From 218d4d1394b2af1e60c53df31a24a04e6a5766bd Mon Sep 17 00:00:00 2001
From: "erwin.coumans@gmail.com"
 <erwin.coumans@gmail.com@08e121b0-ae19-0410-a57b-3be3395fd4fd>
Date: Thu, 31 Oct 2013 16:52:32 +0000
Subject: [PATCH] use a separate default cfm for the MLCP solver, it is a very
 sensitive value for Dantzig (and Lemke)

---
 src/BulletDynamics/MLCPSolvers/btMLCPSolver.cpp |  7 ++++---
 src/BulletDynamics/MLCPSolvers/btMLCPSolver.h   | 10 ++++++++++
 2 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/src/BulletDynamics/MLCPSolvers/btMLCPSolver.cpp b/src/BulletDynamics/MLCPSolvers/btMLCPSolver.cpp
index 0243567ae..2892f192f 100644
--- a/src/BulletDynamics/MLCPSolvers/btMLCPSolver.cpp
+++ b/src/BulletDynamics/MLCPSolvers/btMLCPSolver.cpp
@@ -22,7 +22,8 @@ subject to the following restrictions:
 
 btMLCPSolver::btMLCPSolver(	 btMLCPSolverInterface* solver)
 :m_solver(solver),
-m_fallback(0)
+m_fallback(0),
+m_cfm(0.000001)//0.0000001
 {
 }
 
@@ -435,7 +436,7 @@ void btMLCPSolver::createMLCPFast(const btContactSolverInfo& infoGlobal)
 		// add cfm to the diagonal of m_A
 		for ( int i=0; i<m_A.rows(); ++i) 
 		{
-			m_A.setElem(i,i,m_A(i,i)+ infoGlobal.m_globalCfm / infoGlobal.m_timeStep);
+			m_A.setElem(i,i,m_A(i,i)+ m_cfm / infoGlobal.m_timeStep);
 		}
 	}
 				   
@@ -563,7 +564,7 @@ void btMLCPSolver::createMLCP(const btContactSolverInfo& infoGlobal)
 		// add cfm to the diagonal of m_A
 		for ( int i=0; i<m_A.rows(); ++i) 
 		{
-			m_A.setElem(i,i,m_A(i,i)+ infoGlobal.m_globalCfm / infoGlobal.m_timeStep);
+			m_A.setElem(i,i,m_A(i,i)+ m_cfm / infoGlobal.m_timeStep);
 		}
 	}
 
diff --git a/src/BulletDynamics/MLCPSolvers/btMLCPSolver.h b/src/BulletDynamics/MLCPSolvers/btMLCPSolver.h
index f700db51d..b1900f80c 100644
--- a/src/BulletDynamics/MLCPSolvers/btMLCPSolver.h
+++ b/src/BulletDynamics/MLCPSolvers/btMLCPSolver.h
@@ -42,6 +42,7 @@ protected:
 	btConstraintArray m_allConstraintArray;
 	btMLCPSolverInterface* m_solver;
 	int m_fallback;
+	btScalar m_cfm;
 
 	virtual btScalar solveGroupCacheFriendlySetup(btCollisionObject** bodies, int numBodies, btPersistentManifold** manifoldPtr, int numManifolds,btTypedConstraint** constraints,int numConstraints,const btContactSolverInfo& infoGlobal,btIDebugDraw* debugDrawer);
 	virtual btScalar solveGroupCacheFriendlyIterations(btCollisionObject** bodies ,int numBodies,btPersistentManifold** manifoldPtr, int numManifolds,btTypedConstraint** constraints,int numConstraints,const btContactSolverInfo& infoGlobal,btIDebugDraw* debugDrawer);
@@ -70,6 +71,15 @@ public:
 		m_fallback = num;
 	}
 
+	btScalar	getCfm() const
+	{
+		return m_cfm;
+	}
+	void setCfm(btScalar cfm)
+	{
+		m_cfm = cfm;
+	}
+
 	virtual btConstraintSolverType	getSolverType() const
 	{
 		return BT_MLCP_SOLVER;