Add screen_get_refresh_rate to DisplayServer

doc/classes/DisplayServer.xml

@@ -399,6 +399,14 @@
 			<description>
 			</description>
 		</method>
+		<method name="screen_get_refresh_rate" qualifiers="const">
+			<return type="float" />
+			<argument index="0" name="screen" type="int" default="-1" />
+			<description>
+				Returns the current refresh rate of the specified screen. If [code]screen[/code] is [code]SCREEN_OF_MAIN_WINDOW[/code] (the default value), a screen with the main window will be used.
+				[b]Note:[/b] Returns [code]60.0[/code] if the DisplayServer fails to find the refresh rate for the specified screen. On HTML5, [method screen_get_refresh_rate] will always return [code]60.0[/code] as there is no way to retrieve the refresh rate on that platform.
+			</description>
+		</method>
 		<method name="screen_get_scale" qualifiers="const">
 			<return type="float" />
 			<argument index="0" name="screen" type="int" default="-1" />

platform/android/display_server_android.cpp

@@ -161,6 +161,16 @@ int DisplayServerAndroid::screen_get_dpi(int p_screen) const {
 	return godot_io_java->get_screen_dpi();
 }
 
+float DisplayServerAndroid::screen_get_refresh_rate(int p_screen) const {
+	GodotIOJavaWrapper *godot_io_java = OS_Android::get_singleton()->get_godot_io_java();
+	if (!godot_io_java) {
+		ERR_PRINT("An error occured while trying to get the screen refresh rate.");
+		return SCREEN_REFRESH_RATE_FALLBACK;
+	}
+
+	return godot_io_java->get_screen_refresh_rate(SCREEN_REFRESH_RATE_FALLBACK);
+}
+
 bool DisplayServerAndroid::screen_is_touchscreen(int p_screen) const {
 	return true;
 }

platform/android/display_server_android.h

@@ -106,6 +106,7 @@ public:
 	virtual Size2i screen_get_size(int p_screen = SCREEN_OF_MAIN_WINDOW) const override;
 	virtual Rect2i screen_get_usable_rect(int p_screen = SCREEN_OF_MAIN_WINDOW) const override;
 	virtual int screen_get_dpi(int p_screen = SCREEN_OF_MAIN_WINDOW) const override;
+	virtual float screen_get_refresh_rate(int p_screen = SCREEN_OF_MAIN_WINDOW) const override;
 	virtual bool screen_is_touchscreen(int p_screen = SCREEN_OF_MAIN_WINDOW) const override;
 
 	virtual void virtual_keyboard_show(const String &p_existing_text, const Rect2 &p_screen_rect = Rect2(), bool p_multiline = false, int p_max_length = -1, int p_cursor_start = -1, int p_cursor_end = -1) override;

platform/android/java/lib/src/org/godotengine/godot/GodotIO.java

@@ -226,6 +226,14 @@ public class GodotIO {
 		return (int)(metrics.density * 160f);
 	}
 
+	public double getScreenRefreshRate(double fallback) {
+		Display display = activity.getWindowManager().getDefaultDisplay();
+		if (display != null) {
+			return display.getRefreshRate();
+		}
+		return fallback;
+	}
+
 	public int[] screenGetUsableRect() {
 		DisplayMetrics metrics = activity.getResources().getDisplayMetrics();
 		Display display = activity.getWindowManager().getDefaultDisplay();

platform/android/java_godot_io_wrapper.cpp

@@ -53,6 +53,7 @@ GodotIOJavaWrapper::GodotIOJavaWrapper(JNIEnv *p_env, jobject p_godot_io_instanc
 		_get_locale = p_env->GetMethodID(cls, "getLocale", "()Ljava/lang/String;");
 		_get_model = p_env->GetMethodID(cls, "getModel", "()Ljava/lang/String;");
 		_get_screen_DPI = p_env->GetMethodID(cls, "getScreenDPI", "()I");
+		_get_screen_refresh_rate = p_env->GetMethodID(cls, "getScreenRefreshRate", "(D)D");
 		_screen_get_usable_rect = p_env->GetMethodID(cls, "screenGetUsableRect", "()[I"),
 		_get_unique_id = p_env->GetMethodID(cls, "getUniqueID", "()Ljava/lang/String;");
 		_show_keyboard = p_env->GetMethodID(cls, "showKeyboard", "(Ljava/lang/String;ZIII)V");
@@ -136,6 +137,19 @@ int GodotIOJavaWrapper::get_screen_dpi() {
 	}
 }
 
+float GodotIOJavaWrapper::get_screen_refresh_rate(float fallback) {
+	if (_get_screen_refresh_rate) {
+		JNIEnv *env = get_jni_env();
+		if (env == nullptr) {
+			ERR_PRINT("An error occured while trying to get screen refresh rate.");
+			return fallback;
+		}
+		return (float)env->CallDoubleMethod(godot_io_instance, _get_screen_refresh_rate, (double)fallback);
+	}
+	ERR_PRINT("An error occured while trying to get the screen refresh rate.");
+	return fallback;
+}
+
 void GodotIOJavaWrapper::screen_get_usable_rect(int (&p_rect_xywh)[4]) {
 	if (_screen_get_usable_rect) {
 		JNIEnv *env = get_jni_env();

platform/android/java_godot_io_wrapper.h

@@ -51,6 +51,7 @@ private:
 	jmethodID _get_locale = 0;
 	jmethodID _get_model = 0;
 	jmethodID _get_screen_DPI = 0;
+	jmethodID _get_screen_refresh_rate = 0;
 	jmethodID _screen_get_usable_rect = 0;
 	jmethodID _get_unique_id = 0;
 	jmethodID _show_keyboard = 0;
@@ -71,6 +72,7 @@ public:
 	String get_locale();
 	String get_model();
 	int get_screen_dpi();
+	float get_screen_refresh_rate(float fallback);
 	void screen_get_usable_rect(int (&p_rect_xywh)[4]);
 	String get_unique_id();
 	bool has_vk();

platform/iphone/display_server_iphone.h

@@ -129,6 +129,7 @@ public:
 	virtual Rect2i screen_get_usable_rect(int p_screen = SCREEN_OF_MAIN_WINDOW) const override;
 	virtual int screen_get_dpi(int p_screen = SCREEN_OF_MAIN_WINDOW) const override;
 	virtual float screen_get_scale(int p_screen = SCREEN_OF_MAIN_WINDOW) const override;
+	virtual float screen_get_refresh_rate(int p_screen = SCREEN_OF_MAIN_WINDOW) const override;
 
 	virtual Vector<DisplayServer::WindowID> get_window_list() const override;
 

platform/iphone/display_server_iphone.mm

@@ -393,6 +393,10 @@ int DisplayServerIPhone::screen_get_dpi(int p_screen) const {
 	}
 }
 
+float DisplayServerIPhone::screen_get_refresh_rate(int p_screen) const {
+	return [UIScreen mainScreen].maximumFramesPerSecond;
+}
+
 float DisplayServerIPhone::screen_get_scale(int p_screen) const {
 	return [UIScreen mainScreen].nativeScale;
 }

platform/javascript/display_server_javascript.cpp

@@ -794,6 +794,10 @@ float DisplayServerJavaScript::screen_get_scale(int p_screen) const {
 	return godot_js_display_pixel_ratio_get();
 }
 
+float DisplayServerJavaScript::screen_get_refresh_rate(int p_screen) const {
+	return SCREEN_REFRESH_RATE_FALLBACK; // Javascript doesn't have much of a need for the screen refresh rate, and there's no native way to do so.
+}
+
 Vector<DisplayServer::WindowID> DisplayServerJavaScript::get_window_list() const {
 	Vector<WindowID> ret;
 	ret.push_back(MAIN_WINDOW_ID);

platform/javascript/display_server_javascript.h

@@ -139,6 +139,7 @@ public:
 	virtual Rect2i screen_get_usable_rect(int p_screen = SCREEN_OF_MAIN_WINDOW) const override;
 	virtual int screen_get_dpi(int p_screen = SCREEN_OF_MAIN_WINDOW) const override;
 	virtual float screen_get_scale(int p_screen = SCREEN_OF_MAIN_WINDOW) const override;
+	virtual float screen_get_refresh_rate(int p_screen = SCREEN_OF_MAIN_WINDOW) const override;
 
 	virtual void virtual_keyboard_show(const String &p_existing_text, const Rect2 &p_screen_rect = Rect2(), bool p_multiline = false, int p_max_input_length = -1, int p_cursor_start = -1, int p_cursor_end = -1) override;
 	virtual void virtual_keyboard_hide() override;

platform/linuxbsd/display_server_x11.cpp

@@ -1052,6 +1052,66 @@ int DisplayServerX11::screen_get_dpi(int p_screen) const {
 	return 96;
 }
 
+float DisplayServerX11::screen_get_refresh_rate(int p_screen) const {
+	_THREAD_SAFE_METHOD_
+
+	if (p_screen == SCREEN_OF_MAIN_WINDOW) {
+		p_screen = window_get_current_screen();
+	}
+
+	//invalid screen?
+	ERR_FAIL_INDEX_V(p_screen, get_screen_count(), SCREEN_REFRESH_RATE_FALLBACK);
+
+	//Use xrandr to get screen refresh rate.
+	if (xrandr_ext_ok) {
+		XRRScreenResources *screen_info = XRRGetScreenResources(x11_display, windows[MAIN_WINDOW_ID].x11_window);
+		if (screen_info) {
+			RRMode current_mode = 0;
+			xrr_monitor_info *monitors = nullptr;
+
+			if (xrr_get_monitors) {
+				int count = 0;
+				monitors = xrr_get_monitors(x11_display, windows[MAIN_WINDOW_ID].x11_window, true, &count);
+				ERR_FAIL_INDEX_V(p_screen, count, SCREEN_REFRESH_RATE_FALLBACK);
+			} else {
+				ERR_PRINT("An error occured while trying to get the screen refresh rate.");
+				return SCREEN_REFRESH_RATE_FALLBACK;
+			}
+
+			bool found_active_mode = false;
+			for (int crtc = 0; crtc < screen_info->ncrtc; crtc++) { // Loop through outputs to find which one is currently outputting.
+				XRRCrtcInfo *monitor_info = XRRGetCrtcInfo(x11_display, screen_info, screen_info->crtcs[crtc]);
+				if (monitor_info->x != monitors[p_screen].x || monitor_info->y != monitors[p_screen].y) { // If X and Y aren't the same as the monitor we're looking for, this isn't the right monitor. Continue.
+					continue;
+				}
+
+				if (monitor_info->mode != None) {
+					current_mode = monitor_info->mode;
+					found_active_mode = true;
+					break;
+				}
+			}
+
+			if (found_active_mode) {
+				for (int mode = 0; mode < screen_info->nmode; mode++) {
+					XRRModeInfo m_info = screen_info->modes[mode];
+					if (m_info.id == current_mode) {
+						return (float)m_info.dotClock / ((float)m_info.hTotal * (float)m_info.vTotal);
+					}
+				}
+			}
+
+			ERR_PRINT("An error occured while trying to get the screen refresh rate."); // We should have returned the refresh rate by now. An error must have occured.
+			return SCREEN_REFRESH_RATE_FALLBACK;
+		} else {
+			ERR_PRINT("An error occured while trying to get the screen refresh rate.");
+			return SCREEN_REFRESH_RATE_FALLBACK;
+		}
+	}
+	ERR_PRINT("An error occured while trying to get the screen refresh rate.");
+	return SCREEN_REFRESH_RATE_FALLBACK;
+}
+
 bool DisplayServerX11::screen_is_touchscreen(int p_screen) const {
 	_THREAD_SAFE_METHOD_
 

platform/linuxbsd/display_server_x11.h

@@ -301,6 +301,7 @@ public:
 	virtual Size2i screen_get_size(int p_screen = SCREEN_OF_MAIN_WINDOW) const override;
 	virtual Rect2i screen_get_usable_rect(int p_screen = SCREEN_OF_MAIN_WINDOW) const override;
 	virtual int screen_get_dpi(int p_screen = SCREEN_OF_MAIN_WINDOW) const override;
+	virtual float screen_get_refresh_rate(int p_screen = SCREEN_OF_MAIN_WINDOW) const override;
 	virtual bool screen_is_touchscreen(int p_screen = SCREEN_OF_MAIN_WINDOW) const override;
 
 #if defined(DBUS_ENABLED)

platform/osx/display_server_osx.h

@@ -228,6 +228,7 @@ public:
 	virtual float screen_get_scale(int p_screen = SCREEN_OF_MAIN_WINDOW) const override;
 	virtual float screen_get_max_scale() const override;
 	virtual Rect2i screen_get_usable_rect(int p_screen = SCREEN_OF_MAIN_WINDOW) const override;
+	virtual float screen_get_refresh_rate(int p_screen = SCREEN_OF_MAIN_WINDOW) const override;
 
 	virtual Vector<int> get_window_list() const override;
 

platform/osx/display_server_osx.mm

@@ -2199,6 +2199,24 @@ Rect2i DisplayServerOSX::screen_get_usable_rect(int p_screen) const {
 	return Rect2i();
 }
 
+float DisplayServerOSX::screen_get_refresh_rate(int p_screen) const {
+	_THREAD_SAFE_METHOD_
+
+	if (p_screen == SCREEN_OF_MAIN_WINDOW) {
+		p_screen = window_get_current_screen();
+	}
+
+	NSArray *screenArray = [NSScreen screens];
+	if ((NSUInteger)p_screen < [screenArray count]) {
+		NSDictionary *description = [[screenArray objectAtIndex:p_screen] deviceDescription];
+		const CGDisplayModeRef displayMode = CGDisplayCopyDisplayMode([[description objectForKey:@"NSScreenNumber"] unsignedIntValue]);
+		const double displayRefreshRate = CGDisplayModeGetRefreshRate(displayMode);
+		return (float)displayRefreshRate;
+	}
+	ERR_PRINT("An error occured while trying to get the screen refresh rate.");
+	return SCREEN_REFRESH_RATE_FALLBACK;
+}
+
 Vector<DisplayServer::WindowID> DisplayServerOSX::get_window_list() const {
 	_THREAD_SAFE_METHOD_
 

platform/windows/display_server_windows.cpp

@@ -323,6 +323,12 @@ typedef struct {
 	Rect2i rect;
 } EnumRectData;
 
+typedef struct {
+	int count;
+	int screen;
+	float rate;
+} EnumRefreshRateData;
+
 static BOOL CALLBACK _MonitorEnumProcSize(HMONITOR hMonitor, HDC hdcMonitor, LPRECT lprcMonitor, LPARAM dwData) {
 	EnumSizeData *data = (EnumSizeData *)dwData;
 	if (data->count == data->screen) {
@@ -360,6 +366,26 @@ static BOOL CALLBACK _MonitorEnumProcUsableSize(HMONITOR hMonitor, HDC hdcMonito
 	return TRUE;
 }
 
+static BOOL CALLBACK _MonitorEnumProcRefreshRate(HMONITOR hMonitor, HDC hdcMonitor, LPRECT lprcMonitor, LPARAM dwData) {
+	EnumRefreshRateData *data = (EnumRefreshRateData *)dwData;
+	if (data->count == data->screen) {
+		MONITORINFOEXW minfo;
+		memset(&minfo, 0, sizeof(minfo));
+		minfo.cbSize = sizeof(minfo);
+		GetMonitorInfoW(hMonitor, &minfo);
+
+		DEVMODEW dm;
+		memset(&dm, 0, sizeof(dm));
+		dm.dmSize = sizeof(dm);
+		EnumDisplaySettingsW(minfo.szDevice, ENUM_CURRENT_SETTINGS, &dm);
+
+		data->rate = dm.dmDisplayFrequency;
+	}
+
+	data->count++;
+	return TRUE;
+}
+
 Rect2i DisplayServerWindows::screen_get_usable_rect(int p_screen) const {
 	_THREAD_SAFE_METHOD_
 
@@ -443,6 +469,13 @@ int DisplayServerWindows::screen_get_dpi(int p_screen) const {
 	EnumDisplayMonitors(nullptr, nullptr, _MonitorEnumProcDpi, (LPARAM)&data);
 	return data.dpi;
 }
+float DisplayServerWindows::screen_get_refresh_rate(int p_screen) const {
+	_THREAD_SAFE_METHOD_
+
+	EnumRefreshRateData data = { 0, p_screen == SCREEN_OF_MAIN_WINDOW ? window_get_current_screen() : p_screen, SCREEN_REFRESH_RATE_FALLBACK };
+	EnumDisplayMonitors(nullptr, nullptr, _MonitorEnumProcRefreshRate, (LPARAM)&data);
+	return data.rate;
+}
 
 bool DisplayServerWindows::screen_is_touchscreen(int p_screen) const {
 #ifndef _MSC_VER

platform/windows/display_server_windows.h

@@ -458,6 +458,7 @@ public:
 	virtual Size2i screen_get_size(int p_screen = SCREEN_OF_MAIN_WINDOW) const override;
 	virtual Rect2i screen_get_usable_rect(int p_screen = SCREEN_OF_MAIN_WINDOW) const override;
 	virtual int screen_get_dpi(int p_screen = SCREEN_OF_MAIN_WINDOW) const override;
+	virtual float screen_get_refresh_rate(int p_screen = SCREEN_OF_MAIN_WINDOW) const override;
 	virtual bool screen_is_touchscreen(int p_screen = SCREEN_OF_MAIN_WINDOW) const override;
 
 	virtual void screen_set_orientation(ScreenOrientation p_orientation, int p_screen = SCREEN_OF_MAIN_WINDOW) override;

servers/display_server.cpp

@@ -375,6 +375,7 @@ void DisplayServer::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("screen_get_scale", "screen"), &DisplayServer::screen_get_scale, DEFVAL(SCREEN_OF_MAIN_WINDOW));
 	ClassDB::bind_method(D_METHOD("screen_is_touchscreen", "screen"), &DisplayServer::screen_is_touchscreen, DEFVAL(SCREEN_OF_MAIN_WINDOW));
 	ClassDB::bind_method(D_METHOD("screen_get_max_scale"), &DisplayServer::screen_get_max_scale);
+	ClassDB::bind_method(D_METHOD("screen_get_refresh_rate", "screen"), &DisplayServer::screen_get_refresh_rate, DEFVAL(SCREEN_OF_MAIN_WINDOW));
 
 	ClassDB::bind_method(D_METHOD("screen_set_orientation", "orientation", "screen"), &DisplayServer::screen_set_orientation, DEFVAL(SCREEN_OF_MAIN_WINDOW));
 	ClassDB::bind_method(D_METHOD("screen_get_orientation", "screen"), &DisplayServer::screen_get_orientation, DEFVAL(SCREEN_OF_MAIN_WINDOW));

servers/display_server.h

@@ -168,6 +168,8 @@ public:
 		SCREEN_OF_MAIN_WINDOW = -1
 	};
 
+	const float SCREEN_REFRESH_RATE_FALLBACK = 60.0; // Returned by screen_get_refresh_rate if the method fails. Most screens are 60hz as of 2022.
+
 	virtual int get_screen_count() const = 0;
 	virtual Point2i screen_get_position(int p_screen = SCREEN_OF_MAIN_WINDOW) const = 0;
 	virtual Size2i screen_get_size(int p_screen = SCREEN_OF_MAIN_WINDOW) const = 0;
@@ -182,6 +184,7 @@ public:
 		}
 		return scale;
 	}
+	virtual float screen_get_refresh_rate(int p_screen = SCREEN_OF_MAIN_WINDOW) const = 0;
 	virtual bool screen_is_touchscreen(int p_screen = SCREEN_OF_MAIN_WINDOW) const;
 
 	// Keep the ScreenOrientation enum values in sync with the `display/window/handheld/orientation`

servers/display_server_headless.h

@@ -62,6 +62,7 @@ public:
 	int screen_get_dpi(int p_screen = SCREEN_OF_MAIN_WINDOW) const override { return 96; /* 0 might cause issues */ }
 	float screen_get_scale(int p_screen = SCREEN_OF_MAIN_WINDOW) const override { return 1; }
 	float screen_get_max_scale() const override { return 1; }
+	float screen_get_refresh_rate(int p_screen = SCREEN_OF_MAIN_WINDOW) const override { return SCREEN_REFRESH_RATE_FALLBACK; }
 
 	Vector<DisplayServer::WindowID> get_window_list() const override { return Vector<DisplayServer::WindowID>(); }