Fix crash when launching game with non-default GUI scale in config

See: #459

src/gfx.cpp

@@ -2361,7 +2361,7 @@ void UpdateGUIZoom()
  * @returns true when the zoom level has changed, caller must call ReInitAllWindows(true)
  * after resizing the application's window/buffer.
  */
-bool AdjustGUIZoom(bool automatic)
+bool AdjustGUIZoom(AdjustGUIZoomMode mode)
 {
 	ZoomLevel old_zoom = _gui_zoom;
 	int old_scale = _gui_scale;
@@ -2373,14 +2373,14 @@ bool AdjustGUIZoom(bool automatic)
 		GfxClearSpriteCache();
 		VideoDriver::GetInstance()->ClearSystemSprites();
 		UpdateCursorSize();
-		UpdateRouteStepSpriteSize();
+		if (mode != AGZM_STARTUP) UpdateRouteStepSpriteSize();
 	}
 
 	ClearFontCache();
 	UpdateFontHeightCache();
 	LoadStringWidthTable();
 	UpdateAllVirtCoords();
-	FixTitleGameZoom();
+	if (mode != AGZM_STARTUP) FixTitleGameZoom();
 
 	extern void FlushDeparturesWindowTextCaches();
 	FlushDeparturesWindowTextCaches();
@@ -2389,7 +2389,7 @@ bool AdjustGUIZoom(bool automatic)
 	   to move around when the application is moved to a screen with different DPI. */
 	auto zoom_shift = old_zoom - _gui_zoom;
 	for (Window *w : Window::IterateFromBack()) {
-		if (automatic) {
+		if (mode == AGZM_AUTOMATIC) {
 			w->left   = (w->left   * _gui_scale) / old_scale;
 			w->top    = (w->top    * _gui_scale) / old_scale;
 			w->width  = (w->width  * _gui_scale) / old_scale;

src/gfx_func.h

@@ -83,9 +83,15 @@ void ChangeGameSpeed(bool enable_fast_forward);
 void DrawMouseCursor();
 void ScreenSizeChanged();
 void GameSizeChanged();
-bool AdjustGUIZoom(bool automatic);
 void UndrawMouseCursor();
 
+enum AdjustGUIZoomMode {
+	AGZM_MANUAL,
+	AGZM_AUTOMATIC,
+	AGZM_STARTUP,
+};
+bool AdjustGUIZoom(AdjustGUIZoomMode mode);
+
 /** Size of the buffer used for drawing strings. */
 static const int DRAW_STRING_BUFFER = 2048;
 

src/openttd.cpp

@@ -941,7 +941,7 @@ int openttd_main(int argc, char *argv[])
 	_screen.zoom = ZOOM_LVL_NORMAL;
 
 	/* The video driver is now selected, now initialise GUI zoom */
-	AdjustGUIZoom(false);
+	AdjustGUIZoom(AGZM_STARTUP);
 
 	NetworkStartUp(); // initialize network-core
 

src/settings_gui.cpp

@@ -520,7 +520,7 @@ struct GameOptionsWindow : Window {
 				} else {
 					_gui_scale_cfg = -1;
 					this->SetWidgetLoweredState(WID_GO_GUI_SCALE_AUTO, true);
-					if (AdjustGUIZoom(false)) ReInitAllWindows(true);
+					if (AdjustGUIZoom(AGZM_MANUAL)) ReInitAllWindows(true);
 					this->gui_scale = _gui_scale;
 				}
 				this->SetWidgetDirty(widget);
@@ -564,7 +564,7 @@ struct GameOptionsWindow : Window {
 
 		_gui_scale_cfg = this->gui_scale;
 
-		if (AdjustGUIZoom(false)) {
+		if (AdjustGUIZoom(AGZM_MANUAL)) {
 			ReInitAllWindows(true);
 			this->SetWidgetLoweredState(WID_GO_GUI_SCALE_AUTO, false);
 			this->SetDirty();

src/video/cocoa/cocoa_wnd.mm

@@ -1271,7 +1271,7 @@ void CocoaDialog(const char *title, const char *message, const char *buttonLabel
 /** Screen the window is on changed. */
 - (void)windowDidChangeBackingProperties:(NSNotification *)notification
 {
-	bool did_adjust = AdjustGUIZoom(true);
+	bool did_adjust = AdjustGUIZoom(AGZM_AUTOMATIC);
 
 	/* Reallocate screen buffer if necessary. */
 	driver->AllocateBackingStore();

src/video/win32_v.cpp

@@ -677,7 +677,7 @@ LRESULT CALLBACK WndProcGdi(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
 		}
 
 		case WM_DPICHANGED: {
-			auto did_adjust = AdjustGUIZoom(true);
+			auto did_adjust = AdjustGUIZoom(AGZM_AUTOMATIC);
 
 			/* Resize the window to match the new DPI setting. */
 			RECT *prcNewWindow = (RECT *)lParam;