using System;
using System.Collections.Generic;
using System.Text;
using Tao.Sdl;
using System.Runtime.InteropServices;

namespace LazyFooTut2
{
    class Tutorial2
    {
        //Screen sizes
        const int SCREEN_WIDTH = 640;
        const int SCREEN_HEIGHT = 480;
        const int SCREEN_BPP = 32;

        System.IntPtr message;
        System.IntPtr background;
        System.IntPtr screen;

        Sdl.SDL_Event evt;

        public System.IntPtr load_image( string filename )
        {
            System.IntPtr loadedImage;
            System.IntPtr optimizedImage = IntPtr.Zero;

            //load the image
            loadedImage = SdlImage.IMG_Load(filename);

            if (loadedImage != IntPtr.Zero )
            {
                optimizedImage = Sdl.SDL_DisplayFormat(loadedImage);
                Sdl.SDL_FreeSurface(loadedImage);
            }

            return optimizedImage;
        }

        public void applySurface(short x, short y, System.IntPtr source, System.IntPtr destination)
        {
            Sdl.SDL_Rect offset = new Sdl.SDL_Rect();
            Sdl.SDL_Rect original = new Sdl.SDL_Rect();

            original.x = 0;
            original.y = 0;
            original.w = (short)((Sdl.SDL_Surface)Marshal.PtrToStructure(source, typeof(Sdl.SDL_Surface))).w;
            original.h = (short)((Sdl.SDL_Surface)Marshal.PtrToStructure(source, typeof(Sdl.SDL_Surface))).h;

            offset.x = x;
            offset.y = y;

            Sdl.SDL_BlitSurface(source, ref original, destination, ref offset);
        }

        void run()
        {
            bool quit = false;
            if (Sdl.SDL_Init( Sdl.SDL_INIT_EVERYTHING ) == -1 )
                return;

            screen = Sdl.SDL_SetVideoMode( SCREEN_WIDTH, SCREEN_HEIGHT, SCREEN_BPP, Sdl.SDL_SWSURFACE );

            if ( screen == IntPtr.Zero )
                return;

            Sdl.SDL_WM_SetCaption("Hello World", null);

            message = load_image("hello_world.bmp");
            background = load_image("background.bmp");

            applySurface(0, 0, background, screen);
            applySurface(180, 140, message, screen);

            if (Sdl.SDL_Flip( screen ) == -1 )
                return;

            while (!quit)
            {
                while (Sdl.SDL_PollEvent(out evt) != 0)
                {
                    if (evt.type == Sdl.SDL_QUIT)
                    {
                        quit = true;
                    }
                }
            }

            Sdl.SDL_FreeSurface(message);
            Sdl.SDL_FreeSurface(background);

            Sdl.SDL_Quit();
        }



        static void Main(string[] args)
        {
            Tutorial2 tut2 = new Tutorial2();
            tut2.run();
        }
    }
}