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source: code/branches/gamestates2/src/external/bullet/BulletCollision/Gimpact/btGeometryOperations.h @ 6915

Last change on this file since 6915 was 5781, checked in by rgrieder, 15 years ago

Reverted trunk again. We might want to find a way to delete these revisions again (x3n's changes are still available as diff in the commit mails).

  • Property svn:eol-style set to native
File size: 4.8 KB
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1#ifndef BT_BASIC_GEOMETRY_OPERATIONS_H_INCLUDED
2#define BT_BASIC_GEOMETRY_OPERATIONS_H_INCLUDED
3
4/*! \file btGeometryOperations.h
5*\author Francisco Len Nßjera
6
7*/
8/*
9This source file is part of GIMPACT Library.
10
11For the latest info, see http://gimpact.sourceforge.net/
12
13Copyright (c) 2007 Francisco Leon Najera. C.C. 80087371.
14email: projectileman@yahoo.com
15
16
17This software is provided 'as-is', without any express or implied warranty.
18In no event will the authors be held liable for any damages arising from the use of this software.
19Permission is granted to anyone to use this software for any purpose,
20including commercial applications, and to alter it and redistribute it freely,
21subject to the following restrictions:
22
231. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required.
242. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
253. This notice may not be removed or altered from any source distribution.
26*/
27
28#include "btBoxCollision.h"
29
30
31
32
33
34#define PLANEDIREPSILON 0.0000001f
35#define PARALELENORMALS 0.000001f
36
37
38#define BT_CLAMP(number,minval,maxval) (number<minval?minval:(number>maxval?maxval:number))
39
40/// Calc a plane from a triangle edge an a normal. plane is a vec4f
41SIMD_FORCE_INLINE void bt_edge_plane(const btVector3 & e1,const btVector3 &  e2, const btVector3 & normal,btVector4 & plane)
42{
43        btVector3 planenormal = (e2-e1).cross(normal);
44        planenormal.normalize();
45        plane.setValue(planenormal[0],planenormal[1],planenormal[2],e2.dot(planenormal));
46}
47
48
49
50//***************** SEGMENT and LINE FUNCTIONS **********************************///
51
52/*! Finds the closest point(cp) to (v) on a segment (e1,e2)
53 */
54SIMD_FORCE_INLINE void bt_closest_point_on_segment(
55        btVector3 & cp, const btVector3 & v,
56        const btVector3  &e1,const btVector3 &e2)
57{
58    btVector3 n = e2-e1;
59    cp = v - e1;
60        btScalar _scalar = cp.dot(n)/n.dot(n);
61        if(_scalar <0.0f)
62        {
63            cp = e1;
64        }
65        else if(_scalar >1.0f)
66        {
67            cp = e2;
68        }
69        else
70        {
71                cp = _scalar*n + e1;
72        }
73}
74
75
76//! line plane collision
77/*!
78*\return
79        -0  if the ray never intersects
80        -1 if the ray collides in front
81        -2 if the ray collides in back
82*/
83
84SIMD_FORCE_INLINE int bt_line_plane_collision(
85        const btVector4 & plane,
86        const btVector3 & vDir,
87        const btVector3 & vPoint,
88        btVector3 & pout,
89        btScalar &tparam,
90        btScalar tmin, btScalar tmax)
91{
92
93        btScalar _dotdir = vDir.dot(plane);
94
95        if(btFabs(_dotdir)<PLANEDIREPSILON)
96        {
97                tparam = tmax;
98            return 0;
99        }
100
101        btScalar _dis = bt_distance_point_plane(plane,vPoint);
102        char returnvalue = _dis<0.0f? 2:1;
103        tparam = -_dis/_dotdir;
104
105        if(tparam<tmin)
106        {
107                returnvalue = 0;
108                tparam = tmin;
109        }
110        else if(tparam>tmax)
111        {
112                returnvalue = 0;
113                tparam = tmax;
114        }
115        pout = tparam*vDir + vPoint;
116        return returnvalue;
117}
118
119
120//! Find closest points on segments
121SIMD_FORCE_INLINE void bt_segment_collision(
122        const btVector3 & vA1,
123        const btVector3 & vA2,
124        const btVector3 & vB1,
125        const btVector3 & vB2,
126        btVector3 & vPointA,
127        btVector3 & vPointB)
128{
129    btVector3 AD = vA2 - vA1;
130    btVector3 BD = vB2 - vB1;
131    btVector3 N = AD.cross(BD);
132    btScalar tp = N.length2();
133
134    btVector4 _M;//plane
135
136    if(tp<SIMD_EPSILON)//ARE PARALELE
137    {
138        //project B over A
139        bool invert_b_order = false;
140        _M[0] = vB1.dot(AD);
141        _M[1] = vB2.dot(AD);
142
143        if(_M[0]>_M[1])
144        {
145                invert_b_order  = true;
146                BT_SWAP_NUMBERS(_M[0],_M[1]);
147        }
148        _M[2] = vA1.dot(AD);
149        _M[3] = vA2.dot(AD);
150        //mid points
151        N[0] = (_M[0]+_M[1])*0.5f;
152        N[1] = (_M[2]+_M[3])*0.5f;
153
154        if(N[0]<N[1])
155        {
156                if(_M[1]<_M[2])
157                {
158                        vPointB = invert_b_order?vB1:vB2;
159                        vPointA = vA1;
160                }
161                else if(_M[1]<_M[3])
162                {
163                        vPointB = invert_b_order?vB1:vB2;
164                        bt_closest_point_on_segment(vPointA,vPointB,vA1,vA2);
165                }
166                else
167                {
168                        vPointA = vA2;
169                        bt_closest_point_on_segment(vPointB,vPointA,vB1,vB2);
170                }
171        }
172        else
173        {
174                if(_M[3]<_M[0])
175                {
176                        vPointB = invert_b_order?vB2:vB1;
177                        vPointA = vA2;
178                }
179                else if(_M[3]<_M[1])
180                {
181                        vPointA = vA2;
182                        bt_closest_point_on_segment(vPointB,vPointA,vB1,vB2);
183                }
184                else
185                {
186                        vPointB = invert_b_order?vB1:vB2;
187                        bt_closest_point_on_segment(vPointA,vPointB,vA1,vA2);
188                }
189        }
190        return;
191    }
192
193    N = N.cross(BD);
194    _M.setValue(N[0],N[1],N[2],vB1.dot(N));
195
196        // get point A as the plane collision point
197    bt_line_plane_collision(_M,AD,vA1,vPointA,tp,btScalar(0), btScalar(1));
198
199    /*Closest point on segment*/
200    vPointB = vPointA - vB1;
201        tp = vPointB.dot(BD);
202        tp/= BD.dot(BD);
203        tp = BT_CLAMP(tp,0.0f,1.0f);
204
205        vPointB = tp*BD + vB1;
206}
207
208
209
210
211
212#endif // GIM_VECTOR_H_INCLUDED
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