text: /*************************************************************************/
  /*  proximity_group.cpp                                                  */
  /*************************************************************************/
  /*                       This file is part of:                           */
  /*                           GODOT ENGINE                                */
  /*                      https://godotengine.org                          */
  /*************************************************************************/
  /* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur.                 */
  /* Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md).   */
  /*                                                                       */
  /* 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 "proximity_group.h"
  
  #include "core/math/math_funcs.h"
  
  void ProximityGroup::_clear_groups() {
  
  	Map<StringName, uint32_t>::Element *E;
  
  	{
  		const int size = 16;
  		StringName remove_list[size];
  		E = groups.front();
  		int num = 0;
  		while (E && num < size) {
  
  			if (E->get() != group_version) {
  				remove_list[num++] = E->key();
  			}
  
  			E = E->next();
  		}
  		for (int i = 0; i < num; i++) {
  
  			groups.erase(remove_list[i]);
  		}
  	}
  
  	if (E) {
  		_clear_groups(); // call until we go through the whole list
  	}
  }
  
  void ProximityGroup::_update_groups() {
  
  	if (grid_radius == Vector3(0, 0, 0))
  		return;
  
  	++group_version;
  
  	Vector3 pos = get_global_transform().get_origin();
  	Vector3 vcell = pos / cell_size;
  	int cell[3] = { Math::fast_ftoi(vcell.x), Math::fast_ftoi(vcell.y), Math::fast_ftoi(vcell.z) };
  
  	_add_groups(cell, group_name, 0);
  
  	_clear_groups();
  }
  
  void ProximityGroup::_add_groups(int *p_cell, String p_base, int p_depth) {
  
  	p_base = p_base + "|";
  	if (grid_radius[p_depth] == 0) {
  
  		if (p_depth == 2) {
  			_new_group(p_base);
  		} else {
  			_add_groups(p_cell, p_base, p_depth + 1);
  		}
  	}
  
  	int start = p_cell[p_depth] - grid_radius[p_depth];
  	int end = p_cell[p_depth] + grid_radius[p_depth];
  
  	for (int i = start; i <= end; i++) {
  
  		String gname = p_base + itos(i);
  		if (p_depth == 2) {
  			_new_group(gname);
  		} else {
  			_add_groups(p_cell, gname, p_depth + 1);
  		}
  	}
  }
  
  void ProximityGroup::_new_group(StringName p_name) {
  
  	const Map<StringName, uint32_t>::Element *E = groups.find(p_name);
  	if (!E) {
  		add_to_group(p_name);
  	}
  
  	groups[p_name] = group_version;
  }
  
  void ProximityGroup::_notification(int p_what) {
  
  	switch (p_what) {
  
  		case NOTIFICATION_EXIT_TREE:
  			++group_version;
  			_clear_groups();
  			break;
  		case NOTIFICATION_TRANSFORM_CHANGED:
  			_update_groups();
  			break;
  	}
  }
  
  void ProximityGroup::broadcast(String p_method, Variant p_parameters) {
  
  	Map<StringName, uint32_t>::Element *E;
  	E = groups.front();
  	while (E) {
  
  		get_tree()->call_group_flags(SceneTree::GROUP_CALL_DEFAULT, E->key(), "_proximity_group_broadcast", p_method, p_parameters);
  		E = E->next();
  	}
  }
  
  void ProximityGroup::_proximity_group_broadcast(String p_method, Variant p_parameters) {
  
  	if (dispatch_mode == MODE_PROXY) {
  		ERR_FAIL_COND(!is_inside_tree());
  		get_parent()->call(p_method, p_parameters);
  	} else {
  
  		emit_signal("broadcast", p_method, p_parameters);
  	}
  }
  
  void ProximityGroup::set_group_name(const String &p_group_name) {
  
  	group_name = p_group_name;
  }
  
  String ProximityGroup::get_group_name() const {
  
  	return group_name;
  }
  
  void ProximityGroup::set_dispatch_mode(DispatchMode p_mode) {
  
  	dispatch_mode = p_mode;
  }
  
  ProximityGroup::DispatchMode ProximityGroup::get_dispatch_mode() const {
  
  	return dispatch_mode;
  }
  
  void ProximityGroup::set_grid_radius(const Vector3 &p_radius) {
  
  	grid_radius = p_radius;
  }
  
  Vector3 ProximityGroup::get_grid_radius() const {
  
  	return grid_radius;
  }
  
  void ProximityGroup::_bind_methods() {
  
  	ClassDB::bind_method(D_METHOD("set_group_name", "name"), &ProximityGroup::set_group_name);
  	ClassDB::bind_method(D_METHOD("get_group_name"), &ProximityGroup::get_group_name);
  	ClassDB::bind_method(D_METHOD("set_dispatch_mode", "mode"), &ProximityGroup::set_dispatch_mode);
  	ClassDB::bind_method(D_METHOD("get_dispatch_mode"), &ProximityGroup::get_dispatch_mode);
  	ClassDB::bind_method(D_METHOD("set_grid_radius", "radius"), &ProximityGroup::set_grid_radius);
  	ClassDB::bind_method(D_METHOD("get_grid_radius"), &ProximityGroup::get_grid_radius);
  
  	ClassDB::bind_method(D_METHOD("broadcast", "method", "parameters"), &ProximityGroup::broadcast);
  
  	ClassDB::bind_method(D_METHOD("_proximity_group_broadcast", "method", "parameters"), &ProximityGroup::_proximity_group_broadcast);
  
  	ADD_PROPERTY(PropertyInfo(Variant::STRING, "group_name"), "set_group_name", "get_group_name");
  	ADD_PROPERTY(PropertyInfo(Variant::INT, "dispatch_mode", PROPERTY_HINT_ENUM, "Proxy,Signal"), "set_dispatch_mode", "get_dispatch_mode");
  	ADD_PROPERTY(PropertyInfo(Variant::VECTOR3, "grid_radius"), "set_grid_radius", "get_grid_radius");
  
  	ADD_SIGNAL(MethodInfo("broadcast", PropertyInfo(Variant::STRING, "method"), PropertyInfo(Variant::ARRAY, "parameters")));
  
  	BIND_ENUM_CONSTANT(MODE_PROXY);
  	BIND_ENUM_CONSTANT(MODE_SIGNAL);
  }
  
  ProximityGroup::ProximityGroup() {
  
  	group_version = 0;
  	dispatch_mode = MODE_PROXY;
  
  	cell_size = 1.0;
  	grid_radius = Vector3(1, 1, 1);
  	set_notify_transform(true);
  }
  