LibGUI/WindowServer: Allow custom cursor origin

LibGUI/Window.cpp

@@ -201,11 +201,13 @@ namespace LibGUI
 		set_attributes(attributes);
 	}
 
-	void Window::set_cursor(uint32_t width, uint32_t height, BAN::Span<uint32_t> pixels)
+	void Window::set_cursor(uint32_t width, uint32_t height, BAN::Span<const uint32_t> pixels, int32_t origin_x, int32_t origin_y)
 	{
 		WindowPacket::WindowSetCursor packet;
 		packet.width = width;
 		packet.height = height;
+		packet.origin_x = origin_x;
+		packet.origin_y = origin_y;
 		MUST(packet.pixels.resize(pixels.size()));
 		for (size_t i = 0; i < packet.pixels.size(); i++)
 			packet.pixels[i] = pixels[i];

LibGUI/include/LibGUI/Packet.h

@@ -15,6 +15,7 @@
 #define FOR_EACH_4(macro, type, name, ...) macro(type, name) FOR_EACH_2(macro, __VA_ARGS__)
 #define FOR_EACH_6(macro, type, name, ...) macro(type, name) FOR_EACH_4(macro, __VA_ARGS__)
 #define FOR_EACH_8(macro, type, name, ...) macro(type, name) FOR_EACH_6(macro, __VA_ARGS__)
+#define FOR_EACH_10(macro, type, name, ...) macro(type, name) FOR_EACH_8(macro, __VA_ARGS__)
 
 #define CONCATENATE_2(arg1, arg2) arg1 ## arg2
 #define CONCATENATE_1(arg1, arg2) CONCATENATE_2(arg1, arg2)
@@ -22,8 +23,8 @@
 
 #define FOR_EACH_NARG(...) FOR_EACH_NARG_(__VA_ARGS__ __VA_OPT__(,) FOR_EACH_RSEQ_N())
 #define FOR_EACH_NARG_(...) FOR_EACH_ARG_N(__VA_ARGS__)
-#define FOR_EACH_ARG_N(_1, _2, _3, _4, _5, _6, _7, _8, N, ...) N
+#define FOR_EACH_ARG_N(_1, _2, _3, _4, _5, _6, _7, _8, _9, _10, N, ...) N
-#define FOR_EACH_RSEQ_N() 8, 7, 6, 5, 4, 3, 2, 1, 0
+#define FOR_EACH_RSEQ_N() 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0
 
 #define FOR_EACH_(N, what, ...) CONCATENATE(FOR_EACH_, N)(what __VA_OPT__(,) __VA_ARGS__)
 #define FOR_EACH(what, ...) FOR_EACH_(FOR_EACH_NARG(__VA_ARGS__), what __VA_OPT__(,) __VA_ARGS__)
@@ -303,6 +304,8 @@ namespace LibGUI
 			WindowSetCursor,
 			uint32_t, width,
 			uint32_t, height,
+			int32_t, origin_x,
+			int32_t, origin_y,
 			BAN::Vector<uint32_t>, pixels
 		);
 

LibGUI/include/LibGUI/Window.h

@@ -50,7 +50,7 @@ namespace LibGUI
 		void set_position(int32_t x, int32_t y);
 
 		void set_cursor_visible(bool visible);
-		void set_cursor(uint32_t width, uint32_t height, BAN::Span<uint32_t> pixels);
+		void set_cursor(uint32_t width, uint32_t height, BAN::Span<const uint32_t> pixels, int32_t origin_x = 0, int32_t origin_y = 0);
 
 		Attributes get_attributes() const { return m_attributes; }
 		void set_attributes(Attributes attributes);

WindowServer/Window.h

@@ -16,6 +16,8 @@ public:
 	{
 		uint32_t width;
 		uint32_t height;
+		int32_t origin_x;
+		int32_t origin_y;
 		BAN::Vector<uint32_t> pixels;
 	};
 

WindowServer/WindowServer.cpp

@@ -387,6 +387,8 @@ void WindowServer::on_window_set_cursor(int fd, const LibGUI::WindowPacket::Wind
 		Window::Cursor cursor;
 		cursor.width = packet.width;
 		cursor.height = packet.height;
+		cursor.origin_x = packet.origin_x;
+		cursor.origin_y = packet.origin_y;
 		if (auto ret = cursor.pixels.resize(packet.pixels.size()); ret.is_error())
 		{
 			dwarnln("failed to set cursor: {}", ret.error());
@@ -1179,12 +1181,15 @@ void WindowServer::invalidate_impl(Rectangle area)
 	{
 		if (const auto overlap = cursor_area().get_overlap(area); overlap.has_value())
 		{
+			const int32_t origin_x = window_cursor ? window_cursor->origin_x : 0;
+			const int32_t origin_y = window_cursor ? window_cursor->origin_y : 0;
+
 			for (int32_t y_off = 0; y_off < overlap->height; y_off++)
 			{
 				for (int32_t x_off = 0; x_off < overlap->width; x_off++)
 				{
-					const int32_t rel_x = overlap->x - m_cursor.x + x_off;
+					const int32_t rel_x = overlap->x - m_cursor.x + x_off + origin_x;
-					const int32_t rel_y = overlap->y - m_cursor.y + y_off;
+					const int32_t rel_y = overlap->y - m_cursor.y + y_off + origin_y;
 					const auto pixel = get_cursor_pixel(rel_x, rel_y);
 					if (pixel.has_value())
 						m_framebuffer.pixels[(overlap->y + y_off) * m_framebuffer.width + (overlap->x + x_off)] = pixel.value();
@@ -1248,6 +1253,9 @@ Rectangle WindowServer::cursor_area() const
 	int32_t width = s_default_cursor_width;
 	int32_t height = s_default_cursor_height;
 
+	int32_t origin_x = 0;
+	int32_t origin_y = 0;
+
 	if (auto window = find_hovered_window())
 	{
 		if (!window->get_attributes().cursor_visible)
@@ -1256,10 +1264,12 @@ Rectangle WindowServer::cursor_area() const
 		{
 			width = window->cursor().width;
 			height = window->cursor().height;
+			origin_x = window->cursor().origin_x;
+			origin_y = window->cursor().origin_y;
 		}
 	}
 
-	return { m_cursor.x, m_cursor.y, width, height };
+	return { m_cursor.x - origin_x, m_cursor.y - origin_y, width, height };
 }
 
 Rectangle WindowServer::resize_area(Position cursor) const