build: CMake and public headers

CMakeLists.txt

@@ -0,0 +1,34 @@
+cmake_minimum_required(VERSION 3.16)
+project(openkknd C)
+
+set(CMAKE_C_STANDARD 11)
+set(CMAKE_C_STANDARD_REQUIRED ON)
+set(CMAKE_C_EXTENSIONS OFF)
+
+file(READ "${CMAKE_SOURCE_DIR}/VERSION" OPENKKND_VERSION)
+string(STRIP "${OPENKKND_VERSION}" OPENKKND_VERSION)
+
+add_executable(openkknd
+  src/main.c
+  src/game.c
+  src/map.c
+  src/unit.c
+  src/render.c
+)
+
+target_include_directories(openkknd PRIVATE include)
+target_compile_definitions(openkknd PRIVATE
+  OPENKKND_VERSION="${OPENKKND_VERSION}"
+)
+
+find_package(SDL2 REQUIRED)
+if(TARGET SDL2::SDL2)
+  target_link_libraries(openkknd PRIVATE SDL2::SDL2)
+elseif(TARGET SDL2::SDL2-static)
+  target_link_libraries(openkknd PRIVATE SDL2::SDL2-static)
+else()
+  target_include_directories(openkknd PRIVATE ${SDL2_INCLUDE_DIRS})
+  target_link_libraries(openkknd PRIVATE ${SDL2_LIBRARIES})
+endif()
+
+install(TARGETS openkknd RUNTIME DESTINATION bin)