/*This source code copyrighted by Lazy Foo' Productions (2004-2009) and may not
be redestributed without written permission.*/

//The headers

#include "SDL/SDL.h"
#include <string>

//The attributes of the screen

const int SCREEN_WIDTH = 640;
const int SCREEN_HEIGHT = 480;
const int SCREEN_BPP = 32;

//The surfaces that will be used

SDL_Surface *message = NULL;
SDL_Surface *background = NULL;
SDL_Surface *screen = NULL;

SDL_Surface *load_image( std::string filename )
{
    //Temporary storage for the image that's loaded

    SDL_Surface* loadedImage = NULL;

    //The optimized image that will be used

    SDL_Surface* optimizedImage = NULL;

    //Load the image

    loadedImage = SDL_LoadBMP( filename.c_str() );

    //If nothing went wrong in loading the image

    if( loadedImage != NULL )
    {
        //Create an optimized image

        optimizedImage = SDL_DisplayFormat( loadedImage );

        //Free the old image

        SDL_FreeSurface( loadedImage );
    }

    //Return the optimized image

    return optimizedImage;
}

void apply_surface( int x, int y, SDL_Surface* source, SDL_Surface* destination )
{
    //Make a temporary rectangle to hold the offsets

    SDL_Rect offset;

    //Give the offsets to the rectangle

    offset.x = x;
    offset.y = y;

    //Blit the surface

    SDL_BlitSurface( source, NULL, destination, &offset );
}

int main( int argc, char* args[] )
{
    //Initialize all SDL subsystems

    if( SDL_Init( SDL_INIT_EVERYTHING ) == -1 )
    {
        return 1;
    }

    //Set up the screen

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

    //If there was an error in setting up the screen

    if( screen == NULL )
    {
        return 1;
    }

    //Set the window caption

    SDL_WM_SetCaption( "Hello World", NULL );

    //Load the images

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

    //Apply the background to the screen

    apply_surface( 0, 0, background, screen );

    //Apply the message to the screen

    apply_surface( 180, 140, message, screen );

    //Update the screen

    if( SDL_Flip( screen ) == -1 )
    {
        return 1;
    }

    //Wait 2 seconds

    SDL_Delay( 2000 );

    //Free the surfaces

    SDL_FreeSurface( message );
    SDL_FreeSurface( background );

    //Quit SDL

    SDL_Quit();

    return 0;
}