SDL_LoadBMP() is successful, but the window becomes entirely black - c++

Question

I apologize if this question has already been asked but I've been researching for about a week now and cannot find the answer any where.
The problem that I am having is that while SDL_LoadBMP() is loading the image successfully, The window does not render an image at all, and instead renders an entirely black screen. However I do know something is being loaded (not just because there is no error being returned by SDL_LoadBMP() but also) because when I run the program with the SDL_LoadBMP() call commented out the window stays entirely white.
if it helps I have been writing along with the Lazyfoo tutorial located here. Code below...
From Main.cpp
int main(int argc, char* args[])
{
//the surface that we will be applying an image on
SDL_Surface* ImageSurface = NULL;
//try to initalize SDL
try
{
initSDL();
}
//if an error is caught
catch (string Error)
{
//print out the error
cout << "SDL error occurred! SDL Error: " << Error << endl;
//return an error
return -1;
}
//try loading an image on to the ImageSurface
try
{
loadMedia(ImageSurface, "ImageTest.bmp");
}
//if an error is caught
catch(string Error)
{
//print the error out
cout << "SDL error occurred! SDL Error: " << Error << endl;
//return an error
SDL_Delay(6000);
return -1;
}
//Apply Image surface to the main surface
SDL_BlitSurface(ImageSurface, NULL, Surface, NULL);
//upadte the surface of the main window
SDL_UpdateWindowSurface(Window);
//wait for 2 seconds (2000 miliseconds)
SDL_Delay(10000);
//close SDL
close();
//return
return 0;
}
From SDLBackend.cpp (I will only be posting the code relevant to the image loading process)
void loadMedia(SDL_Surface* surface, string path)
{
cout << "Attempting to load an image!" << endl;
//load the image at path into our surface
surface = SDL_LoadBMP(path.c_str());
//if there was an error in the loading procdure
if(surface == NULL)
{
//make a string to store our error in
string Error = SDL_GetError();
//throw our error
throw Error;
}
cout << "Successfully loaded an image!" << endl;
cout << "Pushing surface into the Surface List" << endl;
//Put the surface in to our list
SurfaceList.push_back(surface);
return;
}
I am compiling using visual studio 2013, and the image ImageTest.bmp is located in the same directory as the vcxproj file.

Answer 1

The problem is in loadMedia(). The loaded surface is being assigned to a local variable. You'll need to use a reference to pointer,
void loadMedia(SDL_Surface*& surface, string path)
{
surface = SDL_LoadBMP(path.c_str());
}
Or a double pointer (maybe preferred, clarifies intent),
void loadMedia(SDL_Surface** surface, string path)
{
*surface = SDL_LoadBMP(path.c_str());
}
Alternately, you could return it or even extract it from SurfaceList.back().