cmake_minimum_required(VERSION 3.20.0)
project(openglsdl2proj VERSION 0.1.0 LANGUAGES C CXX)

set(EXE_NAME project)

set(SDL2_LOCAL OFF)
set(GLEW_LOCAL OFF)
set(GLEW_NOT_GLAD OFF)

function(copy_shaders_to_target_dir target)
add_custom_command(
    TARGET ${target} POST_BUILD
    COMMAND ${CMAKE_COMMAND} -E copy_directory
        "$<TARGET_PROPERTY:${target},SOURCE_DIR>/shaders"
        "$<TARGET_PROPERTY:${target},BINARY_DIR>/"
)
endfunction()

# Option to switch between a system sdl library and a sdl library from in project
# source code
option(SDL2_LOCAL "Use non-system SDL2 library" OFF)
# Same thing but for GLEW
option(GLEW_LOCAL "Use non-system GLEW library" OFF)

# Copied almost verbatim from here https://wiki.libsdl.org/SDL2/README/cmake#including-sdl-in-your-project
# This either gets SDL2 from it's CMakeLists.txt in source or links it from the system dll
if(SDL2_LOCAL)
    add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/thirdparty//SDL2 EXCLUDE_FROM_ALL ${CMAKE_CURRENT_BINARY_DIR}/SDL2)
else()
    # 1. Look for a SDL2 package, 2. look for the SDL2 component and 3. fail if none can be found
    find_package(SDL2 REQUIRED CONFIG REQUIRED COMPONENTS SDL2)
endif()

# Get OpenGL since we need it
#find_package(OpenGL REQUIRED COMPONENTS EGL)

# find glew either by local source code for just link to system dll
if(GLEW_LOCAL AND GLEW_NOT_GLAD)
    add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/thirdparty/GLEW/build/cmake EXCLUDE_FROM_ALL ${CMAKE_CURRENT_BINARY_DIR}/GLEW)
else()
    find_package(GLEW REQUIRED)
endif()

# Main executable
add_executable(${EXE_NAME} ${CMAKE_CURRENT_SOURCE_DIR}/src/main.cc)
# Show all warnings, works for clang and GCC
target_compile_options(${EXE_NAME} PRIVATE -Wall -Wextra -Wpedantic) #-Werror)
# Set c++ standard for executable
set_target_properties(${EXE_NAME}
        PROPERTIES
        CXX_STANDARD 17
        CXX_STANDARD_REQUIRED ON
        CXX_EXTENSIONS ON
)
target_include_directories(${EXE_NAME} PRIVATE ${CMAKE_SOURCE_DIR}/include)
copy_shaders_to_target_dir(${EXE_NAME})

# Link to the actual SDL2 library.
# SDL2::SDL2 is the shared SDL library, SDL2::SDL2-static is the static SDL library.
if(NOT SDL2_LOCAL)
    target_link_libraries(${EXE_NAME} PRIVATE SDL2::SDL2)
else()
    target_link_libraries(${EXE_NAME} PRIVATE SDL2::SDL2-static)
endif()

# Link to OpenGL
#target_link_libraries(${EXE_NAME} PRIVATE OpenGL::EGL)

# Link to GLEW
if(NOT GLEW_LOCAL AND GLEW_NOT_GLAD)
    target_link_libraries(${EXE_NAME} PRIVATE ${GLEW_LIBRARIES})
elseif(GLEW_NOT_GLAD)
    # Static version of GLEW
    target_link_libraries(${EXE_NAME} PRIVATE glew_s)
endif()