Examples with Vec2 org.jbox2d.common.Vec2 used on opensource projects

Example 56 with Vec2

use of org.jbox2d.common.Vec2 in project libgdx by libgdx.

the class DistanceJoint method initVelocityConstraints.

@Override
public void initVelocityConstraints(final SolverData data) {
    m_indexA = m_bodyA.m_islandIndex;
    m_indexB = m_bodyB.m_islandIndex;
    m_localCenterA.set(m_bodyA.m_sweep.localCenter);
    m_localCenterB.set(m_bodyB.m_sweep.localCenter);
    m_invMassA = m_bodyA.m_invMass;
    m_invMassB = m_bodyB.m_invMass;
    m_invIA = m_bodyA.m_invI;
    m_invIB = m_bodyB.m_invI;
    Vec2 cA = data.positions[m_indexA].c;
    float aA = data.positions[m_indexA].a;
    Vec2 vA = data.velocities[m_indexA].v;
    float wA = data.velocities[m_indexA].w;
    Vec2 cB = data.positions[m_indexB].c;
    float aB = data.positions[m_indexB].a;
    Vec2 vB = data.velocities[m_indexB].v;
    float wB = data.velocities[m_indexB].w;
    final Rot qA = pool.popRot();
    final Rot qB = pool.popRot();
    qA.set(aA);
    qB.set(aB);
    // use m_u as temporary variable
    Rot.mulToOutUnsafe(qA, m_u.set(m_localAnchorA).subLocal(m_localCenterA), m_rA);
    Rot.mulToOutUnsafe(qB, m_u.set(m_localAnchorB).subLocal(m_localCenterB), m_rB);
    m_u.set(cB).addLocal(m_rB).subLocal(cA).subLocal(m_rA);
    pool.pushRot(2);
    // Handle singularity.
    float length = m_u.length();
    if (length > Settings.linearSlop) {
        m_u.x *= 1.0f / length;
        m_u.y *= 1.0f / length;
    } else {
        m_u.set(0.0f, 0.0f);
    }
    float crAu = Vec2.cross(m_rA, m_u);
    float crBu = Vec2.cross(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 * MathUtils.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;
        Vec2 P = pool.popVec2();
        P.set(m_u).mulLocal(m_impulse);
        vA.x -= m_invMassA * P.x;
        vA.y -= m_invMassA * P.y;
        wA -= m_invIA * Vec2.cross(m_rA, P);
        vB.x += m_invMassB * P.x;
        vB.y += m_invMassB * P.y;
        wB += m_invIB * Vec2.cross(m_rB, P);
        pool.pushVec2(1);
    } else {
        m_impulse = 0.0f;
    }
    //    data.velocities[m_indexA].v.set(vA);
    data.velocities[m_indexA].w = wA;
    //    data.velocities[m_indexB].v.set(vB);
    data.velocities[m_indexB].w = wB;
}

Example 57 with Vec2

use of org.jbox2d.common.Vec2 in project libgdx by libgdx.

the class DistanceJointDef method initialize.

/**
   * Initialize the bodies, anchors, and length using the world anchors.
   * 
   * @param b1 First body
   * @param b2 Second body
   * @param anchor1 World anchor on first body
   * @param anchor2 World anchor on second body
   */
public void initialize(final Body b1, final Body b2, final Vec2 anchor1, final Vec2 anchor2) {
    bodyA = b1;
    bodyB = b2;
    localAnchorA.set(bodyA.getLocalPoint(anchor1));
    localAnchorB.set(bodyB.getLocalPoint(anchor2));
    Vec2 d = anchor2.sub(anchor1);
    length = d.length();
}

Example 58 with Vec2

use of org.jbox2d.common.Vec2 in project libgdx by libgdx.

the class FrictionJoint method solveVelocityConstraints.

@Override
public void solveVelocityConstraints(final SolverData data) {
    Vec2 vA = data.velocities[m_indexA].v;
    float wA = data.velocities[m_indexA].w;
    Vec2 vB = data.velocities[m_indexB].v;
    float wB = data.velocities[m_indexB].w;
    float mA = m_invMassA, mB = m_invMassB;
    float iA = m_invIA, iB = m_invIB;
    float h = data.step.dt;
    // Solve angular friction
    {
        float Cdot = wB - wA;
        float impulse = -m_angularMass * Cdot;
        float oldImpulse = m_angularImpulse;
        float maxImpulse = h * m_maxTorque;
        m_angularImpulse = MathUtils.clamp(m_angularImpulse + impulse, -maxImpulse, maxImpulse);
        impulse = m_angularImpulse - oldImpulse;
        wA -= iA * impulse;
        wB += iB * impulse;
    }
    // Solve linear friction
    {
        final Vec2 Cdot = pool.popVec2();
        final Vec2 temp = pool.popVec2();
        Vec2.crossToOutUnsafe(wA, m_rA, temp);
        Vec2.crossToOutUnsafe(wB, m_rB, Cdot);
        Cdot.addLocal(vB).subLocal(vA).subLocal(temp);
        final Vec2 impulse = pool.popVec2();
        Mat22.mulToOutUnsafe(m_linearMass, Cdot, impulse);
        impulse.negateLocal();
        final Vec2 oldImpulse = pool.popVec2();
        oldImpulse.set(m_linearImpulse);
        m_linearImpulse.addLocal(impulse);
        float maxImpulse = h * m_maxForce;
        if (m_linearImpulse.lengthSquared() > maxImpulse * maxImpulse) {
            m_linearImpulse.normalize();
            m_linearImpulse.mulLocal(maxImpulse);
        }
        impulse.set(m_linearImpulse).subLocal(oldImpulse);
        temp.set(impulse).mulLocal(mA);
        vA.subLocal(temp);
        wA -= iA * Vec2.cross(m_rA, impulse);
        temp.set(impulse).mulLocal(mB);
        vB.addLocal(temp);
        wB += iB * Vec2.cross(m_rB, impulse);
    }
    //    data.velocities[m_indexA].v.set(vA);
    if (data.velocities[m_indexA].w != wA) {
        assert (data.velocities[m_indexA].w != wA);
    }
    data.velocities[m_indexA].w = wA;
    //    data.velocities[m_indexB].v.set(vB);
    data.velocities[m_indexB].w = wB;
    pool.pushVec2(4);
}

Example 59 with Vec2

use of org.jbox2d.common.Vec2 in project libgdx by libgdx.

the class FrictionJoint method initVelocityConstraints.

/**
   * @see org.jbox2d.dynamics.joints.Joint#initVelocityConstraints(org.jbox2d.dynamics.TimeStep)
   */
@Override
public void initVelocityConstraints(final SolverData data) {
    m_indexA = m_bodyA.m_islandIndex;
    m_indexB = m_bodyB.m_islandIndex;
    m_localCenterA.set(m_bodyA.m_sweep.localCenter);
    m_localCenterB.set(m_bodyB.m_sweep.localCenter);
    m_invMassA = m_bodyA.m_invMass;
    m_invMassB = m_bodyB.m_invMass;
    m_invIA = m_bodyA.m_invI;
    m_invIB = m_bodyB.m_invI;
    float aA = data.positions[m_indexA].a;
    Vec2 vA = data.velocities[m_indexA].v;
    float wA = data.velocities[m_indexA].w;
    float aB = data.positions[m_indexB].a;
    Vec2 vB = data.velocities[m_indexB].v;
    float wB = data.velocities[m_indexB].w;
    final Vec2 temp = pool.popVec2();
    final Rot qA = pool.popRot();
    final Rot qB = pool.popRot();
    qA.set(aA);
    qB.set(aB);
    // Compute the effective mass matrix.
    Rot.mulToOutUnsafe(qA, temp.set(m_localAnchorA).subLocal(m_localCenterA), m_rA);
    Rot.mulToOutUnsafe(qB, temp.set(m_localAnchorB).subLocal(m_localCenterB), m_rB);
    // J = [-I -r1_skew I r2_skew]
    // [ 0 -1 0 1]
    // r_skew = [-ry; rx]
    // Matlab
    // K = [ mA+r1y^2*iA+mB+r2y^2*iB, -r1y*iA*r1x-r2y*iB*r2x, -r1y*iA-r2y*iB]
    // [ -r1y*iA*r1x-r2y*iB*r2x, mA+r1x^2*iA+mB+r2x^2*iB, r1x*iA+r2x*iB]
    // [ -r1y*iA-r2y*iB, r1x*iA+r2x*iB, iA+iB]
    float mA = m_invMassA, mB = m_invMassB;
    float iA = m_invIA, iB = m_invIB;
    final Mat22 K = pool.popMat22();
    K.ex.x = mA + mB + iA * m_rA.y * m_rA.y + iB * m_rB.y * m_rB.y;
    K.ex.y = -iA * m_rA.x * m_rA.y - iB * m_rB.x * m_rB.y;
    K.ey.x = K.ex.y;
    K.ey.y = mA + mB + iA * m_rA.x * m_rA.x + iB * m_rB.x * m_rB.x;
    K.invertToOut(m_linearMass);
    m_angularMass = iA + iB;
    if (m_angularMass > 0.0f) {
        m_angularMass = 1.0f / m_angularMass;
    }
    if (data.step.warmStarting) {
        // Scale impulses to support a variable time step.
        m_linearImpulse.mulLocal(data.step.dtRatio);
        m_angularImpulse *= data.step.dtRatio;
        final Vec2 P = pool.popVec2();
        P.set(m_linearImpulse);
        temp.set(P).mulLocal(mA);
        vA.subLocal(temp);
        wA -= iA * (Vec2.cross(m_rA, P) + m_angularImpulse);
        temp.set(P).mulLocal(mB);
        vB.addLocal(temp);
        wB += iB * (Vec2.cross(m_rB, P) + m_angularImpulse);
        pool.pushVec2(1);
    } else {
        m_linearImpulse.setZero();
        m_angularImpulse = 0.0f;
    }
    //    data.velocities[m_indexA].v.set(vA);
    if (data.velocities[m_indexA].w != wA) {
        assert (data.velocities[m_indexA].w != wA);
    }
    data.velocities[m_indexA].w = wA;
    //    data.velocities[m_indexB].v.set(vB);
    data.velocities[m_indexB].w = wB;
    pool.pushRot(2);
    pool.pushVec2(1);
    pool.pushMat22(1);
}

Example 60 with Vec2

use of org.jbox2d.common.Vec2 in project libgdx by libgdx.

the class GearJoint method solveVelocityConstraints.

@Override
public void solveVelocityConstraints(SolverData data) {
    Vec2 vA = data.velocities[m_indexA].v;
    float wA = data.velocities[m_indexA].w;
    Vec2 vB = data.velocities[m_indexB].v;
    float wB = data.velocities[m_indexB].w;
    Vec2 vC = data.velocities[m_indexC].v;
    float wC = data.velocities[m_indexC].w;
    Vec2 vD = data.velocities[m_indexD].v;
    float wD = data.velocities[m_indexD].w;
    Vec2 temp1 = pool.popVec2();
    Vec2 temp2 = pool.popVec2();
    float Cdot = Vec2.dot(m_JvAC, temp1.set(vA).subLocal(vC)) + Vec2.dot(m_JvBD, temp2.set(vB).subLocal(vD));
    Cdot += (m_JwA * wA - m_JwC * wC) + (m_JwB * wB - m_JwD * wD);
    pool.pushVec2(2);
    float impulse = -m_mass * Cdot;
    m_impulse += impulse;
    vA.x += (m_mA * impulse) * m_JvAC.x;
    vA.y += (m_mA * impulse) * m_JvAC.y;
    wA += m_iA * impulse * m_JwA;
    vB.x += (m_mB * impulse) * m_JvBD.x;
    vB.y += (m_mB * impulse) * m_JvBD.y;
    wB += m_iB * impulse * m_JwB;
    vC.x -= (m_mC * impulse) * m_JvAC.x;
    vC.y -= (m_mC * impulse) * m_JvAC.y;
    wC -= m_iC * impulse * m_JwC;
    vD.x -= (m_mD * impulse) * m_JvBD.x;
    vD.y -= (m_mD * impulse) * m_JvBD.y;
    wD -= m_iD * impulse * m_JwD;
    // data.velocities[m_indexA].v = vA;
    data.velocities[m_indexA].w = wA;
    // data.velocities[m_indexB].v = vB;
    data.velocities[m_indexB].w = wB;
    // data.velocities[m_indexC].v = vC;
    data.velocities[m_indexC].w = wC;
    // data.velocities[m_indexD].v = vD;
    data.velocities[m_indexD].w = wD;
}