Don't print useless false error message when toggling fullscreen

Whenever you would press Alt+Enter, or Alt+F, or on macOS Command+Enter,
or on macOS Command+F, or F11, the game would print this useless error
message to console, every single time: "Error: failed: " and it would
concatenate SDL_GetError() after it, but most of the time SDL_GetError()
is blank, so it would print just that.

Instead, what the fullscreen shortcut will now do is check the result of
the relevant SDL functions, BEFORE it decides to print an error message.
And when it DOES print an error message, it will be less vague and will
say instead "Error: toggling fullscreen failed: <output of
SDL_GetError()>".

This means Screen::ResizeScreen() and Screen::toggleFullScreen() are now
int-returning functions. Ideally, every function interfacing with SDL
would return an error code, but that's too much for this simple patch.

Additionally, I took the opportunity to clean up the surrounding
formatting of the code a bit, most notably dedenting the
keypress-clearing stuff by one tab level, converting the
shortcut-handling code to spaces, and removing commented-out code.

desktop_version/src/Screen.cpp

@@ -89,8 +89,10 @@ Screen::Screen()
     glScreen = true;
 }
 
-void Screen::ResizeScreen(int x , int y)
+int Screen::ResizeScreen(int x, int y)
 {
+	int result = 0; // 0 is success, nonzero is failure
+
 	static int resX = 320;
 	static int resY = 240;
 	if (x != -1 && y != -1)
@@ -102,11 +104,11 @@ void Screen::ResizeScreen(int x , int y)
 
 	if(!isWindowed)
 	{
-		SDL_SetWindowFullscreen(m_window, SDL_WINDOW_FULLSCREEN_DESKTOP);
+		result = SDL_SetWindowFullscreen(m_window, SDL_WINDOW_FULLSCREEN_DESKTOP);
 	}
 	else
 	{
-		SDL_SetWindowFullscreen(m_window, 0);
+		result = SDL_SetWindowFullscreen(m_window, 0);
 		if (x != -1 && y != -1)
 		{
 			SDL_SetWindowSize(m_window, resX, resY);
@@ -118,14 +120,16 @@ void Screen::ResizeScreen(int x , int y)
 		int winX, winY;
 		SDL_GetWindowSize(m_window, &winX, &winY);
 		SDL_RenderSetLogicalSize(m_renderer, winX, winY);
-		SDL_RenderSetIntegerScale(m_renderer, SDL_FALSE);
+		result = SDL_RenderSetIntegerScale(m_renderer, SDL_FALSE);
 	}
 	else
 	{
 		SDL_RenderSetLogicalSize(m_renderer, 320, 240);
-		SDL_RenderSetIntegerScale(m_renderer, (SDL_bool) (stretchMode == 2));
+		result = SDL_RenderSetIntegerScale(m_renderer, (SDL_bool) (stretchMode == 2));
 	}
 	SDL_ShowWindow(m_window);
+
+	return result;
 }
 
 void Screen::GetWindowSize(int* x, int* y)
@@ -180,10 +184,11 @@ void Screen::FlipScreen()
 	SDL_FillRect(m_screen, NULL, 0x00000000);
 }
 
-void Screen::toggleFullScreen()
+int Screen::toggleFullScreen()
 {
 	isWindowed = !isWindowed;
-	ResizeScreen(-1, -1);
+	int result = ResizeScreen(-1, -1);
+	return result;
 }
 
 void Screen::toggleStretchMode()

desktop_version/src/Screen.h

@@ -8,7 +8,7 @@ class Screen
 public:
 	Screen();
 
-	void ResizeScreen(int x, int y);
+	int ResizeScreen(int x, int y);
 	void GetWindowSize(int* x, int* y);
 
 	void UpdateScreen(SDL_Surface* buffer, SDL_Rect* rect);
@@ -17,7 +17,7 @@ public:
 
 	const SDL_PixelFormat* GetFormat();
 
-	void toggleFullScreen();
+	int toggleFullScreen();
 	void toggleStretchMode();
 	void toggleLinearFilter();
 

desktop_version/src/main.cpp

@@ -311,7 +311,6 @@ int main(int argc, char *argv[])
         {
             if(!gameScreen.isWindowed)
             {
-				//SDL_WM_GrabInput(SDL_GRAB_ON);
                 SDL_ShowCursor(SDL_DISABLE);
                 SDL_ShowCursor(SDL_ENABLE);
             }
@@ -326,7 +325,7 @@ int main(int argc, char *argv[])
                 SDL_ShowCursor(SDL_ENABLE);
             }
 
-			gameScreen.toggleFullScreen();
+            int result = gameScreen.toggleFullScreen();
             game.fullscreen = !game.fullscreen;
             key.toggleFullscreen = false;
 
@@ -335,16 +334,12 @@ int main(int argc, char *argv[])
             game.press_right = false;
             game.press_action = true;
             game.press_map = false;
-			printf("Error: failed: %s\n", SDL_GetError());
 
-
+            if(result != 0)
-
-
-		}
-		/*if(key.quitProgram)
             {
-			music.playef(2);
+                printf("Error: toggling fullscreen failed: %s\n", SDL_GetError());
-		}*/
+            }
+        }
 
         game.infocus = key.isActive;
         if(!game.infocus)