internal static Joint Create(JointDef def){
Joint joint = null;
switch (def.type)
{
case JointType.e_distanceJoint:
{
joint = new DistanceJoint((DistanceJointDef)def);
}
break;
case JointType.e_mouseJoint:
{
joint = new MouseJoint((MouseJointDef)def);
}
break;
case JointType.e_prismaticJoint:
{
joint = new PrismaticJoint((PrismaticJointDef)def);
}
break;
case JointType.e_revoluteJoint:
{
joint = new RevoluteJoint((RevoluteJointDef)def);
}
break;
case JointType.e_pulleyJoint:
{
joint = new PulleyJoint((PulleyJointDef)def);
}
break;
case JointType.e_gearJoint:
{
joint = new GearJoint((GearJointDef)def);
}
break;
case JointType.e_wheelJoint:
{
joint = new WheelJoint((WheelJointDef)def);
}
break;
case JointType.e_weldJoint:
{
joint = new WeldJoint((WeldJointDef)def);
}
break;
case JointType.e_frictionJoint:
{
joint = new FrictionJoint((FrictionJointDef)def);
}
break;
case JointType.e_ropeJoint:
{
throw new NotImplementedException();
//joint = new RopeJoint((RopeJointDef)def);
}
break;
case JointType.e_motorJoint:
{
joint = new MotorJoint((MotorJointDef)def);
}
break;
default:
Utilities.Assert(false);
break;
}
return joint;
}
internal GearJoint(GearJointDef def) : base(def)
{
m_joint1 = def.joint1;
m_joint2 = def.joint2;
m_typeA = m_joint1.GetJointType();
m_typeB = m_joint2.GetJointType();
Utilities.Assert(m_typeA == JointType.e_revoluteJoint || m_typeA == JointType.e_prismaticJoint);
Utilities.Assert(m_typeB == JointType.e_revoluteJoint || m_typeB == JointType.e_prismaticJoint);
float coordinateA, coordinateB;
// TODO_ERIN there might be some problem with the joint edges in Joint.
m_bodyC = m_joint1.GetBodyA();
m_bodyA = m_joint1.GetBodyB();
// Get geometry of joint1
Transform xfA = m_bodyA.m_xf;
float aA = m_bodyA.m_sweep.a;
Transform xfC = m_bodyC.m_xf;
float aC = m_bodyC.m_sweep.a;
if (m_typeA == JointType.e_revoluteJoint)
{
RevoluteJoint revolute = (RevoluteJoint)def.joint1;
m_localAnchorC = revolute.m_localAnchorA;
m_localAnchorA = revolute.m_localAnchorB;
m_referenceAngleA = revolute.m_referenceAngle;
m_localAxisC.SetZero();
coordinateA = aA - aC - m_referenceAngleA;
}
else
{
PrismaticJoint prismatic = (PrismaticJoint)def.joint1;
m_localAnchorC = prismatic.m_localAnchorA;
m_localAnchorA = prismatic.m_localAnchorB;
m_referenceAngleA = prismatic.m_referenceAngle;
m_localAxisC = prismatic.m_localXAxisA;
Vec2 pC = m_localAnchorC;
Vec2 pA = Utilities.MulT(xfC.q, Utilities.Mul(xfA.q, m_localAnchorA) + (xfA.p - xfC.p));
coordinateA = Utilities.Dot(pA - pC, m_localAxisC);
}
m_bodyD = m_joint2.GetBodyA();
m_bodyB = m_joint2.GetBodyB();
// Get geometry of joint2
Transform xfB = m_bodyB.m_xf;
float aB = m_bodyB.m_sweep.a;
Transform xfD = m_bodyD.m_xf;
float aD = m_bodyD.m_sweep.a;
if (m_typeB == JointType.e_revoluteJoint)
{
RevoluteJoint revolute = (RevoluteJoint)def.joint2;
m_localAnchorD = revolute.m_localAnchorA;
m_localAnchorB = revolute.m_localAnchorB;
m_referenceAngleB = revolute.m_referenceAngle;
m_localAxisD.SetZero();
coordinateB = aB - aD - m_referenceAngleB;
}
else
{
PrismaticJoint prismatic = (PrismaticJoint)def.joint2;
m_localAnchorD = prismatic.m_localAnchorA;
m_localAnchorB = prismatic.m_localAnchorB;
m_referenceAngleB = prismatic.m_referenceAngle;
m_localAxisD = prismatic.m_localXAxisA;
Vec2 pD = m_localAnchorD;
Vec2 pB = Utilities.MulT(xfD.q, Utilities.Mul(xfB.q, m_localAnchorB) + (xfB.p - xfD.p));
coordinateB = Utilities.Dot(pB - pD, m_localAxisD);
}
m_ratio = def.ratio;
m_constant = coordinateA + m_ratio * coordinateB;
m_impulse = 0.0f;
}