dali-physics/third-party/bullet3/src/BulletCollision/NarrowPhaseCollision/btGjkConvexCast.cpp

   1 /*
   2 Bullet Continuous Collision Detection and Physics Library
   3 Copyright (c) 2003-2006 Erwin Coumans  https://bulletphysics.org
   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 "btGjkConvexCast.h"
  17 #include "BulletCollision/CollisionShapes/btSphereShape.h"
  18 #include "btGjkPairDetector.h"
  19 #include "btPointCollector.h"
  20 #include "LinearMath/btTransformUtil.h"
  21
  22 #ifdef BT_USE_DOUBLE_PRECISION
  23 #define MAX_ITERATIONS 64
  24 #else
  25 #define MAX_ITERATIONS 32
  26 #endif
  27
  28 btGjkConvexCast::btGjkConvexCast(const btConvexShape* convexA, const btConvexShape* convexB, btSimplexSolverInterface* simplexSolver)
  29         : m_simplexSolver(simplexSolver),
  30           m_convexA(convexA),
  31           m_convexB(convexB)
  32 {
  33 }
  34
  35 bool btGjkConvexCast::calcTimeOfImpact(
  36         const btTransform& fromA,
  37         const btTransform& toA,
  38         const btTransform& fromB,
  39         const btTransform& toB,
  40         CastResult& result)
  41 {
  42         m_simplexSolver->reset();
  43
  44         /// compute linear velocity for this interval, to interpolate
  45         //assume no rotation/angular velocity, assert here?
  46         btVector3 linVelA, linVelB;
  47         linVelA = toA.getOrigin() - fromA.getOrigin();
  48         linVelB = toB.getOrigin() - fromB.getOrigin();
  49
  50         btScalar radius = btScalar(0.001);
  51         btScalar lambda = btScalar(0.);
  52         btVector3 v(1, 0, 0);
  53
  54         int maxIter = MAX_ITERATIONS;
  55
  56         btVector3 n;
  57         n.setValue(btScalar(0.), btScalar(0.), btScalar(0.));
  58         bool hasResult = false;
  59         btVector3 c;
  60         btVector3 r = (linVelA - linVelB);
  61
  62         btScalar lastLambda = lambda;
  63         //btScalar epsilon = btScalar(0.001);
  64
  65         int numIter = 0;
  66         //first solution, using GJK
  67
  68         btTransform identityTrans;
  69         identityTrans.setIdentity();
  70
  71         //      result.drawCoordSystem(sphereTr);
  72
  73         btPointCollector pointCollector;
  74
  75         btGjkPairDetector gjk(m_convexA, m_convexB, m_simplexSolver, 0);  //m_penetrationDepthSolver);
  76         btGjkPairDetector::ClosestPointInput input;
  77
  78         //we don't use margins during CCD
  79         //      gjk.setIgnoreMargin(true);
  80
  81         input.m_transformA = fromA;
  82         input.m_transformB = fromB;
  83         gjk.getClosestPoints(input, pointCollector, 0);
  84
  85         hasResult = pointCollector.m_hasResult;
  86         c = pointCollector.m_pointInWorld;
  87
  88         if (hasResult)
  89         {
  90                 btScalar dist;
  91                 dist = pointCollector.m_distance;
  92                 n = pointCollector.m_normalOnBInWorld;
  93
  94                 //not close enough
  95                 while (dist > radius)
  96                 {
  97                         numIter++;
  98                         if (numIter > maxIter)
  99                         {
 100                                 return false;  //todo: report a failure
 101                         }
 102                         btScalar dLambda = btScalar(0.);
 103
 104                         btScalar projectedLinearVelocity = r.dot(n);
 105
 106                         dLambda = dist / (projectedLinearVelocity);
 107
 108                         lambda = lambda - dLambda;
 109
 110                         if (lambda > btScalar(1.))
 111                                 return false;
 112
 113                         if (lambda < btScalar(0.))
 114                                 return false;
 115
 116                         //todo: next check with relative epsilon
 117                         if (lambda <= lastLambda)
 118                         {
 119                                 return false;
 120                                 //n.setValue(0,0,0);
 121                                 break;
 122                         }
 123                         lastLambda = lambda;
 124
 125                         //interpolate to next lambda
 126                         result.DebugDraw(lambda);
 127                         input.m_transformA.getOrigin().setInterpolate3(fromA.getOrigin(), toA.getOrigin(), lambda);
 128                         input.m_transformB.getOrigin().setInterpolate3(fromB.getOrigin(), toB.getOrigin(), lambda);
 129
 130                         gjk.getClosestPoints(input, pointCollector, 0);
 131                         if (pointCollector.m_hasResult)
 132                         {
 133                                 if (pointCollector.m_distance < btScalar(0.))
 134                                 {
 135                                         result.m_fraction = lastLambda;
 136                                         n = pointCollector.m_normalOnBInWorld;
 137                                         result.m_normal = n;
 138                                         result.m_hitPoint = pointCollector.m_pointInWorld;
 139                                         return true;
 140                                 }
 141                                 c = pointCollector.m_pointInWorld;
 142                                 n = pointCollector.m_normalOnBInWorld;
 143                                 dist = pointCollector.m_distance;
 144                         }
 145                         else
 146                         {
 147                                 //??
 148                                 return false;
 149                         }
 150                 }
 151
 152                 //is n normalized?
 153                 //don't report time of impact for motion away from the contact normal (or causes minor penetration)
 154                 if (n.dot(r) >= -result.m_allowedPenetration)
 155                         return false;
 156
 157                 result.m_fraction = lambda;
 158                 result.m_normal = n;
 159                 result.m_hitPoint = c;
 160                 return true;
 161         }
 162
 163         return false;
 164 }