Not sure if this is the right way. But a lot simpler it is.
set(PROJECT_SHORT_NAME "kg")
set(PROJECT_LONG_NAME "Kisna Glista")
set(PROJECT_VERSION_MAJOR 0)
set(PROJECT_VERSION_MINOR 1)
project(${PROJECT_SHORT_NAME})
cmake_minimum_required(VERSION 2.6)
# Avoid source tree pollution
if(CMAKE_SOURCE_DIR STREQUAL CMAKE_BINARY_DIR)
message(FATAL_ERROR "In-source builds are not permitted. Make a separate folder for building:\nmkdir build; cd build; cmake ..\nBefore that, remove the files already created:\nrm -rf CMakeCache.txt CMakeFiles")
endif(CMAKE_SOURCE_DIR STREQUAL CMAKE_BINARY_DIR)
# Where to install project data files
set(PROJECT_DATA_DIR "${CMAKE_INSTALL_PREFIX}/share/${PROJECT_SHORT_NAME}")
# Where to look for Find*.cmake and other modules
set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${CMAKE_SOURCE_DIR}/cmake/Modules/")
# Add a sensible build type default and warning because empty means no optimization and no debug info.
if(NOT CMAKE_BUILD_TYPE)
message("WARNING: CMAKE_BUILD_TYPE is not defined!\n Defaulting to CMAKE_BUILD_TYPE=Release. Use ccmake to set a proper value.")
set(CMAKE_BUILD_TYPE Release CACHE STRING "Choose the type of build, options are: None Debug Release RelWithDebInfo MinSizeRel." FORCE)
endif(NOT CMAKE_BUILD_TYPE)
add_subdirectory(src)
add_subdirectory(data)