POC: use Rust for css color parsing

.github/workflows/android-ci.yml

@@ -71,6 +71,8 @@ jobs:
           distribution: "temurin"
           java-version: "17"
 
+      - name: Add aarch64-linux-android for Rust toolchian
+        run: rustup target add --toolchain stable-x86_64-unknown-linux-gnu aarch64-linux-android armv7-linux-androideabi i686-linux-android x86_64-linux-android
       - name: Get CMake and Ninja
         uses: lukka/get-cmake@latest
         with:
@@ -229,10 +231,9 @@ jobs:
           submodules: recursive
           fetch-depth: 0
 
-      - uses: actions/setup-java@v4
-        with:
-          distribution: "temurin"
-          java-version: "17"
+      - name: Add aarch64-linux-android for Rust toolchian
+        if: ${{ github.ref == 'refs/heads/rust' || github.event.pull_request.base.ref == 'rust' }}
+        run: rustup target add --toolchain stable-x86_64-unknown-linux-gnu aarch64-linux-android armv7-linux-androideabi i686-linux-android x86_64-linux-android
 
       - name: Get CMake and Ninja
         uses: lukka/get-cmake@latest
@@ -313,6 +314,10 @@ jobs:
           distribution: "temurin"
           java-version: "17"
 
+      - name: Add aarch64-linux-android for Rust toolchian
+        if: ${{ github.ref == 'refs/heads/rust' || github.event.pull_request.base.ref == 'rust' }}
+        run: rustup target add --toolchain stable-x86_64-unknown-linux-gnu aarch64-linux-android armv7-linux-androideabi i686-linux-android x86_64-linux-android
+
       - name: Build and Upload Render Test APKs (${{ matrix.flavor }})
         uses: ./.github/actions/android-build-and-upload-render-test
         with:

.github/workflows/linux-ci.yml

@@ -200,6 +200,10 @@ jobs:
             xvfb \
             x11-xserver-utils
 
+      - name: Install cxxbridge-cmd (compile)
+        if: ${{ github.ref == 'refs/heads/rust' || github.event.pull_request.base.ref == 'rust' }}
+        run: cargo install cxxbridge-cmd
+
       - name: Cache Bazel
         uses: actions/cache@v4
         with:

BUILD.bazel

@@ -1,5 +1,5 @@
 load("@aspect_rules_js//js:defs.bzl", "js_binary", "js_library", "js_run_binary")
-load("@bazel_skylib//rules:common_settings.bzl", "string_flag")
+load("@bazel_skylib//rules:common_settings.bzl", "string_flag", "bool_flag")
 load("@npm//:defs.bzl", "npm_link_all_packages")
 load(
     "//bazel:core.bzl",
@@ -124,7 +124,6 @@ cc_library(
         ":mbgl-core-generated-private-artifacts",
         ":mbgl-core-generated-public-artifacts",
         "//vendor:boost",
-        "//vendor:csscolorparser",
         "//vendor:earcut.hpp",
         "//vendor:eternal",
         "//vendor:mapbox-base",
@@ -149,7 +148,14 @@ cc_library(
             "//vendor:metal-cpp",
         ],
         "//conditions:default": [],
-    }),
+    }) + select({
+        ":rust": [
+            "//rustutils:rustutilslib",
+        ],
+        "//conditions:default": [
+            "//vendor:csscolorparser",
+        ]
+    })
 )
 
 genrule(
@@ -195,6 +201,19 @@ config_setting(
     },
 )
 
+bool_flag(
+    name = "use_rust",
+    build_setting_default = False,
+    visibility = ["//visibility:public"],
+)
+
+config_setting(
+    name = "rust",
+    flag_values = {
+        "//:use_rust": "true",
+    },
+)
+
 exports_files(
     [
         "LICENSE.md",

CMakeLists.txt

@@ -17,6 +17,7 @@ option(MLN_LEGACY_RENDERER "Include the legacy rendering pathway" ON)
 option(MLN_DRAWABLE_RENDERER "Include the drawable rendering pathway" OFF)
 option(MLN_USE_UNORDERED_DENSE "Use ankerl dense containers for performance" ON)
 option(MLN_USE_TRACY "Enable Tracy instrumentation" OFF)
+option(MLN_USE_RUST "Use components in Rust" OFF)
 
 if (MLN_WITH_CLANG_TIDY)
     find_program(CLANG_TIDY_COMMAND NAMES clang-tidy)
@@ -940,7 +941,7 @@ list(APPEND SRC_FILES
     ${PROJECT_SOURCE_DIR}/src/mbgl/util/bounding_volumes.cpp
     ${PROJECT_SOURCE_DIR}/src/mbgl/util/chrono.cpp
     ${PROJECT_SOURCE_DIR}/src/mbgl/util/client_options.cpp
-    ${PROJECT_SOURCE_DIR}/src/mbgl/util/color.cpp
+    ${PROJECT_SOURCE_DIR}/src/mbgl/util/color$<IF:$<BOOL:${MLN_USE_RUST}>,.rs.cpp,.cpp>
     ${PROJECT_SOURCE_DIR}/src/mbgl/util/constants.cpp
     ${PROJECT_SOURCE_DIR}/src/mbgl/util/convert.cpp
     ${PROJECT_SOURCE_DIR}/src/mbgl/util/event.cpp
@@ -1458,6 +1459,8 @@ include(${PROJECT_SOURCE_DIR}/vendor/vector-tile.cmake)
 include(${PROJECT_SOURCE_DIR}/vendor/wagyu.cmake)
 include(${PROJECT_SOURCE_DIR}/vendor/metal-cpp.cmake)
 
+include(${PROJECT_SOURCE_DIR}/rustutils/rustutils.cmake)
+
 target_link_libraries(
     mbgl-core
     PRIVATE
@@ -1468,7 +1471,6 @@ target_link_libraries(
         Mapbox::Base::cheap-ruler-cpp
         mbgl-compiler-options
         mbgl-vendor-boost
-        mbgl-vendor-csscolorparser
         mbgl-vendor-earcut.hpp
         mbgl-vendor-eternal
         mbgl-vendor-parsedate
@@ -1479,6 +1481,7 @@ target_link_libraries(
         mbgl-vendor-vector-tile
         mbgl-vendor-wagyu
         $<$<BOOL:${MLN_WITH_METAL}>:mbgl-vendor-metal-cpp>
+        $<IF:$<BOOL:${MLN_USE_RUST}>,mbgl-rustutils,mbgl-vendor-csscolorparser>
     PUBLIC
         Mapbox::Base
         Mapbox::Base::Extras::expected-lite
@@ -1490,9 +1493,8 @@ target_link_libraries(
         unordered_dense
 )
 
-export(TARGETS
+set(EXPORT_TARGETS
     mbgl-core
-
     mapbox-base
     mapbox-base-cheap-ruler-cpp
     mapbox-base-extras-expected-lite
@@ -1508,7 +1510,6 @@ export(TARGETS
     mapbox-base-variant
     mbgl-compiler-options
     mbgl-vendor-boost
-    mbgl-vendor-csscolorparser
     mbgl-vendor-earcut.hpp
     mbgl-vendor-eternal
     mbgl-vendor-parsedate
@@ -1520,10 +1521,16 @@ export(TARGETS
     mbgl-vendor-wagyu
     mbgl-vendor-metal-cpp
     unordered_dense
-
-    FILE MapboxCoreTargets.cmake
 )
 
+if(MLN_USE_RUST)
+    list(APPEND EXPORT_TARGETS mbgl-rustutils rustutils)
+else()
+    list(APPEND EXPORT_TARGETS mbgl-vendor-csscolorparser)
+endif()
+
+export(TARGETS ${EXPORT_TARGETS} FILE MapboxCoreTargets.cmake)
+
 if(MLN_WITH_VULKAN)
     include(${PROJECT_SOURCE_DIR}/vendor/vulkan.cmake)
 

MODULE.bazel

@@ -59,4 +59,25 @@ darwin_config = use_repo_rule("//platform/darwin:bazel/darwin_config_repository_
 
 darwin_config(
     name = "darwin_config",
-)
+)
+
+bazel_dep(name = "rules_rust", version = "0.56.0")
+
+rust = use_extension("@rules_rust//rust:extensions.bzl", "rust")
+
+rust.toolchain(
+    edition = "2021",
+    versions = ["1.80.0"]
+)
+use_repo(rust, "rust_toolchains")
+
+register_toolchains("@rust_toolchains//:all")
+
+crate = use_extension("@rules_rust//crate_universe:extensions.bzl", "crate")
+
+crate.from_cargo(
+    name = "crates",
+    cargo_lockfile = "//rustutils:Cargo.lock",
+    manifests = ["//rustutils:Cargo.toml"],
+)
+use_repo(crate, "crates")

bazel/core.bzl

@@ -584,7 +584,6 @@ MLN_CORE_SOURCE = [
     "src/mbgl/util/bounding_volumes.cpp",
     "src/mbgl/util/chrono.cpp",
     "src/mbgl/util/client_options.cpp",
-    "src/mbgl/util/color.cpp",
     "src/mbgl/util/constants.cpp",
     "src/mbgl/util/convert.cpp",
     "src/mbgl/util/event.cpp",
@@ -652,7 +651,14 @@ MLN_CORE_SOURCE = [
     "src/mbgl/util/version.cpp",
     "src/mbgl/util/version.hpp",
     "src/mbgl/util/work_request.cpp",
-]
+] + select({
+    "//:rust": [
+        "src/mbgl/util/color.rs.cpp",
+    ],
+    "//conditions:default": [
+        "src/mbgl/util/color.cpp",
+    ]
+})
 
 MLN_CORE_HEADERS = [
     "include/mbgl/gfx/context.hpp",

docker/Dockerfile

@@ -1,3 +1,4 @@
+# Ubuntu version should match SWIFT version below
 FROM ubuntu:22.04
 
 # Install build tools and dependencies
@@ -23,20 +24,23 @@ RUN    apt-get update \
         ccache \
         ninja-build \
         pkg-config \
+        python3 \
+        python3-pip \
+        python-is-python3 \
         clang-tidy \
     && : # end of the RUN cmd - easier to keep a colon at the end of the list, than to keep the backslashes in check
 
 # This could also be `.../releases/latest/download/bazelisk-linux-amd64` for the latest version, but for predictability better hardcode it
 # Detect if current CPU is x64 or ARM64 and download the appropriate binary
-RUN if [ "$(uname -m)" = "aarch64" ]; then \
+RUN echo "Download and install Bazel" \
+    && if [ "$(uname -m)" = "aarch64" ]; then \
         curl -fsSL https://github.com/bazelbuild/bazelisk/releases/download/v1.20.0/bazelisk-linux-arm64 -o /usr/local/bin/bazel ;\
     else \
         curl -fsSL https://github.com/bazelbuild/bazelisk/releases/download/v1.20.0/bazelisk-linux-amd64 -o /usr/local/bin/bazel ;\
     fi \
     && chmod +x /usr/local/bin/bazel \
     && :
 
-WORKDIR /app
 
 ARG USERNAME=user
 ARG USER_UID=1000
@@ -50,11 +54,21 @@ RUN groupadd --force --gid $USER_GID $USERNAME \
     && echo $USERNAME ALL=\(root\) NOPASSWD:ALL > /etc/sudoers.d/$USERNAME \
     && chmod 0440 /etc/sudoers.d/$USERNAME
 
+# This allows users to `docker run` without specifying -u and -g
+USER $USERNAME
+
+RUN pip install pre-commit
+
+ENV RUSTUP_HOME=/home/$USERNAME/.cache/.rustup \
+    CARGO_HOME=/home/$USERNAME/.cache/.cargo \
+    PATH=/home/$USERNAME/.cache/.cargo/bin:$PATH
+
+# As the very last step, copy the startup script
+USER root
 COPY startup.sh /usr/local/bin/startup.sh
 RUN chmod +x /usr/local/bin/startup.sh
-
-# This allows users to `docker run` without specifying -u and -g
 USER $USERNAME
 
+WORKDIR /app
 ENTRYPOINT ["/usr/local/bin/startup.sh"]
 CMD ["bash"]

docker/startup.sh

@@ -1,13 +1,51 @@
 #!/bin/sh
 
-if [ ! -d /app/.github ] || [ ! -d /home/user/.cache ]; then
+if [ ! -d /app/.github ] || [ ! -d ~/.cache ]; then
     echo " "
     echo "ERROR: Docker container was not started properly."
     echo "       From the root of this repo, run the following command."
     echo "       You may add any command to perform in the container at the end of this command."
     echo " "
-    echo '  docker run --rm -it -v "$PWD:/app/" -v "$PWD/docker/.cache:/home/user/.cache" maplibre-native-image'
+    echo "  docker run --rm -it -v \"$PWD:/app/\" -v \"$PWD/docker/.cache:/home/$USERNAME/.cache\" maplibre-native-image"
     exit 1
 fi
 
+export PATH="$PATH:~/.local/bin/"
+
+
+# Work in progress:  install and configure Swift and pre-commit
+# Detect if current CPU is x64 or ARM64 and download the appropriate binary
+#RUN echo "Download and install SWIFT" \
+#    && if [ "$(uname -m)" = "aarch64" ]; then \
+#        curl -fsSL https://download.swift.org/swift-5.10.1-release/ubuntu2204-aarch64/swift-5.10.1-RELEASE/swift-5.10.1-RELEASE-ubuntu22.04-aarch64.tar.gz \
+#                -o /tmp/swift.tar.gz ;\
+#    else \
+#        curl -fsSL https://download.swift.org/swift-5.10.1-release/ubuntu2204/swift-5.10.1-RELEASE/swift-5.10.1-RELEASE-ubuntu22.04.tar.gz \
+#                -o /tmp/swift.tar.gz ;\
+#    fi \
+#    && tar -xzf /tmp/swift.tar.gz -C / --strip-components=1 \
+#    && rm /tmp/swift.tar.gz \
+#    && :
+#if [ ! -f "/app/.git/hooks/pre-commit" ]; then
+#    echo "Configuring pre-commit git hooks by creating a .git/hooks/pre-commit file..."
+#    ~/.local/bin/pre-commit install
+#fi
+
+
+
+if [ ! -f "$CARGO_HOME/env" ]; then
+    echo "Downloading and installing Rust..."
+    curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y --profile minimal
+fi
+. "$CARGO_HOME/env"
+
+
+
+if ! command -v cxxbridge > /dev/null; then
+    echo "Installing cxxbridge..."
+    cargo install cxxbridge-cmd
+fi
+
+
+
 exec "$@"

docs/mdbook/src/SUMMARY.md

@@ -22,3 +22,5 @@
 
 - [Profiling applications that use MapLibre Native](./profiling/README.md)
   - [Tracy profiling](./profiling/tracy-profiling.md)
+
+- [Rust](./rust.md)

docs/mdbook/src/rust.md

@@ -0,0 +1,27 @@
+# Rust
+
+We have added experimental support for intergrating Rust code into the source tree.
+
+## Rust Bridge
+
+The Rust bridge lives in `rustutils`. To regenerate the C++ bridge run the following script from the root of the repository.
+
+```
+rustutils/cpp/generate.sh
+```
+
+Check in the generated files under `rustutils/cpp`.
+
+We might intergrate this generation process into the build, but the tools to do so are experimental and immature as of January 2025.
+
+## Building
+
+You need to have the correct Rust toolchain(s) installed.
+
+### CMake
+
+Set `MLN_USE_RUST` to `ON`.
+
+### Bazel
+
+Pass `--//:use_rust` to Bazel.

platform/android/android.cmake

@@ -11,7 +11,6 @@ include(${PROJECT_SOURCE_DIR}/vendor/icu.cmake)
 include(${PROJECT_SOURCE_DIR}/vendor/sqlite.cmake)
 
 # cmake-format: off
-target_compile_options(mbgl-vendor-csscolorparser PRIVATE $<$<CONFIG:Release>:-Oz> $<$<CONFIG:Release>:-Qunused-arguments> $<$<CONFIG:Release>:-flto>)
 target_compile_options(mbgl-vendor-icu PRIVATE $<$<CONFIG:Release>:-Oz> $<$<CONFIG:Release>:-Qunused-arguments> $<$<CONFIG:Release>:-flto>)
 target_compile_options(mbgl-vendor-parsedate PRIVATE $<$<CONFIG:Release>:-Oz> $<$<CONFIG:Release>:-Qunused-arguments> $<$<CONFIG:Release>:-flto>)
 target_compile_options(mbgl-vendor-sqlite PRIVATE $<$<CONFIG:Release>:-Oz> $<$<CONFIG:Release>:-Qunused-arguments> $<$<CONFIG:Release>:-flto>)