2 ===========================================================================
5 Copyright (C) 1999-2011 id Software LLC, a ZeniMax Media company.
7 This file is part of the Doom 3 GPL Source Code (?Doom 3 Source Code?).
9 Doom 3 Source Code is free software: you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation, either version 3 of the License, or
12 (at your option) any later version.
14 Doom 3 Source Code is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with Doom 3 Source Code. If not, see <http://www.gnu.org/licenses/>.
22 In addition, the Doom 3 Source Code is also subject to certain additional terms. You should have received a copy of these additional terms immediately following the terms and conditions of the GNU General Public License which accompanied the Doom 3 Source Code. If not, please request a copy in writing from id Software at the address below.
24 If you have questions concerning this license or the applicable additional terms, you may contact in writing id Software LLC, c/o ZeniMax Media Inc., Suite 120, Rockville, Maryland 20850 USA.
26 ===========================================================================
33 ===============================================================================
35 Physics abstract class
37 A physics object is a tool to manipulate the position and orientation of
38 an entity. The physics object is a container for idClipModels used for
39 collision detection. The physics deals with moving these collision models
40 through the world according to the laws of physics or other rules.
42 The mass of a clip model is the volume of the clip model times the density.
43 An arbitrary mass can however be set for specific clip models or the
44 whole physics object. The contents of a clip model is a set of bit flags
45 that define the contents. The clip mask defines the contents a clip model
48 The linear velocity of a physics object is a vector that defines the
49 translation of the center of mass in units per second. The angular velocity
50 of a physics object is a vector that passes through the center of mass. The
51 direction of this vector defines the axis of rotation and the magnitude
52 defines the rate of rotation about the axis in radians per second.
53 The gravity is the change in velocity per second due to gravitational force.
55 Entities update their visual position and orientation from the physics
56 using GetOrigin() and GetAxis(). Direct origin and axis changes of
57 entities should go through the physics. In other words the physics origin
58 and axis are updated first and the entity updates it's visual position
61 ===============================================================================
64 #define CONTACT_EPSILON 0.25f // maximum contact seperation distance
68 typedef struct impactInfo_s {
69 float invMass; // inverse mass
70 idMat3 invInertiaTensor; // inverse inertia tensor
71 idVec3 position; // impact position relative to center of mass
72 idVec3 velocity; // velocity at the impact position
76 class idPhysics : public idClass {
79 ABSTRACT_PROTOTYPE( idPhysics );
81 virtual ~idPhysics( void );
82 static int SnapTimeToPhysicsFrame( int t );
84 // Must not be virtual
85 void Save( idSaveGame *savefile ) const;
86 void Restore( idRestoreGame *savefile );
88 public: // common physics interface
89 // set pointer to entity using physics
90 virtual void SetSelf( idEntity *e ) = 0;
92 virtual void SetClipModel( idClipModel *model, float density, int id = 0, bool freeOld = true ) = 0;
93 virtual void SetClipBox( const idBounds &bounds, float density );
94 virtual idClipModel * GetClipModel( int id = 0 ) const = 0;
95 virtual int GetNumClipModels( void ) const = 0;
96 // get/set the mass of a specific clip model or the whole physics object
97 virtual void SetMass( float mass, int id = -1 ) = 0;
98 virtual float GetMass( int id = -1 ) const = 0;
99 // get/set the contents of a specific clip model or the whole physics object
100 virtual void SetContents( int contents, int id = -1 ) = 0;
101 virtual int GetContents( int id = -1 ) const = 0;
102 // get/set the contents a specific clip model or the whole physics object collides with
103 virtual void SetClipMask( int mask, int id = -1 ) = 0;
104 virtual int GetClipMask( int id = -1 ) const = 0;
105 // get the bounds of a specific clip model or the whole physics object
106 virtual const idBounds & GetBounds( int id = -1 ) const = 0;
107 virtual const idBounds & GetAbsBounds( int id = -1 ) const = 0;
108 // evaluate the physics with the given time step, returns true if the object moved
109 virtual bool Evaluate( int timeStepMSec, int endTimeMSec ) = 0;
110 // update the time without moving
111 virtual void UpdateTime( int endTimeMSec ) = 0;
112 // get the last physics update time
113 virtual int GetTime( void ) const = 0;
114 // collision interaction between different physics objects
115 virtual void GetImpactInfo( const int id, const idVec3 &point, impactInfo_t *info ) const = 0;
116 virtual void ApplyImpulse( const int id, const idVec3 &point, const idVec3 &impulse ) = 0;
117 virtual void AddForce( const int id, const idVec3 &point, const idVec3 &force ) = 0;
118 virtual void Activate( void ) = 0;
119 virtual void PutToRest( void ) = 0;
120 virtual bool IsAtRest( void ) const = 0;
121 virtual int GetRestStartTime( void ) const = 0;
122 virtual bool IsPushable( void ) const = 0;
123 // save and restore the physics state
124 virtual void SaveState( void ) = 0;
125 virtual void RestoreState( void ) = 0;
126 // set the position and orientation in master space or world space if no master set
127 virtual void SetOrigin( const idVec3 &newOrigin, int id = -1 ) = 0;
128 virtual void SetAxis( const idMat3 &newAxis, int id = -1 ) = 0;
129 // translate or rotate the physics object in world space
130 virtual void Translate( const idVec3 &translation, int id = -1 ) = 0;
131 virtual void Rotate( const idRotation &rotation, int id = -1 ) = 0;
132 // get the position and orientation in world space
133 virtual const idVec3 & GetOrigin( int id = 0 ) const = 0;
134 virtual const idMat3 & GetAxis( int id = 0 ) const = 0;
135 // set linear and angular velocity
136 virtual void SetLinearVelocity( const idVec3 &newLinearVelocity, int id = 0 ) = 0;
137 virtual void SetAngularVelocity( const idVec3 &newAngularVelocity, int id = 0 ) = 0;
138 // get linear and angular velocity
139 virtual const idVec3 & GetLinearVelocity( int id = 0 ) const = 0;
140 virtual const idVec3 & GetAngularVelocity( int id = 0 ) const = 0;
142 virtual void SetGravity( const idVec3 &newGravity ) = 0;
143 virtual const idVec3 & GetGravity( void ) const = 0;
144 virtual const idVec3 & GetGravityNormal( void ) const = 0;
145 // get first collision when translating or rotating this physics object
146 virtual void ClipTranslation( trace_t &results, const idVec3 &translation, const idClipModel *model ) const = 0;
147 virtual void ClipRotation( trace_t &results, const idRotation &rotation, const idClipModel *model ) const = 0;
148 virtual int ClipContents( const idClipModel *model ) const = 0;
149 // disable/enable the clip models contained by this physics object
150 virtual void DisableClip( void ) = 0;
151 virtual void EnableClip( void ) = 0;
152 // link/unlink the clip models contained by this physics object
153 virtual void UnlinkClip( void ) = 0;
154 virtual void LinkClip( void ) = 0;
156 virtual bool EvaluateContacts( void ) = 0;
157 virtual int GetNumContacts( void ) const = 0;
158 virtual const contactInfo_t &GetContact( int num ) const = 0;
159 virtual void ClearContacts( void ) = 0;
160 virtual void AddContactEntity( idEntity *e ) = 0;
161 virtual void RemoveContactEntity( idEntity *e ) = 0;
163 virtual bool HasGroundContacts( void ) const = 0;
164 virtual bool IsGroundEntity( int entityNum ) const = 0;
165 virtual bool IsGroundClipModel( int entityNum, int id ) const = 0;
166 // set the master entity for objects bound to a master
167 virtual void SetMaster( idEntity *master, const bool orientated = true ) = 0;
169 virtual void SetPushed( int deltaTime ) = 0;
170 virtual const idVec3 & GetPushedLinearVelocity( const int id = 0 ) const = 0;
171 virtual const idVec3 & GetPushedAngularVelocity( const int id = 0 ) const = 0;
172 // get blocking info, returns NULL if the object is not blocked
173 virtual const trace_t * GetBlockingInfo( void ) const = 0;
174 virtual idEntity * GetBlockingEntity( void ) const = 0;
175 // movement end times in msec for reached events at the end of predefined motion
176 virtual int GetLinearEndTime( void ) const = 0;
177 virtual int GetAngularEndTime( void ) const = 0;
179 virtual void WriteToSnapshot( idBitMsgDelta &msg ) const = 0;
180 virtual void ReadFromSnapshot( const idBitMsgDelta &msg ) = 0;
183 #endif /* !__PHYSICS_H__ */