6 files changed, 59 insertions, 12 deletions

diff --git a/scene/main/canvas_item.cpp b/scene/main/canvas_item.cpp
index 35176f0edd..cde3503bdf 100644
--- a/scene/main/canvas_item.cpp
+++ b/scene/main/canvas_item.cpp
@@ -400,11 +400,28 @@ void CanvasItem::set_as_top_level(bool p_top_level) {
 
 	_exit_canvas();
 	top_level = p_top_level;
+	_toplevel_changed();
 	_enter_canvas();
 
 	_notify_transform();
 }
 
+void CanvasItem::_toplevel_changed() {
+	// Inform children that toplevel status has changed on a parent.
+	int childs = get_child_count();
+	for (int i = 0; i < childs; i++) {
+		CanvasItem *child = Object::cast_to<CanvasItem>(get_child(i));
+		if (child) {
+			child->_toplevel_changed_on_parent();
+		}
+	}
+}
+
+void CanvasItem::_toplevel_changed_on_parent() {
+	// Inform children that toplevel status has changed on a parent.
+	_toplevel_changed();
+}
+
 bool CanvasItem::is_set_as_top_level() const {
 	return top_level;
 }
diff --git a/scene/main/canvas_item.h b/scene/main/canvas_item.h
index 1c84ea338a..1ddfaa288c 100644
--- a/scene/main/canvas_item.h
+++ b/scene/main/canvas_item.h
@@ -125,6 +125,9 @@ private:
 	void _propagate_visibility_changed(bool p_parent_visible_in_tree);
 	void _handle_visibility_change(bool p_visible);
 
+	virtual void _toplevel_changed();
+	virtual void _toplevel_changed_on_parent();
+
 	void _redraw_callback();
 
 	void _enter_canvas();
diff --git a/scene/main/viewport.cpp b/scene/main/viewport.cpp
index 48cff5aa8e..b6bcbe04a3 100644
--- a/scene/main/viewport.cpp
+++ b/scene/main/viewport.cpp
@@ -1045,6 +1045,25 @@ Transform2D Viewport::get_final_transform() const {
 	return _get_input_pre_xform().affine_inverse() * stretch_transform * global_canvas_transform;
 }
 
+void Viewport::assign_next_enabled_camera_2d(const StringName &p_camera_group) {
+	List<Node *> camera_list;
+	get_tree()->get_nodes_in_group(p_camera_group, &camera_list);
+
+	Camera2D *new_camera = nullptr;
+	for (const Node *E : camera_list) {
+		const Camera2D *cam = Object::cast_to<Camera2D>(E);
+		if (cam->is_enabled()) {
+			new_camera = const_cast<Camera2D *>(cam);
+			break;
+		}
+	}
+
+	_camera_2d_set(new_camera);
+	if (!camera_2d) {
+		set_canvas_transform(Transform2D());
+	}
+}
+
 void Viewport::_update_canvas_items(Node *p_node) {
 	if (p_node != this) {
 		Window *w = Object::cast_to<Window>(p_node);
@@ -1110,14 +1129,11 @@ Viewport::PositionalShadowAtlasQuadrantSubdiv Viewport::get_positional_shadow_at
 }
 
 Transform2D Viewport::_get_input_pre_xform() const {
-	Transform2D pre_xf;
-
-	if (to_screen_rect.size.x != 0 && to_screen_rect.size.y != 0) {
-		pre_xf.columns[2] = -to_screen_rect.position;
-		pre_xf.scale(Vector2(size) / to_screen_rect.size);
+	const Window *this_window = Object::cast_to<Window>(this);
+	if (this_window) {
+		return this_window->window_transform.affine_inverse();
 	}
-
-	return pre_xf;
+	return Transform2D();
 }
 
 Ref<InputEvent> Viewport::_make_input_local(const Ref<InputEvent> &ev) {
diff --git a/scene/main/viewport.h b/scene/main/viewport.h
index d5d5201e9a..e081013fde 100644
--- a/scene/main/viewport.h
+++ b/scene/main/viewport.h
@@ -511,6 +511,7 @@ public:
 	Transform2D get_global_canvas_transform() const;
 
 	Transform2D get_final_transform() const;
+	void assign_next_enabled_camera_2d(const StringName &p_camera_group);
 
 	void gui_set_root_order_dirty();
 
diff --git a/scene/main/window.cpp b/scene/main/window.cpp
index 869d12b4df..b1f2bc65dc 100644
--- a/scene/main/window.cpp
+++ b/scene/main/window.cpp
@@ -907,6 +907,7 @@ void Window::_update_viewport_size() {
 	Rect2i attach_to_screen_rect(Point2i(), size);
 	Transform2D stretch_transform_new;
 	float font_oversampling = 1.0;
+	window_transform = Transform2D();
 
 	if (content_scale_mode == CONTENT_SCALE_MODE_DISABLED || content_scale_size.x == 0 || content_scale_size.y == 0) {
 		font_oversampling = content_scale_factor;
@@ -993,11 +994,18 @@ void Window::_update_viewport_size() {
 				Size2 scale = Vector2(screen_size) / Vector2(final_size_override);
 				stretch_transform_new.scale(scale);
 
+				window_transform.translate_local(margin);
 			} break;
 			case CONTENT_SCALE_MODE_VIEWPORT: {
 				final_size = (viewport_size / content_scale_factor).floor();
 				attach_to_screen_rect = Rect2(margin, screen_size);
 
+				window_transform.translate_local(margin);
+				if (final_size.x != 0 && final_size.y != 0) {
+					Transform2D scale_transform;
+					scale_transform.scale(Vector2(attach_to_screen_rect.size) / Vector2(final_size));
+					window_transform *= scale_transform;
+				}
 			} break;
 		}
 	}
@@ -2127,13 +2135,13 @@ Transform2D Window::get_popup_base_transform() const {
 	if (is_embedding_subwindows()) {
 		return Transform2D();
 	}
-	Transform2D window_transform;
-	window_transform.set_origin(get_position());
-	window_transform *= Viewport::get_screen_transform();
+	Transform2D popup_base_transform;
+	popup_base_transform.set_origin(get_position());
+	popup_base_transform *= Viewport::get_screen_transform();
 	if (_get_embedder()) {
-		return _get_embedder()->get_popup_base_transform() * window_transform;
+		return _get_embedder()->get_popup_base_transform() * popup_base_transform;
 	}
-	return window_transform;
+	return popup_base_transform;
 }
 
 void Window::_bind_methods() {
diff --git a/scene/main/window.h b/scene/main/window.h
index 182caf5f0c..1730de0b33 100644
--- a/scene/main/window.h
+++ b/scene/main/window.h
@@ -173,6 +173,8 @@ private:
 
 	Viewport *embedder = nullptr;
 
+	Transform2D window_transform;
+
 	friend class Viewport; //friend back, can call the methods below
 
 	void _window_input(const Ref<InputEvent> &p_ev);