Change: Zoom title game by UI zoom level

src/main_gui.cpp

@@ -199,6 +199,16 @@ void ZoomInOrOutToCursorWindow(bool in, Window *w)
 	}
 }
 
+void FixTitleGameZoom()
+{
+	if (_game_mode != GM_MENU) return;
+
+	ViewPort *vp = FindWindowByClass(WC_MAIN_WINDOW)->viewport;
+	vp->zoom = _gui_zoom;
+	vp->virtual_width = ScaleByZoom(vp->width, vp->zoom);
+	vp->virtual_height = ScaleByZoom(vp->height, vp->zoom);
+}
+
 static const struct NWidgetPart _nested_main_window_widgets[] = {
 	NWidget(NWID_VIEWPORT, INVALID_COLOUR, WID_M_VIEWPORT), SetResize(1, 1),
 };

src/openttd.cpp

@@ -62,6 +62,7 @@
 #include "town.h"
 #include "subsidy_func.h"
 #include "gfx_layout.h"
+#include "viewport_func.h"
 #include "viewport_sprite_sorter.h"
 #include "framerate_type.h"
 
@@ -336,6 +337,7 @@ static void LoadIntroGame(bool load_newgrfs = true)
 		SetLocalCompany(COMPANY_FIRST);
 	}
 
+	FixTitleGameZoom();
 	_pause_mode = PM_UNPAUSED;
 	_cursor.fix_at = false;
 

src/settings_gui.cpp

@@ -37,6 +37,7 @@
 #include "stringfilter_type.h"
 #include "querystring_gui.h"
 #include "fontcache.h"
+#include "zoom_func.h"
 
 #include <vector>
 
@@ -542,6 +543,7 @@ struct GameOptionsWindow : Window {
 				_gui_zoom = (ZoomLevel)(ZOOM_LVL_OUT_4X - index);
 				UpdateCursorSize();
 				UpdateAllVirtCoords();
+				FixTitleGameZoom();
 				ReInitAllWindows();
 				break;
 

src/viewport_func.h

@@ -34,6 +34,7 @@ void MarkAllViewportsDirty(int left, int top, int right, int bottom);
 bool DoZoomInOutWindow(ZoomStateChange how, Window *w);
 void ZoomInOrOutToCursorWindow(bool in, Window * w);
 Point GetTileZoomCenterWindow(bool in, Window * w);
+void FixTitleGameZoom();
 void HandleZoomMessage(Window *w, const ViewPort *vp, byte widget_zoom_in, byte widget_zoom_out);
 
 /**