175 lines
4.5 KiB
C++
175 lines
4.5 KiB
C++
/*
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Bullet Continuous Collision Detection and Physics Library
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Copyright (c) 2003-2006 Erwin Coumans http://continuousphysics.com/Bullet/
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This software is provided 'as-is', without any express or implied warranty.
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In no event will the authors be held liable for any damages arising from the use of this software.
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Permission is granted to anyone to use this software for any purpose,
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including commercial applications, and to alter it and redistribute it freely,
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subject to the following restrictions:
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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.
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2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
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3. This notice may not be removed or altered from any source distribution.
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*/
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#include "btGjkConvexCast.h"
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#include "BulletCollision/CollisionShapes/btSphereShape.h"
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#include "BulletCollision/CollisionShapes/btMinkowskiSumShape.h"
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#include "btGjkPairDetector.h"
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#include "btPointCollector.h"
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btGjkConvexCast::btGjkConvexCast(const btConvexShape* convexA,const btConvexShape* convexB,btSimplexSolverInterface* simplexSolver)
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:m_simplexSolver(simplexSolver),
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m_convexA(convexA),
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m_convexB(convexB)
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{
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}
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bool btGjkConvexCast::calcTimeOfImpact(
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const btTransform& fromA,
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const btTransform& toA,
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const btTransform& fromB,
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const btTransform& toB,
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CastResult& result)
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{
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btMinkowskiSumShape combi(m_convexA,m_convexB);
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btMinkowskiSumShape* convex = &combi;
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btTransform rayFromLocalA;
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btTransform rayToLocalA;
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rayFromLocalA = fromA.inverse()* fromB;
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rayToLocalA = toA.inverse()* toB;
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btTransform trA,trB;
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trA = btTransform(fromA);
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trB = btTransform(fromB);
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trA.setOrigin(btPoint3(0,0,0));
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trB.setOrigin(btPoint3(0,0,0));
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convex->setTransformA(trA);
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convex->setTransformB(trB);
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btScalar radius = btScalar(0.01);
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btScalar lambda = btScalar(0.);
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btVector3 s = rayFromLocalA.getOrigin();
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btVector3 r = rayToLocalA.getOrigin()-rayFromLocalA.getOrigin();
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btVector3 x = s;
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btVector3 n;
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n.setValue(0,0,0);
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bool hasResult = false;
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btVector3 c;
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btScalar lastLambda = lambda;
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//first solution, using GJK
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//no penetration support for now, perhaps pass a pointer when we really want it
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btConvexPenetrationDepthSolver* penSolverPtr = 0;
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btTransform identityTrans;
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identityTrans.setIdentity();
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btSphereShape raySphere(btScalar(0.0));
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raySphere.setMargin(btScalar(0.));
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btTransform sphereTr;
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sphereTr.setIdentity();
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sphereTr.setOrigin( rayFromLocalA.getOrigin());
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result.drawCoordSystem(sphereTr);
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{
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btPointCollector pointCollector1;
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btGjkPairDetector gjk(&raySphere,convex,m_simplexSolver,penSolverPtr);
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btGjkPairDetector::ClosestPointInput input;
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input.m_transformA = sphereTr;
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input.m_transformB = identityTrans;
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gjk.getClosestPoints(input,pointCollector1,0);
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hasResult = pointCollector1.m_hasResult;
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c = pointCollector1.m_pointInWorld;
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n = pointCollector1.m_normalOnBInWorld;
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}
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if (hasResult)
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{
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btScalar dist;
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dist = (c-x).length();
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if (dist < radius)
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{
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//penetration
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lastLambda = btScalar(1.);
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}
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//not close enough
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while (dist > radius)
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{
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n = x - c;
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btScalar nDotr = n.dot(r);
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if (nDotr >= -(SIMD_EPSILON*SIMD_EPSILON))
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return false;
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lambda = lambda - n.dot(n) / nDotr;
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if (lambda <= lastLambda)
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break;
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lastLambda = lambda;
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x = s + lambda * r;
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sphereTr.setOrigin( x );
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result.drawCoordSystem(sphereTr);
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btPointCollector pointCollector;
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btGjkPairDetector gjk(&raySphere,convex,m_simplexSolver,penSolverPtr);
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btGjkPairDetector::ClosestPointInput input;
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input.m_transformA = sphereTr;
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input.m_transformB = identityTrans;
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gjk.getClosestPoints(input,pointCollector,0);
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if (pointCollector.m_hasResult)
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{
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if (pointCollector.m_distance < btScalar(0.))
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{
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//degeneracy, report a hit
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result.m_fraction = lastLambda;
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result.m_normal = n;
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return true;
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}
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c = pointCollector.m_pointInWorld;
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dist = (c-x).length();
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} else
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{
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//??
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return false;
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}
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}
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if (lastLambda < btScalar(1.))
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{
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result.m_fraction = lastLambda;
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result.m_normal = n;
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return true;
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}
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}
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return false;
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}
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