real_t HingeJointSW::get_hinge_angle() {
const Vector3 refAxis0 = A->get_transform().basis.xform(m_rbAFrame.basis.get_axis(0));
const Vector3 refAxis1 = A->get_transform().basis.xform(m_rbAFrame.basis.get_axis(1));
const Vector3 swingAxis = B->get_transform().basis.xform(m_rbBFrame.basis.get_axis(1));
return atan2fast(swingAxis.dot(refAxis0), swingAxis.dot(refAxis1));
}
void SliderJointSW::testAngLimits(void) {
m_angDepth = real_t(0.);
m_solveAngLim = false;
if (m_lowerAngLimit <= m_upperAngLimit) {
const Vector3 axisA0 = m_calculatedTransformA.basis.get_axis(1);
const Vector3 axisA1 = m_calculatedTransformA.basis.get_axis(2);
const Vector3 axisB0 = m_calculatedTransformB.basis.get_axis(1);
real_t rot = atan2fast(axisB0.dot(axisA1), axisB0.dot(axisA0));
if (rot < m_lowerAngLimit) {
m_angDepth = rot - m_lowerAngLimit;
m_solveAngLim = true;
} else if (rot > m_upperAngLimit) {
m_angDepth = rot - m_upperAngLimit;
m_solveAngLim = true;
}
}
} // SliderJointSW::testAngLimits()
bool ConeTwistJointSW::setup(real_t p_timestep) {
m_appliedImpulse = real_t(0.);
//set bias, sign, clear accumulator
m_swingCorrection = real_t(0.);
m_twistLimitSign = real_t(0.);
m_solveTwistLimit = false;
m_solveSwingLimit = false;
m_accTwistLimitImpulse = real_t(0.);
m_accSwingLimitImpulse = real_t(0.);
if (!m_angularOnly) {
Vector3 pivotAInW = A->get_transform().xform(m_rbAFrame.origin);
Vector3 pivotBInW = B->get_transform().xform(m_rbBFrame.origin);
Vector3 relPos = pivotBInW - pivotAInW;
Vector3 normal[3];
if (relPos.length_squared() > CMP_EPSILON) {
normal[0] = relPos.normalized();
} else {
normal[0] = Vector3(real_t(1.0), 0, 0);
}
plane_space(normal[0], normal[1], normal[2]);
for (int i = 0; i < 3; i++) {
memnew_placement(&m_jac[i], JacobianEntrySW(
A->get_principal_inertia_axes().transposed(),
B->get_principal_inertia_axes().transposed(),
pivotAInW - A->get_transform().origin - A->get_center_of_mass(),
pivotBInW - B->get_transform().origin - B->get_center_of_mass(),
normal[i],
A->get_inv_inertia(),
A->get_inv_mass(),
B->get_inv_inertia(),
B->get_inv_mass()));
}
}
Vector3 b1Axis1, b1Axis2, b1Axis3;
Vector3 b2Axis1, b2Axis2;
b1Axis1 = A->get_transform().basis.xform(this->m_rbAFrame.basis.get_axis(0));
b2Axis1 = B->get_transform().basis.xform(this->m_rbBFrame.basis.get_axis(0));
real_t swing1 = real_t(0.), swing2 = real_t(0.);
real_t swx = real_t(0.), swy = real_t(0.);
real_t thresh = real_t(10.);
real_t fact;
// Get Frame into world space
if (m_swingSpan1 >= real_t(0.05f)) {
b1Axis2 = A->get_transform().basis.xform(this->m_rbAFrame.basis.get_axis(1));
//swing1 = btAtan2Fast( b2Axis1.dot(b1Axis2),b2Axis1.dot(b1Axis1) );
swx = b2Axis1.dot(b1Axis1);
swy = b2Axis1.dot(b1Axis2);
swing1 = atan2fast(swy, swx);
fact = (swy * swy + swx * swx) * thresh * thresh;
fact = fact / (fact + real_t(1.0));
swing1 *= fact;
}
if (m_swingSpan2 >= real_t(0.05f)) {
b1Axis3 = A->get_transform().basis.xform(this->m_rbAFrame.basis.get_axis(2));
//swing2 = btAtan2Fast( b2Axis1.dot(b1Axis3),b2Axis1.dot(b1Axis1) );
swx = b2Axis1.dot(b1Axis1);
swy = b2Axis1.dot(b1Axis3);
swing2 = atan2fast(swy, swx);
fact = (swy * swy + swx * swx) * thresh * thresh;
fact = fact / (fact + real_t(1.0));
swing2 *= fact;
}
real_t RMaxAngle1Sq = 1.0f / (m_swingSpan1 * m_swingSpan1);
real_t RMaxAngle2Sq = 1.0f / (m_swingSpan2 * m_swingSpan2);
real_t EllipseAngle = Math::abs(swing1 * swing1) * RMaxAngle1Sq + Math::abs(swing2 * swing2) * RMaxAngle2Sq;
if (EllipseAngle > 1.0f) {
m_swingCorrection = EllipseAngle - 1.0f;
m_solveSwingLimit = true;
// Calculate necessary axis & factors
m_swingAxis = b2Axis1.cross(b1Axis2 * b2Axis1.dot(b1Axis2) + b1Axis3 * b2Axis1.dot(b1Axis3));
m_swingAxis.normalize();
real_t swingAxisSign = (b2Axis1.dot(b1Axis1) >= 0.0f) ? 1.0f : -1.0f;
m_swingAxis *= swingAxisSign;
m_kSwing = real_t(1.) / (A->compute_angular_impulse_denominator(m_swingAxis) +
B->compute_angular_impulse_denominator(m_swingAxis));
}
// Twist limits
if (m_twistSpan >= real_t(0.)) {
Vector3 b2Axis2 = B->get_transform().basis.xform(this->m_rbBFrame.basis.get_axis(1));
Quat rotationArc = Quat(b2Axis1, b1Axis1);
Vector3 TwistRef = rotationArc.xform(b2Axis2);
real_t twist = atan2fast(TwistRef.dot(b1Axis3), TwistRef.dot(b1Axis2));
real_t lockedFreeFactor = (m_twistSpan > real_t(0.05f)) ? m_limitSoftness : real_t(0.);
if (twist <= -m_twistSpan * lockedFreeFactor) {
m_twistCorrection = -(twist + m_twistSpan);
m_solveTwistLimit = true;
m_twistAxis = (b2Axis1 + b1Axis1) * 0.5f;
m_twistAxis.normalize();
m_twistAxis *= -1.0f;
m_kTwist = real_t(1.) / (A->compute_angular_impulse_denominator(m_twistAxis) +
B->compute_angular_impulse_denominator(m_twistAxis));
} else if (twist > m_twistSpan * lockedFreeFactor) {
m_twistCorrection = (twist - m_twistSpan);
m_solveTwistLimit = true;
m_twistAxis = (b2Axis1 + b1Axis1) * 0.5f;
m_twistAxis.normalize();
m_kTwist = real_t(1.) / (A->compute_angular_impulse_denominator(m_twistAxis) +
B->compute_angular_impulse_denominator(m_twistAxis));
}
}
return true;
}
