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

Example 11 with Rot

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

the class MotorJoint method initVelocityConstraints.

@Override
public void initVelocityConstraints(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;
    final Vec2 cA = data.positions[m_indexA].c;
    float aA = data.positions[m_indexA].a;
    final Vec2 vA = data.velocities[m_indexA].v;
    float wA = data.velocities[m_indexA].w;
    final Vec2 cB = data.positions[m_indexB].c;
    float aB = data.positions[m_indexB].a;
    final Vec2 vB = data.velocities[m_indexB].v;
    float wB = data.velocities[m_indexB].w;
    final Rot qA = pool.popRot();
    final Rot qB = pool.popRot();
    final Vec2 temp = pool.popVec2();
    Mat22 K = pool.popMat22();
    qA.set(aA);
    qB.set(aB);
    // Compute the effective mass matrix.
    // m_rA = b2Mul(qA, -m_localCenterA);
    // m_rB = b2Mul(qB, -m_localCenterB);
    m_rA.x = qA.c * -m_localCenterA.x - qA.s * -m_localCenterA.y;
    m_rA.y = qA.s * -m_localCenterA.x + qA.c * -m_localCenterA.y;
    m_rB.x = qB.c * -m_localCenterB.x - qB.s * -m_localCenterB.y;
    m_rB.y = qB.s * -m_localCenterB.x + qB.c * -m_localCenterB.y;
    // 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;
    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;
    }
    // m_linearError = cB + m_rB - cA - m_rA - b2Mul(qA, m_linearOffset);
    Rot.mulToOutUnsafe(qA, m_linearOffset, temp);
    m_linearError.x = cB.x + m_rB.x - cA.x - m_rA.x - temp.x;
    m_linearError.y = cB.y + m_rB.y - cA.y - m_rA.y - temp.y;
    m_angularError = aB - aA - m_angularOffset;
    if (data.step.warmStarting) {
        // Scale impulses to support a variable time step.
        m_linearImpulse.x *= data.step.dtRatio;
        m_linearImpulse.y *= data.step.dtRatio;
        m_angularImpulse *= data.step.dtRatio;
        final Vec2 P = m_linearImpulse;
        vA.x -= mA * P.x;
        vA.y -= mA * P.y;
        wA -= iA * (m_rA.x * P.y - m_rA.y * P.x + m_angularImpulse);
        vB.x += mB * P.x;
        vB.y += mB * P.y;
        wB += iB * (m_rB.x * P.y - m_rB.y * P.x + m_angularImpulse);
    } else {
        m_linearImpulse.setZero();
        m_angularImpulse = 0.0f;
    }
    pool.pushVec2(1);
    pool.pushMat22(1);
    pool.pushRot(2);
    // data.velocities[m_indexA].v = vA;
    data.velocities[m_indexA].w = wA;
    // data.velocities[m_indexB].v = vB;
    data.velocities[m_indexB].w = wB;
}

Example 12 with Rot

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

the class MouseJoint method initVelocityConstraints.

@Override
public void initVelocityConstraints(final SolverData data) {
    m_indexB = m_bodyB.m_islandIndex;
    m_localCenterB.set(m_bodyB.m_sweep.localCenter);
    m_invMassB = m_bodyB.m_invMass;
    m_invIB = m_bodyB.m_invI;
    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 qB = pool.popRot();
    qB.set(aB);
    float mass = m_bodyB.getMass();
    // Frequency
    float omega = 2.0f * MathUtils.PI * m_frequencyHz;
    // Damping coefficient
    float d = 2.0f * mass * m_dampingRatio * omega;
    // Spring stiffness
    float k = mass * (omega * omega);
    // magic formulas
    // gamma has units of inverse mass.
    // beta has units of inverse time.
    float h = data.step.dt;
    assert (d + h * k > Settings.EPSILON);
    m_gamma = h * (d + h * k);
    if (m_gamma != 0.0f) {
        m_gamma = 1.0f / m_gamma;
    }
    m_beta = h * k * m_gamma;
    Vec2 temp = pool.popVec2();
    // Compute the effective mass matrix.
    Rot.mulToOutUnsafe(qB, temp.set(m_localAnchorB).subLocal(m_localCenterB), m_rB);
    // K = [(1/m1 + 1/m2) * eye(2) - skew(r1) * invI1 * skew(r1) - skew(r2) * invI2 * skew(r2)]
    // = [1/m1+1/m2 0 ] + invI1 * [r1.y*r1.y -r1.x*r1.y] + invI2 * [r1.y*r1.y -r1.x*r1.y]
    // [ 0 1/m1+1/m2] [-r1.x*r1.y r1.x*r1.x] [-r1.x*r1.y r1.x*r1.x]
    final Mat22 K = pool.popMat22();
    K.ex.x = m_invMassB + m_invIB * m_rB.y * m_rB.y + m_gamma;
    K.ex.y = -m_invIB * m_rB.x * m_rB.y;
    K.ey.x = K.ex.y;
    K.ey.y = m_invMassB + m_invIB * m_rB.x * m_rB.x + m_gamma;
    K.invertToOut(m_mass);
    m_C.set(cB).addLocal(m_rB).subLocal(m_targetA);
    m_C.mulLocal(m_beta);
    // Cheat with some damping
    wB *= 0.98f;
    if (data.step.warmStarting) {
        m_impulse.mulLocal(data.step.dtRatio);
        vB.x += m_invMassB * m_impulse.x;
        vB.y += m_invMassB * m_impulse.y;
        wB += m_invIB * Vec2.cross(m_rB, m_impulse);
    } else {
        m_impulse.setZero();
    }
    //    data.velocities[m_indexB].v.set(vB);
    data.velocities[m_indexB].w = wB;
    pool.pushVec2(1);
    pool.pushMat22(1);
    pool.pushRot(1);
}

Example 13 with Rot

use of org.jbox2d.common.Rot 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 14 with Rot

use of org.jbox2d.common.Rot 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 15 with Rot

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

the class GearJoint method solvePositionConstraints.

@Override
public boolean solvePositionConstraints(SolverData data) {
    Vec2 cA = data.positions[m_indexA].c;
    float aA = data.positions[m_indexA].a;
    Vec2 cB = data.positions[m_indexB].c;
    float aB = data.positions[m_indexB].a;
    Vec2 cC = data.positions[m_indexC].c;
    float aC = data.positions[m_indexC].a;
    Vec2 cD = data.positions[m_indexD].c;
    float aD = data.positions[m_indexD].a;
    Rot qA = pool.popRot(), qB = pool.popRot(), qC = pool.popRot(), qD = pool.popRot();
    qA.set(aA);
    qB.set(aB);
    qC.set(aC);
    qD.set(aD);
    float linearError = 0.0f;
    float coordinateA, coordinateB;
    Vec2 temp = pool.popVec2();
    Vec2 JvAC = pool.popVec2();
    Vec2 JvBD = pool.popVec2();
    float JwA, JwB, JwC, JwD;
    float mass = 0.0f;
    if (m_typeA == JointType.REVOLUTE) {
        JvAC.setZero();
        JwA = 1.0f;
        JwC = 1.0f;
        mass += m_iA + m_iC;
        coordinateA = aA - aC - m_referenceAngleA;
    } else {
        Vec2 rC = pool.popVec2();
        Vec2 rA = pool.popVec2();
        Vec2 pC = pool.popVec2();
        Vec2 pA = pool.popVec2();
        Rot.mulToOutUnsafe(qC, m_localAxisC, JvAC);
        Rot.mulToOutUnsafe(qC, temp.set(m_localAnchorC).subLocal(m_lcC), rC);
        Rot.mulToOutUnsafe(qA, temp.set(m_localAnchorA).subLocal(m_lcA), rA);
        JwC = Vec2.cross(rC, JvAC);
        JwA = Vec2.cross(rA, JvAC);
        mass += m_mC + m_mA + m_iC * JwC * JwC + m_iA * JwA * JwA;
        pC.set(m_localAnchorC).subLocal(m_lcC);
        Rot.mulTransUnsafe(qC, temp.set(rA).addLocal(cA).subLocal(cC), pA);
        coordinateA = Vec2.dot(pA.subLocal(pC), m_localAxisC);
        pool.pushVec2(4);
    }
    if (m_typeB == JointType.REVOLUTE) {
        JvBD.setZero();
        JwB = m_ratio;
        JwD = m_ratio;
        mass += m_ratio * m_ratio * (m_iB + m_iD);
        coordinateB = aB - aD - m_referenceAngleB;
    } else {
        Vec2 u = pool.popVec2();
        Vec2 rD = pool.popVec2();
        Vec2 rB = pool.popVec2();
        Vec2 pD = pool.popVec2();
        Vec2 pB = pool.popVec2();
        Rot.mulToOutUnsafe(qD, m_localAxisD, u);
        Rot.mulToOutUnsafe(qD, temp.set(m_localAnchorD).subLocal(m_lcD), rD);
        Rot.mulToOutUnsafe(qB, temp.set(m_localAnchorB).subLocal(m_lcB), rB);
        JvBD.set(u).mulLocal(m_ratio);
        JwD = Vec2.cross(rD, u);
        JwB = Vec2.cross(rB, u);
        mass += m_ratio * m_ratio * (m_mD + m_mB) + m_iD * JwD * JwD + m_iB * JwB * JwB;
        pD.set(m_localAnchorD).subLocal(m_lcD);
        Rot.mulTransUnsafe(qD, temp.set(rB).addLocal(cB).subLocal(cD), pB);
        coordinateB = Vec2.dot(pB.subLocal(pD), m_localAxisD);
        pool.pushVec2(5);
    }
    float C = (coordinateA + m_ratio * coordinateB) - m_constant;
    float impulse = 0.0f;
    if (mass > 0.0f) {
        impulse = -C / mass;
    }
    pool.pushVec2(3);
    pool.pushRot(4);
    cA.x += (m_mA * impulse) * JvAC.x;
    cA.y += (m_mA * impulse) * JvAC.y;
    aA += m_iA * impulse * JwA;
    cB.x += (m_mB * impulse) * JvBD.x;
    cB.y += (m_mB * impulse) * JvBD.y;
    aB += m_iB * impulse * JwB;
    cC.x -= (m_mC * impulse) * JvAC.x;
    cC.y -= (m_mC * impulse) * JvAC.y;
    aC -= m_iC * impulse * JwC;
    cD.x -= (m_mD * impulse) * JvBD.x;
    cD.y -= (m_mD * impulse) * JvBD.y;
    aD -= m_iD * impulse * JwD;
    // data.positions[m_indexA].c = cA;
    data.positions[m_indexA].a = aA;
    // data.positions[m_indexB].c = cB;
    data.positions[m_indexB].a = aB;
    // data.positions[m_indexC].c = cC;
    data.positions[m_indexC].a = aC;
    // data.positions[m_indexD].c = cD;
    data.positions[m_indexD].a = aD;
    // TODO_ERIN not implemented
    return linearError < Settings.linearSlop;
}