CMAKEList leap motion - c++

Question

I am trying to build a cmakelist file from makefile of leap motion, I can compile in a specific directory, I need to copy /include/ and /lib/x64/ directories . The makefile is the follow:
LEAP_LIBRARY := ./lib/x64/libLeap.so -Wl,-rpath,./lib/x64
Sample: Sample.cpp
$(CXX) -Wall -g -I include Sample.cpp -o Sample $(LEAP_LIBRARY)
I have tried to build a cmakelist file as follows:
cmake_minimum_required(VERSION 2.8)
project(Sample)
INCLUDE_DIRECTORIES(/include/)
LINK_DIRECTORIES(/lib/x64/)
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -g -I /include/ -Wl,-rpath,./lib/x64")
add_executable(Sample Sample.cpp )
target_link_libraries(Sample libLeap.so)
But I always get the same error:
Linking CXX executable Sample
/usr/bin/ld: can't find -lLeap
collect2: error: ld returned 1 exit status
make[2]: *** [Sample] Error 1
make[1]: *** [CMakeFiles/Sample.dir/all] Error 2
make: *** [all] Error 2
Thanks and regards.

Answer 1

I could solve with following lines:
cmake_minimum_required(VERSION 2.8)
project(Sample)
SET(CMAKE_INSTALL_RPATH_USE_LINK_PATH TRUE)
INCLUDE_DIRECTORIES(../include/)
LINK_DIRECTORIES(../lib/x64/)
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -g")
add_executable(Sample Sample.cpp )
target_link_libraries(Sample -lLeap)
This solution has warnings but works:
CMake Warning (dev) at CMakeLists.txt:5 (LINK_DIRECTORIES):
This command specifies the relative path
../lib/x64
as a link directory.
Policy CMP0015 is not set: link_directories() treats paths relative to the
source dir. Run "cmake --help-policy CMP0015" for policy details. Use the
cmake_policy command to set the policy and suppress this warning.
This warning is for project developers. Use -Wno-dev to suppress it.
-- Configuring done
-- Generating done
-- Build files....
Two way to delete this warning:
cmake_minimum_required(VERSION 2.8)
project(Sample)
cmake_policy(SET CMP0015 NEW)
SET(CMAKE_INSTALL_RPATH_USE_LINK_PATH TRUE)
INCLUDE_DIRECTORIES(../include/)
LINK_DIRECTORIES(lib/x64/)
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -g")
add_executable(Sample Sample.cpp )
target_link_libraries(Sample -lLeap)
Or use cmake .. -Wno-dev