cmake_minimum_required(VERSION 3.3 FATAL_ERROR)
project(padlab C)
set(TARGET padlab)

option(USE_METAL "use Metal for drawing" ${APPLE})
if (USE_METAL)
	option(USE_OPENGL "Use OpenGL for drawing (WIP)" OFF)
	option(USE_OPENGL_LEGACY "Use legacy OpenGL for drawing" OFF)
	if (USE_OPENGL)
		message(FATAL_ERROR "USE_METAL and USE_OPENGL are both ON but only one backend can be used at a time, turn one OFF and regenerate. (or delete cache and try again)")
	elseif (USE_OPENGL_LEGACY)
		message(FATAL_ERROR "USE_METAL and USE_OPENGL_LEGACY are both ON but only one backend can be used at a time, turn one OFF and regenerate. (or delete cache and try again)")
	endif()
else()
	option(USE_OPENGL "Use OpenGL for drawing (WIP)" OFF)
	if (USE_OPENGL)
		option(USE_OPENGL_LEGACY "Use legacy OpenGL for drawing" OFF)
		if (USE_OPENGL_LEGACY)
			message(FATAL_ERROR "USE_OPENGL and USE_OPENGL_LEGACY are both ON but only one backend can be used at a time, turn one OFF and regenerate. (or delete cache and try again)")
		endif()
	else()
		option(USE_OPENGL_LEGACY "Use legacy OpenGL for drawing" ON)
	endif()
endif()

list(APPEND CMAKE_MODULE_PATH "${CMAKE_SOURCE_DIR}/cmake")
set(CMAKE_C_STANDARD 99)
set(GNU_COMPILERS GNU Clang AppleClang)
if (CMAKE_C_COMPILER_ID IN_LIST GNU_COMPILERS)
	set(GNU 1)
elseif (MSVC)
	string(REPLACE "/W3" "/W4" CMAKE_C_FLAGS "${CMAKE_C_FLAGS}")
endif()

find_package(SDL2 REQUIRED)
if (USE_OPENGL OR USE_OPENGL_LEGACY)
	if (NOT DEFINED OpenGL_GL_PREFERENCE)
		set(OpenGL_GL_PREFERENCE "GLVND")
	endif()
	find_package(OpenGL REQUIRED)
endif()

add_subdirectory(src)