1 files changed, 108 insertions, 0 deletions
diff --git a/thirdparty/bullet/Bullet3Dynamics/ConstraintSolver/b3FixedConstraint.cpp b/thirdparty/bullet/Bullet3Dynamics/ConstraintSolver/b3FixedConstraint.cpp
new file mode 100644
index 0000000000..5e11e74935
--- /dev/null
+++ b/thirdparty/bullet/Bullet3Dynamics/ConstraintSolver/b3FixedConstraint.cpp
@@ -0,0 +1,108 @@
+
+#include "b3FixedConstraint.h"
+#include "Bullet3Collision/NarrowPhaseCollision/shared/b3RigidBodyData.h"
+#include "Bullet3Common/b3TransformUtil.h"
+#include <new>
+
+
+b3FixedConstraint::b3FixedConstraint(int rbA,int rbB, const b3Transform& frameInA,const b3Transform& frameInB)
+:b3TypedConstraint(B3_FIXED_CONSTRAINT_TYPE,rbA,rbB)
+{
+	m_pivotInA = frameInA.getOrigin();
+	m_pivotInB = frameInB.getOrigin();
+	m_relTargetAB = frameInA.getRotation()*frameInB.getRotation().inverse();
+
+}
+
+b3FixedConstraint::~b3FixedConstraint ()
+{
+}
+
+	
+void b3FixedConstraint::getInfo1 (b3ConstraintInfo1* info,const b3RigidBodyData* bodies)
+{
+	info->m_numConstraintRows = 6;
+	info->nub = 6;
+}
+
+void b3FixedConstraint::getInfo2 (b3ConstraintInfo2* info, const b3RigidBodyData* bodies)
+{
+	//fix the 3 linear degrees of freedom
+
+	const b3Vector3& worldPosA = bodies[m_rbA].m_pos;
+	const b3Quaternion& worldOrnA = bodies[m_rbA].m_quat;
+	const b3Vector3& worldPosB= bodies[m_rbB].m_pos;
+	const b3Quaternion& worldOrnB = bodies[m_rbB].m_quat;
+
+	info->m_J1linearAxis[0] = 1;
+	info->m_J1linearAxis[info->rowskip+1] = 1;
+	info->m_J1linearAxis[2*info->rowskip+2] = 1;
+
+	b3Vector3 a1 = b3QuatRotate(worldOrnA,m_pivotInA);
+	{
+		b3Vector3* angular0 = (b3Vector3*)(info->m_J1angularAxis);
+		b3Vector3* angular1 = (b3Vector3*)(info->m_J1angularAxis+info->rowskip);
+		b3Vector3* angular2 = (b3Vector3*)(info->m_J1angularAxis+2*info->rowskip);
+		b3Vector3 a1neg = -a1;
+		a1neg.getSkewSymmetricMatrix(angular0,angular1,angular2);
+	}
+    
+	if (info->m_J2linearAxis)
+	{
+		info->m_J2linearAxis[0] = -1;
+		info->m_J2linearAxis[info->rowskip+1] = -1;
+		info->m_J2linearAxis[2*info->rowskip+2] = -1;
+	}
+	
+	b3Vector3 a2 = b3QuatRotate(worldOrnB,m_pivotInB);
+   
+	{
+	//	b3Vector3 a2n = -a2;
+		b3Vector3* angular0 = (b3Vector3*)(info->m_J2angularAxis);
+		b3Vector3* angular1 = (b3Vector3*)(info->m_J2angularAxis+info->rowskip);
+		b3Vector3* angular2 = (b3Vector3*)(info->m_J2angularAxis+2*info->rowskip);
+		a2.getSkewSymmetricMatrix(angular0,angular1,angular2);
+	}
+
+    // set right hand side for the linear dofs
+	b3Scalar k = info->fps * info->erp;
+	b3Vector3 linearError = k*(a2+worldPosB-a1-worldPosA);
+    int j;
+	for (j=0; j<3; j++)
+    {
+        info->m_constraintError[j*info->rowskip] = linearError[j];
+		//printf("info->m_constraintError[%d]=%f\n",j,info->m_constraintError[j]);
+    }
+
+		//fix the 3 angular degrees of freedom
+
+	int start_row = 3;
+	int s = info->rowskip;
+    int start_index = start_row * s;
+
+    // 3 rows to make body rotations equal
+	info->m_J1angularAxis[start_index] = 1;
+    info->m_J1angularAxis[start_index + s + 1] = 1;
+    info->m_J1angularAxis[start_index + s*2+2] = 1;
+    if ( info->m_J2angularAxis)
+    {
+        info->m_J2angularAxis[start_index] = -1;
+        info->m_J2angularAxis[start_index + s+1] = -1;
+        info->m_J2angularAxis[start_index + s*2+2] = -1;
+    }
+
+
+    // set right hand side for the angular dofs
+
+	b3Vector3 diff;
+	b3Scalar angle;
+	b3Quaternion qrelCur = worldOrnA *worldOrnB.inverse();
+
+	b3TransformUtil::calculateDiffAxisAngleQuaternion(m_relTargetAB,qrelCur,diff,angle);
+	diff*=-angle;
+	for (j=0; j<3; j++)
+    {
+        info->m_constraintError[(3+j)*info->rowskip] = k * diff[j];
+    }
+
+}
+\ No newline at end of file