-identifier-length.MinimumVariableNameLength: 2
   readability-identifier-length.IgnoredVariableNames: ^[nxyz]$
   readability-identifier-length.MinimumParameterNameLength: 2

.docker/Dockerfile

@@ -0,0 +1,65 @@
+# syntax=docker/dockerfile:1.27
+
+# >>> host stage >>>
+###############################################################################
+# Host tools: shared byte for byte by micras-lib, micras-simulation and       #
+# MicrasFirmware, whose CI compares the lines between the two markers         #
+###############################################################################
+FROM ubuntu:26.04 AS host
+
+# The compilers and the clang tooling are pinned to a major version, so that a distribution update
+# can move neither the generated code nor the formatting rules and the enabled check set
+ARG HOST_GCC_VERSION=15
+ARG HOST_CLANG_VERSION=22
+
+# The apt caches are kept in BuildKit cache mounts instead of the image layers, so the hook that
+# deletes the downloaded packages after every install has to go
+RUN rm -f /etc/apt/apt.conf.d/docker-clean
+
+RUN --mount=type=cache,target=/var/cache/apt,sharing=locked \
+    --mount=type=cache,target=/var/lib/apt,sharing=locked \
+    apt-get update && \
+    apt-get install -y --no-install-recommends \
+        ca-certificates \
+        cmake \
+        doxygen \
+        git \
+        graphviz \
+        ninja-build \
+        python3 \
+        python3-matplotlib \
+        python3-numpy \
+        "gcc-${HOST_GCC_VERSION}" \
+        "g++-${HOST_GCC_VERSION}" \
+        "clang-${HOST_CLANG_VERSION}" \
+        "clang-format-${HOST_CLANG_VERSION}" \
+        "clang-tidy-${HOST_CLANG_VERSION}"
+
+WORKDIR /project
+# <<< host stage <<<
+
+###############################################################################
+# The simulator: what the viewer, the video and their checks need on top     #
+###############################################################################
+FROM host AS simulator
+
+ARG HOST_CLANG_VERSION=22
+
+# GLFW and the OpenGL and EGL development files for the viewer and the video, Mesa's software renderer
+# for a machine with no GPU, Xvfb for a window with no display, and ffmpeg, which encodes the video.
+# clang's own sanitizer headers let clang-tidy read a sanitized build: MuJoCo's headers include them.
+RUN --mount=type=cache,target=/var/cache/apt,sharing=locked \
+    --mount=type=cache,target=/var/lib/apt,sharing=locked \
+    apt-get update && \
+    apt-get install -y --no-install-recommends \
+        "libclang-rt-${HOST_CLANG_VERSION}-dev" \
+        ffmpeg \
+        libegl-dev \
+        libegl-mesa0 \
+        libgl-dev \
+        libgl1-mesa-dri \
+        libglfw3-dev \
+        libglx-mesa0 \
+        libopengl-dev \
+        xauth \
+        xvfb

.github/workflows/ci.yaml

@@ -0,0 +1,64 @@
+name: Build test lint and check the simulator
+
+on:
+  push:
+  pull_request:
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: true
+
+# A push to a branch of this repository is checked once by its push run, so a pull request only runs
+# here when it comes from a fork
+jobs:
+  host:
+    name: 🧪 Build, tests, format, lint and checks
+    runs-on: ubuntu-latest
+    if: github.event_name != 'pull_request' || github.event.pull_request.head.repo.full_name != github.repository
+    timeout-minutes: 60
+    steps:
+      - name: 🔀 Checkout
+        uses: actions/checkout@v7
+
+      - name: 🐋 Build the simulator image
+        run: docker build --file .docker/Dockerfile --target simulator --tag micras-simulation:ci .docker
+
+      - name: 🗃️ Restore the fetched dependencies
+        uses: actions/cache@v6
+        with:
+          path: |
+            build/host-ci/_deps
+            build/host-ci/CMakeFiles/fc-stamp
+          key: deps-host-ci-${{ hashFiles('cmake/third_party.cmake', 'cmake/mujoco.cmake') }}
+
+      # One long lived container runs every step below, as the user that owns the checkout
+      - name: 📦 Start the simulator container
+        run: >
+          docker run --detach --name simulator --user "$(id -u):$(id -g)" --env HOME=/tmp
+          --volume "$PWD:/project" --workdir /project micras-simulation:ci sleep infinity
+
+      - name: ⚙️ Configure
+        run: docker exec simulator cmake --preset host-ci
+
+      - name: 🔨 Build
+        run: docker exec simulator cmake --build --preset host-ci
+
+      - name: 🧪 Run the tests
+        run: docker exec simulator ctest --preset host-ci
+
+      - name: 🎨 Check the formatting
+        run: docker exec simulator cmake --build --preset host-ci --target micras_sim_format_check
+
+      - name: 🚨 Lint
+        run: docker exec simulator cmake --build --preset host-ci --target micras_sim_lint
+
+      - name: ✅ Check the simulator
+        run: docker exec simulator cmake --build --preset host-ci --target micras_sim_check
+
+      - name: 🧹 Stop the simulator container
+        if: always()
+        run: docker rm --force simulator

.gitignore

@@ -2,6 +2,4 @@ runs/
 build/
 .cache/
 __pycache__/
-.omc/
 compile_commands.json
-third_party/_deps/