It is indeed raining!

These modifications allowed me to compile on windows fyi:

cmake_minimum_required(VERSION 3.23.1)

project(rain)

set(CMAKE_CXX_STANDARD 20)

if(NOT CMAKE_BUILD_TYPE)

  set(CMAKE_BUILD_TYPE Release)

endif()

set(CMAKE_CXX_FLAGS "-Wall")

set(CMAKE_CXX_FLAGS_DEBUG "-g")

set(CMAKE_CXX_FLAGS_RELEASE "-O3")

add_executable(rain main.cpp)

find_package(OpenGL REQUIRED)

target_link_libraries(rain ${OPENGL_LIBRARIES})

file(COPY umbrella.png DESTINATION .)