main.cr

require "./sdl"

LibSDL.init(LibSDL::INIT_EVERYTHING)

window = LibSDL.create_window("It works!", LibSDL::WINDOWPOS_UNDEFINED, LibSDL::WINDOWPOS_UNDEFINED, 800, 600, 0)

surface = LibSDL.get_window_surface(window)

_format = surface.value.format
LibSDL.fill_rect(surface, nil, LibSDL.map_rgb(pointerof(_format), 0xFF, 0xFF, 0xFF))
LibSDL.update_window_surface(window)
LibSDL.delay(2000)

sdl.cr

# Crystal bindings of SDL2

@[Link("sdl2")]
lib LibSDL
    type Window = Void
    type BlitMap = Void

    struct Rect
        x : Int32
        y : Int32
        w : Int32
        h : Int32
    end

    struct Color
        r, g, b, a : UInt8
    end

    struct Palette
        ncolors : UInt32
        colors : Color*
        version : UInt32
        refcount : UInt32
    end

    struct PixelFormat
        palette : Palette*
        bitsperpixel : UInt8
        bytesperpixel : UInt8
        rmask : UInt32
        gmask : UInt32
        bmask : UInt32
        amask : UInt32
        rloss : UInt8
        gloss : UInt8
        bloss : UInt8
        aloss : UInt8
        rshift : UInt8
        gshift : UInt8
        bshift : UInt8
        ashift : UInt8
        refcount : Int32
        next_pf : PixelFormat*
    end

    struct Surface
        flags : UInt32
        format : PixelFormat
        w, h : Int32
        pitch : Int32
        pixels : Void*
        usedata : Void*
        locked : Int32
        locked_data : Void*
        clip_rect : Rect
        map : BlitMap*
        refcount : Int32
    end
    
    INIT_TIMER = 0x01_u32
    INIT_AUDIO = 0x10_u32
    INIT_VIDEO = 0x20_u32
    INIT_JOYSTICK = 0x200_u32
    INIT_HAPTIC = 0x1000_u32
    INIT_GAMECONTROLLER = 0x2000_u32
    INIT_EVENTS = 0x4000_u32
    INIT_NOPARACHUTE = 0x10000_u32
    INIT_EVERYTHING = 0xFFFF_u32

    WINDOWPOS_CENTERED = 0x2FFF0000
    WINDOWPOS_UNDEFINED = 0x1FFF0000

    fun init = SDL_Init(flags : UInt32) : Int32
    fun create_window = SDL_CreateWindow(title : LibC::Char*, x : Int32, y : Int32, w : Int32, h : Int32, flags : UInt32) : Window*
    fun get_window_surface = SDL_GetWindowSurface(window : Window*) : Surface*
    fun fill_rect = SDL_FillRect(dst : Surface*, rect : Rect*, color : UInt32) : Int32
    fun map_rgb = SDL_MapRGB(format : PixelFormat*, r : UInt8, g : UInt8, b : UInt8) : UInt32
    fun update_window_surface = SDL_UpdateWindowSurface(window : Window*)
    fun delay = SDL_Delay(ms : UInt32)
    fun get_error = SDL_GetError() : LibC::Char*
end