Add love.window.isMaximized

src/modules/window/sdl/Window.cpp

@@ -866,6 +866,11 @@ void Window::maximize()
 	}
 }
 
+bool Window::isMaximized() const
+{
+	return window != nullptr && (SDL_GetWindowFlags(window) & SDL_WINDOW_MAXIMIZED);
+}
+
 void Window::swapBuffers()
 {
 	SDL_GL_SwapWindow(window);

src/modules/window/sdl/Window.h

@@ -76,6 +76,8 @@ public:
 	void minimize();
 	void maximize();
 
+	bool isMaximized() const;
+
 	void swapBuffers();
 
 	bool hasFocus() const;