// Point-to-point constraint
// Cdot = v2 - v1
// = v2 + cross(w2, r2) - v1 - cross(w1, r1)
// J = [-I -r1_skew I r2_skew ]
// Identity used:
// w k % (rx i + ry j) = w * (-ry i + rx j)
// Angle constraint
// Cdot = w2 - w1
// J = [0 0 -1 0 0 1]
// K = invI1 + invI2
public void Initialize(Body b1, Body b2,
Vector2 anchor1, Vector2 anchor2)
{
bodyA = b1;
bodyB = b2;
localAnchorA = bodyA.GetLocalPoint(anchor1);
localAnchorB = bodyB.GetLocalPoint(anchor2);
}
/// Initialize the bodies, anchors, axis, and reference angle using the world
/// anchor and world axis.
public void Initialize(Body b1, Body b2, Vector2 anchor, Vector2 axis)
{
bodyA = b1;
bodyB = b2;
localAnchorA = bodyA.GetLocalPoint(anchor);
localAnchorB = bodyB.GetLocalPoint(anchor);
localAxisA = bodyA.GetLocalVector(axis);
}
// Point-to-point constraint
// C = p2 - p1
// Cdot = v2 - v1
// = v2 + cross(w2, r2) - v1 - cross(w1, r1)
// J = [-I -r1_skew I r2_skew ]
// Identity used:
// w k % (rx i + ry j) = w * (-ry i + rx j)
// Angle constraint
// C = angle2 - angle1 - referenceAngle
// Cdot = w2 - w1
// J = [0 0 -1 0 0 1]
// K = invI1 + invI2
public void Initialize(Body b1, Body b2, Vector2 anchor)
{
bodyA = b1;
bodyB = b2;
localAnchorA = bodyA.GetLocalPoint(anchor);
localAnchorB = bodyB.GetLocalPoint(anchor);
referenceAngle = bodyB.GetAngle() - bodyA.GetAngle();
}
/// Initialize the bodies, anchors, and reference angle using the world
/// anchor.
public void Initialize(Body b1, Body b2, Vector2 anchor)
{
bodyA = b1;
bodyB = b2;
localAnchorA = bodyA.GetLocalPoint(anchor);
localAnchorB = bodyB.GetLocalPoint(anchor);
referenceAngle = bodyB.GetAngle() - bodyA.GetAngle();
}
/// Initialize the bodies, anchors, axis, and reference angle using the world
/// anchor and world axis.
public void Initialize(Body b1, Body b2, Vector2 anchor, Vector2 axis)
{
bodyA = b1;
bodyB = b2;
localAnchorA = bodyA.GetLocalPoint(anchor);
localAnchorB = bodyB.GetLocalPoint(anchor);
localAxisA = bodyA.GetLocalVector(axis);
}
// Point-to-point constraint
// Cdot = v2 - v1
// = v2 + cross(w2, r2) - v1 - cross(w1, r1)
// J = [-I -r1_skew I r2_skew ]
// Identity used:
// w k % (rx i + ry j) = w * (-ry i + rx j)
// Angle constraint
// Cdot = w2 - w1
// J = [0 0 -1 0 0 1]
// K = invI1 + invI2
public void Initialize(Body b1, Body b2,
Vector2 anchor1, Vector2 anchor2)
{
bodyA = b1;
bodyB = b2;
localAnchorA = bodyA.GetLocalPoint(anchor1);
localAnchorB = bodyB.GetLocalPoint(anchor2);
}
/// Initialize the bodies, anchors, and length using the world
/// anchors.
// 1-D rained system
// m (v2 - v1) = lambda
// v2 + (beta/h) * x1 + gamma * lambda = 0, gamma has units of inverse mass.
// x2 = x1 + h * v2
// 1-D mass-damper-spring system
// m (v2 - v1) + h * d * v2 + h * k *
// C = norm(p2 - p1) - L
// u = (p2 - p1) / norm(p2 - p1)
// Cdot = dot(u, v2 + cross(w2, r2) - v1 - cross(w1, r1))
// J = [-u -cross(r1, u) u cross(r2, u)]
// K = J * invM * JT
// = invMass1 + invI1 * cross(r1, u)^2 + invMass2 + invI2 * cross(r2, u)^2
public void Initialize(Body b1, Body b2,
Vector2 anchor1, Vector2 anchor2, float maxlength)
{
bodyA = b1;
bodyB = b2;
localAnchorA = bodyA.GetLocalPoint(anchor1);
localAnchorB = bodyB.GetLocalPoint(anchor2);
length = maxlength;
}
/// Initialize the bodies, anchors, and length using the world
/// anchors.
// 1-D rained system
// m (v2 - v1) = lambda
// v2 + (beta/h) * x1 + gamma * lambda = 0, gamma has units of inverse mass.
// x2 = x1 + h * v2
// 1-D mass-damper-spring system
// m (v2 - v1) + h * d * v2 + h * k *
// C = norm(p2 - p1) - L
// u = (p2 - p1) / norm(p2 - p1)
// Cdot = dot(u, v2 + cross(w2, r2) - v1 - cross(w1, r1))
// J = [-u -cross(r1, u) u cross(r2, u)]
// K = J * invM * JT
// = invMass1 + invI1 * cross(r1, u)^2 + invMass2 + invI2 * cross(r2, u)^2
public void Initialize(Body b1, Body b2,
Vector2 anchor1, Vector2 anchor2, float maxlength)
{
bodyA = b1;
bodyB = b2;
localAnchorA = bodyA.GetLocalPoint(anchor1);
localAnchorB = bodyB.GetLocalPoint(anchor2);
length = maxlength;
}
/// Initialize the bodies, anchors, and length using the world
/// anchors.
// 1-D rained system
// m (v2 - v1) = lambda
// v2 + (beta/h) * x1 + gamma * lambda = 0, gamma has units of inverse mass.
// x2 = x1 + h * v2
// 1-D mass-damper-spring system
// m (v2 - v1) + h * d * v2 + h * k *
// C = norm(p2 - p1) - L
// u = (p2 - p1) / norm(p2 - p1)
// Cdot = dot(u, v2 + cross(w2, r2) - v1 - cross(w1, r1))
// J = [-u -cross(r1, u) u cross(r2, u)]
// K = J * invM * JT
// = invMass1 + invI1 * cross(r1, u)^2 + invMass2 + invI2 * cross(r2, u)^2
public void Initialize(Body b1, Body b2,
Vector2 anchor1, Vector2 anchor2)
{
bodyA = b1;
bodyB = b2;
localAnchorA = bodyA.GetLocalPoint(anchor1);
localAnchorB = bodyB.GetLocalPoint(anchor2);
Vector2 d = anchor2 - anchor1;
length = d.Length();
}
/// Initialize the bodies, anchors, and length using the world
/// anchors.
// 1-D rained system
// m (v2 - v1) = lambda
// v2 + (beta/h) * x1 + gamma * lambda = 0, gamma has units of inverse mass.
// x2 = x1 + h * v2
// 1-D mass-damper-spring system
// m (v2 - v1) + h * d * v2 + h * k *
// C = norm(p2 - p1) - L
// u = (p2 - p1) / norm(p2 - p1)
// Cdot = dot(u, v2 + cross(w2, r2) - v1 - cross(w1, r1))
// J = [-u -cross(r1, u) u cross(r2, u)]
// K = J * invM * JT
// = invMass1 + invI1 * cross(r1, u)^2 + invMass2 + invI2 * cross(r2, u)^2
public void Initialize(Body b1, Body b2,
Vector2 anchor1, Vector2 anchor2)
{
bodyA = b1;
bodyB = b2;
localAnchorA = bodyA.GetLocalPoint(anchor1);
localAnchorB = bodyB.GetLocalPoint(anchor2);
Vector2 d = anchor2 - anchor1;
length = d.Length();
}
/// Initialize the bodies, anchors, lengths, max lengths, and ratio using the world anchors.
public void Initialize(Body b1, Body b2,
Vector2 ga1, Vector2 ga2,
Vector2 anchor1, Vector2 anchor2,
float r)
{
bodyA = b1;
bodyB = b2;
groundAnchorA = ga1;
groundAnchorB = ga2;
localAnchorA = bodyA.GetLocalPoint(anchor1);
localAnchorB = bodyB.GetLocalPoint(anchor2);
Vector2 d1 = anchor1 - ga1;
lengthA = d1.Length();
Vector2 d2 = anchor2 - ga2;
lengthB = d2.Length();
ratio = r;
Debug.Assert(ratio > Settings.b2_epsilon);
float C = lengthA + ratio * lengthB;
maxLengthA = C - ratio * b2_minPulleyLength;
maxLengthB = (C - b2_minPulleyLength) / ratio;
}
/// <summary>
/// Initialize the bodies, anchors, lengths, max lengths, and ratio using the world anchors.
/// </summary>
/// <param name="b1"></param>
/// <param name="b2"></param>
/// <param name="ga1"></param>
/// <param name="ga2"></param>
/// <param name="anchor1"></param>
/// <param name="anchor2"></param>
/// <param name="r"></param>
public void Initialize(Body b1, Body b2,
Vector2 ga1, Vector2 ga2,
Vector2 anchor1, Vector2 anchor2,
float r)
{
bodyA = b1;
bodyB = b2;
groundAnchorA = ga1;
groundAnchorB = ga2;
localAnchorA = bodyA.GetLocalPoint(anchor1);
localAnchorB = bodyB.GetLocalPoint(anchor2);
Vector2 d1 = anchor1 - ga1;
lengthA = d1.Length();
Vector2 d2 = anchor2 - ga2;
lengthB = d2.Length();
ratio = r;
Debug.Assert(ratio > Settings.b2_epsilon);
float C = lengthA + ratio * lengthB;
maxLengthA = C - ratio * b2_minPulleyLength;
maxLengthB = (C - b2_minPulleyLength) / ratio;
}
