public b2Joint(b2JointDef def)
{
Debug.Assert(def.BodyA != def.BodyB);
m_type = def.JointType;
Prev = null;
Next = null;
m_bodyA = def.BodyA;
m_bodyB = def.BodyB;
m_index = 0;
m_collideConnected = def.CollideConnected;
m_islandFlag = false;
m_userData = def.UserData;
m_edgeA = new b2JointEdge();
m_edgeB = new b2JointEdge();
}
public b2Joint(b2JointDef def)
{
Debug.Assert(def.BodyA != def.BodyB);
m_type = def.JointType;
Prev = null;
Next = null;
m_bodyA = def.BodyA;
m_bodyB = def.BodyB;
m_index = 0;
m_collideConnected = def.CollideConnected;
m_islandFlag = false;
m_userData = def.UserData;
m_edgeA.Joint = null;
m_edgeA.Other = null;
m_edgeA.Prev = null;
m_edgeA.Next = null;
m_edgeB.Joint = null;
m_edgeB.Other = null;
m_edgeB.Prev = null;
m_edgeB.Next = null;
}
public b2GearJoint(b2GearJointDef def)
: base(def)
{
m_joint1 = def.joint1;
m_joint2 = def.joint2;
m_typeA = m_joint1.GetJointType();
m_typeB = m_joint2.GetJointType();
Debug.Assert(m_typeA == b2JointType.e_revoluteJoint || m_typeA == b2JointType.e_prismaticJoint);
Debug.Assert(m_typeB == b2JointType.e_revoluteJoint || m_typeB == b2JointType.e_prismaticJoint);
float coordinateA, coordinateB;
// TODO_ERIN there might be some problem with the joint edges in b2Joint.
m_bodyC = m_joint1.GetBodyA();
m_bodyA = m_joint1.GetBodyB();
// Get geometry of joint1
b2Transform xfA = m_bodyA.XF;
float aA = m_bodyA.Sweep.a;
b2Transform xfC = m_bodyC.XF;
float aC = m_bodyC.Sweep.a;
if (m_typeA == b2JointType.e_revoluteJoint)
{
b2RevoluteJoint revolute = (b2RevoluteJoint)def.joint1;
m_localAnchorC = revolute.GetLocalAnchorA();
m_localAnchorA = revolute.GetLocalAnchorB();
m_referenceAngleA = revolute.GetReferenceAngle();
m_localAxisC.SetZero();
coordinateA = aA - aC - m_referenceAngleA;
}
else
{
b2PrismaticJoint prismatic = (b2PrismaticJoint)def.joint1;
m_localAnchorC = prismatic.GetLocalAnchorA();
m_localAnchorA = prismatic.GetLocalAnchorB();
m_referenceAngleA = prismatic.GetReferenceAngle();
m_localAxisC = prismatic.GetLocalXAxisA();
b2Vec2 pC = m_localAnchorC;
b2Vec2 pA = b2Math.b2MulT(xfC.q, b2Math.b2Mul(xfA.q, m_localAnchorA) + (xfA.p - xfC.p));
coordinateA = b2Math.b2Dot(pA - pC, m_localAxisC);
}
m_bodyD = m_joint2.GetBodyA();
m_bodyB = m_joint2.GetBodyB();
// Get geometry of joint2
b2Transform xfB = m_bodyB.XF;
float aB = m_bodyB.Sweep.a;
b2Transform xfD = m_bodyD.XF;
float aD = m_bodyD.Sweep.a;
if (m_typeB == b2JointType.e_revoluteJoint)
{
b2RevoluteJoint revolute = (b2RevoluteJoint)def.joint2;
m_localAnchorD = revolute.GetLocalAnchorA();
m_localAnchorB = revolute.GetLocalAnchorB();
m_referenceAngleB = revolute.GetReferenceAngle();
m_localAxisD.SetZero();
coordinateB = aB - aD - m_referenceAngleB;
}
else
{
b2PrismaticJoint prismatic = (b2PrismaticJoint)def.joint2;
m_localAnchorD = prismatic.GetLocalAnchorA();
m_localAnchorB = prismatic.GetLocalAnchorB();
m_referenceAngleB = prismatic.GetReferenceAngle();
m_localAxisD = prismatic.GetLocalXAxisA();
b2Vec2 pD = m_localAnchorD;
b2Vec2 pB = b2Math.b2MulT(xfD.q, b2Math.b2Mul(xfB.q, m_localAnchorB) + (xfB.p - xfD.p));
coordinateB = b2Math.b2Dot(pB - pD, m_localAxisD);
}
m_ratio = def.ratio;
m_constant = coordinateA + m_ratio * coordinateB;
m_impulse = 0.0f;
}
public b2GearJoint(b2GearJointDef def)
: base(def)
{
m_joint1 = def.joint1;
m_joint2 = def.joint2;
m_typeA = m_joint1.GetJointType();
m_typeB = m_joint2.GetJointType();
Debug.Assert(m_typeA == b2JointType.e_revoluteJoint || m_typeA == b2JointType.e_prismaticJoint);
Debug.Assert(m_typeB == b2JointType.e_revoluteJoint || m_typeB == b2JointType.e_prismaticJoint);
float coordinateA, coordinateB;
// TODO_ERIN there might be some problem with the joint edges in b2Joint.
m_bodyC = m_joint1.GetBodyA();
m_bodyA = m_joint1.GetBodyB();
// Get geometry of joint1
b2Transform xfA = m_bodyA.XF;
float aA = m_bodyA.Sweep.a;
b2Transform xfC = m_bodyC.XF;
float aC = m_bodyC.Sweep.a;
if (m_typeA == b2JointType.e_revoluteJoint)
{
b2RevoluteJoint revolute = (b2RevoluteJoint)def.joint1;
m_localAnchorC = revolute.GetLocalAnchorA();
m_localAnchorA = revolute.GetLocalAnchorB();
m_referenceAngleA = revolute.GetReferenceAngle();
m_localAxisC.SetZero();
coordinateA = aA - aC - m_referenceAngleA;
}
else
{
b2PrismaticJoint prismatic = (b2PrismaticJoint)def.joint1;
m_localAnchorC = prismatic.GetLocalAnchorA();
m_localAnchorA = prismatic.GetLocalAnchorB();
m_referenceAngleA = prismatic.GetReferenceAngle();
m_localAxisC = prismatic.GetLocalXAxisA();
b2Vec2 pC = m_localAnchorC;
b2Vec2 pA = b2Math.b2MulT(xfC.q, b2Math.b2Mul(xfA.q, m_localAnchorA) + (xfA.p - xfC.p));
coordinateA = b2Math.b2Dot(pA - pC, m_localAxisC);
}
m_bodyD = m_joint2.GetBodyA();
m_bodyB = m_joint2.GetBodyB();
// Get geometry of joint2
b2Transform xfB = m_bodyB.XF;
float aB = m_bodyB.Sweep.a;
b2Transform xfD = m_bodyD.XF;
float aD = m_bodyD.Sweep.a;
if (m_typeB == b2JointType.e_revoluteJoint)
{
b2RevoluteJoint revolute = (b2RevoluteJoint)def.joint2;
m_localAnchorD = revolute.GetLocalAnchorA();
m_localAnchorB = revolute.GetLocalAnchorB();
m_referenceAngleB = revolute.GetReferenceAngle();
m_localAxisD.SetZero();
coordinateB = aB - aD - m_referenceAngleB;
}
else
{
b2PrismaticJoint prismatic = (b2PrismaticJoint)def.joint2;
m_localAnchorD = prismatic.GetLocalAnchorA();
m_localAnchorB = prismatic.GetLocalAnchorB();
m_referenceAngleB = prismatic.GetReferenceAngle();
m_localAxisD = prismatic.GetLocalXAxisA();
b2Vec2 pD = m_localAnchorD;
b2Vec2 pB = b2Math.b2MulT(xfD.q, b2Math.b2Mul(xfB.q, m_localAnchorB) + (xfB.p - xfD.p));
coordinateB = b2Math.b2Dot(pB - pD, m_localAxisD);
}
m_ratio = def.ratio;
m_constant = coordinateA + m_ratio * coordinateB;
m_impulse = 0.0f;
}
public b2JointType GetType()
{
b2JointType ret = (b2JointType)Box2DPINVOKE.b2Joint_GetType(swigCPtr);
return(ret);
}
