feat(slam): add cartographer_ros

cartographer/cmake/modules/FindEigen3.cmake

@@ -0,0 +1,30 @@
+# Copyright 2018 The Cartographer Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+find_package(Eigen3 QUIET NO_MODULE)
+if (NOT EIGEN3_FOUND)
+  list(APPEND EIGEN3_POSSIBLE_DIRS
+    /usr/local/include/eigen3
+    /usr/include/eigen3
+  )
+  find_path(EIGEN3_INCLUDE_DIR
+    NAMES Eigen/Core
+    PATHS ${EIGEN3_POSSIBLE_DIRS}
+  )
+  if (EIGEN3_INCLUDE_DIR AND EXISTS ${EIGEN3_INCLUDE_DIR})
+    set(EIGEN3_FOUND TRUE)
+  else()
+    message(WARNING "Failed to find Eigen3. Please, define the path manually.")
+  endif()
+endif()