1 files changed, 176 insertions, 0 deletions
diff --git a/extern/bullet2/BulletCollision/NarrowPhaseCollision/btGjkConvexCast.cpp b/extern/bullet2/BulletCollision/NarrowPhaseCollision/btGjkConvexCast.cpp
new file mode 100644
index 00000000000..bef697a0a11
--- /dev/null
+++ b/extern/bullet2/BulletCollision/NarrowPhaseCollision/btGjkConvexCast.cpp
@@ -0,0 +1,176 @@
+/*
+Bullet Continuous Collision Detection and Physics Library
+Copyright (c) 2003-2006 Erwin Coumans  http://continuousphysics.com/Bullet/
+
+This software is provided 'as-is', without any express or implied warranty.
+In no event will the authors be held liable for any damages arising from the use of this software.
+Permission is granted to anyone to use this software for any purpose, 
+including commercial applications, and to alter it and redistribute it freely, 
+subject to the following restrictions:
+
+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.
+2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
+3. This notice may not be removed or altered from any source distribution.
+*/
+
+
+
+#include "btGjkConvexCast.h"
+#include "BulletCollision/CollisionShapes/btSphereShape.h"
+#include "btGjkPairDetector.h"
+#include "btPointCollector.h"
+#include "LinearMath/btTransformUtil.h"
+
+#ifdef BT_USE_DOUBLE_PRECISION
+#define MAX_ITERATIONS 64
+#else
+#define MAX_ITERATIONS 32
+#endif
+
+btGjkConvexCast::btGjkConvexCast(const btConvexShape* convexA,const btConvexShape* convexB,btSimplexSolverInterface* simplexSolver)
+:m_simplexSolver(simplexSolver),
+m_convexA(convexA),
+m_convexB(convexB)
+{
+}
+
+bool	btGjkConvexCast::calcTimeOfImpact(
+					const btTransform& fromA,
+					const btTransform& toA,
+					const btTransform& fromB,
+					const btTransform& toB,
+					CastResult& result)
+{
+
+
+	m_simplexSolver->reset();
+
+	/// compute linear velocity for this interval, to interpolate
+	//assume no rotation/angular velocity, assert here?
+	btVector3 linVelA,linVelB;
+	linVelA = toA.getOrigin()-fromA.getOrigin();
+	linVelB = toB.getOrigin()-fromB.getOrigin();
+
+	btScalar radius = btScalar(0.001);
+	btScalar lambda = btScalar(0.);
+	btVector3 v(1,0,0);
+
+	int maxIter = MAX_ITERATIONS;
+
+	btVector3 n;
+	n.setValue(btScalar(0.),btScalar(0.),btScalar(0.));
+	bool hasResult = false;
+	btVector3 c;
+	btVector3 r = (linVelA-linVelB);
+
+	btScalar lastLambda = lambda;
+	//btScalar epsilon = btScalar(0.001);
+
+	int numIter = 0;
+	//first solution, using GJK
+
+
+	btTransform identityTrans;
+	identityTrans.setIdentity();
+
+
+//	result.drawCoordSystem(sphereTr);
+
+	btPointCollector	pointCollector;
+
+		
+	btGjkPairDetector gjk(m_convexA,m_convexB,m_simplexSolver,0);//m_penetrationDepthSolver);		
+	btGjkPairDetector::ClosestPointInput input;
+
+	//we don't use margins during CCD
+	//	gjk.setIgnoreMargin(true);
+
+	input.m_transformA = fromA;
+	input.m_transformB = fromB;
+	gjk.getClosestPoints(input,pointCollector,0);
+
+	hasResult = pointCollector.m_hasResult;
+	c = pointCollector.m_pointInWorld;
+
+	if (hasResult)
+	{
+		btScalar dist;
+		dist = pointCollector.m_distance;
+		n = pointCollector.m_normalOnBInWorld;
+
+	
+
+		//not close enough
+		while (dist > radius)
+		{
+			numIter++;
+			if (numIter > maxIter)
+			{
+				return false; //todo: report a failure
+			}
+			btScalar dLambda = btScalar(0.);
+
+			btScalar projectedLinearVelocity = r.dot(n);
+			
+			dLambda = dist / (projectedLinearVelocity);
+
+			lambda = lambda - dLambda;
+
+			if (lambda > btScalar(1.))
+				return false;
+
+			if (lambda < btScalar(0.))
+				return false;
+
+			//todo: next check with relative epsilon
+			if (lambda <= lastLambda)
+			{
+				return false;
+				//n.setValue(0,0,0);
+				break;
+			}
+			lastLambda = lambda;
+
+			//interpolate to next lambda
+			result.DebugDraw( lambda );
+			input.m_transformA.getOrigin().setInterpolate3(fromA.getOrigin(),toA.getOrigin(),lambda);
+			input.m_transformB.getOrigin().setInterpolate3(fromB.getOrigin(),toB.getOrigin(),lambda);
+			
+			gjk.getClosestPoints(input,pointCollector,0);
+			if (pointCollector.m_hasResult)
+			{
+				if (pointCollector.m_distance < btScalar(0.))
+				{
+					result.m_fraction = lastLambda;
+					n = pointCollector.m_normalOnBInWorld;
+					result.m_normal=n;
+					result.m_hitPoint = pointCollector.m_pointInWorld;
+					return true;
+				}
+				c = pointCollector.m_pointInWorld;		
+				n = pointCollector.m_normalOnBInWorld;
+				dist = pointCollector.m_distance;
+			} else
+			{
+				//??
+				return false;
+			}
+
+		}
+
+		//is n normalized?
+		//don't report time of impact for motion away from the contact normal (or causes minor penetration)
+		if (n.dot(r)>=-result.m_allowedPenetration)
+			return false;
+
+		result.m_fraction = lambda;
+		result.m_normal = n;
+		result.m_hitPoint = c;
+		return true;
+	}
+
+	return false;
+
+
+}
+