So, I'm new to C++ and SDL... And I get the linking error : (in SDL_Game.exe, the compiled version of these codes)
LNK 1120 : Unresolved Externals
And I also get these 2 errors :
Error 2 error LNK2001: unresolved external symbol "public: static bool SDL_main::isRunning" (?isRunning@SDL_main@@2_NA) C:\Users\MyName\Desktop\SDL_Game\SDL_Game\Input.obj SDL_Game
Error 3 error LNK2001: unresolved external symbol "public: static bool SDL_main::isRunning" (?isRunning@SDL_main@@2_NA) C:\Users\MyName\Desktop\SDL_Game\SDL_Game\main.obj SDL_Game
My application type is set to console, so that's not the problem.
- I probably did something really stupid...
(Note : There's probably a lot of mistakes in here, you have been warned...)
So, here's my source codes :
main.cpp :
#include "Graphics\Window.h"
#include "Input\Input.h"
#include <string>
#include <iostream>
#include <main.h>
void Debug(std::string text);
int main(int argc, char* argv[])
{
main::isRunning = true;
Window C_Window;
Window window();
Input input();
if (SDL_Init(SDL_INIT_EVERYTHING) < 0)
{
main::isRunning = false;
std::cout << "SDL Video Initialization Failed : " << SDL_GetError() << std::endl;
std::cout << "Press enter to quit..." << std::endl;
system("PAUSE"); // Only works on windows.
}
else
{
while (main::isRunning)
{
SDL_UpdateWindowSurface(C_Window.GetWindow());
}
}
SDL_UpdateWindowSurface(C_Window.GetWindow());
Debug("SDL_winsurupd called in main");
system("PAUSE"); // Only works on windows.
SDL_Quit();
return 0;
}
void Debug(std::string text)
{
std::cout << text << std::endl;
}
main::~main()
{
}
main.h :
#pragma once
#include <SDL.h>
#include <iostream>
#include <Graphics\Window.h>
class main
{
public:
static bool isRunning;
main();
~main();
private:
};
Window.h
#pragma once
#include <SDL.h>
#include <iostream>
class Window
{
public:
Window();
SDL_Window* GetWindow();
~Window();
private:
SDL_Window* window = nullptr;
};
Window.cpp
#include "Window.h"
Window::Window()
{
window = SDL_CreateWindow("Engine Title", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 640, 480, SDL_WINDOW_SHOWN);
if (window == NULL)
{
std::cout << "Window Creation Failed : " << SDL_GetError() << std::endl;
system("PAUSE"); // Only works in windows.
}
else
{
SDL_UpdateWindowSurface(window);
}
}
SDL_Window* Window::GetWindow()
{
if (window != NULL)
{
return window;
}
else
{
std::cout << "Could not get window since it was not created yet." << std::endl;
system("PAUSE");
}
}
Window::~Window()
{
}
Input.h
#pragma once
#include <SDL.h>
#include <iostream>
#include <Graphics\Window.h>
class Input
{
public:
Input();
~Input();
private:
SDL_Event evnt;
};
Input.cpp
#include "Input.h"
#include <main.h>
Input::Input()
{
while (main::isRunning)
{
while (SDL_PollEvent(&evnt) != 0)
{
if (evnt.type == SDL_QUIT) {
SDL_Quit();
}
}
}
}
Input::~Input()
{
}
