File indexing completed on 2024-09-08 06:38:02

 /*
     SPDX-FileCopyrightText: 2007 Vladimir Kuznetsov <ks.vladimir@gmail.com>
 
     SPDX-License-Identifier: GPL-2.0-or-later
 */
 
 /** \file world.h
  *  \brief Item, Body, Force and Tool interfaces, World class
  */
 
 #ifndef STEPCORE_WORLD_H
 #define STEPCORE_WORLD_H
 
 
 // stdc++
 #include <vector> // XXX: replace if QT is enabled
 
 // Qt
 #include <QHash>
 
 // Stepcore
 #include "types.h"
 #include "util.h"
 #include "vector.h"
 #include "object.h"
 #include "item.h"
 #include "body.h"
 #include "force.h"
 #include "joint.h"
 #include "itemgroup.h"
 
 
 // TODO: split this file
 
 namespace StepCore
 {
 
 class World;
 class Solver;
 class Item;
 class CollisionSolver;
 class ConstraintSolver;
 
 
 /** \ingroup tools
  *  \brief Interface for tools
  *
  *  Tools are not physical objects in simulation but utilities to control
  *  simulation or obtain some information
  */
 class Tool
 {
     STEPCORE_OBJECT(Tool)
 public:
     virtual ~Tool() {}
 };
 
 /** \ingroup world
  *  \brief Contains multiple Item, Solver and general properties such as time
  *  \todo Redesign to avoid variable copying (scatter/gatherVariables)
  */
 class World : public ItemGroup
 {
     /*Q_OBJECT*/
     STEPCORE_OBJECT(World)
 
 public:
     /** Constructs empty World */
     World();
     /** Constructs a copy of world (deep copy) */
     World(const World& world);
     /** Destroys World and all objects which belongs to it */
     ~World();
 
     /** Assignment operator (deep copy) */
     World& operator=(const World& world);
 
 
     /** Clear world (removes all items, solver and resets time) */
     void clear();
 
     /** Get current time */
     double time() const { return _time; }
     /** Set current time */
     void setTime(double t) { _time = t; }
 
     /** Get simulation speed scale */
     double timeScale() const { return _timeScale; }
     /** Set simulation speed scale */
     void setTimeScale(double timeScale) { _timeScale = timeScale; }
 
     /** Is errors calculation enabled */
     bool errorsCalculation() const { return _errorsCalculation; }
     /** Enable or disable errors calculation */
     void setErrorsCalculation(bool errorsCalculation) {
         _errorsCalculation = errorsCalculation; }
 
     /** Add new item to the world */
     //void addItem(Item* item);
     /** Remove item from the world (you should delete item yourself) */
     //void removeItem(Item* item);
     /** Delete item from the world (it actually deletes item) */
     //void deleteItem(Item* item) { removeItem(item); delete item; }
     /** Finds item in items() */
     //int  itemIndex(const Item* item) const;
 
     /** Get item by its index */
     //Item* item(int index) const { return _items[index]; }
     /** Get item by its name */
     //Item* item(const QString& name) const;
     /** Get object (item, solver, *Solver or world itself) by its name */
     Object* object(const QString& name);
 
     /** Get list of all items (not including sub-items) in the World */
     //const ItemList&  items() const  { return _items; }
     /** Get list of all bodies (including sub-items) in the World */
     const BodyList&  bodies() const { return _bodies; }
     /** Get list of all forces (including sub-items) in the World */
     const ForceList& forces() const { return _forces; }
     /** Get list of all joints (including sub-items) in the World */
     const JointList& joints() const { return _joints; }
 
     /** Get current Solver */
     Solver* solver() const { return _solver; }
     /** Set new Solver (and delete the old one) */
     void setSolver(Solver* solver);
     /** Get current Solver and remove it from world */
     Solver* removeSolver();
 
     /** Get current CollisionSolver */
     CollisionSolver* collisionSolver() const { return _collisionSolver; }
     /** Set new CollisionSolver (and delete the old one) */
     void setCollisionSolver(CollisionSolver* collisionSolver);
     /** Get current CollisionSolver and remove it from world */
     CollisionSolver* removeCollisionSolver();
 
     /** Get current ConstraintSolver */
     ConstraintSolver* constraintSolver() const { return _constraintSolver; }
     /** Set new ConstraintSolver (and delete the old one) */
     void setConstraintSolver(ConstraintSolver* constraintSolver);
     /** Get current ConstraintSolver and remove it from world */
     ConstraintSolver* removeConstraintSolver();
 
     /** Calculate all forces */
     int doCalcFn();
     /** Integrate.
      *  \param delta Integration interval
      *  \return the same as Solver::doEvolve
      *  \todo Provide error message
      */
     int doEvolve(double delta);
     
     /** Get evolveAbort flag (can be called from separate thread) */
     bool evolveAbort() { return _evolveAbort; }
     /** Set evolveAbort flag (can be called from separate thread). When the flag is set
      *  current (or any subsequent) doEvolve operation will be aborted as soon as possible. */
     void setEvolveAbort(bool evolveAbort = true) { _evolveAbort = evolveAbort; }
 
 private:
     friend class ItemGroup;
 
     /** \internal Creates a map between pointers to items in two groups
      *  (groups should contain identical items). */
     void fillCopyMap(QHash<const Object*, Object*>* map,
                         const ItemGroup* g1, ItemGroup* g2);
     /** \internal Maps all links to other objects in obj using the map */
     void applyCopyMap(QHash<const Object*, Object*>* map, Object* obj);
     /** \internal Recursively add item and all its children into
      *  bodies, forces and joints arrays. Calls applyCopyMap for them.
      *  Called by World::operator=() */
     void worldItemCopied(QHash<const Object*, Object*>* map, Item* item);
     /** \internal Recursively add item and all its children into
      *  bodies, forces and joints arrays. Called by ItemGroup::addItem() */
     void worldItemAdded(Item* item);
     /** \internal Recursively remove item and all its children from
      *  bodies, forces and joints arrays. Called by ItemGroup::removeItem()
      *  and ItemGroup::clear() */
     void worldItemRemoved(Item* item) override;
 
     /** \internal This function iterates over all bodies, assigns indexes
      *  for them in the global array (_variables), calculates total
      *  variables count and reallocates (if necessary) _variables and
      *  _variances arrays. It does the same for joints. */
     void checkVariablesCount();
 
     /** \internal Gathers acceleration (and possibly their variances)
      *  from all bodies into one array */
     void gatherAccelerations(double* acceleration, double* variance);
 
     /** \internal Gathers variables (and possibly their variances)
      *  from all bodies into one array */
     void gatherVariables(double* variables, double* variances);
 
     /** \internal Scatters variable (and possibly their variances)
      *  from one array to all bodies */
     void scatterVariables(const double* variables, const double* variances);
 
     /** \internal Gather information from all joints */
     void gatherJointsInfo(ConstraintsInfo* info);
 
     /** \internal Static wrapper for World::solverFunction */ 
     static int solverFunction(double t, const double* y, const double* yvar,
                                  double* f, double* fvar, void* params);
     /** \internal Called by solver to calculate variable derivatives.
      * This function:
      *      1. Checks collisions between bodies and resolves them if it is possible
      *      2. Iterates over all forces to calculate total force for each body
      *      3. Iterates over all joints and calls constraintSolver to solve them
      */
     int solverFunction(double t, const double* y, const double* yvar,
                                  double* f, double* fvar);
 
 private:
     double    _time;
     double    _timeScale;
     bool      _errorsCalculation;
 
     //ItemList  _items;
     BodyList  _bodies;
     ForceList _forces;
     JointList _joints;
 
     Solver*           _solver;
     CollisionSolver*  _collisionSolver;
     ConstraintSolver* _constraintSolver;
 
     int             _variablesCount;  ///< \internal Count of positions (not including velocities)
     VectorXd    _variables;       ///< \internal Positions and velocities (size == _variablesCount*2)
     VectorXd    _variances;       ///< \internal Variances of positions and velocities
     VectorXd    _tempArray;       ///< \internal Temporary array used in various places
     ConstraintsInfo _constraintsInfo; ///< \internal Constraints information
 
     bool    _stopOnCollision;
     bool    _stopOnIntersection;
     bool    _evolveAbort;
 };
 
 } // namespace StepCore
 
 /** \defgroup world World */
 /** \defgroup vector Fixed-size vector */
 /** \defgroup constants Physical constants */
 /** \defgroup bodies Physical bodies */
 /** \defgroup forces Physical forces */
 /** \defgroup joints Rigid joints */
 /** \defgroup tools Various tools */
 /** \defgroup solvers ODE Solvers */
 /** \defgroup contacts Collision and constraint solvers */
 /** \defgroup reflections Reflections */
 /** \defgroup xmlfile XML file IO */
 /** \defgroup errors ObjectErrors classes */
 
 #endif