Exemple #1
0
  private void computeBounds(int[] lowerValues, int[] upperValues, AABB aabb) {
    if (debugPrint) {
      System.out.println("ComputeBounds()");
    }
    assert (aabb.upperBound.x > aabb.lowerBound.x);
    assert (aabb.upperBound.y > aabb.lowerBound.y);

    Vec2 minVertex =
        MathUtils.clamp(aabb.lowerBound, m_worldAABB.lowerBound, m_worldAABB.upperBound);
    Vec2 maxVertex =
        MathUtils.clamp(aabb.upperBound, m_worldAABB.lowerBound, m_worldAABB.upperBound);

    // System.out.printf("minV = %f %f, maxV = %f %f
    // \n",aabb.minVertex.x,aabb.minVertex.y,aabb.maxVertex.x,aabb.maxVertex.y);

    // Bump lower bounds downs and upper bounds up. This ensures correct
    // sorting of
    // lower/upper bounds that would have equal values.
    // TODO_ERIN implement fast float to int conversion.
    lowerValues[0] =
        (int) (m_quantizationFactor.x * (minVertex.x - m_worldAABB.lowerBound.x))
            & (Integer.MAX_VALUE - 1);
    upperValues[0] = (int) (m_quantizationFactor.x * (maxVertex.x - m_worldAABB.lowerBound.x)) | 1;

    lowerValues[1] =
        (int) (m_quantizationFactor.y * (minVertex.y - m_worldAABB.lowerBound.y))
            & (Integer.MAX_VALUE - 1);
    upperValues[1] = (int) (m_quantizationFactor.y * (maxVertex.y - m_worldAABB.lowerBound.y)) | 1;
  }
Exemple #2
0
  @Override
  public boolean solvePositionConstraints(final org.jbox2d.dynamics.SolverData data) {
    final Rot qA = pool.popRot();
    final Rot qB = pool.popRot();
    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;

    qA.set(aA);
    qB.set(aB);

    float angularError = 0.0f;
    float positionError = 0.0f;

    boolean fixedRotation = (m_invIA + m_invIB == 0.0f);

    // Solve angular limit constraint.
    if (m_enableLimit && m_limitState != LimitState.INACTIVE && fixedRotation == false) {
      float angle = aB - aA - m_referenceAngle;
      float limitImpulse = 0.0f;

      if (m_limitState == LimitState.EQUAL) {
        // Prevent large angular corrections
        float C =
            MathUtils.clamp(
                angle - m_lowerAngle,
                -Settings.maxAngularCorrection,
                Settings.maxAngularCorrection);
        limitImpulse = -m_motorMass * C;
        angularError = MathUtils.abs(C);
      } else if (m_limitState == LimitState.AT_LOWER) {
        float C = angle - m_lowerAngle;
        angularError = -C;

        // Prevent large angular corrections and allow some slop.
        C = MathUtils.clamp(C + Settings.angularSlop, -Settings.maxAngularCorrection, 0.0f);
        limitImpulse = -m_motorMass * C;
      } else if (m_limitState == LimitState.AT_UPPER) {
        float C = angle - m_upperAngle;
        angularError = C;

        // Prevent large angular corrections and allow some slop.
        C = MathUtils.clamp(C - Settings.angularSlop, 0.0f, Settings.maxAngularCorrection);
        limitImpulse = -m_motorMass * C;
      }

      aA -= m_invIA * limitImpulse;
      aB += m_invIB * limitImpulse;
    }
    // Solve point-to-point constraint.
    {
      qA.set(aA);
      qB.set(aB);

      final Vec2 rA = pool.popVec2();
      final Vec2 rB = pool.popVec2();
      final Vec2 C = pool.popVec2();
      final Vec2 impulse = pool.popVec2();

      Rot.mulToOutUnsafe(qA, C.set(m_localAnchorA).subLocal(m_localCenterA), rA);
      Rot.mulToOutUnsafe(qB, C.set(m_localAnchorB).subLocal(m_localCenterB), rB);
      C.set(cB).addLocal(rB).subLocal(cA).subLocal(rA);
      positionError = C.length();

      float mA = m_invMassA, mB = m_invMassB;
      float iA = m_invIA, iB = m_invIB;

      final org.jbox2d.common.Mat22 K = pool.popMat22();
      K.ex.x = mA + mB + iA * rA.y * rA.y + iB * rB.y * rB.y;
      K.ex.y = -iA * rA.x * rA.y - iB * rB.x * rB.y;
      K.ey.x = K.ex.y;
      K.ey.y = mA + mB + iA * rA.x * rA.x + iB * rB.x * rB.x;
      K.solveToOut(C, impulse);
      impulse.negateLocal();

      cA.x -= mA * impulse.x;
      cA.y -= mA * impulse.y;
      aA -= iA * Vec2.cross(rA, impulse);

      cB.x += mB * impulse.x;
      cB.y += mB * impulse.y;
      aB += iB * Vec2.cross(rB, impulse);

      pool.pushVec2(4);
      pool.pushMat22(1);
    }
    // data.positions[m_indexA].c.set(cA);
    data.positions[m_indexA].a = aA;
    // data.positions[m_indexB].c.set(cB);
    data.positions[m_indexB].a = aB;

    pool.pushRot(2);

    return positionError <= Settings.linearSlop && angularError <= Settings.angularSlop;
  }
Exemple #3
0
  @Override
  public void solveVelocityConstraints(final org.jbox2d.dynamics.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;

    boolean fixedRotation = (iA + iB == 0.0f);

    // Solve motor constraint.
    if (m_enableMotor && m_limitState != LimitState.EQUAL && fixedRotation == false) {
      float Cdot = wB - wA - m_motorSpeed;
      float impulse = -m_motorMass * Cdot;
      float oldImpulse = m_motorImpulse;
      float maxImpulse = data.step.dt * m_maxMotorTorque;
      m_motorImpulse = MathUtils.clamp(m_motorImpulse + impulse, -maxImpulse, maxImpulse);
      impulse = m_motorImpulse - oldImpulse;

      wA -= iA * impulse;
      wB += iB * impulse;
    }
    final Vec2 temp = pool.popVec2();

    // Solve limit constraint.
    if (m_enableLimit && m_limitState != LimitState.INACTIVE && fixedRotation == false) {

      final Vec2 Cdot1 = pool.popVec2();
      final Vec3 Cdot = pool.popVec3();

      // Solve point-to-point constraint
      Vec2.crossToOutUnsafe(wA, m_rA, temp);
      Vec2.crossToOutUnsafe(wB, m_rB, Cdot1);
      Cdot1.addLocal(vB).subLocal(vA).subLocal(temp);
      float Cdot2 = wB - wA;
      Cdot.set(Cdot1.x, Cdot1.y, Cdot2);

      Vec3 impulse = pool.popVec3();
      m_mass.solve33ToOut(Cdot, impulse);
      impulse.negateLocal();

      if (m_limitState == LimitState.EQUAL) {
        m_impulse.addLocal(impulse);
      } else if (m_limitState == LimitState.AT_LOWER) {
        float newImpulse = m_impulse.z + impulse.z;
        if (newImpulse < 0.0f) {
          final Vec2 rhs = pool.popVec2();
          rhs.set(m_mass.ez.x, m_mass.ez.y).mulLocal(m_impulse.z).subLocal(Cdot1);
          m_mass.solve22ToOut(rhs, temp);
          impulse.x = temp.x;
          impulse.y = temp.y;
          impulse.z = -m_impulse.z;
          m_impulse.x += temp.x;
          m_impulse.y += temp.y;
          m_impulse.z = 0.0f;
          pool.pushVec2(1);
        } else {
          m_impulse.addLocal(impulse);
        }
      } else if (m_limitState == LimitState.AT_UPPER) {
        float newImpulse = m_impulse.z + impulse.z;
        if (newImpulse > 0.0f) {
          final Vec2 rhs = pool.popVec2();
          rhs.set(m_mass.ez.x, m_mass.ez.y).mulLocal(m_impulse.z).subLocal(Cdot1);
          m_mass.solve22ToOut(rhs, temp);
          impulse.x = temp.x;
          impulse.y = temp.y;
          impulse.z = -m_impulse.z;
          m_impulse.x += temp.x;
          m_impulse.y += temp.y;
          m_impulse.z = 0.0f;
          pool.pushVec2(1);
        } else {
          m_impulse.addLocal(impulse);
        }
      }
      final Vec2 P = pool.popVec2();

      P.set(impulse.x, impulse.y);

      vA.x -= mA * P.x;
      vA.y -= mA * P.y;
      wA -= iA * (Vec2.cross(m_rA, P) + impulse.z);

      vB.x += mB * P.x;
      vB.y += mB * P.y;
      wB += iB * (Vec2.cross(m_rB, P) + impulse.z);

      pool.pushVec2(2);
      pool.pushVec3(2);
    } else {

      // Solve point-to-point constraint
      Vec2 Cdot = pool.popVec2();
      Vec2 impulse = pool.popVec2();

      Vec2.crossToOutUnsafe(wA, m_rA, temp);
      Vec2.crossToOutUnsafe(wB, m_rB, Cdot);
      Cdot.addLocal(vB).subLocal(vA).subLocal(temp);
      m_mass.solve22ToOut(Cdot.negateLocal(), impulse); // just leave negated

      m_impulse.x += impulse.x;
      m_impulse.y += impulse.y;

      vA.x -= mA * impulse.x;
      vA.y -= mA * impulse.y;
      wA -= iA * Vec2.cross(m_rA, impulse);

      vB.x += mB * impulse.x;
      vB.y += mB * impulse.y;
      wB += iB * Vec2.cross(m_rB, impulse);

      pool.pushVec2(2);
    }

    // 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;

    pool.pushVec2(1);
  }