doom3-bfg/neo/d3xp/physics/Force_Spring.cpp
2012-11-26 12:58:24 -06:00

165 lines
4.3 KiB
C++

/*
===========================================================================
Doom 3 BFG Edition GPL Source Code
Copyright (C) 1993-2012 id Software LLC, a ZeniMax Media company.
This file is part of the Doom 3 BFG Edition GPL Source Code ("Doom 3 BFG Edition Source Code").
Doom 3 BFG Edition Source Code 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 3 of the License, or
(at your option) any later version.
Doom 3 BFG Edition Source Code is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with Doom 3 BFG Edition Source Code. If not, see <http://www.gnu.org/licenses/>.
In addition, the Doom 3 BFG Edition 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 BFG Edition Source Code. If not, please request a copy in writing from id Software at the address below.
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.
===========================================================================
*/
#pragma hdrstop
#include "../../idlib/precompiled.h"
#include "../Game_local.h"
CLASS_DECLARATION( idForce, idForce_Spring )
END_CLASS
/*
================
idForce_Spring::idForce_Spring
================
*/
idForce_Spring::idForce_Spring() {
Kstretch = 100.0f;
Kcompress = 100.0f;
damping = 0.0f;
restLength = 0.0f;
physics1 = NULL;
id1 = 0;
p1 = vec3_zero;
physics2 = NULL;
id2 = 0;
p2 = vec3_zero;
}
/*
================
idForce_Spring::~idForce_Spring
================
*/
idForce_Spring::~idForce_Spring() {
}
/*
================
idForce_Spring::InitSpring
================
*/
void idForce_Spring::InitSpring( float Kstretch, float Kcompress, float damping, float restLength ) {
this->Kstretch = Kstretch;
this->Kcompress = Kcompress;
this->damping = damping;
this->restLength = restLength;
}
/*
================
idForce_Spring::SetPosition
================
*/
void idForce_Spring::SetPosition( idPhysics *physics1, int id1, const idVec3 &p1, idPhysics *physics2, int id2, const idVec3 &p2 ) {
this->physics1 = physics1;
this->id1 = id1;
this->p1 = p1;
this->physics2 = physics2;
this->id2 = id2;
this->p2 = p2;
}
/*
================
idForce_Spring::Evaluate
================
*/
void idForce_Spring::Evaluate( int time ) {
float length;
idMat3 axis;
idVec3 pos1, pos2, velocity1, velocity2, force, dampingForce;
impactInfo_t info;
pos1 = p1;
pos2 = p2;
velocity1 = velocity2 = vec3_origin;
if ( physics1 ) {
axis = physics1->GetAxis( id1 );
pos1 = physics1->GetOrigin( id1 );
pos1 += p1 * axis;
if ( damping > 0.0f ) {
physics1->GetImpactInfo( id1, pos1, &info );
velocity1 = info.velocity;
}
}
if ( physics2 ) {
axis = physics2->GetAxis( id2 );
pos2 = physics2->GetOrigin( id2 );
pos2 += p2 * axis;
if ( damping > 0.0f ) {
physics2->GetImpactInfo( id2, pos2, &info );
velocity2 = info.velocity;
}
}
force = pos2 - pos1;
dampingForce = ( damping * ( ((velocity2 - velocity1) * force) / (force * force) ) ) * force;
length = force.Normalize();
// if the spring is stretched
if ( length > restLength ) {
if ( Kstretch > 0.0f ) {
force = ( Square( length - restLength ) * Kstretch ) * force - dampingForce;
if ( physics1 ) {
physics1->AddForce( id1, pos1, force );
}
if ( physics2 ) {
physics2->AddForce( id2, pos2, -force );
}
}
}
else {
if ( Kcompress > 0.0f ) {
force = ( Square( length - restLength ) * Kcompress ) * force - dampingForce;
if ( physics1 ) {
physics1->AddForce( id1, pos1, -force );
}
if ( physics2 ) {
physics2->AddForce( id2, pos2, force );
}
}
}
}
/*
================
idForce_Spring::RemovePhysics
================
*/
void idForce_Spring::RemovePhysics( const idPhysics *phys ) {
if ( physics1 == phys ) {
physics1 = NULL;
}
if ( physics2 == phys ) {
physics2 = NULL;
}
}