# SPDX-License-Identifier: MPL-2.0
#
# CMake package interface for the Eigen submodule (eigen/), pinned at the
# official tag 3.4.0 (commit
# 3147391d946bb4b6c68edd901f2add6ac1f31f8c - the exact release libCZI pins in
# its cmake/ExternalEIGEN3.cmake). The Eigen release tree only ships the
# template cmake/Eigen3Config.cmake.in, which is expanded by Eigen's own CMake
# build (deliberately skipped by libCZI), so this small config provides the
# Eigen3::Eigen interface target used via
#   find_package(Eigen3 REQUIRED NO_MODULE)
# with LIBCZI_BUILD_PREFER_EXTERNALPACKAGE_EIGEN3=ON.
#
# Eigen is header-only (MPL-2.0; see COPYING.MPL2 in the submodule) and the
# submodule is checked out shallow (see .gitmodules), so libczirw-sys builds
# need neither network access during the build (libCZI's default Eigen
# ExternalProject clone from gitlab.com is flaky in CI), a full eigen git
# history, nor a system libeigen3-dev package.
if(NOT TARGET Eigen3::Eigen)
  get_filename_component(_eigen3_root "${CMAKE_CURRENT_LIST_DIR}/../eigen" ABSOLUTE)
  add_library(Eigen3::Eigen INTERFACE IMPORTED GLOBAL)
  set_target_properties(Eigen3::Eigen PROPERTIES
    INTERFACE_INCLUDE_DIRECTORIES "${_eigen3_root}")
  set(EIGEN3_INCLUDE_DIR "${_eigen3_root}")
endif()