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C# b2Vec2.Length方法代码示例

本文整理汇总了C#中Box2D.Common.b2Vec2.Length方法的典型用法代码示例。如果您正苦于以下问题:C# b2Vec2.Length方法的具体用法?C# b2Vec2.Length怎么用?C# b2Vec2.Length使用的例子?那么恭喜您, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在Box2D.Common.b2Vec2的用法示例。


在下文中一共展示了b2Vec2.Length方法的4个代码示例,这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞,您的评价将有助于系统推荐出更棒的C#代码示例。

示例1: SolveVelocityConstraints

        public override void SolveVelocityConstraints(b2SolverData data)
        {
            b2Vec2 vB = data.velocities[m_indexB].v;
            float wB = data.velocities[m_indexB].w;

            // Cdot = v + cross(w, r)
            b2Vec2 Cdot = vB + b2Math.b2Cross(wB, m_rB);
            b2Vec2 impulse = b2Math.b2Mul(m_mass, -(Cdot + m_C + m_gamma * m_impulse));

            b2Vec2 oldImpulse = m_impulse;
            m_impulse += impulse;
            float maxImpulse = data.step.dt * m_maxForce;
            if (m_impulse.LengthSquared() > maxImpulse * maxImpulse)
            {
                m_impulse *= maxImpulse / m_impulse.Length();
            }
            impulse = m_impulse - oldImpulse;

            vB += m_invMassB * impulse;
            wB += m_invIB * b2Math.b2Cross(m_rB, impulse);

            data.velocities[m_indexB].v = vB;
            data.velocities[m_indexB].w = wB;
        }
开发者ID:homocury,项目名称:cocos2d-xna,代码行数:24,代码来源:b2MouseJoint.cs

示例2: InitVelocityConstraints

        public override void InitVelocityConstraints(b2SolverData data)
        {
            m_indexA = m_bodyA.IslandIndex;
            m_indexB = m_bodyB.IslandIndex;
            m_localCenterA = m_bodyA.Sweep.localCenter;
            m_localCenterB = m_bodyB.Sweep.localCenter;
            m_invMassA = m_bodyA.InvertedMass;
            m_invMassB = m_bodyB.InvertedMass;
            m_invIA = m_bodyA.InvertedI;
            m_invIB = m_bodyB.InvertedI;

            b2Vec2 cA = data.positions[m_indexA].c;
            float aA = data.positions[m_indexA].a;
            b2Vec2 vA = data.velocities[m_indexA].v;
            float wA = data.velocities[m_indexA].w;

            b2Vec2 cB = data.positions[m_indexB].c;
            float aB = data.positions[m_indexB].a;
            b2Vec2 vB = data.velocities[m_indexB].v;
            float wB = data.velocities[m_indexB].w;

            b2Rot qA = new b2Rot(aA);
            b2Rot qB = new b2Rot(aB);

            m_rA = b2Math.b2Mul(qA, m_localAnchorA - m_localCenterA);
            m_rB = b2Math.b2Mul(qB, m_localAnchorB - m_localCenterB);
            m_u = cB + m_rB - cA - m_rA;

            // Handle singularity.
            float length = m_u.Length();
            if (length > b2Settings.b2_linearSlop)
            {
                m_u *= 1.0f / length;
            }
            else
            {
                m_u.Set(0.0f, 0.0f);
            }

            float crAu = b2Math.b2Cross(m_rA, m_u);
            float crBu = b2Math.b2Cross(m_rB, m_u);
            float invMass = m_invMassA + m_invIA * crAu * crAu + m_invMassB + m_invIB * crBu * crBu;

            // Compute the effective mass matrix.
            m_mass = invMass != 0.0f ? 1.0f / invMass : 0.0f;

            if (m_frequencyHz > 0.0f)
            {
                float C = length - m_length;

                // Frequency
                float omega = 2.0f * (float)Math.PI * m_frequencyHz;

                // Damping coefficient
                float d = 2.0f * m_mass * m_dampingRatio * omega;

                // Spring stiffness
                float k = m_mass * omega * omega;

                // magic formulas
                float h = data.step.dt;
                m_gamma = h * (d + h * k);
                m_gamma = m_gamma != 0.0f ? 1.0f / m_gamma : 0.0f;
                m_bias = C * h * k * m_gamma;

                invMass += m_gamma;
                m_mass = invMass != 0.0f ? 1.0f / invMass : 0.0f;
            }
            else
            {
                m_gamma = 0.0f;
                m_bias = 0.0f;
            }

            if (data.step.warmStarting)
            {
                // Scale the impulse to support a variable time step.
                m_impulse *= data.step.dtRatio;

                b2Vec2 P = m_impulse * m_u;
                vA -= m_invMassA * P;
                wA -= m_invIA * b2Math.b2Cross(m_rA, P);
                vB += m_invMassB * P;
                wB += m_invIB * b2Math.b2Cross(m_rB, P);
            }
            else
            {
                m_impulse = 0.0f;
            }

            data.velocities[m_indexA].v = vA;
            data.velocities[m_indexA].w = wA;
            data.velocities[m_indexB].v = vB;
            data.velocities[m_indexB].w = wB;
        }
开发者ID:eickegao,项目名称:cocos2d-xna,代码行数:95,代码来源:b2DistanceJoint.cs

示例3: InitVelocityConstraints

        public override void InitVelocityConstraints(b2SolverData data)
        {
            m_indexA = m_bodyA.IslandIndex;
            m_indexB = m_bodyB.IslandIndex;
            m_localCenterA = m_bodyA.Sweep.localCenter;
            m_localCenterB = m_bodyB.Sweep.localCenter;
            m_invMassA = m_bodyA.InvertedMass;
            m_invMassB = m_bodyB.InvertedMass;
            m_invIA = m_bodyA.InvertedI;
            m_invIB = m_bodyB.InvertedI;

            b2Vec2 cA = data.positions[m_indexA].c;
            float aA = data.positions[m_indexA].a;
            b2Vec2 vA = data.velocities[m_indexA].v;
            float wA = data.velocities[m_indexA].w;

            b2Vec2 cB = data.positions[m_indexB].c;
            float aB = data.positions[m_indexB].a;
            b2Vec2 vB = data.velocities[m_indexB].v;
            float wB = data.velocities[m_indexB].w;

            b2Rot qA = new b2Rot(aA);
            b2Rot qB = new b2Rot(aB);

            m_rA = b2Math.b2Mul(qA, m_localAnchorA - m_localCenterA);
            m_rB = b2Math.b2Mul(qB, m_localAnchorB - m_localCenterB);

            // Get the pulley axes.
            m_uA = cA + m_rA - m_groundAnchorA;
            m_uB = cB + m_rB - m_groundAnchorB;

            float lengthA = m_uA.Length();
            float lengthB = m_uB.Length();

            if (lengthA > 10.0f * b2Settings.b2_linearSlop)
            {
                m_uA *= 1.0f / lengthA;
            }
            else
            {
                m_uA.SetZero();
            }

            if (lengthB > 10.0f * b2Settings.b2_linearSlop)
            {
                m_uB *= 1.0f / lengthB;
            }
            else
            {
                m_uB.SetZero();
            }

            // Compute effective mass.
            float ruA = b2Math.b2Cross(m_rA, m_uA);
            float ruB = b2Math.b2Cross(m_rB, m_uB);

            float mA = m_invMassA + m_invIA * ruA * ruA;
            float mB = m_invMassB + m_invIB * ruB * ruB;

            m_mass = mA + m_ratio * m_ratio * mB;

            if (m_mass > 0.0f)
            {
                m_mass = 1.0f / m_mass;
            }

            if (data.step.warmStarting)
            {
                // Scale impulses to support variable time steps.
                m_impulse *= data.step.dtRatio;

                // Warm starting.
                b2Vec2 PA = -(m_impulse) * m_uA;
                b2Vec2 PB = (-m_ratio * m_impulse) * m_uB;

                vA += m_invMassA * PA;
                wA += m_invIA * b2Math.b2Cross(m_rA, PA);
                vB += m_invMassB * PB;
                wB += m_invIB * b2Math.b2Cross(m_rB, PB);
            }
            else
            {
                m_impulse = 0.0f;
            }

            data.velocities[m_indexA].v = vA;
            data.velocities[m_indexA].w = wA;
            data.velocities[m_indexB].v = vB;
            data.velocities[m_indexB].w = wB;
        }
开发者ID:HarkDev,项目名称:cocos2d-xna,代码行数:90,代码来源:b2PulleyJoint.cs

示例4: InitVelocityConstraints

        public override void InitVelocityConstraints(b2SolverData data)
        {
            m_indexA = m_bodyA.IslandIndex;
            m_indexB = m_bodyB.IslandIndex;
            m_localCenterA = m_bodyA.Sweep.localCenter;
            m_localCenterB = m_bodyB.Sweep.localCenter;
            m_invMassA = m_bodyA.InvertedMass;
            m_invMassB = m_bodyB.InvertedMass;
            m_invIA = m_bodyA.InvertedI;
            m_invIB = m_bodyB.InvertedI;

            b2Vec2 cA = data.positions[m_indexA].c;
            float aA = data.positions[m_indexA].a;
            b2Vec2 vA = data.velocities[m_indexA].v;
            float wA = data.velocities[m_indexA].w;

            b2Vec2 cB = data.positions[m_indexB].c;
            float aB = data.positions[m_indexB].a;
            b2Vec2 vB = data.velocities[m_indexB].v;
            float wB = data.velocities[m_indexB].w;

            b2Rot qA = new b2Rot(aA);
            b2Rot qB = new b2Rot(aB);

            m_rA = b2Math.b2Mul(qA, m_localAnchorA - m_localCenterA);
            m_rB = b2Math.b2Mul(qB, m_localAnchorB - m_localCenterB);
            m_u = cB + m_rB - cA - m_rA;

            m_length = m_u.Length();

            float C = m_length - m_maxLength;
            if (C > 0.0f)
            {
                m_state = b2LimitState.e_atUpperLimit;
            }
            else
            {
                m_state = b2LimitState.e_inactiveLimit;
            }

            if (m_length > b2Settings.b2_linearSlop)
            {
                m_u *= 1.0f / m_length;
            }
            else
            {
                m_u.SetZero();
                m_mass = 0.0f;
                m_impulse = 0.0f;
                return;
            }

            // Compute effective mass.
            float crA = b2Math.b2Cross(m_rA, m_u);
            float crB = b2Math.b2Cross(m_rB, m_u);
            float invMass = m_invMassA + m_invIA * crA * crA + m_invMassB + m_invIB * crB * crB;

            m_mass = invMass != 0.0f ? 1.0f / invMass : 0.0f;

            if (data.step.warmStarting)
            {
                // Scale the impulse to support a variable time step.
                m_impulse *= data.step.dtRatio;

                b2Vec2 P = m_impulse * m_u;
                vA -= m_invMassA * P;
                wA -= m_invIA * b2Math.b2Cross(m_rA, P);
                vB += m_invMassB * P;
                wB += m_invIB * b2Math.b2Cross(m_rB, P);
            }
            else
            {
                m_impulse = 0.0f;
            }

            data.velocities[m_indexA].v = vA;
            data.velocities[m_indexA].w = wA;
            data.velocities[m_indexB].v = vB;
            data.velocities[m_indexB].w = wB;
        }
开发者ID:HarkDev,项目名称:cocos2d-xna,代码行数:80,代码来源:b2RopeJoint.cs


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