Method Initialize

DynamicsB2JointPrismatic.go:201–208

Linear constraint (point-to-line) d = p2 - p1 = x2 + r2 - x1 - r1 C = dot(perp, d) Cdot = dot(d, cross(w1, perp)) + dot(perp, v2 + cross(w2, r2) - v1 - cross(w1, r1)) = -dot(perp, v1) - dot(cross(d + r1, perp), w1) + dot(perp, v2) + dot(cross(r2, perp), v2) J = [-perp, -cross(d + r1, perp), perp, cr

(bA *B2Body, bB *B2Body, anchor B2Vec2, axis B2Vec2)

// df = f2 - f1

func (joint *B2PrismaticJointDef) Initialize(bA *B2Body, bB *B2Body, anchor B2Vec2, axis B2Vec2) {
	joint.BodyA = bA
	joint.BodyB = bB
	joint.LocalAnchorA = joint.BodyA.GetLocalPoint(anchor)
	joint.LocalAnchorB = joint.BodyB.GetLocalPoint(anchor)
	joint.LocalAxisA = joint.BodyA.GetLocalVector(axis)
	joint.ReferenceAngle = joint.BodyB.GetAngle() - joint.BodyA.GetAngle()
}

func MakeB2PrismaticJoint(def *B2PrismaticJointDef) *B2PrismaticJoint {
	res := B2PrismaticJoint{