source: OGRE/trunk/ogrenew/PlugIns/ParticleFX/include/OgreLinearForceAffector.h @ 692

Revision 692, 4.4 KB checked in by mattausch, 19 years ago (diff)

adding ogre 1.2 and dependencies

Line 
1/*
2-----------------------------------------------------------------------------
3This source file is part of OGRE
4        (Object-oriented Graphics Rendering Engine)
5For the latest info, see http://www.ogre3d.org/
6
7Copyright (c) 2000-2005 The OGRE Team
8Also see acknowledgements in Readme.html
9
10This program is free software; you can redistribute it and/or modify it under
11the terms of the GNU Lesser General Public License as published by the Free Software
12Foundation; either version 2 of the License, or (at your option) any later
13version.
14
15This program is distributed in the hope that it will be useful, but WITHOUT
16ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
17FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
18
19You should have received a copy of the GNU Lesser General Public License along with
20this program; if not, write to the Free Software Foundation, Inc., 59 Temple
21Place - Suite 330, Boston, MA 02111-1307, USA, or go to
22http://www.gnu.org/copyleft/lesser.txt.
23-----------------------------------------------------------------------------
24*/
25#ifndef __LinearForceAffector_H__
26#define __LinearForceAffector_H__
27
28#include "OgreParticleFXPrerequisites.h"
29#include "OgreParticleAffector.h"
30#include "OgreVector3.h"
31
32
33namespace Ogre {
34
35    /** This class defines a ParticleAffector which applies a linear force to particles in a system.
36    @remarks
37        This affector (see ParticleAffector) applies a linear force, such as gravity, to a particle system.
38        This force can be applied in 2 ways: by taking the average of the particle's current momentum and the
39        force vector, or by adding the force vector to the current particle's momentum.
40    @par
41        The former approach is self-stabilising i.e. once a particle's momentum
42        is equal to the force vector, no further change is made to it's momentum. It also results in
43        a non-linear acceleration of particles.
44        The latter approach is simpler and applies a constant acceleration to particles. However,
45        it is not self-stabilising and can lead to perpetually increasing particle velocities.
46        You choose the approach by calling the setForceApplication method.
47    */
48    class _OgreParticleFXExport LinearForceAffector : public ParticleAffector
49    {
50    public:
51        /** Command object for force vector (see ParamCommand).*/
52        class CmdForceVector : public ParamCommand
53        {
54        public:
55            String doGet(const void* target) const;
56            void doSet(void* target, const String& val);
57        };
58
59        /** Command object for force application (see ParamCommand).*/
60        class CmdForceApp : public ParamCommand
61        {
62        public:
63            String doGet(const void* target) const;
64            void doSet(void* target, const String& val);
65        };
66        /// Choice of how to apply the force vector to particles
67        enum ForceApplication
68        {
69            /// Take the average of the force vector and the particle momentum
70            FA_AVERAGE,
71            /// Add the force vector to the particle momentum
72            FA_ADD
73        };
74        /// Default constructor
75        LinearForceAffector(ParticleSystem* psys);
76
77        /** See ParticleAffector. */
78        void _affectParticles(ParticleSystem* pSystem, Real timeElapsed);
79
80
81        /** Sets the force vector to apply to the particles in a system. */
82        void setForceVector(const Vector3& force);
83
84        /** Gets the force vector to apply to the particles in a system. */
85        Vector3 getForceVector(void) const;
86
87        /** Sets how the force vector is applied to a particle.
88        @remarks
89          The default is FA_ADD.
90        @param fa A member of the ForceApplication enum.
91        */
92        void setForceApplication(ForceApplication fa);
93
94        /** Retrieves how the force vector is applied to a particle.
95        @param fa A member of the ForceApplication enum.
96        */
97        ForceApplication getForceApplication(void) const;
98
99        /// Command objects
100        static CmdForceVector msForceVectorCmd;
101        static CmdForceApp msForceAppCmd;
102
103    protected:
104        /// Force vector
105        Vector3 mForceVector;
106
107        /// How to apply force
108        ForceApplication mForceApplication;
109
110    };
111
112
113}
114
115
116#endif
117
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