Add: Display refresh rate game option

src/lang/english.txt

@@ -994,17 +994,6 @@ STR_GAME_OPTIONS_AUTOSAVE_DROPDOWN_EVERY_12_MONTHS              :Every 12 months
 STR_GAME_OPTIONS_LANGUAGE                                       :{BLACK}Language
 STR_GAME_OPTIONS_LANGUAGE_TOOLTIP                               :{BLACK}Select the interface language to use
 
-STR_GAME_OPTIONS_FULLSCREEN                                     :{BLACK}Fullscreen
-STR_GAME_OPTIONS_FULLSCREEN_TOOLTIP                             :{BLACK}Check this box to play OpenTTD fullscreen mode
-
-STR_GAME_OPTIONS_RESOLUTION                                     :{BLACK}Screen resolution
-STR_GAME_OPTIONS_RESOLUTION_TOOLTIP                             :{BLACK}Select the screen resolution to use
-STR_GAME_OPTIONS_RESOLUTION_OTHER                               :other
-
-STR_GAME_OPTIONS_VIDEO_ACCELERATION                             :{BLACK}Hardware acceleration
-STR_GAME_OPTIONS_VIDEO_ACCELERATION_TOOLTIP                     :{BLACK}Check this box to allow OpenTTD to try to use hardware acceleration. A changed setting will only be applied upon game restart
-STR_GAME_OPTIONS_VIDEO_ACCELERATION_RESTART                     :{WHITE}The setting will only take effect after a game restart
-
 STR_GAME_OPTIONS_GUI_ZOOM_FRAME                                 :{BLACK}Interface size
 STR_GAME_OPTIONS_GUI_ZOOM_DROPDOWN_TOOLTIP                      :{BLACK}Select the interface element size to use
 
@@ -1021,6 +1010,25 @@ STR_GAME_OPTIONS_FONT_ZOOM_DROPDOWN_NORMAL                      :Normal
 STR_GAME_OPTIONS_FONT_ZOOM_DROPDOWN_2X_ZOOM                     :Double size
 STR_GAME_OPTIONS_FONT_ZOOM_DROPDOWN_4X_ZOOM                     :Quad size
 
+STR_GAME_OPTIONS_GRAPHICS                                       :{BLACK}Graphics
+
+STR_GAME_OPTIONS_FULLSCREEN                                     :{BLACK}Fullscreen
+STR_GAME_OPTIONS_FULLSCREEN_TOOLTIP                             :{BLACK}Check this box to play OpenTTD fullscreen mode
+
+STR_GAME_OPTIONS_RESOLUTION                                     :{BLACK}Screen resolution
+STR_GAME_OPTIONS_RESOLUTION_TOOLTIP                             :{BLACK}Select the screen resolution to use
+STR_GAME_OPTIONS_RESOLUTION_OTHER                               :other
+
+STR_GAME_OPTIONS_VIDEO_ACCELERATION                             :{BLACK}Hardware acceleration
+STR_GAME_OPTIONS_VIDEO_ACCELERATION_TOOLTIP                     :{BLACK}Check this box to allow OpenTTD to try to use hardware acceleration. A changed setting will only be applied upon game restart
+STR_GAME_OPTIONS_VIDEO_ACCELERATION_RESTART                     :{WHITE}The setting will only take effect after a game restart
+
+STR_GAME_OPTIONS_REFRESH_RATE                                   :{BLACK}Display refresh rate
+STR_GAME_OPTIONS_REFRESH_RATE_TOOLTIP                           :{BLACK}Select the screen refresh rate to use
+STR_GAME_OPTIONS_REFRESH_RATE_OTHER                             :other
+STR_GAME_OPTIONS_REFRESH_RATE_ITEM                              :{BLACK}{COMMA}Hz
+STR_GAME_OPTIONS_REFRESH_RATE_WARNING                           :{WHITE}Refresh rates higher than 60Hz might impact performance.
+
 STR_GAME_OPTIONS_BASE_GRF                                       :{BLACK}Base graphics set
 STR_GAME_OPTIONS_BASE_GRF_TOOLTIP                               :{BLACK}Select the base graphics set to use
 STR_GAME_OPTIONS_BASE_GRF_STATUS                                :{RED}{NUM} missing/corrupted file{P "" s}

src/settings_gui.cpp

@@ -38,8 +38,11 @@
 #include "video/video_driver.hpp"
 
 #include <vector>
+#include <iterator>
 
 #include "safeguards.h"
+#include "video/video_driver.hpp"
+#include <unordered_set>
 
 
 static const StringID _autosave_dropdown[] = {
@@ -140,6 +143,23 @@ void ShowBaseSetTextfileWindow(TextfileType file_type, const TBaseSet* baseset,
 	new BaseSetTextfileWindow<TBaseSet>(file_type, baseset, content_type);
 }
 
+std::set<int> _refresh_rates = { 30, 60, 75, 90, 100, 120, 144, 240 };
+
+/**
+ * Add the refresh rate from the config and the refresh rates from all the monitors to
+ * our list of refresh rates shown in the GUI.
+ */
+static void AddRefreshRatesAndSelect()
+{
+	/* Add the refresh rate as selected in the config. */
+	int wantedRate = _settings_client.gui.refresh_rate;
+	_refresh_rates.insert(_settings_client.gui.refresh_rate);
+
+	/* Add all the refresh rates of all monitors connected to the machine.  */
+	std::vector<int> monitorRates = VideoDriver::GetInstance()->GetListOfMonitorRefreshRates();
+	std::copy(monitorRates.begin(), monitorRates.end(), std::inserter(_refresh_rates, _refresh_rates.end()));
+}
+
 struct GameOptionsWindow : Window {
 	GameSettings *opt;
 	bool reload;
@@ -149,6 +169,8 @@ struct GameOptionsWindow : Window {
 		this->opt = &GetGameSettings();
 		this->reload = false;
 
+		AddRefreshRatesAndSelect();
+
 		this->InitNested(WN_GAME_OPTIONS_GAME_OPTIONS);
 		this->OnInvalidateData(0);
 	}
@@ -215,6 +237,14 @@ struct GameOptionsWindow : Window {
 				}
 				break;
 
+			case WID_GO_REFRESH_RATE_DROPDOWN: // Setup refresh rate dropdown
+				for (uint i = 0; i < _refresh_rates.size(); i++) {
+					auto item = new DropDownListParamStringItem(STR_GAME_OPTIONS_REFRESH_RATE_ITEM, i, false);
+                    item->SetParam(0, *std::next(_refresh_rates.begin(), i));
+					list.emplace_back(item);
+				}
+				break;
+
 			case WID_GO_GUI_ZOOM_DROPDOWN: {
 				*selected_index = _gui_zoom_cfg != ZOOM_LVL_CFG_AUTO ? ZOOM_LVL_OUT_4X - _gui_zoom + 1 : 0;
 				const StringID *items = _gui_zoom_dropdown;
@@ -252,17 +282,21 @@ struct GameOptionsWindow : Window {
 	void SetStringParameters(int widget) const override
 	{
 		switch (widget) {
-			case WID_GO_CURRENCY_DROPDOWN:   SetDParam(0, _currency_specs[this->opt->locale.currency].name); break;
-			case WID_GO_AUTOSAVE_DROPDOWN:   SetDParam(0, _autosave_dropdown[_settings_client.gui.autosave]); break;
-			case WID_GO_LANG_DROPDOWN:       SetDParamStr(0, _current_language->own_name); break;
-			case WID_GO_RESOLUTION_DROPDOWN: SetDParam(0, GetCurRes() == _resolutions.size() ? STR_GAME_OPTIONS_RESOLUTION_OTHER : SPECSTR_RESOLUTION_START + GetCurRes()); break;
-			case WID_GO_GUI_ZOOM_DROPDOWN:   SetDParam(0, _gui_zoom_dropdown[_gui_zoom_cfg != ZOOM_LVL_CFG_AUTO ? ZOOM_LVL_OUT_4X - _gui_zoom_cfg + 1 : 0]); break;
-			case WID_GO_FONT_ZOOM_DROPDOWN:  SetDParam(0, _font_zoom_dropdown[_font_zoom_cfg != ZOOM_LVL_CFG_AUTO ? ZOOM_LVL_OUT_4X - _font_zoom_cfg + 1 : 0]); break;
-			case WID_GO_BASE_GRF_DROPDOWN:   SetDParamStr(0, BaseGraphics::GetUsedSet()->name.c_str()); break;
-			case WID_GO_BASE_GRF_STATUS:     SetDParam(0, BaseGraphics::GetUsedSet()->GetNumInvalid()); break;
-			case WID_GO_BASE_SFX_DROPDOWN:   SetDParamStr(0, BaseSounds::GetUsedSet()->name.c_str()); break;
-			case WID_GO_BASE_MUSIC_DROPDOWN: SetDParamStr(0, BaseMusic::GetUsedSet()->name.c_str()); break;
-			case WID_GO_BASE_MUSIC_STATUS:   SetDParam(0, BaseMusic::GetUsedSet()->GetNumInvalid()); break;
+			case WID_GO_CURRENCY_DROPDOWN:     SetDParam(0, _currency_specs[this->opt->locale.currency].name); break;
+			case WID_GO_AUTOSAVE_DROPDOWN:     SetDParam(0, _autosave_dropdown[_settings_client.gui.autosave]); break;
+			case WID_GO_LANG_DROPDOWN:         SetDParamStr(0, _current_language->own_name); break;
+			case WID_GO_RESOLUTION_DROPDOWN:   SetDParam(0, GetCurRes() == _resolutions.size() ? STR_GAME_OPTIONS_RESOLUTION_OTHER : SPECSTR_RESOLUTION_START + GetCurRes()); break;
+			case WID_GO_GUI_ZOOM_DROPDOWN:     SetDParam(0, _gui_zoom_dropdown[_gui_zoom_cfg != ZOOM_LVL_CFG_AUTO ? ZOOM_LVL_OUT_4X - _gui_zoom_cfg + 1 : 0]); break;
+			case WID_GO_FONT_ZOOM_DROPDOWN:    SetDParam(0, _font_zoom_dropdown[_font_zoom_cfg != ZOOM_LVL_CFG_AUTO ? ZOOM_LVL_OUT_4X - _font_zoom_cfg + 1 : 0]); break;
+			case WID_GO_BASE_GRF_DROPDOWN:     SetDParamStr(0, BaseGraphics::GetUsedSet()->name.c_str()); break;
+			case WID_GO_BASE_GRF_STATUS:       SetDParam(0, BaseGraphics::GetUsedSet()->GetNumInvalid()); break;
+			case WID_GO_BASE_SFX_DROPDOWN:     SetDParamStr(0, BaseSounds::GetUsedSet()->name.c_str()); break;
+			case WID_GO_BASE_MUSIC_DROPDOWN:   SetDParamStr(0, BaseMusic::GetUsedSet()->name.c_str()); break;
+			case WID_GO_BASE_MUSIC_STATUS:     SetDParam(0, BaseMusic::GetUsedSet()->GetNumInvalid()); break;
+			case WID_GO_REFRESH_RATE_DROPDOWN: {
+                SetDParam(0, STR_GAME_OPTIONS_REFRESH_RATE_ITEM);
+                SetDParam(1, _settings_client.gui.refresh_rate);
+            }
 		}
 	}
 
@@ -451,6 +485,16 @@ struct GameOptionsWindow : Window {
 				}
 				break;
 
+			case WID_GO_REFRESH_RATE_DROPDOWN: {
+				_settings_client.gui.refresh_rate = *std::next(_refresh_rates.begin(), index);
+				if (_settings_client.gui.refresh_rate > 60) {
+					/* Show warning to the user that this refresh rate might not be suitable on
+					 * larger maps with many NewGRFs and vehicles. */
+					ShowErrorMessage(STR_GAME_OPTIONS_REFRESH_RATE_WARNING, INVALID_STRING_ID, WL_INFO);
+				}
+				break;
+			}
+
 			case WID_GO_GUI_ZOOM_DROPDOWN: {
 				int8 new_zoom = index > 0 ? ZOOM_LVL_OUT_4X - index + 1 : ZOOM_LVL_CFG_AUTO;
 				if (new_zoom != _gui_zoom_cfg) {
@@ -528,36 +572,47 @@ static const NWidgetPart _nested_game_options_widgets[] = {
 				NWidget(WWT_FRAME, COLOUR_GREY), SetDataTip(STR_GAME_OPTIONS_AUTOSAVE_FRAME, STR_NULL),
 					NWidget(WWT_DROPDOWN, COLOUR_GREY, WID_GO_AUTOSAVE_DROPDOWN), SetMinimalSize(150, 12), SetDataTip(STR_BLACK_STRING, STR_GAME_OPTIONS_AUTOSAVE_DROPDOWN_TOOLTIP), SetFill(1, 0),
 				EndContainer(),
-				NWidget(WWT_FRAME, COLOUR_GREY), SetDataTip(STR_GAME_OPTIONS_RESOLUTION, STR_NULL),
-					NWidget(WWT_DROPDOWN, COLOUR_GREY, WID_GO_RESOLUTION_DROPDOWN), SetMinimalSize(150, 12), SetDataTip(STR_BLACK_STRING, STR_GAME_OPTIONS_RESOLUTION_TOOLTIP), SetFill(1, 0), SetPadding(0, 0, 3, 0),
-					NWidget(NWID_HORIZONTAL), SetPIP(0, 3, 0), SetPadding(0, 0, 3, 0),
-						NWidget(WWT_TEXT, COLOUR_GREY), SetMinimalSize(0, 12), SetFill(1, 0), SetDataTip(STR_GAME_OPTIONS_FULLSCREEN, STR_NULL),
-						NWidget(WWT_TEXTBTN, COLOUR_GREY, WID_GO_FULLSCREEN_BUTTON), SetMinimalSize(21, 9), SetDataTip(STR_EMPTY, STR_GAME_OPTIONS_FULLSCREEN_TOOLTIP),
-					EndContainer(),
-					NWidget(NWID_HORIZONTAL), SetPIP(0, 3, 0),
-						NWidget(WWT_TEXT, COLOUR_GREY), SetMinimalSize(0, 12), SetFill(1, 0), SetDataTip(STR_GAME_OPTIONS_VIDEO_ACCELERATION, STR_NULL),
-						NWidget(WWT_TEXTBTN, COLOUR_GREY, WID_GO_VIDEO_ACCEL_BUTTON),  SetMinimalSize(21, 9), SetDataTip(STR_EMPTY, STR_GAME_OPTIONS_VIDEO_ACCELERATION_TOOLTIP),
-					EndContainer(),
+				NWidget(WWT_FRAME, COLOUR_GREY), SetDataTip(STR_GAME_OPTIONS_GUI_ZOOM_FRAME, STR_NULL),
+					NWidget(WWT_DROPDOWN, COLOUR_GREY, WID_GO_GUI_ZOOM_DROPDOWN), SetMinimalSize(150, 12), SetDataTip(STR_BLACK_STRING, STR_GAME_OPTIONS_GUI_ZOOM_DROPDOWN_TOOLTIP), SetFill(1, 0),
+				EndContainer(),
+				NWidget(WWT_FRAME, COLOUR_GREY), SetDataTip(STR_GAME_OPTIONS_CURRENCY_UNITS_FRAME, STR_NULL),
+					NWidget(WWT_DROPDOWN, COLOUR_GREY, WID_GO_CURRENCY_DROPDOWN), SetMinimalSize(150, 12), SetDataTip(STR_BLACK_STRING, STR_GAME_OPTIONS_CURRENCY_UNITS_DROPDOWN_TOOLTIP), SetFill(1, 0),
 				EndContainer(),
-				NWidget(NWID_SPACER), SetMinimalSize(0, 0), SetFill(0, 1),
 			EndContainer(),
 
 			NWidget(NWID_VERTICAL), SetPIP(0, 6, 0),
 				NWidget(WWT_FRAME, COLOUR_GREY), SetDataTip(STR_GAME_OPTIONS_LANGUAGE, STR_NULL),
 					NWidget(WWT_DROPDOWN, COLOUR_GREY, WID_GO_LANG_DROPDOWN), SetMinimalSize(150, 12), SetDataTip(STR_BLACK_RAW_STRING, STR_GAME_OPTIONS_LANGUAGE_TOOLTIP), SetFill(1, 0),
 				EndContainer(),
-				NWidget(WWT_FRAME, COLOUR_GREY), SetDataTip(STR_GAME_OPTIONS_CURRENCY_UNITS_FRAME, STR_NULL),
-					NWidget(WWT_DROPDOWN, COLOUR_GREY, WID_GO_CURRENCY_DROPDOWN), SetMinimalSize(150, 12), SetDataTip(STR_BLACK_STRING, STR_GAME_OPTIONS_CURRENCY_UNITS_DROPDOWN_TOOLTIP), SetFill(1, 0),
-				EndContainer(),
-				NWidget(WWT_FRAME, COLOUR_GREY), SetDataTip(STR_GAME_OPTIONS_GUI_ZOOM_FRAME, STR_NULL),
-					NWidget(WWT_DROPDOWN, COLOUR_GREY, WID_GO_GUI_ZOOM_DROPDOWN), SetMinimalSize(150, 12), SetDataTip(STR_BLACK_STRING, STR_GAME_OPTIONS_GUI_ZOOM_DROPDOWN_TOOLTIP), SetFill(1, 0),
-				EndContainer(),
 				NWidget(WWT_FRAME, COLOUR_GREY), SetDataTip(STR_GAME_OPTIONS_FONT_ZOOM, STR_NULL),
 					NWidget(WWT_DROPDOWN, COLOUR_GREY, WID_GO_FONT_ZOOM_DROPDOWN), SetMinimalSize(150, 12), SetDataTip(STR_BLACK_STRING, STR_GAME_OPTIONS_FONT_ZOOM_DROPDOWN_TOOLTIP), SetFill(1, 0),
 				EndContainer(),
 			EndContainer(),
 		EndContainer(),
 
+		NWidget(WWT_FRAME, COLOUR_GREY), SetDataTip(STR_GAME_OPTIONS_GRAPHICS, STR_NULL), SetPadding(0, 10, 0, 10),
+			NWidget(NWID_HORIZONTAL),
+				NWidget(NWID_VERTICAL),
+					NWidget(WWT_TEXT, COLOUR_GREY), SetMinimalSize(0, 12), SetFill(1, 0), SetDataTip(STR_GAME_OPTIONS_RESOLUTION, STR_NULL), SetPadding(0, 0, 2, 0),
+					NWidget(WWT_TEXT, COLOUR_GREY), SetMinimalSize(0, 12), SetFill(1, 0), SetDataTip(STR_GAME_OPTIONS_REFRESH_RATE, STR_NULL), SetPadding(0, 0, 2, 0),
+					NWidget(WWT_TEXT, COLOUR_GREY), SetMinimalSize(0, 12), SetFill(1, 0), SetDataTip(STR_GAME_OPTIONS_FULLSCREEN, STR_NULL), SetPadding(0, 0, 2, 0),
+					NWidget(WWT_TEXT, COLOUR_GREY), SetMinimalSize(0, 12), SetFill(1, 0), SetDataTip(STR_GAME_OPTIONS_VIDEO_ACCELERATION, STR_NULL),
+				EndContainer(),
+				NWidget(NWID_VERTICAL),
+					NWidget(WWT_DROPDOWN, COLOUR_GREY, WID_GO_RESOLUTION_DROPDOWN), SetMinimalSize(100, 12), SetDataTip(STR_BLACK_STRING, STR_GAME_OPTIONS_RESOLUTION_TOOLTIP), SetFill(1, 0), SetPadding(0, 0, 2, 0),
+					NWidget(WWT_DROPDOWN, COLOUR_GREY, WID_GO_REFRESH_RATE_DROPDOWN), SetMinimalSize(120, 12), SetDataTip(STR_BLACK_STRING, STR_GAME_OPTIONS_REFRESH_RATE_TOOLTIP), SetFill(1, 0), SetPadding(0, 0, 2, 0),
+					NWidget(NWID_HORIZONTAL), SetPadding(0, 0, 2, 0),
+						NWidget(NWID_SPACER), SetMinimalSize(1, 0), SetFill(1, 0),
+						NWidget(WWT_TEXTBTN, COLOUR_GREY, WID_GO_FULLSCREEN_BUTTON), SetMinimalSize(21, 9), SetDataTip(STR_EMPTY, STR_GAME_OPTIONS_FULLSCREEN_TOOLTIP),
+					EndContainer(),
+					NWidget(NWID_HORIZONTAL),
+						NWidget(NWID_SPACER), SetMinimalSize(1, 0), SetFill(1, 0),
+						NWidget(WWT_TEXTBTN, COLOUR_GREY, WID_GO_VIDEO_ACCEL_BUTTON), SetMinimalSize(21, 9), SetDataTip(STR_EMPTY, STR_GAME_OPTIONS_VIDEO_ACCELERATION_TOOLTIP),
+					EndContainer(),
+				EndContainer(),
+			EndContainer(),
+		EndContainer(),
+
 		NWidget(WWT_FRAME, COLOUR_GREY), SetDataTip(STR_GAME_OPTIONS_BASE_GRF, STR_NULL), SetPadding(0, 10, 0, 10),
 			NWidget(NWID_HORIZONTAL), SetPIP(0, 30, 0),
 				NWidget(WWT_DROPDOWN, COLOUR_GREY, WID_GO_BASE_GRF_DROPDOWN), SetMinimalSize(150, 12), SetDataTip(STR_BLACK_RAW_STRING, STR_GAME_OPTIONS_BASE_GRF_TOOLTIP),

src/video/allegro_v.cpp

@@ -236,6 +236,16 @@ bool VideoDriver_Allegro::ClaimMousePointer()
 	return true;
 }
 
+std::vector<int> VideoDriver_Allegro::GetListOfMonitorRefreshRates()
+{
+	std::vector<int> rates = {};
+
+	int refresh_rate = get_refresh_rate();
+	if (refresh_rate != 0) rates.push_back(refresh_rate);
+
+	return rates;
+}
+
 struct AllegroVkMapping {
 	uint16 vk_from;
 	byte vk_count;

src/video/allegro_v.h

@@ -31,6 +31,8 @@ class VideoDriver_Allegro : public VideoDriver {
 
 	bool ClaimMousePointer() override;
 
+    std::vector<int> GetListOfMonitorRefreshRates() override;
+
 	const char *GetName() const override { return "allegro"; }
 
 protected:

src/video/cocoa/cocoa_v.h

@@ -47,6 +47,8 @@ class VideoDriver_Cocoa : public VideoDriver {
 
 	void EditBoxLostFocus() override;
 
+	std::vector<int> GetListOfMonitorRefreshRates() override;
+
 	/* --- The following methods should be private, but can't be due to Obj-C limitations. --- */
 
 	void MainLoopReal();

src/video/cocoa/cocoa_v.mm

@@ -228,6 +228,24 @@
 	HandleTextInput(nullptr, true);
 }
 
+/**
+ * Get refresh rate of the current screen.
+ */
+std::vector<int> VideoDriver_Cocoa::GetListOfMonitorRefreshRates()
+{
+	std::vector<int> rates{};
+
+	NSNumber *scr = [ [ [ this->window screen ] deviceDescription ] objectForKey:@"NSScreenNumber" ];
+	if (scr != nil && MacOSVersionIsAtLeast(10, 6, 0)) {
+		CGDisplayModeRef mode = CGDisplayCopyDisplayMode((CGDirectDisplayID)[ scr unsignedIntValue ]);
+		int rate = (int)CGDisplayModeGetRefreshRate(mode);
+		if (rate > 0) rates.push_back(rate);
+		CGDisplayModeRelease(mode);
+	}
+
+	return rates;
+}
+
 /**
  * Get the resolution of the main screen.
  */

src/video/sdl2_v.cpp

@@ -237,6 +237,17 @@ void VideoDriver_SDL_Base::EditBoxLostFocus()
 	}
 }
 
+std::vector<int> VideoDriver_SDL_Base::GetListOfMonitorRefreshRates()
+{
+	std::vector<int> rates = {};
+	for (int i = 0; i < SDL_GetNumVideoDisplays(); i++) {
+		SDL_DisplayMode mode = {};
+		if (SDL_GetDisplayMode(i, 0, &mode) != 0) continue;
+		if (mode.refresh_rate != 0) rates.push_back(mode.refresh_rate);
+	}
+	return rates;
+}
+
 
 struct SDLVkMapping {
 	SDL_Keycode vk_from;

src/video/sdl2_v.h

@@ -39,6 +39,8 @@ class VideoDriver_SDL_Base : public VideoDriver {
 
 	void EditBoxLostFocus() override;
 
+	std::vector<int> GetListOfMonitorRefreshRates() override;
+
 	const char *GetName() const override { return "sdl"; }
 
 protected:

src/video/video_driver.hpp

@@ -149,6 +149,15 @@ class VideoDriver : public Driver {
 	 */
 	virtual void EditBoxGainedFocus() {}
 
+	/**
+	 * Get a list of refresh rates of each available monitor.
+	 * @return A vector of the refresh rates of all available monitors.
+	 */
+	virtual std::vector<int> GetListOfMonitorRefreshRates()
+	{
+		return {};
+	}
+
 	/**
 	 * Get a suggested default GUI zoom taking screen DPI into account.
 	 */

src/video/win32_v.cpp

@@ -916,6 +916,27 @@ void VideoDriver_Win32Base::EditBoxLostFocus()
 	SetCandidatePos(this->main_wnd);
 }
 
+std::vector<int> VideoDriver_Win32Base::GetListOfMonitorRefreshRates()
+{
+	std::vector<int> rates = {};
+	EnumDisplayMonitors(nullptr, nullptr, [](HMONITOR hMonitor, HDC hDC, LPRECT rc, LPARAM data) -> BOOL {
+		auto &list = *reinterpret_cast<std::vector<int>*>(data);
+
+		MONITORINFOEX monitorInfo = {};
+		monitorInfo.cbSize = sizeof(MONITORINFOEX);
+		GetMonitorInfo(hMonitor, &monitorInfo);
+
+		DEVMODE devMode = {};
+		devMode.dmSize = sizeof(DEVMODE);
+		devMode.dmDriverExtra = 0;
+		EnumDisplaySettings(monitorInfo.szDevice, ENUM_CURRENT_SETTINGS, &devMode);
+
+		if (devMode.dmDisplayFrequency != 0) list.push_back(devMode.dmDisplayFrequency);
+		return true;
+	}, reinterpret_cast<LPARAM>(&rates));
+	return rates;
+}
+
 Dimension VideoDriver_Win32Base::GetScreenSize() const
 {
 	return { static_cast<uint>(GetSystemMetrics(SM_CXSCREEN)), static_cast<uint>(GetSystemMetrics(SM_CYSCREEN)) };

src/video/win32_v.h

@@ -33,6 +33,8 @@ class VideoDriver_Win32Base : public VideoDriver {
 
 	void EditBoxLostFocus() override;
 
+	std::vector<int> GetListOfMonitorRefreshRates() override;
+
 protected:
 	HWND main_wnd;          ///< Handle to system window.
 	bool fullscreen;        ///< Whether to use (true) fullscreen mode.

src/widgets/settings_widget.h

@@ -33,6 +33,7 @@ enum GameOptionsWidgets {
 	WID_GO_BASE_MUSIC_DESCRIPTION = WID_GO_BASE_MUSIC_TEXTFILE + TFT_END, ///< Description of selected base music set.
 	WID_GO_FONT_ZOOM_DROPDOWN,     ///< Dropdown for the font zoom level.
 	WID_GO_VIDEO_ACCEL_BUTTON,     ///< Toggle for video acceleration.
+	WID_GO_REFRESH_RATE_DROPDOWN,  ///< Dropdown for all available refresh rates.
 };
 
 /** Widgets of the #GameSettingsWindow class. */