示例#1
0
        internal GearJoint(IWorldPool argWorldPool, GearJointDef def)
            : base(argWorldPool, def)
        {
            m_joint1 = def.joint1;
            m_joint2 = def.joint2;

            m_typeA = m_joint1.getType();
            m_typeB = m_joint2.getType();

            Debug.Assert(m_typeA == JointType.REVOLUTE || m_typeA == JointType.PRISMATIC);
            Debug.Assert(m_typeB == JointType.REVOLUTE || m_typeB == JointType.PRISMATIC);

            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.REVOLUTE)
            {
                RevoluteJoint revolute = (RevoluteJoint) def.joint1;
                m_localAnchorC.set(revolute.m_localAnchorA);
                m_localAnchorA.set(revolute.m_localAnchorB);
                m_referenceAngleA = revolute.m_referenceAngle;
                m_localAxisC.setZero();

                coordinateA = aA - aC - m_referenceAngleA;
            }
            else
            {
                Vec2 pA = pool.popVec2();
                Vec2 temp = pool.popVec2();
                PrismaticJoint prismatic = (PrismaticJoint) def.joint1;
                m_localAnchorC.set(prismatic.m_localAnchorA);
                m_localAnchorA.set(prismatic.m_localAnchorB);
                m_referenceAngleA = prismatic.m_referenceAngle;
                m_localAxisC.set(prismatic.m_localXAxisA);

                Vec2 pC = m_localAnchorC;
                Rot.mulToOutUnsafe(xfA.q, m_localAnchorA, ref temp);
                temp.addLocal(xfA.p);
                temp.subLocal(xfC.p);
                Rot.mulTransUnsafe(xfC.q, temp, ref pA);
                pA.subLocal(pC);
                coordinateA = Vec2.dot(pA, m_localAxisC);
                pool.pushVec2(2);
            }

            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.REVOLUTE)
            {
                RevoluteJoint revolute = (RevoluteJoint) def.joint2;
                m_localAnchorD.set(revolute.m_localAnchorA);
                m_localAnchorB.set(revolute.m_localAnchorB);
                m_referenceAngleB = revolute.m_referenceAngle;
                m_localAxisD.setZero();

                coordinateB = aB - aD - m_referenceAngleB;
            }
            else
            {
                Vec2 pB = pool.popVec2();
                Vec2 temp = pool.popVec2();
                PrismaticJoint prismatic = (PrismaticJoint) def.joint2;
                m_localAnchorD.set(prismatic.m_localAnchorA);
                m_localAnchorB.set(prismatic.m_localAnchorB);
                m_referenceAngleB = prismatic.m_referenceAngle;
                m_localAxisD.set(prismatic.m_localXAxisA);

                Vec2 pD = m_localAnchorD;
                Rot.mulToOutUnsafe(xfB.q, m_localAnchorB, ref temp);
                temp.addLocal(xfB.p);
                temp.subLocal(xfD.p);
                Rot.mulTransUnsafe(xfD.q, temp, ref pB);
                pB.subLocal(pD);
                coordinateB = Vec2.dot(pB, m_localAxisD);
                pool.pushVec2(2);
            }

            m_ratio = def.ratio;

            m_constant = coordinateA + m_ratio*coordinateB;

            m_impulse = 0.0f;
        }
示例#2
0
        private void drawJoint(Joint joint)
        {
            Body bodyA = joint.getBodyA();
            Body bodyB = joint.getBodyB();
            Transform xf1 = bodyA.getTransform();
            Transform xf2 = bodyB.getTransform();
            Vec2 x1 = xf1.p;
            Vec2 x2 = xf2.p;
            Vec2 p1 = pool.popVec2();
            Vec2 p2 = pool.popVec2();
            joint.getAnchorA(ref p1);
            joint.getAnchorB(ref p2);

            color.set(0.5f, 0.8f, 0.8f);

            switch (joint.getType())
            {
                    // TODO djm write after writing joints
                case JointType.DISTANCE:
                    m_debugDraw.drawSegment(p1, p2, color);
                    break;

                case JointType.PULLEY:
                {
                    PulleyJoint pulley = (PulleyJoint) joint;
                    Vec2 s1 = pulley.getGroundAnchorA();
                    Vec2 s2 = pulley.getGroundAnchorB();
                    m_debugDraw.drawSegment(s1, p1, color);
                    m_debugDraw.drawSegment(s2, p2, color);
                    m_debugDraw.drawSegment(s1, s2, color);
                }
                    break;
                case JointType.CONSTANT_VOLUME:
                case JointType.MOUSE:
                    // don't draw this
                    break;
                default:
                    m_debugDraw.drawSegment(x1, p1, color);
                    m_debugDraw.drawSegment(p1, p2, color);
                    m_debugDraw.drawSegment(x2, p2, color);
                    break;
            }
            pool.pushVec2(2);
        }