godot/scene/3d/shape_cast_3d.cpp
Rémi Verschelde d95794ec8a
One Copyright Update to rule them all
As many open source projects have started doing it, we're removing the
current year from the copyright notice, so that we don't need to bump
it every year.

It seems like only the first year of publication is technically
relevant for copyright notices, and even that seems to be something
that many companies stopped listing altogether (in a version controlled
codebase, the commits are a much better source of date of publication
than a hardcoded copyright statement).

We also now list Godot Engine contributors first as we're collectively
the current maintainers of the project, and we clarify that the
"exclusive" copyright of the co-founders covers the timespan before
opensourcing (their further contributions are included as part of Godot
Engine contributors).

Also fixed "cf." Frenchism - it's meant as "refer to / see".
2023-01-05 13:25:55 +01:00

641 lines
21 KiB
C++

/**************************************************************************/
/* shape_cast_3d.cpp */
/**************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* https://godotengine.org */
/**************************************************************************/
/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur. */
/* */
/* Permission is hereby granted, free of charge, to any person obtaining */
/* a copy of this software and associated documentation files (the */
/* "Software"), to deal in the Software without restriction, including */
/* without limitation the rights to use, copy, modify, merge, publish, */
/* distribute, sublicense, and/or sell copies of the Software, and to */
/* permit persons to whom the Software is furnished to do so, subject to */
/* the following conditions: */
/* */
/* The above copyright notice and this permission notice shall be */
/* included in all copies or substantial portions of the Software. */
/* */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. */
/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */
/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, */
/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */
/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
/**************************************************************************/
#include "shape_cast_3d.h"
#include "collision_object_3d.h"
#include "mesh_instance_3d.h"
#include "scene/resources/concave_polygon_shape_3d.h"
void ShapeCast3D::_notification(int p_what) {
switch (p_what) {
case NOTIFICATION_ENTER_TREE: {
if (Engine::get_singleton()->is_editor_hint()) {
_update_debug_shape_vertices();
}
if (enabled && !Engine::get_singleton()->is_editor_hint()) {
set_physics_process_internal(true);
} else {
set_physics_process_internal(false);
}
if (get_tree()->is_debugging_collisions_hint()) {
_update_debug_shape();
}
if (Object::cast_to<CollisionObject3D>(get_parent())) {
if (exclude_parent_body) {
exclude.insert(Object::cast_to<CollisionObject3D>(get_parent())->get_rid());
} else {
exclude.erase(Object::cast_to<CollisionObject3D>(get_parent())->get_rid());
}
}
} break;
case NOTIFICATION_EXIT_TREE: {
if (enabled) {
set_physics_process_internal(false);
}
if (debug_shape) {
_clear_debug_shape();
}
} break;
case NOTIFICATION_INTERNAL_PHYSICS_PROCESS: {
if (!enabled) {
break;
}
bool prev_collision_state = collided;
_update_shapecast_state();
if (get_tree()->is_debugging_collisions_hint()) {
if (prev_collision_state != collided) {
_update_debug_shape_material(true);
}
if (collided) {
_update_debug_shape();
}
if (prev_collision_state == collided && !collided) {
_update_debug_shape();
}
}
} break;
}
}
void ShapeCast3D::_bind_methods() {
ClassDB::bind_method(D_METHOD("resource_changed", "resource"), &ShapeCast3D::resource_changed);
ClassDB::bind_method(D_METHOD("set_enabled", "enabled"), &ShapeCast3D::set_enabled);
ClassDB::bind_method(D_METHOD("is_enabled"), &ShapeCast3D::is_enabled);
ClassDB::bind_method(D_METHOD("set_shape", "shape"), &ShapeCast3D::set_shape);
ClassDB::bind_method(D_METHOD("get_shape"), &ShapeCast3D::get_shape);
ClassDB::bind_method(D_METHOD("set_target_position", "local_point"), &ShapeCast3D::set_target_position);
ClassDB::bind_method(D_METHOD("get_target_position"), &ShapeCast3D::get_target_position);
ClassDB::bind_method(D_METHOD("set_margin", "margin"), &ShapeCast3D::set_margin);
ClassDB::bind_method(D_METHOD("get_margin"), &ShapeCast3D::get_margin);
ClassDB::bind_method(D_METHOD("set_max_results", "max_results"), &ShapeCast3D::set_max_results);
ClassDB::bind_method(D_METHOD("get_max_results"), &ShapeCast3D::get_max_results);
ClassDB::bind_method(D_METHOD("is_colliding"), &ShapeCast3D::is_colliding);
ClassDB::bind_method(D_METHOD("get_collision_count"), &ShapeCast3D::get_collision_count);
ClassDB::bind_method(D_METHOD("force_shapecast_update"), &ShapeCast3D::force_shapecast_update);
ClassDB::bind_method(D_METHOD("get_collider", "index"), &ShapeCast3D::get_collider);
ClassDB::bind_method(D_METHOD("get_collider_rid", "index"), &ShapeCast3D::get_collider_rid);
ClassDB::bind_method(D_METHOD("get_collider_shape", "index"), &ShapeCast3D::get_collider_shape);
ClassDB::bind_method(D_METHOD("get_collision_point", "index"), &ShapeCast3D::get_collision_point);
ClassDB::bind_method(D_METHOD("get_collision_normal", "index"), &ShapeCast3D::get_collision_normal);
ClassDB::bind_method(D_METHOD("get_closest_collision_safe_fraction"), &ShapeCast3D::get_closest_collision_safe_fraction);
ClassDB::bind_method(D_METHOD("get_closest_collision_unsafe_fraction"), &ShapeCast3D::get_closest_collision_unsafe_fraction);
ClassDB::bind_method(D_METHOD("add_exception_rid", "rid"), &ShapeCast3D::add_exception_rid);
ClassDB::bind_method(D_METHOD("add_exception", "node"), &ShapeCast3D::add_exception);
ClassDB::bind_method(D_METHOD("remove_exception_rid", "rid"), &ShapeCast3D::remove_exception_rid);
ClassDB::bind_method(D_METHOD("remove_exception", "node"), &ShapeCast3D::remove_exception);
ClassDB::bind_method(D_METHOD("clear_exceptions"), &ShapeCast3D::clear_exceptions);
ClassDB::bind_method(D_METHOD("set_collision_mask", "mask"), &ShapeCast3D::set_collision_mask);
ClassDB::bind_method(D_METHOD("get_collision_mask"), &ShapeCast3D::get_collision_mask);
ClassDB::bind_method(D_METHOD("set_collision_mask_value", "layer_number", "value"), &ShapeCast3D::set_collision_mask_value);
ClassDB::bind_method(D_METHOD("get_collision_mask_value", "layer_number"), &ShapeCast3D::get_collision_mask_value);
ClassDB::bind_method(D_METHOD("set_exclude_parent_body", "mask"), &ShapeCast3D::set_exclude_parent_body);
ClassDB::bind_method(D_METHOD("get_exclude_parent_body"), &ShapeCast3D::get_exclude_parent_body);
ClassDB::bind_method(D_METHOD("set_collide_with_areas", "enable"), &ShapeCast3D::set_collide_with_areas);
ClassDB::bind_method(D_METHOD("is_collide_with_areas_enabled"), &ShapeCast3D::is_collide_with_areas_enabled);
ClassDB::bind_method(D_METHOD("set_collide_with_bodies", "enable"), &ShapeCast3D::set_collide_with_bodies);
ClassDB::bind_method(D_METHOD("is_collide_with_bodies_enabled"), &ShapeCast3D::is_collide_with_bodies_enabled);
ClassDB::bind_method(D_METHOD("_get_collision_result"), &ShapeCast3D::_get_collision_result);
ClassDB::bind_method(D_METHOD("set_debug_shape_custom_color", "debug_shape_custom_color"), &ShapeCast3D::set_debug_shape_custom_color);
ClassDB::bind_method(D_METHOD("get_debug_shape_custom_color"), &ShapeCast3D::get_debug_shape_custom_color);
ADD_PROPERTY(PropertyInfo(Variant::BOOL, "enabled"), "set_enabled", "is_enabled");
ADD_PROPERTY(PropertyInfo(Variant::OBJECT, "shape", PROPERTY_HINT_RESOURCE_TYPE, "Shape3D"), "set_shape", "get_shape");
ADD_PROPERTY(PropertyInfo(Variant::BOOL, "exclude_parent"), "set_exclude_parent_body", "get_exclude_parent_body");
ADD_PROPERTY(PropertyInfo(Variant::VECTOR3, "target_position", PROPERTY_HINT_NONE, "suffix:m"), "set_target_position", "get_target_position");
ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "margin", PROPERTY_HINT_RANGE, "0,100,0.01,suffix:m"), "set_margin", "get_margin");
ADD_PROPERTY(PropertyInfo(Variant::INT, "max_results"), "set_max_results", "get_max_results");
ADD_PROPERTY(PropertyInfo(Variant::INT, "collision_mask", PROPERTY_HINT_LAYERS_3D_PHYSICS), "set_collision_mask", "get_collision_mask");
ADD_PROPERTY(PropertyInfo(Variant::ARRAY, "collision_result", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_NO_EDITOR), "", "_get_collision_result");
ADD_GROUP("Collide With", "collide_with");
ADD_PROPERTY(PropertyInfo(Variant::BOOL, "collide_with_areas", PROPERTY_HINT_LAYERS_3D_PHYSICS), "set_collide_with_areas", "is_collide_with_areas_enabled");
ADD_PROPERTY(PropertyInfo(Variant::BOOL, "collide_with_bodies", PROPERTY_HINT_LAYERS_3D_PHYSICS), "set_collide_with_bodies", "is_collide_with_bodies_enabled");
ADD_GROUP("Debug Shape", "debug_shape");
ADD_PROPERTY(PropertyInfo(Variant::COLOR, "debug_shape_custom_color"), "set_debug_shape_custom_color", "get_debug_shape_custom_color");
}
PackedStringArray ShapeCast3D::get_configuration_warnings() const {
PackedStringArray warnings = Node3D::get_configuration_warnings();
if (shape.is_null()) {
warnings.push_back(RTR("This node cannot interact with other objects unless a Shape3D is assigned."));
}
if (shape.is_valid() && Object::cast_to<ConcavePolygonShape3D>(*shape)) {
warnings.push_back(RTR("ShapeCast3D does not support ConcavePolygonShape3Ds. Collisions will not be reported."));
}
return warnings;
}
void ShapeCast3D::set_enabled(bool p_enabled) {
enabled = p_enabled;
update_gizmos();
if (is_inside_tree() && !Engine::get_singleton()->is_editor_hint()) {
set_physics_process_internal(p_enabled);
}
if (!p_enabled) {
collided = false;
}
if (is_inside_tree() && get_tree()->is_debugging_collisions_hint()) {
if (p_enabled) {
_update_debug_shape();
} else {
_clear_debug_shape();
}
}
}
bool ShapeCast3D::is_enabled() const {
return enabled;
}
void ShapeCast3D::set_target_position(const Vector3 &p_point) {
target_position = p_point;
if (is_inside_tree() && get_tree()->is_debugging_collisions_hint()) {
_update_debug_shape();
}
update_gizmos();
if (Engine::get_singleton()->is_editor_hint()) {
if (is_inside_tree()) {
_update_debug_shape_vertices();
}
} else if (debug_shape) {
_update_debug_shape();
}
}
Vector3 ShapeCast3D::get_target_position() const {
return target_position;
}
void ShapeCast3D::set_margin(real_t p_margin) {
margin = p_margin;
}
real_t ShapeCast3D::get_margin() const {
return margin;
}
void ShapeCast3D::set_max_results(int p_max_results) {
max_results = p_max_results;
}
int ShapeCast3D::get_max_results() const {
return max_results;
}
void ShapeCast3D::set_collision_mask(uint32_t p_mask) {
collision_mask = p_mask;
}
uint32_t ShapeCast3D::get_collision_mask() const {
return collision_mask;
}
void ShapeCast3D::set_collision_mask_value(int p_layer_number, bool p_value) {
ERR_FAIL_COND_MSG(p_layer_number < 1, "Collision layer number must be between 1 and 32 inclusive.");
ERR_FAIL_COND_MSG(p_layer_number > 32, "Collision layer number must be between 1 and 32 inclusive.");
uint32_t mask = get_collision_mask();
if (p_value) {
mask |= 1 << (p_layer_number - 1);
} else {
mask &= ~(1 << (p_layer_number - 1));
}
set_collision_mask(mask);
}
bool ShapeCast3D::get_collision_mask_value(int p_layer_number) const {
ERR_FAIL_COND_V_MSG(p_layer_number < 1, false, "Collision layer number must be between 1 and 32 inclusive.");
ERR_FAIL_COND_V_MSG(p_layer_number > 32, false, "Collision layer number must be between 1 and 32 inclusive.");
return get_collision_mask() & (1 << (p_layer_number - 1));
}
int ShapeCast3D::get_collision_count() const {
return result.size();
}
bool ShapeCast3D::is_colliding() const {
return collided;
}
Object *ShapeCast3D::get_collider(int p_idx) const {
ERR_FAIL_INDEX_V_MSG(p_idx, result.size(), nullptr, "No collider found.");
if (result[p_idx].collider_id.is_null()) {
return nullptr;
}
return ObjectDB::get_instance(result[p_idx].collider_id);
}
RID ShapeCast3D::get_collider_rid(int p_idx) const {
ERR_FAIL_INDEX_V_MSG(p_idx, result.size(), RID(), "No collider RID found.");
return result[p_idx].rid;
}
int ShapeCast3D::get_collider_shape(int p_idx) const {
ERR_FAIL_INDEX_V_MSG(p_idx, result.size(), -1, "No collider shape found.");
return result[p_idx].shape;
}
Vector3 ShapeCast3D::get_collision_point(int p_idx) const {
ERR_FAIL_INDEX_V_MSG(p_idx, result.size(), Vector3(), "No collision point found.");
return result[p_idx].point;
}
Vector3 ShapeCast3D::get_collision_normal(int p_idx) const {
ERR_FAIL_INDEX_V_MSG(p_idx, result.size(), Vector3(), "No collision normal found.");
return result[p_idx].normal;
}
real_t ShapeCast3D::get_closest_collision_safe_fraction() const {
return collision_safe_fraction;
}
real_t ShapeCast3D::get_closest_collision_unsafe_fraction() const {
return collision_unsafe_fraction;
}
void ShapeCast3D::resource_changed(Ref<Resource> p_res) {
if (is_inside_tree() && get_tree()->is_debugging_collisions_hint()) {
_update_debug_shape();
}
update_gizmos();
}
void ShapeCast3D::set_shape(const Ref<Shape3D> &p_shape) {
if (p_shape == shape) {
return;
}
if (!shape.is_null()) {
shape->unregister_owner(this);
}
shape = p_shape;
if (!shape.is_null()) {
shape->register_owner(this);
}
if (p_shape.is_valid()) {
shape_rid = shape->get_rid();
}
if (is_inside_tree() && get_tree()->is_debugging_collisions_hint()) {
_update_debug_shape();
}
update_gizmos();
update_configuration_warnings();
}
Ref<Shape3D> ShapeCast3D::get_shape() const {
return shape;
}
void ShapeCast3D::set_exclude_parent_body(bool p_exclude_parent_body) {
if (exclude_parent_body == p_exclude_parent_body) {
return;
}
exclude_parent_body = p_exclude_parent_body;
if (!is_inside_tree()) {
return;
}
if (Object::cast_to<CollisionObject3D>(get_parent())) {
if (exclude_parent_body) {
exclude.insert(Object::cast_to<CollisionObject3D>(get_parent())->get_rid());
} else {
exclude.erase(Object::cast_to<CollisionObject3D>(get_parent())->get_rid());
}
}
}
bool ShapeCast3D::get_exclude_parent_body() const {
return exclude_parent_body;
}
void ShapeCast3D::_update_shapecast_state() {
result.clear();
ERR_FAIL_COND_MSG(shape.is_null(), "Null reference to shape. ShapeCast3D requires a Shape3D to sweep for collisions.");
Ref<World3D> w3d = get_world_3d();
ERR_FAIL_COND(w3d.is_null());
PhysicsDirectSpaceState3D *dss = PhysicsServer3D::get_singleton()->space_get_direct_state(w3d->get_space());
ERR_FAIL_COND(!dss);
Transform3D gt = get_global_transform();
PhysicsDirectSpaceState3D::ShapeParameters params;
params.shape_rid = shape_rid;
params.transform = gt;
params.motion = gt.basis.xform(target_position);
params.margin = margin;
params.exclude = exclude;
params.collision_mask = collision_mask;
params.collide_with_bodies = collide_with_bodies;
params.collide_with_areas = collide_with_areas;
collision_safe_fraction = 0.0;
collision_unsafe_fraction = 0.0;
if (target_position != Vector3()) {
dss->cast_motion(params, collision_safe_fraction, collision_unsafe_fraction);
if (collision_unsafe_fraction < 1.0) {
// Move shape transform to the point of impact,
// so we can collect contact info at that point.
gt.set_origin(gt.get_origin() + params.motion * (collision_unsafe_fraction + CMP_EPSILON));
params.transform = gt;
}
}
// Regardless of whether the shape is stuck or it's moved along
// the motion vector, we'll only consider static collisions from now on.
params.motion = Vector3();
bool intersected = true;
while (intersected && result.size() < max_results) {
PhysicsDirectSpaceState3D::ShapeRestInfo info;
intersected = dss->rest_info(params, &info);
if (intersected) {
result.push_back(info);
params.exclude.insert(info.rid);
}
}
collided = !result.is_empty();
}
void ShapeCast3D::force_shapecast_update() {
_update_shapecast_state();
}
void ShapeCast3D::add_exception_rid(const RID &p_rid) {
exclude.insert(p_rid);
}
void ShapeCast3D::add_exception(const Object *p_object) {
ERR_FAIL_NULL(p_object);
const CollisionObject3D *co = Object::cast_to<CollisionObject3D>(p_object);
if (!co) {
return;
}
add_exception_rid(co->get_rid());
}
void ShapeCast3D::remove_exception_rid(const RID &p_rid) {
exclude.erase(p_rid);
}
void ShapeCast3D::remove_exception(const Object *p_object) {
ERR_FAIL_NULL(p_object);
const CollisionObject3D *co = Object::cast_to<CollisionObject3D>(p_object);
if (!co) {
return;
}
remove_exception_rid(co->get_rid());
}
void ShapeCast3D::clear_exceptions() {
exclude.clear();
}
void ShapeCast3D::set_collide_with_areas(bool p_clip) {
collide_with_areas = p_clip;
}
bool ShapeCast3D::is_collide_with_areas_enabled() const {
return collide_with_areas;
}
void ShapeCast3D::set_collide_with_bodies(bool p_clip) {
collide_with_bodies = p_clip;
}
bool ShapeCast3D::is_collide_with_bodies_enabled() const {
return collide_with_bodies;
}
Array ShapeCast3D::_get_collision_result() const {
Array ret;
for (int i = 0; i < result.size(); ++i) {
const PhysicsDirectSpaceState3D::ShapeRestInfo &sri = result[i];
Dictionary col;
col["point"] = sri.point;
col["normal"] = sri.normal;
col["rid"] = sri.rid;
col["collider"] = ObjectDB::get_instance(sri.collider_id);
col["collider_id"] = sri.collider_id;
col["shape"] = sri.shape;
col["linear_velocity"] = sri.linear_velocity;
ret.push_back(col);
}
return ret;
}
void ShapeCast3D::_update_debug_shape_vertices() {
debug_shape_vertices.clear();
debug_line_vertices.clear();
if (!shape.is_null()) {
debug_shape_vertices.append_array(shape->get_debug_mesh_lines());
for (int i = 0; i < debug_shape_vertices.size(); i++) {
debug_shape_vertices.set(i, debug_shape_vertices[i] + Vector3(target_position * get_closest_collision_safe_fraction()));
}
}
if (target_position == Vector3()) {
return;
}
debug_line_vertices.push_back(Vector3());
debug_line_vertices.push_back(target_position);
}
const Vector<Vector3> &ShapeCast3D::get_debug_shape_vertices() const {
return debug_shape_vertices;
}
const Vector<Vector3> &ShapeCast3D::get_debug_line_vertices() const {
return debug_line_vertices;
}
void ShapeCast3D::set_debug_shape_custom_color(const Color &p_color) {
debug_shape_custom_color = p_color;
if (debug_material.is_valid()) {
_update_debug_shape_material();
}
}
Ref<StandardMaterial3D> ShapeCast3D::get_debug_material() {
_update_debug_shape_material();
return debug_material;
}
const Color &ShapeCast3D::get_debug_shape_custom_color() const {
return debug_shape_custom_color;
}
void ShapeCast3D::_create_debug_shape() {
_update_debug_shape_material();
Ref<ArrayMesh> mesh = memnew(ArrayMesh);
MeshInstance3D *mi = memnew(MeshInstance3D);
mi->set_mesh(mesh);
add_child(mi);
debug_shape = mi;
}
void ShapeCast3D::_update_debug_shape_material(bool p_check_collision) {
if (!debug_material.is_valid()) {
Ref<StandardMaterial3D> material = memnew(StandardMaterial3D);
debug_material = material;
material->set_shading_mode(StandardMaterial3D::SHADING_MODE_UNSHADED);
// Use double-sided rendering so that the RayCast can be seen if the camera is inside.
material->set_cull_mode(BaseMaterial3D::CULL_DISABLED);
material->set_transparency(BaseMaterial3D::TRANSPARENCY_ALPHA);
}
Color color = debug_shape_custom_color;
if (color == Color(0.0, 0.0, 0.0)) {
// Use the default debug shape color defined in the Project Settings.
color = get_tree()->get_debug_collisions_color();
}
if (p_check_collision && collided) {
if ((color.get_h() < 0.055 || color.get_h() > 0.945) && color.get_s() > 0.5 && color.get_v() > 0.5) {
// If base color is already quite reddish, highlight collision with green color
color = Color(0.0, 1.0, 0.0, color.a);
} else {
// Else, highlight collision with red color
color = Color(1.0, 0, 0, color.a);
}
}
Ref<StandardMaterial3D> material = static_cast<Ref<StandardMaterial3D>>(debug_material);
material->set_albedo(color);
}
void ShapeCast3D::_update_debug_shape() {
if (!enabled) {
return;
}
if (!debug_shape) {
_create_debug_shape();
}
_update_debug_shape_vertices();
if (Engine::get_singleton()->is_editor_hint()) {
return;
}
MeshInstance3D *mi = static_cast<MeshInstance3D *>(debug_shape);
Ref<ArrayMesh> mesh = mi->get_mesh();
if (!mesh.is_valid()) {
return;
}
mesh->clear_surfaces();
Array a;
a.resize(Mesh::ARRAY_MAX);
uint32_t flags = 0;
int surface_count = 0;
if (!debug_shape_vertices.is_empty()) {
a[Mesh::ARRAY_VERTEX] = debug_shape_vertices;
mesh->add_surface_from_arrays(Mesh::PRIMITIVE_LINES, a, Array(), Dictionary(), flags);
mesh->surface_set_material(surface_count, debug_material);
++surface_count;
}
if (!debug_line_vertices.is_empty()) {
a[Mesh::ARRAY_VERTEX] = debug_line_vertices;
mesh->add_surface_from_arrays(Mesh::PRIMITIVE_LINES, a, Array(), Dictionary(), flags);
mesh->surface_set_material(surface_count, debug_material);
++surface_count;
}
}
void ShapeCast3D::_clear_debug_shape() {
if (!debug_shape) {
return;
}
MeshInstance3D *mi = static_cast<MeshInstance3D *>(debug_shape);
if (mi->is_inside_tree()) {
mi->queue_free();
} else {
memdelete(mi);
}
debug_shape = nullptr;
}
ShapeCast3D::~ShapeCast3D() {
if (!shape.is_null()) {
shape->unregister_owner(this);
}
}