Merge pull request #71 from Ryanf55/fix-export-libraries

Export the right library names

CMakeLists.txt

@@ -33,6 +33,11 @@ target_link_libraries(realtime_circular_buffer
     Boost::boost
 )
 
+# filter_base is an INTERFACE library because it only has header files.
+# It is not compiled, but sets up the following properties for consumers
+# to link to a target.
+# For more info, see the CMake Wiki on INTERFACE targets.
+# https://cmake.org/cmake/help/latest/command/add_library.html#interface-libraries
 add_library(filter_base
   INTERFACE
     include/filters/filter_base.h
@@ -204,9 +209,8 @@ endif()
 # Install
 ##############################################################################
 
-# Export old-style CMake variables
+# Export old-style CMake variables for includes
 ament_export_include_directories("include/${PROJECT_NAME}")
-ament_export_libraries(${PROJECT_NAME})
 
 # Export modern CMake targets
 ament_export_targets(export_${PROJECT_NAME} HAS_LIBRARY_TARGET)

README.md

@@ -0,0 +1,30 @@
+# Filters
+
+## Usage with ament_cmake
+
+Here is recommended approach on how to link `filters` to your project, using the `filters::realtime_circular_buffer` target.
+
+```cmake
+find_package(filters CONFIG REQUIRED)
+
+add_library(my_library)
+# Other library stuff here
+
+target_link_libraries(my_library PUBLIC filters::realtime_circular_buffer)
+```
+
+For more information on using ament_cmake, 
+see the [ament_cmake](https://docs.ros.org/en/rolling/How-To-Guides/Ament-CMake-Documentation.html)
+tutorial.
+
+Filters creates all of the following CMake targets, including:
+* filters::realtime_circular_buffer
+* filters::filter_chain
+* filters::mean
+* filters::params
+* filters::increment
+* filters::median
+* filters::transfer_function
+
+It is recommended to only link to the libraries needed.
+Linking to `filters::filter_base` pulls in all necessary libraries and include directories for targets with classes that extend `FilterBase`. This is useful if you are writing your own filter.