Update CMakeLists.txt

CMakeLists.txt

@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.20)
+cmake_minimum_required(VERSION 3.18)
 project(glad
         VERSION 1.0
         LANGUAGES C
@@ -6,8 +6,19 @@ project(glad
 
 file(GLOB_RECURSE HEADERS "include/*.h")
 file(GLOB_RECURSE SOURCES "src/*.c")
-include_directories("include")
+find_package(OpenGL REQUIRED)
+
+include_directories("include")
+include_directories(${OPENGL_INCLUDE_DIRS})
+
+if (UNIX AND NOT APPLE)
+    add_library(glad SHARED ${SOURCES})
+endif()
+
+if (WIN32)
+    add_library(glad STATIC ${SOURCES})
+endif()
+
 
-add_library(glad SHARED ${SOURCES})
 set_target_properties(glad PROPERTIES LINKER_LANGUAGE C)
-target_link_libraries(glad PUBLIC GL)
+target_link_libraries(glad PUBLIC ${OPENGL_LIBRARIES})