cmake: add minimum required eigen3 version

src/helpers/CMakeLists.txt

@@ -34,7 +34,7 @@ message("Running CMakeLists.txt in /src/helpers")
 #                   (ifcopenshell.util.element)
 #   * Element     — get_predefined_type (ifcopenshell.util.element)
 
-find_package(Eigen3 REQUIRED)
+find_package(Eigen3 ${EIGEN_MIN_VERSION} REQUIRED)
 
 # helpers_math: the schema-free subset — unit conversion tables and Helmert
 # matrix math over plain numbers. No IfcParse, no Qt, no schema dispatch, so it

src/ifcgeom/CMakeLists.txt

@@ -41,7 +41,7 @@ if(UNIX)
     find_package(Threads)
 endif()
 
-find_package(Eigen3 REQUIRED)
+find_package(Eigen3 ${EIGEN_MIN_VERSION} REQUIRED)
 
 add_subdirectory(kernels)
 set(kernel_libraries ${kernel_libraries} PARENT_SCOPE)

src/ifcgeom/mapping/CMakeLists.txt

@@ -1,4 +1,4 @@
-find_package(Eigen3 REQUIRED)
+find_package(Eigen3 ${EIGEN_MIN_VERSION} REQUIRED)
 
 set(mapping_plugin_runtime_dir "$<TARGET_FILE_DIR:IfcGeom>")
 

src/ifcviewer/CMakeLists.txt

@@ -30,7 +30,7 @@ endif()
 # Eigen3 — used by Federation matrices, ViewportWindow's instance compose,
 # the per-model coordinate-operation matrices stored on ModelGpuData, and
 # everywhere a 4x4 transform shows up. Header-only, works under Emscripten.
-find_package(Eigen3 REQUIRED)
+find_package(Eigen3 ${EIGEN_MIN_VERSION} REQUIRED)
 
 # wgpu-native — fetched as a pre-built binary release from upstream.
 # Under Emscripten this whole block is skipped; the web build links

src/ifcviewer/tests/CMakeLists.txt

@@ -93,7 +93,7 @@ add_ifcviewer_unit_test(test_sidecar_layout
 # InstanceCompose: matrix composition + cross-model object_id lookup.
 # Pulls in wgpu_native for the WGPUBuffer typedef via ModelGpuData.h
 # (never touched at runtime). Eigen for Matrix4d.
-find_package(Eigen3 REQUIRED)
+find_package(Eigen3 ${EIGEN_MIN_VERSION} REQUIRED)
 add_ifcviewer_unit_test(test_instance_compose
     SOURCES ${IFCVIEWER_SRC}/InstanceCompose.cpp
     LIBS wgpu_native Eigen3::Eigen
@@ -150,7 +150,7 @@ endif()
 # directly and enable AUTOMOC for the Q_OBJECT moc-generation.
 find_package(Qt${QT_VERSION} COMPONENTS Core Gui Test REQUIRED PATHS ${QT_DIR})
 
-find_package(Eigen3 REQUIRED)
+find_package(Eigen3 ${EIGEN_MIN_VERSION} REQUIRED)
 
 add_executable(test_federation
     test_federation.cpp