hello_world_sdl2.cr

#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