fixed qt related compilation errors

rtabmap_viz/CMakeLists.txt

@@ -16,6 +16,15 @@ catkin_package(
   CATKIN_DEPENDS cv_bridge geometry_msgs std_msgs std_srvs nav_msgs rtabmap_msgs rtabmap_sync tf
 )
 
+# catkin is not using cmake targets for dependencies,
+# so we should explcitly look for Qt to get compilation
+# flags (-fPIC missing)
+FIND_PACKAGE(Qt5 COMPONENTS Widgets Core Gui QUIET)
+IF(NOT Qt5_FOUND)
+    FIND_PACKAGE(Qt4 COMPONENTS QtCore QtGui REQUIRED)
+    INCLUDE(${QT_USE_FILE})
+ENDIF(NOT Qt5_FOUND)
+
 ###########
 ## Build ##
 ###########
@@ -27,6 +36,9 @@ include_directories(
 )
 
 add_executable(rtabmap_viz src/GuiNode.cpp src/GuiWrapper.cpp src/PreferencesDialogROS.cpp)
+IF(Qt5_FOUND)
+    QT5_USE_MODULES(rtabmap_viz Widgets Core Gui)
+ENDIF(Qt5_FOUND)
 target_link_libraries(rtabmap_viz ${catkin_LIBRARIES})