Cherry-pick godotengine#86361

Optimize mouse UI picking on BoxContainer, FlowContainer and GridContainer

scene/gui/box_container.cpp

@@ -200,6 +200,8 @@ void BoxContainer::_resort() {
 		delta = -1;
 	}
 
+	cached_children_nodes.clear();
+
 	for (int i = start; i != end; i += delta) {
 		Control *c = Object::cast_to<Control>(get_child(i));
 		if (!c || !c->is_visible_in_tree()) {
@@ -238,6 +240,7 @@ void BoxContainer::_resort() {
 		}
 
 		fit_child_in_rect(c, rect);
+		cached_children_nodes.push_back(c);
 
 		ofs = to;
 		idx++;
@@ -289,6 +292,35 @@ Size2 BoxContainer::get_minimum_size() const {
 	return minimum;
 }
 
+Vector<CanvasItem *> BoxContainer::get_children_at_pos(const Point2 &p_pos) const {
+	if (cached_children_nodes.is_empty()) {
+		return Vector<CanvasItem *>();
+	}
+
+	int coord = vertical ? p_pos.y : p_pos.x;
+	// Custom binary search; we are searching for the closest value to coord, not an exact one.
+	int bin_start = 0;
+	int bin_end = cached_children_nodes.size();
+	while (bin_start < bin_end) {
+		int mid = (bin_start + bin_end) / 2;
+		if (coord < (vertical ? cached_children_nodes[mid]->get_rect().position.y : cached_children_nodes[mid]->get_rect().position.x)) {
+			bin_end = mid;
+		} else {
+			bin_start = mid + 1;
+		}
+	}
+
+	Vector<CanvasItem *> children;
+	int idx = MAX(bin_start - 1, 0);
+	ERR_FAIL_INDEX_V(idx, cached_children_nodes.size(), children);
+
+	CanvasItem *child = Object::cast_to<CanvasItem>(cached_children_nodes[idx]);
+	if (child) {
+		children.push_back(child);
+	}
+	return children;
+}
+
 void BoxContainer::_notification(int p_what) {
 	switch (p_what) {
 		case NOTIFICATION_SORT_CHILDREN: {

scene/gui/box_container.h

@@ -51,6 +51,8 @@ class BoxContainer : public Container {
 		int separation = 0;
 	} theme_cache;
 
+	Vector<Control *> cached_children_nodes;
+
 	void _resort();
 
 protected:
@@ -70,6 +72,7 @@ class BoxContainer : public Container {
 	bool is_vertical() const;
 
 	virtual Size2 get_minimum_size() const override;
+	virtual Vector<CanvasItem *> get_children_at_pos(const Point2 &p_pos) const override;
 
 	virtual Vector<int> get_allowed_size_flags_horizontal() const override;
 	virtual Vector<int> get_allowed_size_flags_vertical() const override;

scene/gui/container.cpp

@@ -81,6 +81,17 @@ void Container::remove_child_notify(Node *p_child) {
 	queue_sort();
 }
 
+Vector<CanvasItem *> Container::get_children_at_pos(const Point2 &p_pos) const {
+	Vector<CanvasItem *> children;
+	for (int i = get_child_count() - 1; i >= 0; i--) {
+		CanvasItem *child = Object::cast_to<CanvasItem>(get_child(i));
+		if (child && child->is_visible()) {
+			children.push_back(child);
+		}
+	}
+	return children;
+}
+
 void Container::_sort_children() {
 	if (!is_inside_tree()) {
 		return;

scene/gui/container.h

@@ -59,6 +59,7 @@ class Container : public Control {
 	};
 
 	void fit_child_in_rect(Control *p_child, const Rect2 &p_rect);
+	virtual Vector<CanvasItem *> get_children_at_pos(const Point2 &p_pos) const;
 
 	virtual Vector<int> get_allowed_size_flags_horizontal() const;
 	virtual Vector<int> get_allowed_size_flags_vertical() const;

scene/gui/flow_container.cpp

@@ -59,6 +59,8 @@ void FlowContainer::_resort() {
 	int current_container_size = vertical ? get_rect().size.y : get_rect().size.x;
 	int children_in_current_line = 0;
 
+	cached_children_nodes.clear();
+
 	// First pass for line wrapping and minimum size calculation.
 	for (int i = 0; i < get_child_count(); i++) {
 		Control *child = Object::cast_to<Control>(get_child(i));
@@ -140,6 +142,11 @@ void FlowContainer::_resort() {
 		}
 		Size2i child_size = children_minsize_cache[child];
 
+		if (cached_children_nodes.is_empty()) {
+			// Add the first child.
+			cached_children_nodes.push_back(child);
+		}
+
 		_LineData line_data = lines_data[current_line_idx];
 		if (child_idx_in_line >= lines_data[current_line_idx].child_count) {
 			current_line_idx++;
@@ -151,6 +158,7 @@ void FlowContainer::_resort() {
 				ofs.x = 0;
 				ofs.y += line_data.min_line_height + theme_cache.v_separation;
 			}
+			cached_children_nodes.push_back(child);
 			line_data = lines_data[current_line_idx];
 		}
 
@@ -247,6 +255,47 @@ Size2 FlowContainer::get_minimum_size() const {
 	return minimum;
 }
 
+Vector<CanvasItem *> FlowContainer::get_children_at_pos(const Point2 &p_pos) const {
+	if (cached_children_nodes.is_empty()) {
+		return Vector<CanvasItem *>();
+	}
+
+	int coord = vertical ? p_pos.x : p_pos.y;
+	// Custom binary search; we are searching for the closest value to coord, not an exact one.
+	int bin_start = 0;
+	int bin_end = cached_children_nodes.size();
+	while (bin_start < bin_end) {
+		int mid = (bin_start + bin_end) / 2;
+		if (coord < (vertical ? cached_children_nodes[mid]->get_rect().position.x : cached_children_nodes[mid]->get_rect().position.y)) {
+			bin_end = mid;
+		} else {
+			bin_start = mid + 1;
+		}
+	}
+
+	int start_idx = MAX(bin_start - 1, 0);
+	int end_idx = MIN(bin_end, cached_children_nodes.size() - 1);
+	ERR_FAIL_INDEX_V(start_idx, cached_children_nodes.size(), Vector<CanvasItem *>());
+	ERR_FAIL_INDEX_V(end_idx, cached_children_nodes.size(), Vector<CanvasItem *>());
+
+	int start_node_idx = cached_children_nodes[start_idx]->get_index();
+	int end_node_idx = cached_children_nodes[end_idx]->get_index();
+
+	if (start_node_idx == end_node_idx) {
+		// Last row, so include the remaining children.
+		end_node_idx = get_child_count();
+	}
+
+	Vector<CanvasItem *> children;
+	for (end_node_idx--; end_node_idx >= start_node_idx; end_node_idx--) {
+		CanvasItem *child = Object::cast_to<CanvasItem>(get_child(end_node_idx));
+		if (child && child->is_visible()) {
+			children.push_back(child);
+		}
+	}
+	return children;
+}
+
 Vector<int> FlowContainer::get_allowed_size_flags_horizontal() const {
 	Vector<int> flags;
 	flags.append(SIZE_FILL);

scene/gui/flow_container.h

@@ -57,6 +57,8 @@ class FlowContainer : public Container {
 
 	void _resort();
 
+	Vector<Control *> cached_children_nodes;
+
 protected:
 	bool is_fixed = false;
 
@@ -74,6 +76,7 @@ class FlowContainer : public Container {
 	bool is_vertical() const;
 
 	virtual Size2 get_minimum_size() const override;
+	virtual Vector<CanvasItem *> get_children_at_pos(const Point2 &p_pos) const override;
 
 	virtual Vector<int> get_allowed_size_flags_horizontal() const override;
 	virtual Vector<int> get_allowed_size_flags_vertical() const override;

scene/gui/grid_container.cpp

@@ -185,11 +185,18 @@ void GridContainer::_notification(int p_what) {
 			}
 
 			valid_controls_index = 0;
+			cached_children_nodes.clear();
+
 			for (int i = 0; i < get_child_count(); i++) {
 				Control *c = Object::cast_to<Control>(get_child(i));
 				if (!c || !c->is_visible_in_tree()) {
 					continue;
 				}
+				if (cached_children_nodes.is_empty()) {
+					// Add the first child.
+					cached_children_nodes.push_back(c);
+				}
+
 				int row = valid_controls_index / columns;
 				int col = valid_controls_index % columns;
 				valid_controls_index++;
@@ -207,6 +214,7 @@ void GridContainer::_notification(int p_what) {
 							// Apply the remaining pixel of the previous row.
 							row_ofs++;
 						}
+						cached_children_nodes.push_back(c);
 					}
 				}
 
@@ -322,4 +330,44 @@ Size2 GridContainer::get_minimum_size() const {
 	return ms;
 }
 
+Vector<CanvasItem *> GridContainer::get_children_at_pos(const Point2 &p_pos) const {
+	if (cached_children_nodes.is_empty()) {
+		return Vector<CanvasItem *>();
+	}
+
+	// Custom binary search; we are searching for the closest value to coord, not an exact one.
+	int bin_start = 0;
+	int bin_end = cached_children_nodes.size();
+	while (bin_start < bin_end) {
+		int mid = (bin_start + bin_end) / 2;
+		if (p_pos.y < cached_children_nodes[mid]->get_rect().position.y) {
+			bin_end = mid;
+		} else {
+			bin_start = mid + 1;
+		}
+	}
+
+	int start_idx = MAX(bin_start - 1, 0);
+	int end_idx = MIN(bin_end, cached_children_nodes.size() - 1);
+	ERR_FAIL_INDEX_V(start_idx, cached_children_nodes.size(), Vector<CanvasItem *>());
+	ERR_FAIL_INDEX_V(end_idx, cached_children_nodes.size(), Vector<CanvasItem *>());
+
+	int start_node_idx = cached_children_nodes[start_idx]->get_index();
+	int end_node_idx = cached_children_nodes[end_idx]->get_index();
+
+	if (start_node_idx == end_node_idx) {
+		// Last row, so include the remaining children.
+		end_node_idx = get_child_count();
+	}
+
+	Vector<CanvasItem *> children;
+	for (end_node_idx--; end_node_idx >= start_node_idx; end_node_idx--) {
+		CanvasItem *child = Object::cast_to<CanvasItem>(get_child(end_node_idx));
+		if (child && child->is_visible()) {
+			children.push_back(child);
+		}
+	}
+	return children;
+}
+
 GridContainer::GridContainer() {}

scene/gui/grid_container.h

@@ -43,6 +43,8 @@ class GridContainer : public Container {
 		int v_separation = 0;
 	} theme_cache;
 
+	Vector<Control *> cached_children_nodes;
+
 protected:
 	void _notification(int p_what);
 	static void _bind_methods();
@@ -51,6 +53,7 @@ class GridContainer : public Container {
 	void set_columns(int p_columns);
 	int get_columns() const;
 	virtual Size2 get_minimum_size() const override;
+	virtual Vector<CanvasItem *> get_children_at_pos(const Point2 &p_pos) const override;
 
 	int get_h_separation() const;
 

scene/main/viewport.cpp

@@ -1699,8 +1699,25 @@ Control *Viewport::_gui_find_control_at_pos(CanvasItem *p_node, const Point2 &p_
 	}
 
 	Control *c = Object::cast_to<Control>(p_node);
+	Point2 point = matrix.affine_inverse().xform(p_global);
+
+	if (!c || !c->is_clipping_contents() || c->has_point(point)) {
+		// If node is a Container, it can optimize the search at the given position.
+		Container *container = Object::cast_to<Container>(p_node);
+		if (container && container->has_point(point)) {
+			Vector<CanvasItem *> children = container->get_children_at_pos(point);
+			for (CanvasItem *ci : children) {
+				if (ci->is_set_as_top_level()) {
+					continue;
+				}
 
-	if (!c || !c->is_clipping_contents() || c->has_point(matrix.affine_inverse().xform(p_global))) {
+				Control *ret = _gui_find_control_at_pos(ci, p_global, matrix);
+				if (ret) {
+					return ret;
+				}
+			}
+		}
+		// Fallback: Iterate over all children.
 		for (int i = p_node->get_child_count() - 1; i >= 0; i--) {
 			CanvasItem *ci = Object::cast_to<CanvasItem>(p_node->get_child(i));
 			if (!ci || ci->is_set_as_top_level()) {