Merge pull request #1267 from brendan-duncan/experiment_wasm

Add support for building cesium-native with Unity Web

Author: kring

.github/workflows/build.yml

@@ -217,3 +217,70 @@ jobs:
         run: |
           cd build
           ctest -V
+  EmscriptenBuild:
+    strategy:
+      fail-fast: false
+      matrix:
+        version: [ "3.1.39", "4.0.13" ]
+        memory: [ "32", "64" ]
+        exclude:
+          - version: "3.1.39"
+            memory: "64"
+    name: Emscripten v${{matrix.version}} ${{matrix.memory}}bit memory
+    env:
+      CACHE_KEY: "emscripten-${{matrix.version}}-${{matrix.memory}}"
+    runs-on: windows-2022
+    steps:
+      - name: Check out repository code
+        uses: actions/checkout@v4
+        with:
+          submodules: recursive
+      - name: Use NodeJS 24 for WebAssembly 64-bit memory support
+        if: ${{ matrix.memory == '64' }}
+        uses: actions/setup-node@v6
+        with:
+          node-version: '>=24'
+      - name: Checkout vcpkg 2025.02.14 packages for use with Emscripten 3.1.39
+        if: ${{ matrix.version == '3.1.39' }}
+        uses: actions/checkout@v4
+        with:
+          repository: microsoft/vcpkg
+          clean: false
+          ref: 2025.02.14
+          path: extern/vcpkg/temp
+          sparse-checkout-cone-mode: false
+          sparse-checkout: |
+            ports/ada-url
+      - name: Move overlay ports to the correct location
+        if: ${{ matrix.version == '3.1.39' }}
+        run: |
+          mv extern/vcpkg/temp/ports/* extern/vcpkg/ports/
+      - name: Add OpenSSL "no-dso" option on older Emscripten versions
+        if: ${{ matrix.version == '3.1.39' }}
+        run: |
+          echo "
+            if(PORT MATCHES "openssl")
+              set(VCPKG_CONFIGURE_MAKE_OPTIONS "no-dso")
+            endif()
+            " >> extern/vcpkg/triplets/wasm32-emscripten-cesium.cmake
+      - name: Install latest CMake 3 and Ninja
+        uses: lukka/get-cmake@latest
+        with:
+          cmakeVersion: "3.31.6"
+      - name: Install nasm
+        uses: ilammy/setup-nasm@v1
+      - name: Setup emsdk
+        uses: mymindstorm/setup-emsdk@v14
+        with:
+          version: ${{matrix.version}}
+      - name: Verify
+        run: emcc -v
+      - name: Compile Debug Configuration
+        run: |
+          $env:VCPKG_ROOT="$env:VCPKG_INSTALLATION_ROOT"
+          $MEMORYPROPERTY="${{matrix.memory}}" -eq "64" ? "-DCESIUM_WASM64=ON" : ""
+          emcmake cmake -B build -S . -DCMAKE_BUILD_TYPE=Debug $MEMORYPROPERTY
+          cmake --build build --config Debug --parallel
+      - name: Test Debug Configuration
+        run: |
+          node build/CesiumNativeTests/cesium-native-tests.js

.gitignore

@@ -1,4 +1,5 @@
 build
+build-*
 doxygen
 Testing
 node_modules
@@ -8,7 +9,5 @@ CMakeSettings.json
 .cache
 *.DS_Store
 test.db
-build-wsl
 .idea
-build-debug
 clang-tidy.log

CMakeLists.txt

@@ -4,6 +4,14 @@ if (NOT VCPKG_LIBRARY_LINKAGE)
     set(VCPKG_LIBRARY_LINKAGE static)
 endif()
 
+get_filename_component(toolchainFile "${CMAKE_TOOLCHAIN_FILE}" NAME)
+if(toolchainFile STREQUAL "Emscripten.cmake")
+    set(CESIUM_TARGET_WASM ON)
+    # Include the toolchain directly as ezvcpkg will overwrite the 
+    # toolchain before it's loaded
+    include(${CMAKE_TOOLCHAIN_FILE})
+endif()
+
 # By default, Use ezvcpkg to install dependencies. But don't use
 # ezvcpkg if it appears that this configuration is using vcpkg
 # manifest mode already, either by building cesium-native directly,
@@ -24,6 +32,13 @@ endif()
 
 option(CESIUM_USE_EZVCPKG "use ezvcpkg helper" ${CESIUM_USE_EZVCPKG_DEFAULT})
 option(CESIUM_DISABLE_CURL "Disable cesium-native's use of libcurl" OFF)
+option(CESIUM_DISABLE_LIBJPEG_TURBO "Disable cesium-native's use of libjpeg-turbo. JPEG images will be decoded with STB instead." OFF)
+option(CESIUM_WASM64 "Enable 64-bit WebAssembly target" OFF)
+
+if (CESIUM_TARGET_WASM)
+    # Make sure curl is disabled on wasm builds, as it is not supported.
+    set(CESIUM_DISABLE_CURL ON)
+endif()
 
 if(CESIUM_USE_EZVCPKG)
   # Keep vcpkg from running in manifset mode. It will try to because
@@ -50,6 +65,15 @@ if (NOT VCPKG_TRIPLET)
     elseif(DETECTED_VCPKG_TRIPLET STREQUAL "x64-windows")
         # cesium-native requires static linking on Windows
         set(VCPKG_TRIPLET "x64-windows-static-md")
+    elseif(DETECTED_VCPKG_TRIPLET STREQUAL "wasm32-emscripten")
+        # Use our custom triplet for wasm builds. Most importantly, this
+        # enables multithreading support. Also switch to 64-bit wasm if
+        # requested.
+        if (CESIUM_WASM64)
+            set(VCPKG_TRIPLET "wasm64-emscripten-cesium")
+        else()
+            set(VCPKG_TRIPLET "wasm32-emscripten-cesium")
+        endif()
     else()
         set(VCPKG_TRIPLET "${DETECTED_VCPKG_TRIPLET}")
     endif()
@@ -87,6 +111,10 @@ if (NOT VCPKG_OVERLAY_TRIPLETS)
     endif()
 endif()
 
+if (EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/extern/vcpkg/triplets")
+    list(APPEND VCPKG_OVERLAY_TRIPLETS "${CMAKE_CURRENT_SOURCE_DIR}/extern/vcpkg/triplets")
+endif()
+
 message(STATUS "VCPKG_OVERLAY_TRIPLETS ${VCPKG_OVERLAY_TRIPLETS}")
 
 # These packages are used in the public headers of Cesium libraries, so we need to distribute the headers and binaries
@@ -98,13 +126,13 @@ set(PACKAGES_PUBLIC asyncplusplus expected-lite fmt glm rapidjson spdlog stb ada
 # to distribute the binaries for linking, but not the headers, as downstream consumers don't need them
 # OpenSSL and abseil are both dependencies of s2geometry
 set(PACKAGES_PRIVATE
-    abseil draco ktx modp-base64 meshoptimizer openssl s2geometry
-    libjpeg-turbo sqlite3 tinyxml2 libwebp zlib-ng picosha2
-    earcut-hpp cpp-httplib[core] libmorton zstd
+    abseil draco ktx[core] modp-base64 meshoptimizer openssl s2geometry
+    sqlite3 tinyxml2 libwebp zlib-ng picosha2
+    earcut-hpp libmorton zstd
 )
 
-# asmjit needed by blend2d on non-iOS platforms (iOS doesn't support JIT)
-if(NOT IOS AND NOT VCPKG_CMAKE_SYSTEM_NAME MATCHES "iOS")
+# asmjit needed by blend2d on non-iOS platforms (iOS and Wasm don't support JIT)
+if(NOT CESIUM_TARGET_WASM AND NOT IOS AND NOT VCPKG_CMAKE_SYSTEM_NAME MATCHES "iOS")
     list(APPEND PACKAGES_PRIVATE blend2d asmjit)
 else()
     # Use [core] feature to disable default jit feature.
@@ -115,16 +143,37 @@ if(NOT CESIUM_DISABLE_CURL)
     list(APPEND PACKAGES_PRIVATE curl)
 endif()
 
+if(NOT CESIUM_DISABLE_LIBJPEG_TURBO)
+    list(APPEND PACKAGES_PRIVATE libjpeg-turbo)
+endif()
+
+# We use cpp-httplib to host a local web server for OAuth2 authorization. That's not
+# going to work at all on the web, and the latest versions of cpp-httplib only support
+# 64-bit platforms anyway, so skip it entirely for WebAssembly builds.
+if(NOT CESIUM_TARGET_WASM)
+    list(APPEND PACKAGES_PRIVATE "cpp-httplib[core]")
+endif()
+
 # Packages only used for testing
 set(PACKAGES_TEST doctest)
 
+if(CESIUM_TARGET_WASM)
+    # vcpkg will attempt to second-guess our CMAKE_C_COMPILER setting, choosing to go with the value of CC instead.
+    # While normally this is the correct value to go with, for wasm we need to be using emcc and em++.
+    # So we set CC and CXX to emcc and em++ here so vcpkg will pick them up properly.
+    # Does this make sense? No. Does it work? Somehow. ¯\_(ツ)_/¯
+    set(ENV{CC} ${CMAKE_C_COMPILER})
+    set(ENV{CXX} ${CMAKE_CXX_COMPILER})
+endif()
+
 if(CESIUM_USE_EZVCPKG)
     set(PACKAGES_ALL ${PACKAGES_PUBLIC})
     list(APPEND PACKAGES_ALL ${PACKAGES_PRIVATE})
     list(APPEND PACKAGES_ALL ${PACKAGES_TEST})
 
     ezvcpkg_fetch(
-        COMMIT 2025.09.17
+        COMMIT afc0a2e01ae104a2474216a2df0e8d78516fd5af
+        REPO microsoft/vcpkg
         PACKAGES ${PACKAGES_ALL}
         # Clean the build trees after building, so that we don't use a ton a disk space on the CI cache
         CLEAN_BUILDTREES
@@ -149,6 +198,16 @@ project(cesium-native
     LANGUAGES CXX C
 )
 
+if(CESIUM_TARGET_WASM)
+    if(CESIUM_WASM64)
+        set(CMAKE_SIZEOF_VOID_P 8)
+    else()
+        set(CMAKE_SIZEOF_VOID_P 4)
+    endif()
+    # Tells emscripten to output an HTML harness for the generated WASM
+    set(CMAKE_EXECUTABLE_SUFFIX ".html")
+endif()
+
 include(GNUInstallDirs)
 include(CMakeDependentOption)
 
@@ -318,9 +377,7 @@ find_package(doctest CONFIG REQUIRED)
 find_package(draco CONFIG REQUIRED)
 find_package(expected-lite CONFIG REQUIRED)
 find_package(glm CONFIG REQUIRED)
-find_package(httplib CONFIG REQUIRED)
 find_package(Ktx CONFIG REQUIRED)
-find_package(libjpeg-turbo CONFIG REQUIRED)
 find_package(libmorton CONFIG REQUIRED)
 find_package(meshoptimizer CONFIG REQUIRED)
 find_package(OpenSSL REQUIRED)
@@ -331,15 +388,23 @@ find_package(unofficial-sqlite3 CONFIG REQUIRED)
 find_package(WebP CONFIG REQUIRED)
 find_package(zlib-ng CONFIG REQUIRED)
 
-# asmjit should not be included with iOS builds as iOS doesn't support JIT compilation.
-if(NOT IOS AND NOT VCPKG_CMAKE_SYSTEM_NAME MATCHES "iOS")
+# asmjit should not be included with iOS or Wasm builds as they don't support JIT compilation.
+if(NOT CESIUM_TARGET_WASM AND NOT IOS AND NOT VCPKG_CMAKE_SYSTEM_NAME MATCHES "iOS")
     find_package(asmjit CONFIG REQUIRED)
 endif()
 
 if(NOT CESIUM_DISABLE_CURL)
     find_package(CURL REQUIRED)
 endif()
 
+if(NOT CESIUM_DISABLE_LIBJPEG_TURBO)
+    find_package(libjpeg-turbo CONFIG REQUIRED)
+endif()
+
+if(NOT CESIUM_TARGET_WASM)
+    find_package(httplib CONFIG REQUIRED)
+endif()
+
 # Private Library (s2geometry)
 add_subdirectory(extern EXCLUDE_FROM_ALL)
 

Cesium3DTilesContent/include/Cesium3DTilesContent/SubtreeAvailability.h

@@ -234,7 +234,7 @@ class SubtreeAvailability {
   bool isContentAvailable(
       const CesiumGeometry::QuadtreeTileID& subtreeId,
       const CesiumGeometry::QuadtreeTileID& tileId,
-      uint64_t contentId) const noexcept;
+      size_t contentId) const noexcept;
 
   /**
    * @brief Determines if content for a given tile in the octree is available.
@@ -247,7 +247,7 @@ class SubtreeAvailability {
   bool isContentAvailable(
       const CesiumGeometry::OctreeTileID& subtreeId,
       const CesiumGeometry::OctreeTileID& tileId,
-      uint64_t contentId) const noexcept;
+      size_t contentId) const noexcept;
 
   /**
    * @brief Determines if content for a given tile in the subtree is available.
@@ -262,7 +262,7 @@ class SubtreeAvailability {
   bool isContentAvailable(
       uint32_t relativeTileLevel,
       uint64_t relativeTileMortonId,
-      uint64_t contentId) const noexcept;
+      size_t contentId) const noexcept;
 
   /**
    * @brief Sets the availability state of the content for a given tile in the
@@ -276,7 +276,7 @@ class SubtreeAvailability {
   void setContentAvailable(
       const CesiumGeometry::QuadtreeTileID& subtreeId,
       const CesiumGeometry::QuadtreeTileID& tileId,
-      uint64_t contentId,
+      size_t contentId,
       bool isAvailable) noexcept;
 
   /**
@@ -291,7 +291,7 @@ class SubtreeAvailability {
   void setContentAvailable(
       const CesiumGeometry::OctreeTileID& subtreeId,
       const CesiumGeometry::OctreeTileID& tileId,
-      uint64_t contentId,
+      size_t contentId,
       bool isAvailable) noexcept;
 
   /**
@@ -309,7 +309,7 @@ class SubtreeAvailability {
   void setContentAvailable(
       uint32_t relativeTileLevel,
       uint64_t relativeTileMortonId,
-      uint64_t contentId,
+      size_t contentId,
       bool isAvailable) noexcept;
 
   /**

Cesium3DTilesContent/src/BatchTableToGltfStructuralMetadata.cpp

@@ -1014,7 +1014,10 @@ void copyStringsToBuffers(
     for (const auto& str : arrayMember.GetArray()) {
       OffsetType byteLength = static_cast<OffsetType>(
           str.GetStringLength() * sizeof(rapidjson::Value::Ch));
-      std::memcpy(valueBuffer.data() + offset, str.GetString(), byteLength);
+      std::memcpy(
+          valueBuffer.data() + offset,
+          str.GetString(),
+          size_t(byteLength));
       std::memcpy(
           offsetBuffer.data() + offsetIndex * sizeof(OffsetType),
           &offset,
@@ -1075,8 +1078,7 @@ void updateStringArrayProperty(
     ++it;
   }
 
-  const uint64_t totalByteLength =
-      totalCharCount * sizeof(rapidjson::Value::Ch);
+  const size_t totalByteLength = totalCharCount * sizeof(rapidjson::Value::Ch);
   std::vector<std::byte> valueBuffer;
   std::vector<std::byte> stringOffsetBuffer;
   PropertyComponentType stringOffsetType = PropertyComponentType::None;

Cesium3DTilesContent/src/PntsToGltfConverter.cpp

@@ -823,7 +823,7 @@ void decodeDracoMetadata(
     const std::unique_ptr<draco::PointCloud>& pPointCloud,
     rapidjson::Document& batchTableJson,
     PntsContent& parsedContent) {
-  const uint64_t pointsLength = parsedContent.pointsLength;
+  const size_t pointsLength = parsedContent.pointsLength;
   std::vector<std::byte>& data = parsedContent.dracoBatchTableBinary;
 
   const auto& dracoMetadataSemantics = parsedContent.dracoMetadataSemantics;