SDL: Blitting BMP to window surface black screen mystery - c++

Question

I've written the following code to load a BMP image as a surface and then blit that image onto the window:
#include "stdafx.h"
#include "SDL.h"
#include <iostream>
int main(int argc, char *argv[])
{
//init
SDL_Init(SDL_INIT_VIDEO);
SDL_Window* window = SDL_CreateWindow("Playground", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 500, 500, 0);
std::cout << SDL_GetError() << std::endl;
SDL_Surface* surface = SDL_GetWindowSurface(window);
//load file and convert to texture
SDL_Surface* bmp = SDL_LoadBMP("sample.bmp");
std::cout << SDL_GetError() << std::endl;
//render texture
SDL_Rect area;
area.x, area.y = 3;
area.h, area.w = 25;
SDL_BlitSurface(bmp, &area, surface, &area);
std::cout << SDL_GetError() << std::endl;
SDL_UpdateWindowSurface(window);
std::cout << SDL_GetError() << std::endl;
SDL_Delay(3000);
//clean up
SDL_FreeSurface(bmp);
SDL_DestroyWindow(window);
SDL_Quit();
return 0;
}
When I press F5 (I'm working in Visual Studio Express 2017) to build and run the program, the program created runs, creates a window, and then the window remains entirely black as the program runs. I receive no error messages from V.S., SDL_GetError(), or Windows.
There appears to be no problems but the image just gets lost somewhere, it seems. Would anyone be able to help me?
P.S. Here is the bmp I am trying to display:

Answer 1

This code doesn't do what you think it does:
area.x, area.y = 3;
area.h, area.w = 25;
You should change it to
area.x = area.y = 3;
area.h = area.w = 25;
to have multiple assignments. Or even better just initialize SDL_Rect inline:
SDL_Rect area = { 3, 3, 25, 25 };