Allow reconnecting AnimationNodeStateMachine transitions

2025-11-11 13:10:58 +00:00 · 2025-08-11 21:24:47 +05:30
parent 80a219a58a
commit 51a54636c1
2 changed files with 325 additions and 32 deletions
--- a/editor/animation/animation_state_machine_editor.cpp
+++ b/editor/animation/animation_state_machine_editor.cpp
@@ -125,6 +125,86 @@ String AnimationNodeStateMachineEditor::_get_root_playback_path(String &r_node_d
 	return base_path;
 }

+void AnimationNodeStateMachineEditor::_reconnect_transition() {
+	if (reconnecting_transition_index < 0 || reconnecting_transition_target.is_empty()) {
+		return;
+	}
+
+	StringName old_from = state_machine->get_transition_from(reconnecting_transition_index);
+	StringName old_to = state_machine->get_transition_to(reconnecting_transition_index);
+	StringName new_from;
+	StringName new_to;
+
+	if (reconnecting_transition_start) {
+		new_from = reconnecting_transition_target;
+		new_to = old_to;
+	} else {
+		new_from = old_from;
+		new_to = reconnecting_transition_target;
+	}
+
+	// Preserve transition properties.
+	Ref<AnimationNodeStateMachineTransition> transition = state_machine->get_transition(reconnecting_transition_index);
+
+	updating = true;
+	EditorUndoRedoManager *undo_redo = EditorUndoRedoManager::get_singleton();
+	undo_redo->create_action(TTR("Reconnect Transition"));
+
+	// Remove old transition.
+	undo_redo->add_do_method(state_machine.ptr(), "remove_transition", old_from, old_to);
+	undo_redo->add_undo_method(state_machine.ptr(), "add_transition", old_from, old_to, transition);
+
+	// Add new transition.
+	undo_redo->add_do_method(state_machine.ptr(), "add_transition", new_from, new_to, transition);
+	undo_redo->add_undo_method(state_machine.ptr(), "remove_transition", new_from, new_to);
+
+	undo_redo->add_do_method(this, "_select_transition", new_from, new_to);
+	undo_redo->add_undo_method(this, "_select_transition", old_from, old_to);
+
+	undo_redo->add_do_method(this, "_update_graph");
+	undo_redo->add_undo_method(this, "_update_graph");
+	undo_redo->commit_action();
+	updating = false;
+
+	selected_transition_from = new_from;
+	selected_transition_to = new_to;
+	_update_mode();
+}
+
+void AnimationNodeStateMachineEditor::_select_transition(const StringName &p_from, const StringName &p_to) {
+	selected_transition_from = p_from;
+	selected_transition_to = p_to;
+	selected_transition_index = -1;
+
+	// Find transition index.
+	for (int i = 0; i < state_machine->get_transition_count(); i++) {
+		if (state_machine->get_transition_from(i) == p_from && state_machine->get_transition_to(i) == p_to) {
+			selected_transition_index = i;
+			break;
+		}
+	}
+
+	selected_node = StringName();
+	selected_nodes.clear();
+
+	connected_nodes.clear();
+	connected_nodes.insert(selected_transition_from);
+	connected_nodes.insert(selected_transition_to);
+
+	// Push transition to the inspector.
+	if (selected_transition_index >= 0) {
+		Ref<AnimationNodeStateMachineTransition> tr = state_machine->get_transition(selected_transition_index);
+		if (!state_machine->is_transition_across_group(selected_transition_index)) {
+			EditorNode::get_singleton()->push_item(tr.ptr(), "", true);
+		} else {
+			EditorNode::get_singleton()->push_item(tr.ptr(), "", true);
+			EditorNode::get_singleton()->push_item(nullptr, "", true);
+		}
+	}
+
+	_update_mode();
+}
+
 void AnimationNodeStateMachineEditor::_state_machine_gui_input(const Ref<InputEvent> &p_event) {
 	AnimationTree *tree = AnimationTreeEditor::get_singleton()->get_animation_tree();
 	if (!tree) {
@@ -266,22 +346,7 @@ void AnimationNodeStateMachineEditor::_state_machine_gui_input(const Ref<InputEv
 		}

 		if (closest >= 0) {
-			selected_transition_from = transition_lines[closest].from_node;
-			selected_transition_to = transition_lines[closest].to_node;
-			selected_transition_index = closest;
-
-			// Update connected_nodes for the selected transition.
-			connected_nodes.clear();
-			connected_nodes.insert(selected_transition_from);
-			connected_nodes.insert(selected_transition_to);
-
-			Ref<AnimationNodeStateMachineTransition> tr = state_machine->get_transition(closest);
-			if (!state_machine->is_transition_across_group(closest)) {
-				EditorNode::get_singleton()->push_item(tr.ptr(), "", true);
-			} else {
-				EditorNode::get_singleton()->push_item(tr.ptr(), "", true);
-				EditorNode::get_singleton()->push_item(nullptr, "", true);
-			}
+			_select_transition(transition_lines[closest].from_node, transition_lines[closest].to_node);
 		}

 		state_machine_draw->queue_redraw();
@@ -354,6 +419,72 @@ void AnimationNodeStateMachineEditor::_state_machine_gui_input(const Ref<InputEv
 		state_machine_draw->queue_redraw();
 	}

+	// Start transition reconnection.
+	if (mb.is_valid() && mb->is_pressed() && tool_select->is_pressed() && mb->get_button_index() == MouseButton::LEFT) {
+		// Check if we're clicking on a hovered transition endpoint to start dragging.
+		if (hovered_transition_index >= 0 && !read_only) {
+			reconnecting = true;
+			reconnecting_transition_index = hovered_transition_index;
+			reconnecting_transition_start = hovered_transition_start;
+			reconnecting_transition_pos = mb->get_position();
+			reconnecting_transition_target = StringName();
+
+			StringName connected_node = reconnecting_transition_start ? transition_lines[reconnecting_transition_index].to_node : transition_lines[reconnecting_transition_index].from_node;
+
+			reconnecting_from_node_rect_index = -1;
+			for (int i = 0; i < node_rects.size(); i++) {
+				if (node_rects[i].node_name == connected_node) {
+					reconnecting_from_node_rect_index = i;
+					break;
+				}
+			}
+
+			// Clear other selections when starting transition drag.
+			selected_transition_from = StringName();
+			selected_transition_to = StringName();
+			selected_transition_index = -1;
+			selected_node = StringName();
+			selected_nodes.clear();
+			connected_nodes.clear();
+
+			state_machine_draw->queue_redraw();
+			return;
+		}
+	}
+
+	// End transition reconnection.
+	if (mb.is_valid() && reconnecting && mb->get_button_index() == MouseButton::LEFT && !mb->is_pressed()) {
+		if (reconnecting_transition_target != StringName()) {
+			// Check if reconnection is valid.
+			StringName old_from = state_machine->get_transition_from(reconnecting_transition_index);
+			StringName old_to = state_machine->get_transition_to(reconnecting_transition_index);
+			StringName new_from = reconnecting_transition_start ? reconnecting_transition_target : old_from;
+			StringName new_to = reconnecting_transition_start ? old_to : reconnecting_transition_target;
+
+			if (new_from == old_from && new_to == old_to) {
+				// No change.
+			} else if (new_from == new_to) {
+				EditorNode::get_singleton()->show_warning(TTR("Cannot transition to self!"));
+			} else if (new_to == SceneStringName(Start)) {
+				EditorNode::get_singleton()->show_warning(TTR("Cannot transition to \"Start\"!"));
+			} else if (new_from == SceneStringName(End)) {
+				EditorNode::get_singleton()->show_warning(TTR("Cannot transition from \"End\"!"));
+			} else if (state_machine->has_transition(new_from, new_to)) {
+				EditorNode::get_singleton()->show_warning(vformat(TTR("Transition from \"%s\" to \"%s\" already exists!"), new_from, new_to));
+			} else {
+				_reconnect_transition();
+			}
+		}
+
+		// Reset dragging state.
+		reconnecting = false;
+		reconnecting_transition_index = -1;
+		reconnecting_transition_start = false;
+		reconnecting_transition_target = StringName();
+		state_machine_draw->queue_redraw();
+		return;
+	}
+
 	// Start box selecting
 	if (mb.is_valid() && mb->is_pressed() && mb->get_button_index() == MouseButton::LEFT && tool_select->is_pressed()) {
 		box_selecting = true;
@@ -439,6 +570,24 @@ void AnimationNodeStateMachineEditor::_state_machine_gui_input(const Ref<InputEv
 		}
 	}

+	// Move mouse while reconnecting.
+	if (mm.is_valid() && reconnecting && !read_only) {
+		reconnecting_transition_pos = mm->get_position();
+		reconnecting_transition_target = StringName();
+		reconnecting_to_node_rect_index = -1;
+
+		for (int i = node_rects.size() - 1; i >= 0; i--) {
+			if (node_rects[i].node.has_point(reconnecting_transition_pos)) {
+				reconnecting_transition_target = node_rects[i].node_name;
+				reconnecting_to_node_rect_index = i;
+				break;
+			}
+		}
+
+		state_machine_draw->queue_redraw();
+		return;
+	}
+
 	// Move mouse while moving a node
 	if (mm.is_valid() && dragging_selected_attempt && !read_only) {
 		dragging_selected = true;
@@ -535,10 +684,27 @@ void AnimationNodeStateMachineEditor::_state_machine_gui_input(const Ref<InputEv
 			state_machine_draw->queue_redraw();
 		}

-		// set tooltip for transition
+		// Skip if over node.
+		for (int i = node_rects.size() - 1; i >= 0; i--) {
+			if (node_rects[i].node.has_point(mm->get_position())) {
+				if (hovered_transition_index != -1) {
+					hovered_transition_index = -1;
+					hovered_transition_start = false;
+					state_machine_draw->queue_redraw();
+				}
+				state_machine_draw->set_tooltip_text("");
+				return;
+			}
+		}
+
+		// Set transition tooltip or reconnection endpoint.
 		if (tool_select->is_pressed()) {
-			int closest = -1;
-			float closest_d = 1e20;
+			int closest_for_highlight = -1;
+			int closest_for_tooltip = -1;
+			float closest_d_highlight = 1e20;
+			float closest_d_tooltip = 1e20;
+			bool closest_is_start = false;
+
 			for (int i = 0; i < transition_lines.size(); i++) {
 				Vector2 cpoint = Geometry2D::get_closest_point_to_segment(mm->get_position(), transition_lines[i].from, transition_lines[i].to);
 				float d = cpoint.distance_to(mm->get_position());
@@ -546,15 +712,48 @@ void AnimationNodeStateMachineEditor::_state_machine_gui_input(const Ref<InputEv
 					continue;
 				}

-				if (d < closest_d) {
-					closest = i;
-					closest_d = d;
+				// Check for tooltip (anywhere along the line).
+				if (d < closest_d_tooltip) {
+					closest_d_tooltip = d;
+					closest_for_tooltip = i;
+				}
+
+				// Calculate dynamic hover distance based on transition length.
+				float transition_length = transition_lines[i].from.distance_to(transition_lines[i].to);
+				float hover_distance = MIN(20.0f, transition_length * 0.2f); // 20px or 20% of length, whichever is smaller.
+
+				// Check distance to both endpoints for highlighting.
+				float dist_to_start = mm->get_position().distance_to(transition_lines[i].from);
+				float dist_to_end = mm->get_position().distance_to(transition_lines[i].to);
+
+				bool near_start = (dist_to_start <= hover_distance);
+				bool near_end = (dist_to_end <= hover_distance);
+
+				// Determine which end is closer if both are within range.
+				bool is_start_closer = dist_to_start < dist_to_end;
+
+				if ((near_start || near_end) && d < closest_d_highlight) {
+					StringName from_node = transition_lines[i].from_node;
+					StringName to_node = transition_lines[i].to_node;
+
+					bool is_start_endpoint = near_start && (is_start_closer || !near_end);
+					closest_d_highlight = d;
+					closest_for_highlight = i;
+					closest_is_start = is_start_endpoint;
 				}
 			}

-			if (closest >= 0) {
-				String from = String(transition_lines[closest].from_node);
-				String to = String(transition_lines[closest].to_node);
+			// Update hovered endpoint for reconnection.
+			if (hovered_transition_index != closest_for_highlight || hovered_transition_start != closest_is_start) {
+				hovered_transition_index = closest_for_highlight;
+				hovered_transition_start = closest_is_start;
+				state_machine_draw->queue_redraw();
+			}
+
+			// Set tooltip for any part of the transition line.
+			if (closest_for_tooltip >= 0) {
+				String from = transition_lines[closest_for_tooltip].from_node;
+				String to = transition_lines[closest_for_tooltip].to_node;
 				String tooltip = from + " -> " + to;
 				state_machine_draw->set_tooltip_text(tooltip);
 			} else {
@@ -834,9 +1033,7 @@ void AnimationNodeStateMachineEditor::_add_transition(const bool p_nested_action
 			updating = false;
 		}

-		selected_transition_from = connecting_from;
-		selected_transition_to = connecting_to_node;
-		selected_transition_index = transition_lines.size();
+		_select_transition(connecting_from, connecting_to_node);

 		if (!state_machine->is_transition_across_group(selected_transition_index)) {
 			EditorNode::get_singleton()->push_item(tr.ptr(), "", true);
@@ -850,7 +1047,7 @@ void AnimationNodeStateMachineEditor::_add_transition(const bool p_nested_action
 	connecting = false;
 }

-void AnimationNodeStateMachineEditor::_connection_draw(const Vector2 &p_from, const Vector2 &p_to, AnimationNodeStateMachineTransition::SwitchMode p_mode, bool p_enabled, bool p_selected, bool p_travel, float p_fade_ratio, bool p_auto_advance, bool p_is_across_group, float p_opacity) {
+void AnimationNodeStateMachineEditor::_connection_draw(const Vector2 &p_from, const Vector2 &p_to, AnimationNodeStateMachineTransition::SwitchMode p_mode, bool p_enabled, bool p_selected, bool p_travel, float p_fade_ratio, bool p_auto_advance, bool p_is_across_group, float p_opacity, bool p_endpoint_hovered, bool p_endpoint_hovered_start) {
 	Color line_color = p_enabled ? theme_cache.transition_color : theme_cache.transition_disabled_color;
 	Color icon_color = p_enabled ? theme_cache.transition_icon_color : theme_cache.transition_icon_disabled_color;
 	Color highlight_color = p_enabled ? theme_cache.highlight_color : theme_cache.highlight_disabled_color;
@@ -863,6 +1060,51 @@ void AnimationNodeStateMachineEditor::_connection_draw(const Vector2 &p_from, co
 		line_color = highlight_color;
 	}

+	// Add gradient on hovered endpoint.
+	if (p_endpoint_hovered) {
+		// Calculate gradient length based on transition length.
+		float transition_length = p_from.distance_to(p_to);
+		float gradient_distance = MIN(20.0f, transition_length * 0.2f);
+
+		Vector2 gradient_start;
+		Vector2 gradient_end;
+		if (p_endpoint_hovered_start) {
+			gradient_start = p_from;
+			gradient_end = p_from + (p_to - p_from).normalized() * gradient_distance;
+		} else {
+			gradient_end = p_to;
+			gradient_start = p_to - (p_to - p_from).normalized() * gradient_distance;
+		}
+
+		PackedVector2Array points;
+		PackedColorArray colors;
+
+		points.push_back(gradient_start);
+		points.push_back(gradient_end);
+
+		Color start_color = highlight_color;
+		Color end_color = highlight_color;
+
+		if (p_endpoint_hovered_start) {
+			end_color.a = 0.0f;
+		} else {
+			start_color.a = 0.0f;
+		}
+
+		if (p_selected) {
+			start_color = start_color.lightened(0.2f);
+			end_color = end_color.lightened(0.2f);
+			start_color.a *= 1.5f;
+			end_color.a *= 1.5f;
+		}
+
+		colors.push_back(start_color);
+		colors.push_back(end_color);
+
+		float line_width = p_selected ? 10.0f : 8.0f;
+		state_machine_draw->draw_polyline_colors(points, colors, line_width, true);
+	}
+
 	if (p_selected) {
 		state_machine_draw->draw_line(p_from, p_to, highlight_color, 6, true);
 	}
@@ -1124,7 +1366,44 @@ void AnimationNodeStateMachineEditor::_state_machine_draw() {

 	for (int i = 0; i < transition_lines.size(); i++) {
 		TransitionLine tl = transition_lines[i];
-		if (!tl.hidden) {
+
+		if (reconnecting && i == reconnecting_transition_index) {
+			Vector2 transition_drag_from;
+			Vector2 transition_drag_to;
+
+			if (reconnecting_transition_start) {
+				transition_drag_from = reconnecting_transition_pos;
+				transition_drag_to = (state_machine->get_node_position(tl.to_node) * EDSCALE) - state_machine->get_graph_offset() * EDSCALE;
+			} else {
+				transition_drag_from = (state_machine->get_node_position(tl.from_node) * EDSCALE) - state_machine->get_graph_offset() * EDSCALE;
+				transition_drag_to = reconnecting_transition_pos;
+			}
+
+			// Check if we're attempting a self-connection.
+			StringName connected_node = reconnecting_transition_start ? tl.to_node : tl.from_node;
+
+			// Don't draw the line if attempting self-connection.
+			if (reconnecting_transition_target != connected_node) {
+				if (reconnecting_from_node_rect_index >= 0) {
+					if (reconnecting_transition_start) {
+						_clip_dst_line_to_rect(transition_drag_from, transition_drag_to, node_rects[reconnecting_from_node_rect_index].node);
+					} else {
+						_clip_src_line_to_rect(transition_drag_from, transition_drag_to, node_rects[reconnecting_from_node_rect_index].node);
+					}
+				}
+
+				if (reconnecting_to_node_rect_index >= 0) {
+					if (reconnecting_transition_start) {
+						_clip_src_line_to_rect(transition_drag_from, transition_drag_to, node_rects[reconnecting_to_node_rect_index].node);
+					} else {
+						_clip_dst_line_to_rect(transition_drag_from, transition_drag_to, node_rects[reconnecting_to_node_rect_index].node);
+					}
+				}
+
+				_connection_draw(transition_drag_from, transition_drag_to, tl.mode, !tl.disabled, false, false, 0.0f, tl.auto_advance, tl.is_across_group, 0.8f, false, false);
+			}
+
+		} else if (!tl.hidden) {
 			float opacity = 0.2; // Default to reduced opacity.

 			if (selected_transition_from != StringName() && selected_transition_to != StringName()) {
@@ -1148,7 +1427,8 @@ void AnimationNodeStateMachineEditor::_state_machine_draw() {
 				opacity = 1.0;
 			}

-			_connection_draw(tl.from, tl.to, tl.mode, !tl.disabled, tl.selected, tl.travel, tl.fade_ratio, tl.auto_advance, tl.is_across_group, opacity);
+			bool is_hovered = (hovered_transition_index == i);
+			_connection_draw(tl.from, tl.to, tl.mode, !tl.disabled, tl.selected, tl.travel, tl.fade_ratio, tl.auto_advance, tl.is_across_group, opacity, is_hovered, hovered_transition_start);
 		}
 	}

@@ -1699,6 +1979,7 @@ void AnimationNodeStateMachineEditor::_update_mode() {

 void AnimationNodeStateMachineEditor::_bind_methods() {
 	ClassDB::bind_method("_update_graph", &AnimationNodeStateMachineEditor::_update_graph);
+	ClassDB::bind_method("_select_transition", &AnimationNodeStateMachineEditor::_select_transition);

 	BIND_THEME_ITEM_EXT(Theme::DATA_TYPE_STYLEBOX, AnimationNodeStateMachineEditor, panel_style, "panel", "GraphStateMachine");
 	BIND_THEME_ITEM_EXT(Theme::DATA_TYPE_STYLEBOX, AnimationNodeStateMachineEditor, error_panel_style, "error_panel", "GraphStateMachine");