Examples with Body org.jbox2d.dynamics.Body used on opensource projects

Example 11 with Body

use of org.jbox2d.dynamics.Body in project libgdx by libgdx.

the class Contact method getWorldManifold.

/**
   * Get the world manifold.
   */
public void getWorldManifold(WorldManifold worldManifold) {
    final Body bodyA = m_fixtureA.getBody();
    final Body bodyB = m_fixtureB.getBody();
    final Shape shapeA = m_fixtureA.getShape();
    final Shape shapeB = m_fixtureB.getShape();
    worldManifold.initialize(m_manifold, bodyA.getTransform(), shapeA.m_radius, bodyB.getTransform(), shapeB.m_radius);
}

Example 12 with Body

use of org.jbox2d.dynamics.Body in project libgdx by libgdx.

the class PositionSolverManifold method init.

public final void init(ContactSolverDef def) {
    // System.out.println("Initializing contact solver");
    m_step = def.step;
    m_count = def.count;
    if (m_positionConstraints.length < m_count) {
        ContactPositionConstraint[] old = m_positionConstraints;
        m_positionConstraints = new ContactPositionConstraint[MathUtils.max(old.length * 2, m_count)];
        System.arraycopy(old, 0, m_positionConstraints, 0, old.length);
        for (int i = old.length; i < m_positionConstraints.length; i++) {
            m_positionConstraints[i] = new ContactPositionConstraint();
        }
    }
    if (m_velocityConstraints.length < m_count) {
        ContactVelocityConstraint[] old = m_velocityConstraints;
        m_velocityConstraints = new ContactVelocityConstraint[MathUtils.max(old.length * 2, m_count)];
        System.arraycopy(old, 0, m_velocityConstraints, 0, old.length);
        for (int i = old.length; i < m_velocityConstraints.length; i++) {
            m_velocityConstraints[i] = new ContactVelocityConstraint();
        }
    }
    m_positions = def.positions;
    m_velocities = def.velocities;
    m_contacts = def.contacts;
    for (int i = 0; i < m_count; ++i) {
        // System.out.println("contacts: " + m_count);
        final Contact contact = m_contacts[i];
        final Fixture fixtureA = contact.m_fixtureA;
        final Fixture fixtureB = contact.m_fixtureB;
        final Shape shapeA = fixtureA.getShape();
        final Shape shapeB = fixtureB.getShape();
        final float radiusA = shapeA.m_radius;
        final float radiusB = shapeB.m_radius;
        final Body bodyA = fixtureA.getBody();
        final Body bodyB = fixtureB.getBody();
        final Manifold manifold = contact.getManifold();
        int pointCount = manifold.pointCount;
        assert (pointCount > 0);
        ContactVelocityConstraint vc = m_velocityConstraints[i];
        vc.friction = contact.m_friction;
        vc.restitution = contact.m_restitution;
        vc.tangentSpeed = contact.m_tangentSpeed;
        vc.indexA = bodyA.m_islandIndex;
        vc.indexB = bodyB.m_islandIndex;
        vc.invMassA = bodyA.m_invMass;
        vc.invMassB = bodyB.m_invMass;
        vc.invIA = bodyA.m_invI;
        vc.invIB = bodyB.m_invI;
        vc.contactIndex = i;
        vc.pointCount = pointCount;
        vc.K.setZero();
        vc.normalMass.setZero();
        ContactPositionConstraint pc = m_positionConstraints[i];
        pc.indexA = bodyA.m_islandIndex;
        pc.indexB = bodyB.m_islandIndex;
        pc.invMassA = bodyA.m_invMass;
        pc.invMassB = bodyB.m_invMass;
        pc.localCenterA.set(bodyA.m_sweep.localCenter);
        pc.localCenterB.set(bodyB.m_sweep.localCenter);
        pc.invIA = bodyA.m_invI;
        pc.invIB = bodyB.m_invI;
        pc.localNormal.set(manifold.localNormal);
        pc.localPoint.set(manifold.localPoint);
        pc.pointCount = pointCount;
        pc.radiusA = radiusA;
        pc.radiusB = radiusB;
        pc.type = manifold.type;
        // System.out.println("contact point count: " + pointCount);
        for (int j = 0; j < pointCount; j++) {
            ManifoldPoint cp = manifold.points[j];
            VelocityConstraintPoint vcp = vc.points[j];
            if (m_step.warmStarting) {
                // assert(cp.normalImpulse == 0);
                // System.out.println("contact normal impulse: " + cp.normalImpulse);
                vcp.normalImpulse = m_step.dtRatio * cp.normalImpulse;
                vcp.tangentImpulse = m_step.dtRatio * cp.tangentImpulse;
            } else {
                vcp.normalImpulse = 0;
                vcp.tangentImpulse = 0;
            }
            vcp.rA.setZero();
            vcp.rB.setZero();
            vcp.normalMass = 0;
            vcp.tangentMass = 0;
            vcp.velocityBias = 0;
            pc.localPoints[j].x = cp.localPoint.x;
            pc.localPoints[j].y = cp.localPoint.y;
        }
    }
}

Example 13 with Body

use of org.jbox2d.dynamics.Body in project libgdx by libgdx.

the class PrismaticJoint method getJointSpeed.

/**
   * Get the current joint translation, usually in meters.
   */
public float getJointSpeed() {
    Body bA = m_bodyA;
    Body bB = m_bodyB;
    Vec2 temp = pool.popVec2();
    Vec2 rA = pool.popVec2();
    Vec2 rB = pool.popVec2();
    Vec2 p1 = pool.popVec2();
    Vec2 p2 = pool.popVec2();
    Vec2 d = pool.popVec2();
    Vec2 axis = pool.popVec2();
    Vec2 temp2 = pool.popVec2();
    Vec2 temp3 = pool.popVec2();
    temp.set(m_localAnchorA).subLocal(bA.m_sweep.localCenter);
    Rot.mulToOutUnsafe(bA.m_xf.q, temp, rA);
    temp.set(m_localAnchorB).subLocal(bB.m_sweep.localCenter);
    Rot.mulToOutUnsafe(bB.m_xf.q, temp, rB);
    p1.set(bA.m_sweep.c).addLocal(rA);
    p2.set(bB.m_sweep.c).addLocal(rB);
    d.set(p2).subLocal(p1);
    Rot.mulToOutUnsafe(bA.m_xf.q, m_localXAxisA, axis);
    Vec2 vA = bA.m_linearVelocity;
    Vec2 vB = bB.m_linearVelocity;
    float wA = bA.m_angularVelocity;
    float wB = bB.m_angularVelocity;
    Vec2.crossToOutUnsafe(wA, axis, temp);
    Vec2.crossToOutUnsafe(wB, rB, temp2);
    Vec2.crossToOutUnsafe(wA, rA, temp3);
    temp2.addLocal(vB).subLocal(vA).subLocal(temp3);
    float speed = Vec2.dot(d, temp) + Vec2.dot(axis, temp2);
    pool.pushVec2(9);
    return speed;
}

Example 14 with Body

use of org.jbox2d.dynamics.Body in project libgdx by libgdx.

the class ParticleSystem method solveViscous.

void solveViscous(final TimeStep step) {
    float viscousStrength = m_viscousStrength;
    for (int k = 0; k < m_bodyContactCount; k++) {
        final ParticleBodyContact contact = m_bodyContactBuffer[k];
        int a = contact.index;
        if ((m_flagsBuffer.data[a] & ParticleType.b2_viscousParticle) != 0) {
            Body b = contact.body;
            float w = contact.weight;
            float m = contact.mass;
            Vec2 p = m_positionBuffer.data[a];
            final Vec2 va = m_velocityBuffer.data[a];
            final float tempX = p.x - b.m_sweep.c.x;
            final float tempY = p.y - b.m_sweep.c.y;
            final float vx = -b.m_angularVelocity * tempY + b.m_linearVelocity.x - va.x;
            final float vy = b.m_angularVelocity * tempX + b.m_linearVelocity.y - va.y;
            final Vec2 f = tempVec;
            final float pInvMass = getParticleInvMass();
            f.x = viscousStrength * m * w * vx;
            f.y = viscousStrength * m * w * vy;
            va.x += pInvMass * f.x;
            va.y += pInvMass * f.y;
            f.x = -f.x;
            f.y = -f.y;
            b.applyLinearImpulse(f, p, true);
        }
    }
    for (int k = 0; k < m_contactCount; k++) {
        final ParticleContact contact = m_contactBuffer[k];
        if ((contact.flags & ParticleType.b2_viscousParticle) != 0) {
            int a = contact.indexA;
            int b = contact.indexB;
            float w = contact.weight;
            final Vec2 va = m_velocityBuffer.data[a];
            final Vec2 vb = m_velocityBuffer.data[b];
            final float vx = vb.x - va.x;
            final float vy = vb.y - va.y;
            final float fx = viscousStrength * w * vx;
            final float fy = viscousStrength * w * vy;
            va.x += fx;
            va.y += fy;
            vb.x -= fx;
            vb.y -= fy;
        }
    }
}

Example 15 with Body

use of org.jbox2d.dynamics.Body in project libgdx by libgdx.

the class WheelJoint method getJointTranslation.

public float getJointTranslation() {
    Body b1 = m_bodyA;
    Body b2 = m_bodyB;
    Vec2 p1 = pool.popVec2();
    Vec2 p2 = pool.popVec2();
    Vec2 axis = pool.popVec2();
    b1.getWorldPointToOut(m_localAnchorA, p1);
    b2.getWorldPointToOut(m_localAnchorA, p2);
    p2.subLocal(p1);
    b1.getWorldVectorToOut(m_localXAxisA, axis);
    float translation = Vec2.dot(p2, axis);
    pool.pushVec2(3);
    return translation;
}