Display an image with SDL_DisplayOverlay

[kovicic]

Hi everyone, I need to scale an image and due the lack of CPU/RAM I need it to be done the lesser consumming resources task as it possible.
I planned to do it with SDL_DisplayOverlay in order to scale it, is it possible.
I can't see the the whole bmp, I appreciate any suggestion on this.

Here is the code:

Code: Select all

   
SDL_Surface* screen = SDL_SetVideoMode(800, 400, 16,SDL_HWSURFACE|SDL_DOUBLEBUF);

    // load an image
    SDL_Surface* bmp = SDL_LoadBMP("cb.bmp");
    if (!bmp)
    {
        printf("Unable to load bitmap: %s\n", SDL_GetError());
        return 1;
    }

    SDL_Overlay *overlay = NULL;

    // centre the bitmap on screen
    SDL_Rect dstrect;
    dstrect.x = 0;
    dstrect.y = 0;

    // program main loop
    bool done = false;
    while (!done)
    {
        // message processing loop
        SDL_Event event;
        while (SDL_PollEvent(&event))
        {
            // check for messages
            switch (event.type)
            {
                // exit if the window is closed
            case SDL_QUIT:
                done = true;
                break;

                // check for keypresses
            case SDL_KEYDOWN:
                {
                    // exit if ESCAPE is pressed
                    if (event.key.keysym.sym == SDLK_ESCAPE)
                        done = true;
                    break;
                }
            } // end switch
        } // end of message processing

        // DRAWING STARTS HERE

        // clear screen
        SDL_FillRect(screen, 0, SDL_MapRGB(screen->format, 0, 0, 0));

        // draw bitmap
        SDL_BlitSurface(bmp, 0, screen, &dstrect);       

        overlay = SDL_CreateYUVOverlay(bmp->w,bmp->h, SDL_IYUV_OVERLAY , screen);

        SDL_Rect video_rect;

        video_rect.x = 0;
        video_rect.y = 0;
        video_rect.w = screen->w;
        video_rect.h = screen->h;

        SDL_DisplayYUVOverlay(overlay, &video_rect);

        // DRAWING ENDS HERE

        // finally, update the screen :)
        //SDL_Flip(screen);
    } // end main loop


Thanks and regards

kovicic