File indexing completed on 2024-04-28 13:39:24

 /***************************************************************************
  *   Copyright (C) 2005 by David Saxton                                    *
  *   david@bluehaze.org                                                    *
  *                                                                         *
  *   This program is free software; you can redistribute it and/or modify  *
  *   it under the terms of the GNU General Public License as published by  *
  *   the Free Software Foundation; either version 2 of the License, or     *
  *   (at your option) any later version.                                   *
  ***************************************************************************/
 
 #ifndef MECHANICSSIMULATION_H
 #define MECHANICSSIMULATION_H
 
 #include <QList>
 #include <QObject>
 #include <QPointer>
 
 class QTimer;
 class MechanicsItem;
 class MechanicsDocument;
 typedef QList<MechanicsItem *> MechanicsItemList;
 
 /**
 @short 2 dimensional vector with associated length functions et al
 @author David Saxton
 */
 class Vector2D
 {
 public:
     Vector2D();
 
     double length() const;
     double lengthSquared() const
     {
         return x * x + y * y;
     }
 
     double x;
     double y;
 };
 
 /**
 @short State of a rigid body, in an inertial MechanicsDocument frame
 @author David Saxton
 */
 class RigidBodyState
 {
 public:
     RigidBodyState();
 
     Vector2D linearMomentum;
     double angularMomentum;
     Vector2D position; // Position of center of mass
 };
 
 /**
 @author David Saxton
 */
 class MechanicsSimulation : public QObject
 {
     Q_OBJECT
 public:
     MechanicsSimulation(MechanicsDocument *mechanicsDocument);
     ~MechanicsSimulation() override;
 
     MechanicsDocument *mechanicsDocument() const
     {
         return p_mechanicsDocument;
     }
 
 protected slots:
     void slotAdvance();
 
 protected:
     QPointer<MechanicsDocument> p_mechanicsDocument;
     QTimer *m_advanceTmr;
 };
 
 /**
 Rigid body with mass, inertia, etc. Collection of mechanics items with
 functionality for moving them about, rotating, etc. Only one mother-parent
 (has no parent itself, all other items are descendents) allowed.
 @short Rigid body, handles MechanicsItems
 @author David Saxton
 */
 class RigidBody
 {
 public:
     RigidBody(MechanicsDocument *mechanicsDocument);
     ~RigidBody();
 
     /**
      *
      */
     void advance(int phase, double delta);
     /**
      * Add the MechanicsItem to the entity.
      * @returns true iff successful in adding
      */
     bool addMechanicsItem(MechanicsItem *item);
     /**
      * Pointer to the mother MechanicsItem.
      */
     MechanicsItem *overallParent() const
     {
         return p_overallParent;
     }
     /**
      * Updates the mass and the moment of inertia info
      */
     void updateRigidBodyInfo();
 
 protected:
     /**
      * Attempt to find the overall parent.
      * @returns false iff unsucessful (including if there are no MechanicsItems present)
      */
     bool findOverallParent();
     /**
      * Move the set of MechanicsItems by the given amount
      */
     void moveBy(double dx, double dy);
     /**
      * Rotate the set of MechanicsItems by the given amount about the center of
      * mass.
      * @param dtheta Rotate amount in radians
      */
     void rotateBy(double dtheta);
 
     MechanicsItemList m_mechanicsItemList;
     MechanicsItem *p_overallParent;
     MechanicsDocument *p_mechanicsDocument;
 
     RigidBodyState m_rigidBodyState;
     double m_mass;
     double m_momentOfInertia;
 };
 
 #endif