text: /*************************************************************************/
  /*  world_2d.cpp                                                         */
  /*************************************************************************/
  /*                       This file is part of:                           */
  /*                           GODOT ENGINE                                */
  /*                    http://www.godotengine.org                         */
  /*************************************************************************/
  /* Copyright (c) 2007-2017 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 "world_2d.h"
  #include "servers/visual_server.h"
  #include "servers/physics_2d_server.h"
  //#include "servers/spatial_sound_2d_server.h"
  #include "globals.h"
  #include "scene/2d/visibility_notifier_2d.h"
  #include "scene/main/viewport.h"
  #include "scene/2d/camera_2d.h"
  #include "globals.h"
  
  struct SpatialIndexer2D {
  
  
  	struct CellRef {
  
  		int ref;
  
  		_FORCE_INLINE_ int inc() {
  			ref++;
  			return ref;
  		}
  		_FORCE_INLINE_ int dec() {
  			ref--;
  			return ref;
  		}
  
  		_FORCE_INLINE_ CellRef() {
  			ref=0;
  		}
  	};
  
  
  
  	struct CellKey {
  
  		union {
  			struct {
  				int32_t x;
  				int32_t y;
  			};
  			uint64_t key;
  		};
  
  		bool operator==(const CellKey& p_key) const { return key==p_key.key; }
  		_FORCE_INLINE_ bool operator<(const CellKey& p_key) const {
  			return key < p_key.key;
  		}
  
  	};
  
  	struct CellData {
  
  		Map<VisibilityNotifier2D*,CellRef> notifiers;
  	};
  
  
  	Map<CellKey,CellData> cells;
  	int cell_size;
  
  	Map<VisibilityNotifier2D*,Rect2> notifiers;
  
  	struct ViewportData {
  
  		Map<VisibilityNotifier2D*,uint64_t> notifiers;
  		Rect2 rect;
  	};
  
  	Map<Viewport*,ViewportData> viewports;
  
  	bool changed;
  
  	uint64_t pass;
  
  
  	void _notifier_update_cells(VisibilityNotifier2D *p_notifier,const Rect2& p_rect,bool p_add) {
  
  		Point2i begin = p_rect.pos;
  		begin/=cell_size;
  		Point2i end = p_rect.pos+p_rect.size;
  		end/=cell_size;
  		for(int i=begin.x;i<=end.x;i++) {
  
  			for(int j=begin.y;j<=end.y;j++) {
  
  				CellKey ck;
  				ck.x=i;
  				ck.y=j;
  				Map<CellKey,CellData>::Element *E=cells.find(ck);
  
  				if (p_add) {
  
  					if (!E)
  						E=cells.insert(ck,CellData());
  					E->get().notifiers[p_notifier].inc();
  				} else {
  
  					ERR_CONTINUE(!E);
  					if (E->get().notifiers[p_notifier].dec()==0) {
  
  						E->get().notifiers.erase(p_notifier);
  						if (E->get().notifiers.empty()) {
  							cells.erase(E);
  						}
  					}
  				}
  			}
  		}
  	}
  
  	void _notifier_add(VisibilityNotifier2D* p_notifier,const Rect2& p_rect) {
  
  		ERR_FAIL_COND(notifiers.has(p_notifier));
  		notifiers[p_notifier]=p_rect;
  		_notifier_update_cells(p_notifier,p_rect,true);
  		changed=true;
  	}
  
  	void _notifier_update(VisibilityNotifier2D* p_notifier,const Rect2& p_rect) {
  
  		Map<VisibilityNotifier2D*,Rect2>::Element *E=notifiers.find(p_notifier);
  		ERR_FAIL_COND(!E);
  		if (E->get()==p_rect)
  			return;
  
  		_notifier_update_cells(p_notifier,p_rect,true);
  		_notifier_update_cells(p_notifier,E->get(),false);
  		E->get()=p_rect;
  		changed=true;
  	}
  
  	void _notifier_remove(VisibilityNotifier2D* p_notifier) {
  
  		Map<VisibilityNotifier2D*,Rect2>::Element *E=notifiers.find(p_notifier);
  		ERR_FAIL_COND(!E);
  		_notifier_update_cells(p_notifier,E->get(),false);
  		notifiers.erase(p_notifier);
  
  		List<Viewport*> removed;
  		for (Map<Viewport*,ViewportData>::Element*F=viewports.front();F;F=F->next()) {
  
  			Map<VisibilityNotifier2D*,uint64_t>::Element*G=F->get().notifiers.find(p_notifier);
  
  			if (G) {
  				F->get().notifiers.erase(G);
  				removed.push_back(F->key());
  			}
  		}
  
  		while(!removed.empty()) {
  
  			p_notifier->_exit_viewport(removed.front()->get());
  			removed.pop_front();
  		}
  
  		changed=true;
  	}
  
  	void _add_viewport(Viewport* p_viewport,const Rect2& p_rect) {
  
  		ERR_FAIL_COND(viewports.has(p_viewport));
  		ViewportData vd;
  		vd.rect=p_rect;
  		viewports[p_viewport]=vd;
  		changed=true;
  
  	}
  
  	void _update_viewport(Viewport* p_viewport, const Rect2& p_rect) {
  
  		Map<Viewport*,ViewportData>::Element *E= viewports.find(p_viewport);
  		ERR_FAIL_COND(!E);
  		if (E->get().rect==p_rect)
  			return;
  		E->get().rect=p_rect;
  		changed=true;
  	}
  
  	void _remove_viewport(Viewport* p_viewport) {
  		ERR_FAIL_COND(!viewports.has(p_viewport));
  		List<VisibilityNotifier2D*> removed;
  		for(Map<VisibilityNotifier2D*,uint64_t>::Element *E=viewports[p_viewport].notifiers.front();E;E=E->next()) {
  
  			removed.push_back(E->key());
  		}
  
  		while(!removed.empty()) {
  			removed.front()->get()->_exit_viewport(p_viewport);
  			removed.pop_front();
  		}
  
  		viewports.erase(p_viewport);
  	}
  
  	void _update() {
  
  
  		if (!changed)
  			return;
  
  		for (Map<Viewport*,ViewportData>::Element *E=viewports.front();E;E=E->next()) {
  
  			Point2i begin = E->get().rect.pos;
  			begin/=cell_size;
  			Point2i end = E->get().rect.pos+E->get().rect.size;
  			end/=cell_size;
  			pass++;
  			List<VisibilityNotifier2D*> added;
  			List<VisibilityNotifier2D*> removed;
  
  			int visible_cells=(end.x-begin.x)*(end.y-begin.y);
  
  			if (visible_cells>10000) {
  
  				//well you zoomed out a lot, it's your problem. To avoid freezing in the for loops below, we'll manually check cell by cell
  
  				for (Map<CellKey,CellData>::Element *F=cells.front();F;F=F->next()) {
  
  					const CellKey &ck=F->key();
  
  					if (ck.x<begin.x || ck.x>end.x)
  						continue;
  					if (ck.y<begin.y || ck.y>end.y)
  						continue;
  
  					//notifiers in cell
  					for (Map<VisibilityNotifier2D*,CellRef>::Element *G=F->get().notifiers.front();G;G=G->next()) {
  
  						Map<VisibilityNotifier2D*,uint64_t>::Element *H=E->get().notifiers.find(G->key());
  						if (!H) {
  
  							H=E->get().notifiers.insert(G->key(),pass);
  							added.push_back(G->key());
  						} else {
  							H->get()=pass;
  						}
  					}
  				}
  
  			} else {
  
  				//check cells in grid fashion
  				for(int i=begin.x;i<=end.x;i++) {
  
  					for(int j=begin.y;j<=end.y;j++) {
  
  						CellKey ck;
  						ck.x=i;
  						ck.y=j;
  
  						Map<CellKey,CellData>::Element *F=cells.find(ck);
  						if (!F) {
  							continue;
  						}
  
  
  						//notifiers in cell
  						for (Map<VisibilityNotifier2D*,CellRef>::Element *G=F->get().notifiers.front();G;G=G->next()) {
  
  							Map<VisibilityNotifier2D*,uint64_t>::Element *H=E->get().notifiers.find(G->key());
  							if (!H) {
  
  								H=E->get().notifiers.insert(G->key(),pass);
  								added.push_back(G->key());
  							} else {
  								H->get()=pass;
  							}
  						}
  					}
  				}
  			}
  
  			for (Map<VisibilityNotifier2D*,uint64_t>::Element *F=E->get().notifiers.front();F;F=F->next()) {
  
  				if (F->get()!=pass)
  					removed.push_back(F->key());
  			}
  
  			while(!added.empty()) {
  				added.front()->get()->_enter_viewport(E->key());
  				added.pop_front();
  			}
  
  			while(!removed.empty()) {
  				E->get().notifiers.erase(removed.front()->get());
  				removed.front()->get()->_exit_viewport(E->key());
  				removed.pop_front();
  			}
  		}
  
  		changed=false;
  	}
  
  
  	SpatialIndexer2D() {
  
  		pass=0;
  		changed=false;
  		cell_size=100; //should be configurable with GLOBAL_DEF("") i guess
  	}
  
  };
  
  
  
  void World2D::_register_viewport(Viewport* p_viewport,const Rect2& p_rect) {
  
  	indexer->_add_viewport(p_viewport,p_rect);
  }
  
  void World2D::_update_viewport(Viewport* p_viewport,const Rect2& p_rect){
  
  	indexer->_update_viewport(p_viewport,p_rect);
  
  }
  void World2D::_remove_viewport(Viewport* p_viewport){
  
  	indexer->_remove_viewport(p_viewport);
  }
  
  void World2D::_register_notifier(VisibilityNotifier2D* p_notifier, const Rect2 &p_rect){
  
  	indexer->_notifier_add(p_notifier,p_rect);
  
  }
  void World2D::_update_notifier(VisibilityNotifier2D* p_notifier,const Rect2& p_rect){
  
  	indexer->_notifier_update(p_notifier,p_rect);
  }
  void World2D::_remove_notifier(VisibilityNotifier2D* p_notifier){
  
  	indexer->_notifier_remove(p_notifier);
  }
  
  void World2D::_update() {
  
  	indexer->_update();
  }
  
  
  RID World2D::get_canvas() {
  
  	return canvas;
  }
  
  RID World2D::get_space() {
  
  	return space;
  }
  
  RID World2D::get_sound_space() {
  
  	return sound_space;
  }
  
  void World2D::_bind_methods() {
  
  	ClassDB::bind_method(_MD("get_canvas"),&World2D::get_canvas);
  	ClassDB::bind_method(_MD("get_space"),&World2D::get_space);
  	ClassDB::bind_method(_MD("get_sound_space"),&World2D::get_sound_space);
  
  	ClassDB::bind_method(_MD("get_direct_space_state:Physics2DDirectSpaceState"),&World2D::get_direct_space_state);
  
  }
  
  Physics2DDirectSpaceState *World2D::get_direct_space_state() {
  
  	return Physics2DServer::get_singleton()->space_get_direct_state(space);
  }
  
  
  World2D::World2D() {
  
  	canvas = VisualServer::get_singleton()->canvas_create();
  	space = Physics2DServer::get_singleton()->space_create();
  
  	//set space2D to be more friendly with pixels than meters, by adjusting some constants
  	Physics2DServer::get_singleton()->space_set_active(space,true);
  	Physics2DServer::get_singleton()->area_set_param(space,Physics2DServer::AREA_PARAM_GRAVITY,GLOBAL_DEF("physics/2d/default_gravity",98));
  	Physics2DServer::get_singleton()->area_set_param(space,Physics2DServer::AREA_PARAM_GRAVITY_VECTOR,GLOBAL_DEF("physics/2d/default_gravity_vector",Vector2(0,1)));
  	Physics2DServer::get_singleton()->area_set_param(space,Physics2DServer::AREA_PARAM_LINEAR_DAMP,GLOBAL_DEF("physics/2d/default_linear_damp",0.1));
  	Physics2DServer::get_singleton()->area_set_param(space,Physics2DServer::AREA_PARAM_ANGULAR_DAMP,GLOBAL_DEF("physics/2d/default_angular_damp",1));
  	indexer = memnew( SpatialIndexer2D );
  
  }
  
  
  World2D::~World2D() {
  
  	VisualServer::get_singleton()->free(canvas);
  	Physics2DServer::get_singleton()->free(space);
  	memdelete(indexer);
  }
  