== SoC Bullet - Bullet Upgrade to 2.76 ==
[blender.git] / extern / bullet2 / BulletCollision / NarrowPhaseCollision / btContinuousConvexCollision.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
17 #include "btContinuousConvexCollision.h"
18 #include "BulletCollision/CollisionShapes/btConvexShape.h"
19 #include "BulletCollision/NarrowPhaseCollision/btSimplexSolverInterface.h"
20 #include "LinearMath/btTransformUtil.h"
21 #include "BulletCollision/CollisionShapes/btSphereShape.h"
22
23 #include "btGjkPairDetector.h"
24 #include "btPointCollector.h"
25
26
27
28 btContinuousConvexCollision::btContinuousConvexCollision ( const btConvexShape* convexA,const btConvexShape*    convexB,btSimplexSolverInterface* simplexSolver, btConvexPenetrationDepthSolver* penetrationDepthSolver)
29 :m_simplexSolver(simplexSolver),
30 m_penetrationDepthSolver(penetrationDepthSolver),
31 m_convexA(convexA),m_convexB(convexB)
32 {
33 }
34
35 /// This maximum should not be necessary. It allows for untested/degenerate cases in production code.
36 /// You don't want your game ever to lock-up.
37 #define MAX_ITERATIONS 64
38
39 bool    btContinuousConvexCollision::calcTimeOfImpact(
40                                 const btTransform& fromA,
41                                 const btTransform& toA,
42                                 const btTransform& fromB,
43                                 const btTransform& toB,
44                                 CastResult& result)
45 {
46
47         m_simplexSolver->reset();
48
49         /// compute linear and angular velocity for this interval, to interpolate
50         btVector3 linVelA,angVelA,linVelB,angVelB;
51         btTransformUtil::calculateVelocity(fromA,toA,btScalar(1.),linVelA,angVelA);
52         btTransformUtil::calculateVelocity(fromB,toB,btScalar(1.),linVelB,angVelB);
53
54
55         btScalar boundingRadiusA = m_convexA->getAngularMotionDisc();
56         btScalar boundingRadiusB = m_convexB->getAngularMotionDisc();
57
58         btScalar maxAngularProjectedVelocity = angVelA.length() * boundingRadiusA + angVelB.length() * boundingRadiusB;
59         btVector3 relLinVel = (linVelB-linVelA);
60
61         btScalar relLinVelocLength = (linVelB-linVelA).length();
62         
63         if ((relLinVelocLength+maxAngularProjectedVelocity) == 0.f)
64                 return false;
65
66
67         btScalar radius = btScalar(0.001);
68
69         btScalar lambda = btScalar(0.);
70         btVector3 v(1,0,0);
71
72         int maxIter = MAX_ITERATIONS;
73
74         btVector3 n;
75         n.setValue(btScalar(0.),btScalar(0.),btScalar(0.));
76         bool hasResult = false;
77         btVector3 c;
78
79         btScalar lastLambda = lambda;
80         //btScalar epsilon = btScalar(0.001);
81
82         int numIter = 0;
83         //first solution, using GJK
84
85
86         btTransform identityTrans;
87         identityTrans.setIdentity();
88
89         btSphereShape   raySphere(btScalar(0.0));
90         raySphere.setMargin(btScalar(0.));
91
92
93 //      result.drawCoordSystem(sphereTr);
94
95         btPointCollector        pointCollector1;
96
97         {
98                 
99                 btGjkPairDetector gjk(m_convexA,m_convexB,m_convexA->getShapeType(),m_convexB->getShapeType(),m_convexA->getMargin(),m_convexB->getMargin(),m_simplexSolver,m_penetrationDepthSolver);          
100                 btGjkPairDetector::ClosestPointInput input;
101         
102                 //we don't use margins during CCD
103         //      gjk.setIgnoreMargin(true);
104
105                 input.m_transformA = fromA;
106                 input.m_transformB = fromB;
107                 gjk.getClosestPoints(input,pointCollector1,0);
108
109                 hasResult = pointCollector1.m_hasResult;
110                 c = pointCollector1.m_pointInWorld;
111         }
112
113         if (hasResult)
114         {
115                 btScalar dist;
116                 dist = pointCollector1.m_distance;
117                 n = pointCollector1.m_normalOnBInWorld;
118
119                 btScalar projectedLinearVelocity = relLinVel.dot(n);
120                 
121                 //not close enough
122                 while (dist > radius)
123                 {
124                         if (result.m_debugDrawer)
125                         {
126                                 result.m_debugDrawer->drawSphere(c,0.2f,btVector3(1,1,1));
127                         }
128                         numIter++;
129                         if (numIter > maxIter)
130                         {
131                                 return false; //todo: report a failure
132                         }
133                         btScalar dLambda = btScalar(0.);
134
135                         projectedLinearVelocity = relLinVel.dot(n);
136
137                         //calculate safe moving fraction from distance / (linear+rotational velocity)
138                         
139                         //btScalar clippedDist  = GEN_min(angularConservativeRadius,dist);
140                         //btScalar clippedDist  = dist;
141                         
142                         //don't report time of impact for motion away from the contact normal (or causes minor penetration)
143                         if ((projectedLinearVelocity+ maxAngularProjectedVelocity)<=SIMD_EPSILON)
144                                 return false;
145                         
146                         dLambda = dist / (projectedLinearVelocity+ maxAngularProjectedVelocity);
147
148                         
149                         
150                         lambda = lambda + dLambda;
151
152                         if (lambda > btScalar(1.))
153                                 return false;
154
155                         if (lambda < btScalar(0.))
156                                 return false;
157
158
159                         //todo: next check with relative epsilon
160                         if (lambda <= lastLambda)
161                         {
162                                 return false;
163                                 //n.setValue(0,0,0);
164                                 break;
165                         }
166                         lastLambda = lambda;
167
168                         
169
170                         //interpolate to next lambda
171                         btTransform interpolatedTransA,interpolatedTransB,relativeTrans;
172
173                         btTransformUtil::integrateTransform(fromA,linVelA,angVelA,lambda,interpolatedTransA);
174                         btTransformUtil::integrateTransform(fromB,linVelB,angVelB,lambda,interpolatedTransB);
175                         relativeTrans = interpolatedTransB.inverseTimes(interpolatedTransA);
176
177                         if (result.m_debugDrawer)
178                         {
179                                 result.m_debugDrawer->drawSphere(interpolatedTransA.getOrigin(),0.2f,btVector3(1,0,0));
180                         }
181
182                         result.DebugDraw( lambda );
183
184                         btPointCollector        pointCollector;
185                         btGjkPairDetector gjk(m_convexA,m_convexB,m_simplexSolver,m_penetrationDepthSolver);
186                         btGjkPairDetector::ClosestPointInput input;
187                         input.m_transformA = interpolatedTransA;
188                         input.m_transformB = interpolatedTransB;
189                         gjk.getClosestPoints(input,pointCollector,0);
190                         if (pointCollector.m_hasResult)
191                         {
192                                 if (pointCollector.m_distance < btScalar(0.))
193                                 {
194                                         //degenerate ?!
195                                         result.m_fraction = lastLambda;
196                                         n = pointCollector.m_normalOnBInWorld;
197                                         result.m_normal=n;//.setValue(1,1,1);// = n;
198                                         result.m_hitPoint = pointCollector.m_pointInWorld;
199                                         return true;
200                                 }
201                                 c = pointCollector.m_pointInWorld;              
202                                 n = pointCollector.m_normalOnBInWorld;
203                                 dist = pointCollector.m_distance;
204                         } else
205                         {
206                                 //??
207                                 return false;
208                         }
209                         
210
211                 }
212         
213                 if ((projectedLinearVelocity+ maxAngularProjectedVelocity)<=result.m_allowedPenetration)//SIMD_EPSILON)
214                         return false;
215                         
216                 result.m_fraction = lambda;
217                 result.m_normal = n;
218                 result.m_hitPoint = c;
219                 return true;
220         }
221
222         return false;
223
224 /*
225 //todo:
226         //if movement away from normal, discard result
227         btVector3 move = transBLocalTo.getOrigin() - transBLocalFrom.getOrigin();
228         if (result.m_fraction < btScalar(1.))
229         {
230                 if (move.dot(result.m_normal) <= btScalar(0.))
231                 {
232                 }
233         }
234 */
235
236 }