Hello World SDL2

#Instead of this:

require "sdl2/sdl2"

SCREEN_WIDTH  = 1280
SCREEN_HEIGHT = 720

SDL2.init 

window = SDL2.create_window("SDL Tutorial", LibSDL2::WINDOWPOS_UNDEFINED, LibSDL2::WINDOWPOS_UNDEFINED, SCREEN_WIDTH, SCREEN_HEIGHT, LibSDL2::WINDOW_SHOWN)

raise "Window could not be created! SDL_Error: #{SDL2.error}" unless window

screen_surface = LibSDL2.get_window_surface window.window

format = screen_surface.value.format

rgb_map = LibSDL2.map_rgb format, 0xFF_u8, 0xFF_u8, 0xFF_u8

LibSDL2.fill_rect screen_surface, nil, rgb_map

LibSDL2.update_window_surface window.window

LibSDL2.delay 2000_u32

SDL2.quit

###### Do this:

require "sdl2/sdl2"

SCREEN_WIDTH  = 1280
SCREEN_HEIGHT = 720

SDL2.init do
  window = SDL2.create_window("SDL Tutorial", LibSDL2::WINDOWPOS_UNDEFINED, LibSDL2::WINDOWPOS_UNDEFINED, SCREEN_WIDTH, SCREEN_HEIGHT, LibSDL2::WINDOW_SHOWN)

  raise "Window could not be created! SDL_Error: #{SDL2.error}" unless window

  screen_surface = LibSDL2.get_window_surface window.window

  format = screen_surface.value.format

  rgb_map = LibSDL2.map_rgb format, 0xFF_u8, 0xFF_u8, 0xFF_u8

  LibSDL2.fill_rect screen_surface, nil, rgb_map

  LibSDL2.update_window_surface window.window

  LibSDL2.delay 2000_u32
end # SDL2.quit after block is executed