Draw relationship lines for items offscreen

1 files changed, 67 insertions, 53 deletions

diff --git a/scene/gui/tree.cpp b/scene/gui/tree.cpp
index ccd24ed2cf..32dddde36e 100644
--- a/scene/gui/tree.cpp
+++ b/scene/gui/tree.cpp
@@ -2088,7 +2088,6 @@ int Tree::draw_item(const Point2i &p_pos, const Point2 &p_draw_ofs, const Size2
 	}
 
 	if (!p_item->collapsed) { /* if not collapsed, check the children */
-
 		TreeItem *c = p_item->first_child;
 
 		int base_ofs = children_pos.y - cache.offset.y + p_draw_ofs.y;
@@ -2096,82 +2095,97 @@ int Tree::draw_item(const Point2i &p_pos, const Point2 &p_draw_ofs, const Size2
 		int prev_hl_ofs = base_ofs;
 
 		while (c) {
+			int child_h = -1;
 			if (htotal >= 0) {
-				int child_h = draw_item(children_pos, p_draw_ofs, p_draw_size, c);
+				child_h = draw_item(children_pos, p_draw_ofs, p_draw_size, c);
+			}
 
-				// Draw relationship lines.
-				if (cache.draw_relationship_lines > 0 && (!hide_root || c->parent != root)) {
-					int root_ofs = children_pos.x + ((p_item->disable_folding || hide_folding) ? cache.hseparation : cache.item_margin);
-					int parent_ofs = p_pos.x + cache.item_margin;
-					Point2i root_pos = Point2i(root_ofs, children_pos.y + label_h / 2) - cache.offset + p_draw_ofs;
+			// Draw relationship lines.
+			if (cache.draw_relationship_lines > 0 && (!hide_root || c->parent != root)) {
+				int root_ofs = children_pos.x + ((p_item->disable_folding || hide_folding) ? cache.hseparation : cache.item_margin);
+				int parent_ofs = p_pos.x + cache.item_margin;
+				Point2i root_pos = Point2i(root_ofs, children_pos.y + label_h / 2) - cache.offset + p_draw_ofs;
 
-					if (c->get_first_child() != nullptr) {
-						root_pos -= Point2i(cache.arrow->get_width(), 0);
-					}
+				if (c->get_first_child() != nullptr) {
+					root_pos -= Point2i(cache.arrow->get_width(), 0);
+				}
 
-					float line_width = cache.relationship_line_width * Math::round(cache.base_scale);
-					float parent_line_width = cache.parent_hl_line_width * Math::round(cache.base_scale);
-					float children_line_width = cache.children_hl_line_width * Math::round(cache.base_scale);
+				float line_width = cache.relationship_line_width * Math::round(cache.base_scale);
+				float parent_line_width = cache.parent_hl_line_width * Math::round(cache.base_scale);
+				float children_line_width = cache.children_hl_line_width * Math::round(cache.base_scale);
 
-					Point2i parent_pos = Point2i(parent_ofs - cache.arrow->get_width() / 2, p_pos.y + label_h / 2 + cache.arrow->get_height() / 2) - cache.offset + p_draw_ofs;
+				Point2i parent_pos = Point2i(parent_ofs - cache.arrow->get_width() / 2, p_pos.y + label_h / 2 + cache.arrow->get_height() / 2) - cache.offset + p_draw_ofs;
 
-					int more_prev_ofs = 0;
+				int more_prev_ofs = 0;
 
-					if (root_pos.y + line_width >= 0) {
-						if (rtl) {
-							root_pos.x = get_size().width - root_pos.x;
-							parent_pos.x = get_size().width - parent_pos.x;
-						}
+				if (root_pos.y + line_width >= 0) {
+					if (rtl) {
+						root_pos.x = get_size().width - root_pos.x;
+						parent_pos.x = get_size().width - parent_pos.x;
+					}
 
-						// Order of parts on this bend: the horizontal line first, then the vertical line.
-						if (_is_branch_selected(c)) {
-							// If this item or one of its children is selected, we draw the line using parent highlight style.
+					// Order of parts on this bend: the horizontal line first, then the vertical line.
+					if (_is_branch_selected(c)) {
+						// If this item or one of its children is selected, we draw the line using parent highlight style.
+						if (htotal >= 0) {
 							RenderingServer::get_singleton()->canvas_item_add_line(ci, root_pos, Point2i(parent_pos.x + Math::floor(parent_line_width / 2), root_pos.y), cache.parent_hl_line_color, parent_line_width);
+						}
+						RenderingServer::get_singleton()->canvas_item_add_line(ci, Point2i(parent_pos.x, root_pos.y + Math::floor(parent_line_width / 2)), Point2i(parent_pos.x, prev_hl_ofs), cache.parent_hl_line_color, parent_line_width);
+
+						more_prev_ofs = cache.parent_hl_line_margin;
+						prev_hl_ofs = root_pos.y + Math::floor(parent_line_width / 2);
+					} else if (p_item->is_selected(0)) {
+						// If parent item is selected (but this item is not), we draw the line using children highlight style.
+						// Siblings of the selected branch can be drawn with a slight offset and their vertical line must appear as highlighted.
+						if (_is_sibling_branch_selected(c)) {
+							if (htotal >= 0) {
+								RenderingServer::get_singleton()->canvas_item_add_line(ci, root_pos, Point2i(parent_pos.x + Math::floor(parent_line_width / 2), root_pos.y), cache.children_hl_line_color, children_line_width);
+							}
 							RenderingServer::get_singleton()->canvas_item_add_line(ci, Point2i(parent_pos.x, root_pos.y + Math::floor(parent_line_width / 2)), Point2i(parent_pos.x, prev_hl_ofs), cache.parent_hl_line_color, parent_line_width);
 
-							more_prev_ofs = cache.parent_hl_line_margin;
 							prev_hl_ofs = root_pos.y + Math::floor(parent_line_width / 2);
-						} else if (p_item->is_selected(0)) {
-							// If parent item is selected (but this item is not), we draw the line using children highlight style.
-							// Siblings of the selected branch can be drawn with a slight offset and their vertical line must appear as highlighted.
-							if (_is_sibling_branch_selected(c)) {
-								RenderingServer::get_singleton()->canvas_item_add_line(ci, root_pos, Point2i(parent_pos.x + Math::floor(parent_line_width / 2), root_pos.y), cache.children_hl_line_color, children_line_width);
-								RenderingServer::get_singleton()->canvas_item_add_line(ci, Point2i(parent_pos.x, root_pos.y + Math::floor(parent_line_width / 2)), Point2i(parent_pos.x, prev_hl_ofs), cache.parent_hl_line_color, parent_line_width);
-
-								prev_hl_ofs = root_pos.y + Math::floor(parent_line_width / 2);
-							} else {
+						} else {
+							if (htotal >= 0) {
 								RenderingServer::get_singleton()->canvas_item_add_line(ci, root_pos, Point2i(parent_pos.x + Math::floor(children_line_width / 2), root_pos.y), cache.children_hl_line_color, children_line_width);
-								RenderingServer::get_singleton()->canvas_item_add_line(ci, Point2i(parent_pos.x, root_pos.y + Math::floor(children_line_width / 2)), Point2i(parent_pos.x, prev_ofs + Math::floor(children_line_width / 2)), cache.children_hl_line_color, children_line_width);
 							}
-						} else {
-							// If nothing of the above is true, we draw the line using normal style.
-							// Siblings of the selected branch can be drawn with a slight offset and their vertical line must appear as highlighted.
-							if (_is_sibling_branch_selected(c)) {
+							RenderingServer::get_singleton()->canvas_item_add_line(ci, Point2i(parent_pos.x, root_pos.y + Math::floor(children_line_width / 2)), Point2i(parent_pos.x, prev_ofs + Math::floor(children_line_width / 2)), cache.children_hl_line_color, children_line_width);
+						}
+					} else {
+						// If nothing of the above is true, we draw the line using normal style.
+						// Siblings of the selected branch can be drawn with a slight offset and their vertical line must appear as highlighted.
+						if (_is_sibling_branch_selected(c)) {
+							if (htotal >= 0) {
 								RenderingServer::get_singleton()->canvas_item_add_line(ci, root_pos, Point2i(parent_pos.x + cache.parent_hl_line_margin, root_pos.y), cache.relationship_line_color, line_width);
-								RenderingServer::get_singleton()->canvas_item_add_line(ci, Point2i(parent_pos.x, root_pos.y + Math::floor(parent_line_width / 2)), Point2i(parent_pos.x, prev_hl_ofs), cache.parent_hl_line_color, parent_line_width);
+							}
+							RenderingServer::get_singleton()->canvas_item_add_line(ci, Point2i(parent_pos.x, root_pos.y + Math::floor(parent_line_width / 2)), Point2i(parent_pos.x, prev_hl_ofs), cache.parent_hl_line_color, parent_line_width);
 
-								prev_hl_ofs = root_pos.y + Math::floor(parent_line_width / 2);
-							} else {
+							prev_hl_ofs = root_pos.y + Math::floor(parent_line_width / 2);
+						} else {
+							if (htotal >= 0) {
 								RenderingServer::get_singleton()->canvas_item_add_line(ci, root_pos, Point2i(parent_pos.x + Math::floor(line_width / 2), root_pos.y), cache.relationship_line_color, line_width);
-								RenderingServer::get_singleton()->canvas_item_add_line(ci, Point2i(parent_pos.x, root_pos.y + Math::floor(line_width / 2)), Point2i(parent_pos.x, prev_ofs + Math::floor(line_width / 2)), cache.relationship_line_color, line_width);
 							}
+							RenderingServer::get_singleton()->canvas_item_add_line(ci, Point2i(parent_pos.x, root_pos.y + Math::floor(line_width / 2)), Point2i(parent_pos.x, prev_ofs + Math::floor(line_width / 2)), cache.relationship_line_color, line_width);
 						}
 					}
-
-					prev_ofs = root_pos.y + more_prev_ofs;
 				}
 
-				if (child_h < 0) {
-					if (cache.draw_relationship_lines == 0) {
-						return -1; // break, stop drawing, no need to anymore
-					}
+				prev_ofs = root_pos.y + more_prev_ofs;
+			}
 
-					htotal = -1;
-					children_pos.y = cache.offset.y + p_draw_size.height;
-				} else {
-					htotal += child_h;
-					children_pos.y += child_h;
+			if (child_h < 0) {
+				if (htotal == -1) {
+					break; // Last loop done, stop.
 				}
+
+				if (cache.draw_relationship_lines == 0) {
+					return -1; // No need to draw anymore, full stop.
+				}
+
+				htotal = -1;
+				children_pos.y = cache.offset.y + p_draw_size.height;
+			} else {
+				htotal += child_h;
+				children_pos.y += child_h;
 			}
 
 			c = c->next;