Snapmaker · abehrman · Jun 3, 2026 · Jun 3, 2026 · Jun 3, 2026 · Jun 3, 2026
diff --git a/.github/workflows/build_windows_arm64.yml b/.github/workflows/build_windows_arm64.yml
@@ -0,0 +1,130 @@
+name: Build Windows ARM64
+
+on:
+  push:
+    branches: [ feat/windows-arm64 ]
+  pull_request:
+    branches: [ main ]
+    paths:
+      - 'deps/**'
+      - 'src/**'
+      - 'CMakeLists.txt'
+      - 'build_release_vs2022.bat'
+      - '.github/workflows/build_windows_arm64.yml'
+
+jobs:
+  build-arm64:
+    name: Windows ARM64 (native)
+    runs-on: windows-11-arm
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          submodules: recursive
+
+      - name: Install MSYS2 (clangarm64) with GMP/MPFR and LLVM tools
+        uses: msys2/setup-msys2@v2
+        with:
+          msystem: CLANGARM64
+          update: true
+          install: >-
+            mingw-w64-clang-aarch64-gmp
+            mingw-w64-clang-aarch64-mpfr
+            mingw-w64-clang-aarch64-llvm
+
+      - name: Generate MSVC-compatible import libs for GMP and MPFR
+        # llvm-readobj --coff-exports parses PE DLL export tables.
+        # llvm-dlltool -m arm64 emits a COFF .lib that MSVC link.exe accepts.
+        shell: msys2 {0}
+        run: |
+          set -euo pipefail
+          BIN=/clangarm64/bin
+          REPO=$(cygpath -u "$GITHUB_WORKSPACE")
+
+          # Diagnose available tools if something goes wrong
+          echo "=== llvm tools in PATH ==="
+          ls /clangarm64/bin/llvm-* 2>/dev/null | head -20 || echo "(none found)"
+
+          make_import_lib() {
+            local dll="$1"
+            local lib="$2"
+            local def="/tmp/${dll%.dll}.def"
+            echo "--- $dll ---"
+            echo "EXPORTS" > "$def"
+            llvm-readobj --coff-exports "$BIN/$dll" \
+              | awk '/Name: /{print $2}' >> "$def"
+            echo "  $(( $(wc -l < "$def") - 1 )) exports"
+            llvm-dlltool -m arm64 -D "$dll" -d "$def" -l "$BIN/$lib"
+            echo "  $lib: $(wc -c < "$BIN/$lib") bytes"
+          }
+
+          make_import_lib libgmp-10.dll  libgmp-10.lib
+
+          # MPFR 4.x (soname 6) ships as libmpfr-6.dll in MSYS2 CLANGARM64;
+          # fall back to libmpfr-4.dll if an older package is installed.
+          MPFR_DLL=$(ls $BIN/libmpfr-*.dll 2>/dev/null | head -1 | xargs basename)
+          echo "Found MPFR DLL: $MPFR_DLL"
+          make_import_lib "$MPFR_DLL"  "${MPFR_DLL%.dll}.lib"
+          # cmake expects libmpfr-4.{dll,lib} — copy under that canonical name
+          if [ "$MPFR_DLL" != "libmpfr-4.dll" ]; then
+            cp "$BIN/$MPFR_DLL"                    "$BIN/libmpfr-4.dll"
+            cp "$BIN/${MPFR_DLL%.dll}.lib"         "$BIN/libmpfr-4.lib"
+          fi
+
+          # Stage into repo blob dirs so cmake's win-${DEPS_ARCH} lookup works
+          mkdir -p $REPO/deps/GMP/gmp/lib/win-arm64
+          mkdir -p $REPO/deps/MPFR/mpfr/lib/win-arm64
+
+          cp $BIN/libgmp-10.dll  $REPO/deps/GMP/gmp/lib/win-arm64/
+          cp $BIN/libgmp-10.lib  $REPO/deps/GMP/gmp/lib/win-arm64/
+          cp $BIN/libmpfr-4.dll  $REPO/deps/MPFR/mpfr/lib/win-arm64/
+          cp $BIN/libmpfr-4.lib  $REPO/deps/MPFR/mpfr/lib/win-arm64/
+          cp /clangarm64/include/gmp.h  $REPO/deps/GMP/gmp/include/
+          cp /clangarm64/include/mpfr.h $REPO/deps/MPFR/mpfr/include/ || true
+          echo "Done staging GMP/MPFR win-arm64 blobs."
+
+      - name: Cache deps
+        uses: actions/cache@v4
+        id: cache-deps
+        with:
+          path: deps/build-arm64/OrcaSlicer_dep
+          key: deps-arm64-${{ hashFiles('deps/**') }}-${{ runner.os }}
+
+      - name: Build dependencies (ARM64)
+        if: steps.cache-deps.outputs.cache-hit != 'true'
+        shell: cmd
+        run: |
+          cd deps
+          mkdir build-arm64
+          cd build-arm64
+          cmake ../ -G "Visual Studio 17 2022" -A ARM64 ^
+            -DDESTDIR="%CD%/OrcaSlicer_dep" ^
+            -DCMAKE_BUILD_TYPE=Release ^
+            -DDEP_DEBUG=OFF ^
+            -DCMAKE_POLICY_VERSION_MINIMUM=3.5
+          cmake --build . --config Release --target deps -- -m
+
+      - name: Build Snapmaker OrcaSlicer (ARM64)
+        shell: cmd
+        run: |
+          set DEPS=%CD%\deps\build-arm64\OrcaSlicer_dep
+          mkdir build-arm64
+          cd build-arm64
+          cmake .. -G "Visual Studio 17 2022" -A ARM64 ^
+            -DBBL_RELEASE_TO_PUBLIC=1 ^
+            -DORCA_TOOLS=ON ^
+            -DSLIC3R_ENABLE_STEP=OFF ^
+            -DCMAKE_PREFIX_PATH="%DEPS%/usr/local" ^
+            -DCMAKE_INSTALL_PREFIX="./Snapmaker_Orca" ^
+            -DCMAKE_BUILD_TYPE=Release ^
+            -DWIN10SDK_PATH="%WindowsSdkDir%Include\%WindowsSDKVersion%\"
+          cmake --build . --config Release --target ALL_BUILD -- -m
+          cmake --build . --target install --config Release
+
+      - name: Upload artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: Snapmaker-OrcaSlicer-Windows-ARM64
+          path: build-arm64/Snapmaker_Orca/
+          retention-days: 30
diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -101,6 +101,14 @@ endif()
 option(SLIC3R_STATIC 			"Compile Snapmaker_Orca with static libraries (Boost, TBB, glew)" ${SLIC3R_STATIC_INITIAL})
 option(SLIC3R_GUI    			"Compile Snapmaker_Orca with GUI components (OpenGL, wxWidgets)" 1)
 option(SLIC3R_FHS               "Assume Snapmaker_Orca is to be installed in a FHS directory structure" 0)
+
+# STEP/OCCT support requires OpenCASCADE 7.7+ for Windows ARM64. Default OFF on ARM64.
+if (WIN32 AND "${CMAKE_GENERATOR_PLATFORM}" STREQUAL "ARM64")
+    set(_step_default OFF)
+else()
+    set(_step_default ON)
+endif()
+option(SLIC3R_ENABLE_STEP "Compile with STEP file import support (requires OpenCASCADE)" ${_step_default})
 option(SLIC3R_WX_STABLE         "Build against wxWidgets stable (3.0) as oppsed to dev (3.1) on Linux" 0)
 option(SLIC3R_PROFILE 			"Compile Snapmaker_Orca with an invasive Shiny profiler" 0)
 option(SLIC3R_PCH               "Use precompiled headers" 1)
@@ -764,6 +772,8 @@ function(Snapmaker_Orca_copy_dlls target config postfix output_dlls)
         set(_arch "x64")
     elseif ("${CMAKE_SYSTEM_PROCESSOR}" STREQUAL "X86")
         set(_arch "x86")
+    elseif ("${CMAKE_SYSTEM_PROCESSOR}" STREQUAL "ARM64")
+        set(_arch "arm64")
     else ()
         message(FATAL_ERROR "Unable to detect architecture")
     endif ()
@@ -782,9 +792,12 @@ function(Snapmaker_Orca_copy_dlls target config postfix output_dlls)
         message ("set out_dir to CMAKE_CURRENT_BINARY_DIR: ${_out_dir}")
     endif ()
 
-    file(COPY ${TOP_LEVEL_PROJECT_DIR}/deps/GMP/gmp/lib/win-${_arch}/libgmp-10.dll
-            ${TOP_LEVEL_PROJECT_DIR}/deps/MPFR/mpfr/lib/win-${_arch}/libmpfr-4.dll
-            ${TOP_LEVEL_PROJECT_DIR}/deps/WebView2/lib/win-${_arch}/WebView2Loader.dll
+    if (NOT "${_arch}" STREQUAL "arm64")
+        file(COPY ${TOP_LEVEL_PROJECT_DIR}/deps/GMP/gmp/lib/win-${_arch}/libgmp-10.dll
+                ${TOP_LEVEL_PROJECT_DIR}/deps/MPFR/mpfr/lib/win-${_arch}/libmpfr-4.dll
+            DESTINATION ${_out_dir})
+    endif()
+    file(COPY ${TOP_LEVEL_PROJECT_DIR}/deps/WebView2/lib/win-${_arch}/WebView2Loader.dll
         DESTINATION ${_out_dir})
 
     # Copy Sentry and Crashpad artifacts if they were built by deps
@@ -795,6 +808,7 @@ function(Snapmaker_Orca_copy_dlls target config postfix output_dlls)
         )
     endif()
 
+    if (SLIC3R_ENABLE_STEP)
     file(COPY ${CMAKE_PREFIX_PATH}/bin/occt/TKBO.dll
             ${CMAKE_PREFIX_PATH}/bin/occt/TKBRep.dll
             ${CMAKE_PREFIX_PATH}/bin/occt/TKCAF.dll
@@ -823,43 +837,52 @@ function(Snapmaker_Orca_copy_dlls target config postfix output_dlls)
             ${CMAKE_PREFIX_PATH}/bin/occt/TKXSBase.dll
             ${CMAKE_PREFIX_PATH}/bin/freetype.dll
          DESTINATION ${_out_dir})
+    endif() # SLIC3R_ENABLE_STEP
 
     # Build the DLL list in a local variable first
     set(_dll_list
-        ${_out_dir}/libgmp-10.dll
-        ${_out_dir}/libmpfr-4.dll
         ${_out_dir}/WebView2Loader.dll
-
-        ${_out_dir}/TKBO.dll
-        ${_out_dir}/TKBRep.dll
-        ${_out_dir}/TKCAF.dll
-        ${_out_dir}/TKCDF.dll
-        ${_out_dir}/TKernel.dll
-        ${_out_dir}/TKG2d.dll
-        ${_out_dir}/TKG3d.dll
-        ${_out_dir}/TKGeomAlgo.dll
-        ${_out_dir}/TKGeomBase.dll
-        ${_out_dir}/TKHLR.dll
-        ${_out_dir}/TKLCAF.dll
-        ${_out_dir}/TKMath.dll
-        ${_out_dir}/TKMesh.dll
-        ${_out_dir}/TKPrim.dll
-        ${_out_dir}/TKService.dll
-        ${_out_dir}/TKShHealing.dll
-        ${_out_dir}/TKSTEP.dll
-        ${_out_dir}/TKSTEP209.dll
-        ${_out_dir}/TKSTEPAttr.dll
-        ${_out_dir}/TKSTEPBase.dll
-        ${_out_dir}/TKTopAlgo.dll
-        ${_out_dir}/TKV3d.dll
-        ${_out_dir}/TKVCAF.dll
-        ${_out_dir}/TKXCAF.dll
-        ${_out_dir}/TKXDESTEP.dll
-        ${_out_dir}/TKXSBase.dll
-
-        ${_out_dir}/freetype.dll
     )
 
+    if (NOT "${_arch}" STREQUAL "arm64")
+        list(APPEND _dll_list
+            ${_out_dir}/libgmp-10.dll
+            ${_out_dir}/libmpfr-4.dll
+        )
+    endif()
+
+    if (SLIC3R_ENABLE_STEP)
+        list(APPEND _dll_list
+            ${_out_dir}/TKBO.dll
+            ${_out_dir}/TKBRep.dll
+            ${_out_dir}/TKCAF.dll
+            ${_out_dir}/TKCDF.dll
+            ${_out_dir}/TKernel.dll
+            ${_out_dir}/TKG2d.dll
+            ${_out_dir}/TKG3d.dll
+            ${_out_dir}/TKGeomAlgo.dll
+            ${_out_dir}/TKGeomBase.dll
+            ${_out_dir}/TKHLR.dll
+            ${_out_dir}/TKLCAF.dll
+            ${_out_dir}/TKMath.dll
+            ${_out_dir}/TKMesh.dll
+            ${_out_dir}/TKPrim.dll
+            ${_out_dir}/TKService.dll
+            ${_out_dir}/TKShHealing.dll
+            ${_out_dir}/TKSTEP.dll
+            ${_out_dir}/TKSTEP209.dll
+            ${_out_dir}/TKSTEPAttr.dll
+            ${_out_dir}/TKSTEPBase.dll
+            ${_out_dir}/TKTopAlgo.dll
+            ${_out_dir}/TKV3d.dll
+            ${_out_dir}/TKVCAF.dll
+            ${_out_dir}/TKXCAF.dll
+            ${_out_dir}/TKXDESTEP.dll
+            ${_out_dir}/TKXSBase.dll
+            ${_out_dir}/freetype.dll
+        )
+    endif()
+
     # Add Sentry DLLs to the list if Sentry is enabled
     if (SLIC3R_SENTRY)
         list(APPEND _dll_list

diff --git a/build_release_vs2022.bat b/build_release_vs2022.bat
@@ -15,10 +15,13 @@ if "%1"=="pack" (
 
 set debug=OFF
 set debuginfo=OFF
+set arch=x64
 if "%1"=="debug" set debug=ON
 if "%2"=="debug" set debug=ON
 if "%1"=="debuginfo" set debuginfo=ON
 if "%2"=="debuginfo" set debuginfo=ON
+if "%1"=="arm64" set arch=ARM64
+if "%2"=="arm64" set arch=ARM64
 if "%debug%"=="ON" (
     set build_type=Debug
     set build_dir=build-dbg
@@ -31,7 +34,8 @@ if "%debug%"=="ON" (
         set build_dir=build
     )
 )
-echo build type set to %build_type%
+if "%arch%"=="ARM64" set build_dir=%build_dir%-arm64
+echo build type set to %build_type%, arch=%arch%
 
 setlocal DISABLEDELAYEDEXPANSION 
 cd deps
@@ -47,7 +51,7 @@ if "%1"=="slicer" (
 echo "building deps.."
 
 echo on
-cmake ../ -G "Visual Studio 17 2022" -A x64 -DDESTDIR="%DEPS%" -DCMAKE_BUILD_TYPE=%build_type% -DDEP_DEBUG=%debug% -DORCA_INCLUDE_DEBUG_INFO=%debuginfo%
+cmake ../ -G "Visual Studio 17 2022" -A %arch% -DDESTDIR="%DEPS%" -DCMAKE_BUILD_TYPE=%build_type% -DDEP_DEBUG=%debug% -DORCA_INCLUDE_DEBUG_INFO=%debuginfo%
 cmake --build . --config %build_type% --target deps -- -m
 @echo off
 
@@ -60,7 +64,7 @@ mkdir %build_dir%
 cd %build_dir%
 
 echo on
-cmake .. -G "Visual Studio 17 2022" -A x64 -DBBL_RELEASE_TO_PUBLIC=1 -DORCA_TOOLS=ON %SIG_FLAG% -DCMAKE_PREFIX_PATH="%DEPS%/usr/local" -DCMAKE_INSTALL_PREFIX="./Snapmaker_Orca" -DCMAKE_BUILD_TYPE=%build_type% -DWIN10SDK_PATH="%WindowsSdkDir%Include\%WindowsSDKVersion%\"
+cmake .. -G "Visual Studio 17 2022" -A %arch% -DBBL_RELEASE_TO_PUBLIC=1 -DORCA_TOOLS=ON %SIG_FLAG% -DCMAKE_PREFIX_PATH="%DEPS%/usr/local" -DCMAKE_INSTALL_PREFIX="./Snapmaker_Orca" -DCMAKE_BUILD_TYPE=%build_type% -DWIN10SDK_PATH="%WindowsSdkDir%Include\%WindowsSDKVersion%\"
 cmake --build . --config %build_type% --target ALL_BUILD -- -m
 @echo off
 cd ..

diff --git a/cmake/modules/FindGLEW.cmake b/cmake/modules/FindGLEW.cmake
@@ -124,6 +124,8 @@ endif()
 
 if("${CMAKE_GENERATOR_PLATFORM}" MATCHES "x64" OR "${CMAKE_GENERATOR}" MATCHES "Win64")
   set(_arch "x64")
+elseif("${CMAKE_GENERATOR_PLATFORM}" MATCHES "ARM64")
+  set(_arch "x64")  # GLEW ships a single set of headers; ARM64 uses x64 import path
 else()
   set(_arch "Win32")
 endif()

diff --git a/deps/CGAL/CGAL.cmake b/deps/CGAL/CGAL.cmake
@@ -2,15 +2,28 @@ if (IN_GIT_REPO)
     set(CGAL_DIRECTORY_FLAG --directory ${BINARY_DIR_REL}/dep_CGAL-prefix/src/dep_CGAL)
 endif ()
 
-Snapmaker_Orca_add_cmake_project(
-    CGAL
-    # GIT_REPOSITORY https://github.com/CGAL/cgal.git
-    # GIT_TAG        bec70a6d52d8aacb0b3d82a7b4edc3caa899184b # releases/CGAL-5.0
-    # For whatever reason, this keeps downloading forever (repeats downloads if finished)
-    URL      https://github.com/CGAL/cgal/archive/refs/tags/v5.4.zip
-    URL_HASH SHA256=d7605e0a5a5ca17da7547592f6f6e4a59430a0bc861948974254d0de43eab4c0
-    PATCH_COMMAND git apply ${CGAL_DIRECTORY_FLAG} --verbose --ignore-space-change --whitespace=fix ${CMAKE_CURRENT_LIST_DIR}/0001-clang19.patch
-    DEPENDS dep_Boost dep_GMP dep_MPFR
-)
+if (MSVC AND "${DEPS_ARCH}" STREQUAL "arm64")
+    # Windows ARM64: build CGAL without GMP/MPFR (exact-arithmetic kernels unavailable).
+    # STEP/OCCT import is disabled on ARM64 (OCCT 7.6 has no ARM64 support).
+    Snapmaker_Orca_add_cmake_project(
+        CGAL
+        URL      https://github.com/CGAL/cgal/archive/refs/tags/v5.4.zip
+        URL_HASH SHA256=d7605e0a5a5ca17da7547592f6f6e4a59430a0bc861948974254d0de43eab4c0
+        PATCH_COMMAND git apply ${CGAL_DIRECTORY_FLAG} --verbose --ignore-space-change --whitespace=fix ${CMAKE_CURRENT_LIST_DIR}/0001-clang19.patch
+        DEPENDS dep_Boost
+        CMAKE_ARGS -DCGAL_DISABLE_GMP=ON
+    )
+else()
+    Snapmaker_Orca_add_cmake_project(
+        CGAL
+        # GIT_REPOSITORY https://github.com/CGAL/cgal.git
+        # GIT_TAG        bec70a6d52d8aacb0b3d82a7b4edc3caa899184b # releases/CGAL-5.0
+        # For whatever reason, this keeps downloading forever (repeats downloads if finished)
+        URL      https://github.com/CGAL/cgal/archive/refs/tags/v5.4.zip
+        URL_HASH SHA256=d7605e0a5a5ca17da7547592f6f6e4a59430a0bc861948974254d0de43eab4c0
+        PATCH_COMMAND git apply ${CGAL_DIRECTORY_FLAG} --verbose --ignore-space-change --whitespace=fix ${CMAKE_CURRENT_LIST_DIR}/0001-clang19.patch
+        DEPENDS dep_Boost dep_GMP dep_MPFR
+    )
+endif()
 
 include(GNUInstallDirs)