separate game and townengine builds for reuse in tools

CMakeLists.txt

@@ -31,7 +31,7 @@ else()
         set(SYSTEM_SOURCE_FILES)
 endif()
 
-set(SOURCE_FILES
+set(TOWNENGINE_SOURCE_FILES
         third-party/physfs/extras/physfsrwops.c
         third-party/stb/stb_vorbis.c
         third-party/glad/src/glad.c
@@ -46,6 +46,11 @@ set(SOURCE_FILES
         src/input.c src/input.h
         src/text.c src/text.h
         src/camera.c src/camera.h
+
+        ${SYSTEM_SOURCE_FILES}
+)
+
+set(GAME_SOURCE_FILES
         src/game_api.h
 
         src/game/game.c src/game/game.h
@@ -57,13 +62,11 @@ set(SOURCE_FILES
         src/game/scenes/scene.c src/game/scenes/scene.h
         src/game/scenes/title.c src/game/scenes/title.h
         src/game/scenes/ingame.c src/game/scenes/ingame.h
-
-        ${SYSTEM_SOURCE_FILES}
 )
 
-# target
+# base engine code, reused for games and tools
-add_executable(${PROJECT_NAME} ${SOURCE_FILES})
+add_library(${PROJECT_NAME} ${TOWNENGINE_SOURCE_FILES})
-source_group(TREE ${CMAKE_CURRENT_SOURCE_DIR} FILES ${SOURCE_FILES})
+source_group(TREE ${CMAKE_CURRENT_SOURCE_DIR} FILES ${TOWNENGINE_SOURCE_FILES})
 
 set_target_properties(${PROJECT_NAME} PROPERTIES
                                       C_STANDARD 11
@@ -78,15 +81,14 @@ set(APP_NAME "townengine" CACHE STRING
 set(PACKAGE_EXTENSION "btw" CACHE STRING
                       "File extension used to look for data archives")
 
-# build options
+function(give_options target)
-# LTO will be used on release builds
         if(MSVC)
                 # close enough i say
-        target_compile_options(${PROJECT_NAME} PRIVATE
+                target_compile_options(${target} PRIVATE
                                                  /W4
                                                  $<$<CONFIG:Release>:/GL>)
 
-        target_link_options(${PROJECT_NAME} PRIVATE
+                target_link_options(${target} PRIVATE
                                               $<$<CONFIG:Release>:/LTCG>)
 
         else()
@@ -136,27 +138,30 @@ else()
                         -fsanitize=undefined
                         -fsanitize=address)
 
-        target_compile_options(${PROJECT_NAME} PRIVATE
+                target_compile_options(${target} PRIVATE
                                                  ${WARNING_FLAGS}
                                                  ${BUILD_FLAGS}
                                                  $<$<CONFIG:Release>:${BUILD_FLAGS_RELEASE}>
                                                  $<$<CONFIG:Debug>:${BUILD_FLAGS_DEBUG}>)
 
-        target_link_options(${PROJECT_NAME} PRIVATE
+                target_link_options(${target} PRIVATE
                                               ${BUILD_FLAGS}
                                               $<$<CONFIG:Release>:${BUILD_FLAGS_RELEASE}>
                                               $<$<CONFIG:Debug>:${BUILD_FLAGS_DEBUG}>)
                                                     
         endif()
 
-target_compile_definitions(${PROJECT_NAME} PRIVATE
+        target_compile_definitions(${target} PRIVATE
                                              ORGANIZATION_NAME="${ORGANIZATION_NAME}"
                                              APP_NAME="${APP_NAME}"
                                              PACKAGE_EXTENSION="${PACKAGE_EXTENSION}")
+endfunction()
 
+
+function(link_and_include_deps target)
         # header-only libraries should be marked as "system includes"
         # to suppress compiler warnings in their code (it's not my problem after all)
-target_include_directories(${PROJECT_NAME}
+        target_include_directories(${target}
                 SYSTEM  
                 PRIVATE
                 third-party/physfs/src
@@ -166,14 +171,30 @@ target_include_directories(${PROJECT_NAME}
                 third-party/stb
         )
 
+        target_link_libraries(${target} PUBLIC
+                                        SDL2::SDL2
+                                        SDL2::SDL2main
+                                        SDL2_image::SDL2_image
+                                        SDL2_ttf::SDL2_ttf
+                                        physfs-static
+                                        xms
+        )
+endfunction()
+
+
+function(use_townengine target)
         # system libraries
         find_library(MATH_LIBRARY m)
         if(MATH_LIBRARY)
-        target_link_libraries(${PROJECT_NAME} PUBLIC ${MATH_LIBRARY})
+                target_link_libraries(${target} PUBLIC ${MATH_LIBRARY})
         endif()
 
+        give_options(${target})
+        link_and_include_deps(${target})
+
         # third-party libraries
-target_link_libraries(${PROJECT_NAME} PUBLIC
+        target_link_libraries(${target} PUBLIC
+                                        ${PROJECT_NAME}
                                         SDL2::SDL2
                                         SDL2::SDL2main
                                         SDL2_image::SDL2_image
@@ -183,11 +204,18 @@ target_link_libraries(${PROJECT_NAME} PUBLIC
         )
 
         # copy dlls for baby windows
-add_custom_command(TARGET ${PROJECT_NAME} POST_BUILD
+        add_custom_command(TARGET ${target} POST_BUILD
-        COMMAND ${CMAKE_COMMAND} -E copy -t $<TARGET_FILE_DIR:${PROJECT_NAME}>
+                COMMAND ${CMAKE_COMMAND} -E copy -t $<TARGET_FILE_DIR:${target}>
-                                            $<TARGET_RUNTIME_DLLS:${PROJECT_NAME}>
+                                                    $<TARGET_RUNTIME_DLLS:${target}>
                 COMMAND_EXPAND_LISTS
         )
+endfunction()
+
+give_options(${PROJECT_NAME})
+link_and_include_deps(${PROJECT_NAME})
+
+add_executable(game ${GAME_SOURCE_FILES})
+use_townengine(game)
 
 # zip up assets
 # currently, you must run cmake from the project root dir for this to work correctly