octomap: Fix binding build when octomap is missing

cmake: Fix comment

doc/CMakeLists.txt

@@ -4,5 +4,16 @@ SET(DOXYGEN_GENERATE_XML        "YES"              PARENT_SCOPE)
 SET(DOXYGEN_EXPAND_ONLY_PREDEF  "NO"               PARENT_SCOPE)
 SET(DOXYGEN_ENABLE_PREPROCESSING "YES" PARENT_SCOPE)
 SET(DOXYGEN_MACRO_EXPANSION      "YES" PARENT_SCOPE)
+SET(DOXYGEN_EXCLUDE "${PROJECT_SOURCE_DIR}/include/hpp/")
+
+# We must not document octree if Octomap is not setup.
+# This create a build issue when building the bindings because doxygen-autodoc will
+# include octree.h that will include octomap.h.
+IF(NOT COAL_HAS_OCTOMAP)
+  SET(DOXYGEN_EXCLUDE "${DOXYGEN_EXCLUDE} ${PROJECT_SOURCE_DIR}/include/coal/octree.h")
+  SET(DOXYGEN_EXCLUDE "${DOXYGEN_EXCLUDE} ${PROJECT_SOURCE_DIR}/include/coal/serialization/octree.h")
+  SET(DOXYGEN_EXCLUDE "${DOXYGEN_EXCLUDE} ${PROJECT_SOURCE_DIR}/include/coal/internal/traversal_node_octree.h")
+ENDIF()
+SET(DOXYGEN_EXCLUDE ${DOXYGEN_EXCLUDE} PARENT_SCOPE)
 
 SET(DOXYGEN_PREDEFINED          "IS_DOXYGEN"       PARENT_SCOPE)