root/OpenSceneGraph/trunk/include/osgParticle/ExplosionOperator @ 13041

Revision 13041, 3.9 kB (checked in by robert, 2 years ago)

Ran script to remove trailing spaces and tabs

  • Property svn:eol-style set to native
  • Property svn:keywords set to Author Date Id Revision
Line 
1/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2010 Robert Osfield
2 *
3 * This library is open source and may be redistributed and/or modified under
4 * the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or
5 * (at your option) any later version.  The full license is in LICENSE file
6 * included with this distribution, and on the openscenegraph.org website.
7 *
8 * This library is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11 * OpenSceneGraph Public License for more details.
12*/
13// Written by Wang Rui, (C) 2010
14
15#ifndef OSGPARTICLE_EXPLOSIONOPERATOR
16#define OSGPARTICLE_EXPLOSIONOPERATOR
17
18#include <osgParticle/ModularProgram>
19#include <osgParticle/Operator>
20#include <osgParticle/Particle>
21
22namespace osgParticle
23{
24
25
26/** An explosion operator exerts force on each particle away from the explosion center.
27    Refer to David McAllister's Particle System API (http://www.particlesystems.org)
28*/
29class ExplosionOperator : public Operator
30{
31public:
32    ExplosionOperator()
33    :   Operator(), _radius(1.0f),
34        _magnitude(1.0f), _epsilon(1e-3), _sigma(1.0f),
35        _inexp(0.0f), _outexp(0.0f)
36    {}
37
38    ExplosionOperator( const ExplosionOperator& copy, const osg::CopyOp& copyop = osg::CopyOp::SHALLOW_COPY )
39    :   Operator(copy, copyop), _center(copy._center), _radius(copy._radius),
40        _magnitude(copy._magnitude), _epsilon(copy._epsilon), _sigma(copy._sigma),
41        _inexp(copy._inexp), _outexp(copy._outexp)
42    {}
43
44    META_Object( osgParticle, ExplosionOperator );
45
46    /// Set the center of shock wave
47    void setCenter( const osg::Vec3& c ) { _center = c; }
48
49    /// Get the center of shock wave
50    const osg::Vec3& getCenter() const { return _center; }
51
52    /// Set the radius of wave peak
53    void setRadius( float r ) { _radius = r; }
54
55    /// Get the radius of wave peak
56    float getRadius() const { return _radius; }
57
58    /// Set the acceleration scale
59    void setMagnitude( float mag ) { _magnitude = mag; }
60
61    /// Get the acceleration scale
62    float getMagnitude() const { return _magnitude; }
63
64    /// Set the acceleration epsilon
65    void setEpsilon( float eps ) { _epsilon = eps; }
66
67    /// Get the acceleration epsilon
68    float getEpsilon() const { return _epsilon; }
69
70    /// Set broadness of the strength of the wave
71    void setSigma( float s ) { _sigma = s; }
72
73    /// Get broadness of the strength of the wave
74    float getSigma() const { return _sigma; }
75
76    /// Apply the acceleration to a particle. Do not call this method manually.
77    inline void operate( Particle* P, double dt );
78
79    /// Perform some initializations. Do not call this method manually.
80    inline void beginOperate( Program* prg );
81
82protected:
83    virtual ~ExplosionOperator() {}
84    ExplosionOperator& operator=( const ExplosionOperator& ) { return *this; }
85
86    osg::Vec3 _center;
87    osg::Vec3 _xf_center;
88    float _radius;
89    float _magnitude;
90    float _epsilon;
91    float _sigma;
92    float _inexp;
93    float _outexp;
94};
95
96// INLINE METHODS
97
98inline void ExplosionOperator::operate( Particle* P, double dt )
99{
100    osg::Vec3 dir = P->getPosition() - _xf_center;
101    float length = dir.length();
102    float distanceFromWave2 = (_radius - length) * (_radius - length);
103    float Gd = exp(distanceFromWave2 * _inexp) * _outexp;
104    float factor = (_magnitude * dt) / (length * (_epsilon+length*length));
105    P->addVelocity( dir * (Gd * factor) );
106}
107
108inline void ExplosionOperator::beginOperate( Program* prg )
109{
110    if ( prg->getReferenceFrame()==ModularProgram::RELATIVE_RF )
111    {
112        _xf_center = prg->transformLocalToWorld(_center);
113    }
114    else
115    {
116        _xf_center = _center;
117    }
118
119    float oneOverSigma = (_sigma!=0.0f ? (1.0f / _sigma) : 1.0f);
120    _inexp = -0.5f * oneOverSigma * oneOverSigma;
121    _outexp = oneOverSigma / sqrt(osg::PI * 2.0f);
122}
123
124
125}
126
127#endif
Note: See TracBrowser for help on using the browser.