Client builds & runs, can't test the gameplay without the server

SDL_ttf is now being initialized, and all usages of fonts are now checked for nullptr.
A bug where the renderer's logical size was not properly set has been fixed.
The FPS counter is disabled for now.

client/menu_scenes/disconnected_screen.cpp

@@ -25,6 +25,7 @@
 #include "config_utility.hpp"
 #include "udp_network_utility.hpp"
 
+#include <sstream>
 #include <stdexcept>
 
 //-------------------------
@@ -39,6 +40,13 @@ DisconnectedScreen::DisconnectedScreen() {
 	image.Load(GetRenderer(), config["dir.interface"] + "button.png");
 	font = TTF_OpenFont(config["client.font"].c_str(), 12);
 
+	//check that the font loaded
+	if (!font) {
+		std::ostringstream msg;
+		msg << "Failed to load a font file; " << SDL_GetError();
+		throw(std::runtime_error(msg.str()));
+	}
+
 	//setup the button
 	backButton.SetBackgroundTexture(GetRenderer(), image.GetTexture());
 	backButton.SetText(GetRenderer(), font, "Back", {255, 255, 255, 255});
@@ -105,6 +113,10 @@ void DisconnectedScreen::MouseButtonUp(SDL_MouseButtonEvent const& event) {
 	}
 }
 
+void DisconnectedScreen::MouseWheel(SDL_MouseWheelEvent const& event) {
+	//
+}
+
 void DisconnectedScreen::KeyDown(SDL_KeyboardEvent const& event) {
 	switch(event.keysym.sym) {
 		case SDLK_ESCAPE: