runtimes/native: make glfw selectable with a cmake option

runtimes/native/CMakeLists.txt

@@ -2,6 +2,7 @@ cmake_minimum_required(VERSION 3.7)
 project(WASM4)
 
 set(WASM_BACKEND "wasm3" CACHE STRING "webassembly runtime")
+set(WINDOW_BACKEND "minifb" CACHE STRING "window backend")
 
 set (WASM3 OFF)
 set (TOYWASM OFF)
@@ -13,6 +14,16 @@ else ()
 message (FATAL_ERROR "Unrecognized WASM_BACKEND value: ${WASM_BACKEND}")
 endif ()
 
+set (MINIFB OFF)
+set (GLFW OFF)
+if (WINDOW_BACKEND STREQUAL "minifb")
+set (MINIFB ON)
+elseif (WINDOW_BACKEND STREQUAL "glfw")
+set (GLFW ON)
+else ()
+message (FATAL_ERROR "Unrecognized WINDOW_BACKEND value: ${WINDOW_BACKEND}")
+endif ()
+
 # Prevent BUILD_SHARED_LIBS and other options from being cleared by vendor CMakeLists
 # https://stackoverflow.com/a/66342383
 set(CMAKE_POLICY_DEFAULT_CMP0077 NEW)
@@ -94,8 +105,12 @@ if (LIBRETRO)
 endif ()
 
 if (NOT LIBRETRO)
-# add_subdirectory(vendor/glfw)
+if (GLFW)
+add_subdirectory(vendor/glfw)
+endif ()
+if (MINIFB)
 add_subdirectory(vendor/minifb)
+endif ()
 add_subdirectory(vendor/cubeb)
 endif ()
 
@@ -111,28 +126,41 @@ endif ()
 if (NOT LIBRETRO)
 
 #
-# Desktop (minifb + cubeb) backend
+# Desktop ([minifb|glfw] + cubeb) backend
 #
 
-set(MINIFB_SOURCES
+set(MAIN_SOURCES
     src/backend/main.c
+)
+
+set(MINIFB_SOURCES
     src/backend/window_minifb.c
 )
 
-add_executable(wasm4 ${COMMON_SOURCES} ${MINIFB_SOURCES}
+set(GLFW_SOURCES
+    src/backend/window_glfw.c
+    vendor/glad/src/glad.c
+)
+
+add_executable(wasm4 ${COMMON_SOURCES} ${MAIN_SOURCES}
+    $<$<BOOL:${MINIFB}>:${MINIFB_SOURCES}>
+    $<$<BOOL:${GLFW}>:${GLFW_SOURCES}>
     $<$<BOOL:${WASM3}>:${WASM3_SOURCES}>
     $<$<BOOL:${TOYWASM}>:${TOYWASM_SOURCES}>)
 if (TOYWASM)
 add_dependencies(wasm4 toywasm)
 endif ()
 
 target_include_directories(wasm4 PRIVATE
+    $<$<BOOL:${GLFW}>:${CMAKE_SOURCE_DIR}/vendor/glad/include>
     $<$<BOOL:${WASM3}>:${CMAKE_SOURCE_DIR}/vendor/wasm3/source>
     $<$<BOOL:${TOYWASM}>:${toywasm_tmp_install}/include>)
 target_link_directories(wasm4 PRIVATE
     $<$<BOOL:${TOYWASM}>:${toywasm_tmp_install}/lib>)
 
-target_link_libraries(wasm4 minifb cubeb
+target_link_libraries(wasm4 cubeb
+    $<$<BOOL:${MINIFB}>:minifb>
+    $<$<BOOL:${GLFW}>:glfw>
     $<$<BOOL:${TOYWASM}>:toywasm-core>)
 set_target_properties(wasm4 PROPERTIES C_STANDARD 99)
 install(TARGETS wasm4)
@@ -153,24 +181,6 @@ if (WASMER_DIR)
     install(TARGETS wasm4_wasmer)
 endif ()
 
-# #
-# # Desktop (glfw + cubeb) backend
-# #
-# 
-# set(GLFW_SOURCES
-#     src/backend/main.c
-#     src/backend/wasm_wasm3.c
-#     src/backend/window_glfw.c
-#     vendor/glad/src/glad.c
-# )
-# add_executable(wasm4_glfw)
-# target_sources(wasm4_glfw PRIVATE ${COMMON_SOURCES} ${GLFW_SOURCES} ${M3_SOURCES})
-# target_include_directories(wasm4_glfw PRIVATE "${CMAKE_SOURCE_DIR}/vendor/wasm3/source")
-# target_include_directories(wasm4_glfw PRIVATE "${CMAKE_SOURCE_DIR}/vendor/glad/include")
-# target_link_libraries(wasm4_glfw glfw cubeb)
-# set_target_properties(wasm4_glfw PROPERTIES C_STANDARD 99)
-# install(TARGETS wasm4_glfw)
-
 #
 # Libretro backend
 #