bullet: Update to current svn, r2636
[blender.git] / extern / bullet2 / src / BulletCollision / CollisionDispatch / btSphereBoxCollisionAlgorithm.cpp
1 /*
2 Bullet Continuous Collision Detection and Physics Library
3 Copyright (c) 2003-2006 Erwin Coumans  http://continuousphysics.com/Bullet/
4
5 This software is provided 'as-is', without any express or implied warranty.
6 In no event will the authors be held liable for any damages arising from the use of this software.
7 Permission is granted to anyone to use this software for any purpose, 
8 including commercial applications, and to alter it and redistribute it freely, 
9 subject to the following restrictions:
10
11 1. 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.
12 2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
13 3. This notice may not be removed or altered from any source distribution.
14 */
15
16 #include "btSphereBoxCollisionAlgorithm.h"
17 #include "BulletCollision/CollisionDispatch/btCollisionDispatcher.h"
18 #include "BulletCollision/CollisionShapes/btSphereShape.h"
19 #include "BulletCollision/CollisionShapes/btBoxShape.h"
20 #include "BulletCollision/CollisionDispatch/btCollisionObject.h"
21 #include "BulletCollision/CollisionDispatch/btCollisionObjectWrapper.h"
22 //#include <stdio.h>
23
24 btSphereBoxCollisionAlgorithm::btSphereBoxCollisionAlgorithm(btPersistentManifold* mf,const btCollisionAlgorithmConstructionInfo& ci,const btCollisionObjectWrapper* col0Wrap,const btCollisionObjectWrapper* col1Wrap, bool isSwapped)
25 : btActivatingCollisionAlgorithm(ci,col0Wrap,col1Wrap),
26 m_ownManifold(false),
27 m_manifoldPtr(mf),
28 m_isSwapped(isSwapped)
29 {
30         const btCollisionObjectWrapper* sphereObjWrap = m_isSwapped? col1Wrap : col0Wrap;
31         const btCollisionObjectWrapper* boxObjWrap = m_isSwapped? col0Wrap : col1Wrap;
32         
33         if (!m_manifoldPtr && m_dispatcher->needsCollision(sphereObjWrap->getCollisionObject(),boxObjWrap->getCollisionObject()))
34         {
35                 m_manifoldPtr = m_dispatcher->getNewManifold(sphereObjWrap->getCollisionObject(),boxObjWrap->getCollisionObject());
36                 m_ownManifold = true;
37         }
38 }
39
40
41 btSphereBoxCollisionAlgorithm::~btSphereBoxCollisionAlgorithm()
42 {
43         if (m_ownManifold)
44         {
45                 if (m_manifoldPtr)
46                         m_dispatcher->releaseManifold(m_manifoldPtr);
47         }
48 }
49
50
51
52 void btSphereBoxCollisionAlgorithm::processCollision (const btCollisionObjectWrapper* body0Wrap, const btCollisionObjectWrapper* body1Wrap, const btDispatcherInfo& dispatchInfo, btManifoldResult* resultOut)
53 {
54         (void)dispatchInfo;
55         (void)resultOut;
56         if (!m_manifoldPtr)
57                 return;
58
59         const btCollisionObjectWrapper* sphereObjWrap = m_isSwapped? body1Wrap : body0Wrap;
60         const btCollisionObjectWrapper* boxObjWrap = m_isSwapped? body0Wrap : body1Wrap;
61
62         btVector3 pOnBox;
63
64         btVector3 normalOnSurfaceB;
65         btScalar penetrationDepth;
66         btVector3 sphereCenter = sphereObjWrap->getWorldTransform().getOrigin();
67         const btSphereShape* sphere0 = (const btSphereShape*)sphereObjWrap->getCollisionShape();
68         btScalar radius = sphere0->getRadius();
69         btScalar maxContactDistance = m_manifoldPtr->getContactBreakingThreshold();
70
71         resultOut->setPersistentManifold(m_manifoldPtr);
72
73         if (getSphereDistance(boxObjWrap, pOnBox, normalOnSurfaceB, penetrationDepth, sphereCenter, radius, maxContactDistance))
74         {
75                 /// report a contact. internally this will be kept persistent, and contact reduction is done
76                 resultOut->addContactPoint(normalOnSurfaceB, pOnBox, penetrationDepth);
77         }
78
79         if (m_ownManifold)
80         {
81                 if (m_manifoldPtr->getNumContacts())
82                 {
83                         resultOut->refreshContactPoints();
84                 }
85         }
86
87 }
88
89 btScalar btSphereBoxCollisionAlgorithm::calculateTimeOfImpact(btCollisionObject* col0,btCollisionObject* col1,const btDispatcherInfo& dispatchInfo,btManifoldResult* resultOut)
90 {
91         (void)resultOut;
92         (void)dispatchInfo;
93         (void)col0;
94         (void)col1;
95
96         //not yet
97         return btScalar(1.);
98 }
99
100
101 bool btSphereBoxCollisionAlgorithm::getSphereDistance(const btCollisionObjectWrapper* boxObjWrap, btVector3& pointOnBox, btVector3& normal, btScalar& penetrationDepth, const btVector3& sphereCenter, btScalar fRadius, btScalar maxContactDistance ) 
102 {
103         const btBoxShape* boxShape= (const btBoxShape*)boxObjWrap->getCollisionShape();
104         btVector3 const &boxHalfExtent = boxShape->getHalfExtentsWithoutMargin();
105         btScalar boxMargin = boxShape->getMargin();
106         penetrationDepth = 1.0f;
107
108         // convert the sphere position to the box's local space
109         btTransform const &m44T = boxObjWrap->getWorldTransform();
110         btVector3 sphereRelPos = m44T.invXform(sphereCenter);
111
112         // Determine the closest point to the sphere center in the box
113         btVector3 closestPoint = sphereRelPos;
114         closestPoint.setX( btMin(boxHalfExtent.getX(), closestPoint.getX()) );
115         closestPoint.setX( btMax(-boxHalfExtent.getX(), closestPoint.getX()) );
116         closestPoint.setY( btMin(boxHalfExtent.getY(), closestPoint.getY()) );
117         closestPoint.setY( btMax(-boxHalfExtent.getY(), closestPoint.getY()) );
118         closestPoint.setZ( btMin(boxHalfExtent.getZ(), closestPoint.getZ()) );
119         closestPoint.setZ( btMax(-boxHalfExtent.getZ(), closestPoint.getZ()) );
120         
121         btScalar intersectionDist = fRadius + boxMargin;
122         btScalar contactDist = intersectionDist + maxContactDistance;
123         normal = sphereRelPos - closestPoint;
124
125         //if there is no penetration, we are done
126         btScalar dist2 = normal.length2();
127         if (dist2 > contactDist * contactDist)
128         {
129                 return false;
130         }
131
132         btScalar distance;
133
134         //special case if the sphere center is inside the box
135         if (dist2 <= SIMD_EPSILON)
136         {
137                 distance = -getSpherePenetration(boxHalfExtent, sphereRelPos, closestPoint, normal);
138         }
139         else //compute the penetration details
140         {
141                 distance = normal.length();
142                 normal /= distance;
143         }
144
145         pointOnBox = closestPoint + normal * boxMargin;
146 //      v3PointOnSphere = sphereRelPos - (normal * fRadius);    
147         penetrationDepth = distance - intersectionDist;
148
149         // transform back in world space
150         btVector3 tmp = m44T(pointOnBox);
151         pointOnBox = tmp;
152 //      tmp = m44T(v3PointOnSphere);
153 //      v3PointOnSphere = tmp;
154         tmp = m44T.getBasis() * normal;
155         normal = tmp;
156
157         return true;
158 }
159
160 btScalar btSphereBoxCollisionAlgorithm::getSpherePenetration( btVector3 const &boxHalfExtent, btVector3 const &sphereRelPos, btVector3 &closestPoint, btVector3& normal ) 
161 {
162         //project the center of the sphere on the closest face of the box
163         btScalar faceDist = boxHalfExtent.getX() - sphereRelPos.getX();
164         btScalar minDist = faceDist;
165         closestPoint.setX( boxHalfExtent.getX() );
166         normal.setValue(btScalar(1.0f),  btScalar(0.0f),  btScalar(0.0f));
167
168         faceDist = boxHalfExtent.getX() + sphereRelPos.getX();
169         if (faceDist < minDist)
170         {
171                 minDist = faceDist;
172                 closestPoint = sphereRelPos;
173                 closestPoint.setX( -boxHalfExtent.getX() );
174                 normal.setValue(btScalar(-1.0f),  btScalar(0.0f),  btScalar(0.0f));
175         }
176
177         faceDist = boxHalfExtent.getY() - sphereRelPos.getY();
178         if (faceDist < minDist)
179         {
180                 minDist = faceDist;
181                 closestPoint = sphereRelPos;
182                 closestPoint.setY( boxHalfExtent.getY() );
183                 normal.setValue(btScalar(0.0f),  btScalar(1.0f),  btScalar(0.0f));
184         }
185
186         faceDist = boxHalfExtent.getY() + sphereRelPos.getY();
187         if (faceDist < minDist)
188         {
189                 minDist = faceDist;
190                 closestPoint = sphereRelPos;
191                 closestPoint.setY( -boxHalfExtent.getY() );
192                 normal.setValue(btScalar(0.0f),  btScalar(-1.0f),  btScalar(0.0f));
193         }
194
195         faceDist = boxHalfExtent.getZ() - sphereRelPos.getZ();
196         if (faceDist < minDist)
197         {
198                 minDist = faceDist;
199                 closestPoint = sphereRelPos;
200                 closestPoint.setZ( boxHalfExtent.getZ() );
201                 normal.setValue(btScalar(0.0f),  btScalar(0.0f),  btScalar(1.0f));
202         }
203
204         faceDist = boxHalfExtent.getZ() + sphereRelPos.getZ();
205         if (faceDist < minDist)
206         {
207                 minDist = faceDist;
208                 closestPoint = sphereRelPos;
209                 closestPoint.setZ( -boxHalfExtent.getZ() );
210                 normal.setValue(btScalar(0.0f),  btScalar(0.0f),  btScalar(-1.0f));
211         }
212
213         return minDist;
214 }