provide a way to disable conan support

CMakeLists.txt

 cmake_minimum_required(VERSION 3.16)
 set(namespace "fggl")
 
+option(FGGL_CONAN "Should we use conan to find missing dependencies?" ON)
 set(CONAN_BUILD_TYPE "Debug")
 
 # Define the project
@@ -13,44 +14,46 @@ project(fggl
 if (CMAKE_PROJECT_NAME STREQUAL PROJECT_NAME)
 
 	# slightly cleaner conan support
-	set(CMAKE_MODULE_PATH ${CMAKE_BINARY_DIR} ${CMAKE_MODULE_PATH})
-	set(CMAKE_PREFIX_PATH ${CMAKE_BINARY_DIR} ${CMAKE_PREFIX_PATH})
-	include( cmake/conan.cmake )
-
-	conan_cmake_configure(
-		REQUIRES
-			opengl/system
-			glfw/3.3.7
-			glad/0.1.35
-			glm/0.9.9.8
-			spdlog/1.10.0
-		GENERATORS 
-			cmake_find_package
-			cmake_find_package_multi
-		OPTIONS
-            glfw:shared=True
-			glad:gl_profile=core
-			glad:gl_version=4.5
-			glad:extensions="GL_ARB_get_program_binary"
-	)
-
-	if ( CMAKE_CONFIGURATION_TYPES )
-		foreach(TYPE ${CMAKE_CONFIGURATION_TYPES})
-			conan_cmake_autodetect( settings BUILD_TYPE ${TYPE} )
-			conan_cmake_install(
-				PATH_OR_REFERENCE .
-				BUILD missing
-				SETTINGS ${settings}
-			)
-		endforeach()
-	else()
-		conan_cmake_autodetect( settings BUILD_TYPE ${TYPE} )
-		conan_cmake_install(
-			PATH_OR_REFERENCE .
-			BUILD missing
-			SETTINGS ${settings}
-		)
-	endif()
+    if ( FGGL_CONAN )
+        set(CMAKE_MODULE_PATH ${CMAKE_BINARY_DIR} ${CMAKE_MODULE_PATH})
+        set(CMAKE_PREFIX_PATH ${CMAKE_BINARY_DIR} ${CMAKE_PREFIX_PATH})
+        include( cmake/conan.cmake )
+
+        conan_cmake_configure(
+            REQUIRES
+                opengl/system
+                glfw/3.3.7
+                glad/0.1.35
+                glm/0.9.9.8
+                spdlog/1.10.0
+            GENERATORS 
+                cmake_find_package
+                cmake_find_package_multi
+            OPTIONS
+                glfw:shared=True
+                glad:gl_profile=core
+                glad:gl_version=4.5
+                glad:extensions="GL_ARB_get_program_binary"
+        )
+
+        if ( CMAKE_CONFIGURATION_TYPES )
+            foreach(TYPE ${CMAKE_CONFIGURATION_TYPES})
+                conan_cmake_autodetect( settings BUILD_TYPE ${TYPE} )
+                conan_cmake_install(
+                    PATH_OR_REFERENCE .
+                    BUILD missing
+                    SETTINGS ${settings}
+                )
+            endforeach()
+        else()
+            conan_cmake_autodetect( settings BUILD_TYPE ${TYPE} )
+            conan_cmake_install(
+                PATH_OR_REFERENCE .
+                BUILD missing
+                SETTINGS ${settings}
+            )
+        endif()
+    endif()
 
 	# testing support
 	include(CTest)