Merge pull request #74087 from bruvzg/get_screen_px

[DisplayServer] Implement screen_get_pixel method for LinuxBSD/X11, macOS and Windows.

doc/classes/DisplayServer.xml

@@ -865,6 +865,15 @@
 				[b]Note:[/b] This method is implemented on Android and iOS.
 			</description>
 		</method>
+		<method name="screen_get_pixel" qualifiers="const">
+			<return type="Color" />
+			<param index="0" name="position" type="Vector2i" />
+			<description>
+				Returns color of the display pixel at the [param position].
+				[b]Note:[/b] This method is implemented on Linux (X11), macOS, and Windows.
+				[b]Note:[/b] On macOS, this method requires "Screen Recording" permission, if permission is not granted it will return desktop wallpaper color.
+			</description>
+		</method>
 		<method name="screen_get_position" qualifiers="const">
 			<return type="Vector2i" />
 			<param index="0" name="screen" type="int" default="-1" />
@@ -1543,6 +1552,9 @@
 		<constant name="FEATURE_EXTEND_TO_TITLE" value="20" enum="Feature">
 			Display server supports expanding window content to the title. See [constant WINDOW_FLAG_EXTEND_TO_TITLE]. [b]macOS[/b]
 		</constant>
+		<constant name="FEATURE_SCREEN_CAPTURE" value="21" enum="Feature">
+			Display server supports reading screen pixels. See [method screen_get_pixel].
+		</constant>
 		<constant name="MOUSE_MODE_VISIBLE" value="0" enum="MouseMode">
 			Makes the mouse cursor visible if it is hidden.
 		</constant>

platform/linuxbsd/x11/display_server_x11.cpp

@@ -128,6 +128,7 @@ bool DisplayServerX11::has_feature(Feature p_feature) const {
 #endif
 		case FEATURE_CLIPBOARD_PRIMARY:
 		case FEATURE_TEXT_TO_SPEECH:
+		case FEATURE_SCREEN_CAPTURE:
 			return true;
 		default: {
 		}
@@ -1169,6 +1170,29 @@ int DisplayServerX11::screen_get_dpi(int p_screen) const {
 	return 96;
 }
 
+Color DisplayServerX11::screen_get_pixel(const Point2i &p_position) const {
+	Point2i pos = p_position;
+
+	int number_of_screens = XScreenCount(x11_display);
+	for (int i = 0; i < number_of_screens; i++) {
+		Window root = XRootWindow(x11_display, i);
+		XWindowAttributes root_attrs;
+		XGetWindowAttributes(x11_display, root, &root_attrs);
+		if ((pos.x >= root_attrs.x) && (pos.x <= root_attrs.x + root_attrs.width) && (pos.y >= root_attrs.y) && (pos.y <= root_attrs.y + root_attrs.height)) {
+			XImage *image = XGetImage(x11_display, root, pos.x, pos.y, 1, 1, AllPlanes, XYPixmap);
+			if (image) {
+				XColor c;
+				c.pixel = XGetPixel(image, 0, 0);
+				XFree(image);
+				XQueryColor(x11_display, XDefaultColormap(x11_display, i), &c);
+				return Color(float(c.red) / 65535.0, float(c.green) / 65535.0, float(c.blue) / 65535.0, 1.0);
+			}
+		}
+	}
+
+	return Color();
+}
+
 float DisplayServerX11::screen_get_refresh_rate(int p_screen) const {
 	_THREAD_SAFE_METHOD_
 

platform/linuxbsd/x11/display_server_x11.h

@@ -409,6 +409,7 @@ 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_refresh_rate(int p_screen = SCREEN_OF_MAIN_WINDOW) const override;
+	virtual Color screen_get_pixel(const Point2i &p_position) const override;
 
 #if defined(DBUS_ENABLED)
 	virtual void screen_set_keep_on(bool p_enable) override;

platform/macos/display_server_macos.h

@@ -334,6 +334,7 @@ public:
 	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 Color screen_get_pixel(const Point2i &p_position) const override;
 	virtual void screen_set_keep_on(bool p_enable) override;
 	virtual bool screen_is_kept_on() const override;
 

platform/macos/display_server_macos.mm

@@ -765,6 +765,7 @@ bool DisplayServerMacOS::has_feature(Feature p_feature) const {
 		case FEATURE_SWAP_BUFFERS:
 		case FEATURE_TEXT_TO_SPEECH:
 		case FEATURE_EXTEND_TO_TITLE:
+		case FEATURE_SCREEN_CAPTURE:
 			return true;
 		default: {
 		}
@@ -2249,6 +2250,35 @@ Rect2i DisplayServerMacOS::screen_get_usable_rect(int p_screen) const {
 	return Rect2i();
 }
 
+Color DisplayServerMacOS::screen_get_pixel(const Point2i &p_position) const {
+	Point2i position = p_position;
+	// OS X native y-coordinate relative to _get_screens_origin() is negative,
+	// Godot passes a positive value.
+	position.y *= -1;
+	position += _get_screens_origin();
+	position /= screen_get_max_scale();
+
+	for (NSScreen *screen in [NSScreen screens]) {
+		NSRect frame = [screen frame];
+		if (NSMouseInRect(NSMakePoint(position.x, position.y), frame, NO)) {
+			NSDictionary *screenDescription = [screen deviceDescription];
+			CGDirectDisplayID display_id = [[screenDescription objectForKey:@"NSScreenNumber"] unsignedIntValue];
+			CGImageRef image = CGDisplayCreateImageForRect(display_id, CGRectMake(position.x - frame.origin.x, frame.size.height - (position.y - frame.origin.y), 1, 1));
+			if (image) {
+				NSBitmapImageRep *bitmap = [[NSBitmapImageRep alloc] initWithCGImage:image];
+				CGImageRelease(image);
+				NSColor *color = [bitmap colorAtX:0 y:0];
+				if (color) {
+					CGFloat components[4];
+					[color getRed:&components[0] green:&components[1] blue:&components[2] alpha:&components[3]];
+					return Color(components[0], components[1], components[2], components[3]);
+				}
+			}
+		}
+	}
+	return Color();
+}
+
 float DisplayServerMacOS::screen_get_refresh_rate(int p_screen) const {
 	_THREAD_SAFE_METHOD_
 

platform/windows/display_server_windows.cpp

@@ -90,6 +90,7 @@ bool DisplayServerWindows::has_feature(Feature p_feature) const {
 		case FEATURE_SWAP_BUFFERS:
 		case FEATURE_KEEP_SCREEN_ON:
 		case FEATURE_TEXT_TO_SPEECH:
+		case FEATURE_SCREEN_CAPTURE:
 			return true;
 		default:
 			return false;
@@ -631,6 +632,26 @@ int DisplayServerWindows::screen_get_dpi(int p_screen) const {
 	EnumDisplayMonitors(nullptr, nullptr, _MonitorEnumProcDpi, (LPARAM)&data);
 	return data.dpi;
 }
+
+Color DisplayServerWindows::screen_get_pixel(const Point2i &p_position) const {
+	Point2i pos = p_position + _get_screens_origin();
+
+	POINT p;
+	p.x = pos.x;
+	p.y = pos.y;
+	if (win81p_LogicalToPhysicalPointForPerMonitorDPI) {
+		win81p_LogicalToPhysicalPointForPerMonitorDPI(0, &p);
+	}
+	HDC dc = GetDC(0);
+	COLORREF col = GetPixel(dc, p.x, p.y);
+	if (col != CLR_INVALID) {
+		return Color(float(col & 0x000000FF) / 256.0, float((col & 0x0000FF00) >> 8) / 256.0, float((col & 0x00FF0000) >> 16) / 256.0, 1.0);
+	}
+	ReleaseDC(NULL, dc);
+
+	return Color();
+}
+
 float DisplayServerWindows::screen_get_refresh_rate(int p_screen) const {
 	_THREAD_SAFE_METHOD_
 
@@ -4023,6 +4044,7 @@ GetImmersiveUserColorSetPreferencePtr DisplayServerWindows::GetImmersiveUserColo
 bool DisplayServerWindows::winink_available = false;
 GetPointerTypePtr DisplayServerWindows::win8p_GetPointerType = nullptr;
 GetPointerPenInfoPtr DisplayServerWindows::win8p_GetPointerPenInfo = nullptr;
+LogicalToPhysicalPointForPerMonitorDPIPtr DisplayServerWindows::win81p_LogicalToPhysicalPointForPerMonitorDPI = nullptr;
 
 typedef enum _SHC_PROCESS_DPI_AWARENESS {
 	SHC_PROCESS_DPI_UNAWARE = 0,
@@ -4151,10 +4173,12 @@ DisplayServerWindows::DisplayServerWindows(const String &p_rendering_driver, Win
 	}
 
 	// Note: Windows Ink API for pen input, available on Windows 8+ only.
+	// Note: DPI conversion API, available on Windows 8.1+ only.
 	HMODULE user32_lib = LoadLibraryW(L"user32.dll");
 	if (user32_lib) {
 		win8p_GetPointerType = (GetPointerTypePtr)GetProcAddress(user32_lib, "GetPointerType");
 		win8p_GetPointerPenInfo = (GetPointerPenInfoPtr)GetProcAddress(user32_lib, "GetPointerPenInfo");
+		win81p_LogicalToPhysicalPointForPerMonitorDPI = (LogicalToPhysicalPointForPerMonitorDPIPtr)GetProcAddress(user32_lib, "LogicalToPhysicalPointForPerMonitorDPI");
 
 		winink_available = win8p_GetPointerType && win8p_GetPointerPenInfo;
 	}

platform/windows/display_server_windows.h

@@ -259,6 +259,7 @@ typedef struct tagPOINTER_PEN_INFO {
 
 typedef BOOL(WINAPI *GetPointerTypePtr)(uint32_t p_id, POINTER_INPUT_TYPE *p_type);
 typedef BOOL(WINAPI *GetPointerPenInfoPtr)(uint32_t p_id, POINTER_PEN_INFO *p_pen_info);
+typedef BOOL(WINAPI *LogicalToPhysicalPointForPerMonitorDPIPtr)(HWND hwnd, LPPOINT lpPoint);
 
 typedef struct {
 	BYTE bWidth; // Width, in pixels, of the image
@@ -305,6 +306,9 @@ class DisplayServerWindows : public DisplayServer {
 	static GetPointerTypePtr win8p_GetPointerType;
 	static GetPointerPenInfoPtr win8p_GetPointerPenInfo;
 
+	// DPI conversion API
+	static LogicalToPhysicalPointForPerMonitorDPIPtr win81p_LogicalToPhysicalPointForPerMonitorDPI;
+
 	void _update_tablet_ctx(const String &p_old_driver, const String &p_new_driver);
 	String tablet_driver;
 	Vector<String> tablet_drivers;
@@ -524,6 +528,7 @@ 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_refresh_rate(int p_screen = SCREEN_OF_MAIN_WINDOW) const override;
+	virtual Color screen_get_pixel(const Point2i &p_position) const override;
 
 	virtual void screen_set_keep_on(bool p_enable) override; //disable screensaver
 	virtual bool screen_is_kept_on() const override;

servers/display_server.cpp

@@ -658,6 +658,7 @@ void DisplayServer::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("is_touchscreen_available"), &DisplayServer::is_touchscreen_available, 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_get_pixel", "position"), &DisplayServer::screen_get_pixel);
 
 	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));
@@ -785,6 +786,7 @@ void DisplayServer::_bind_methods() {
 	BIND_ENUM_CONSTANT(FEATURE_CLIPBOARD_PRIMARY);
 	BIND_ENUM_CONSTANT(FEATURE_TEXT_TO_SPEECH);
 	BIND_ENUM_CONSTANT(FEATURE_EXTEND_TO_TITLE);
+	BIND_ENUM_CONSTANT(FEATURE_SCREEN_CAPTURE);
 
 	BIND_ENUM_CONSTANT(MOUSE_MODE_VISIBLE);
 	BIND_ENUM_CONSTANT(MOUSE_MODE_HIDDEN);

servers/display_server.h

@@ -124,6 +124,7 @@ public:
 		FEATURE_CLIPBOARD_PRIMARY,
 		FEATURE_TEXT_TO_SPEECH,
 		FEATURE_EXTEND_TO_TITLE,
+		FEATURE_SCREEN_CAPTURE,
 	};
 
 	virtual bool has_feature(Feature p_feature) const = 0;
@@ -275,6 +276,7 @@ public:
 		return scale;
 	}
 	virtual float screen_get_refresh_rate(int p_screen = SCREEN_OF_MAIN_WINDOW) const = 0;
+	virtual Color screen_get_pixel(const Point2i &p_position) const { return Color(); };
 	virtual bool is_touchscreen_available() const;
 
 	// Keep the ScreenOrientation enum values in sync with the `display/window/handheld/orientation`