godot/servers/physics/joints/slider_joint_sw.cpp

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/*************************************************************************/
/* slider_joint_sw.cpp */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* http://www.godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2017 Juan Linietsky, Ariel Manzur. */
/* */
/* Permission is hereby granted, free of charge, to any person obtaining */
/* a copy of this software and associated documentation files (the */
/* "Software"), to deal in the Software without restriction, including */
/* without limitation the rights to use, copy, modify, merge, publish, */
/* distribute, sublicense, and/or sell copies of the Software, and to */
/* permit persons to whom the Software is furnished to do so, subject to */
/* the following conditions: */
/* */
/* The above copyright notice and this permission notice shall be */
/* included in all copies or substantial portions of the Software. */
/* */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */
/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, */
/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */
/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
/*************************************************************************/
/*
Adapted to Godot from the Bullet library.
See corresponding header file for licensing info.
*/
#include "slider_joint_sw.h"
//-----------------------------------------------------------------------------
static _FORCE_INLINE_ real_t atan2fast(real_t y, real_t x) {
real_t coeff_1 = Math_PI / 4.0f;
real_t coeff_2 = 3.0f * coeff_1;
real_t abs_y = Math::abs(y);
real_t angle;
if (x >= 0.0f) {
real_t r = (x - abs_y) / (x + abs_y);
angle = coeff_1 - coeff_1 * r;
} else {
real_t r = (x + abs_y) / (abs_y - x);
angle = coeff_2 - coeff_1 * r;
}
return (y < 0.0f) ? -angle : angle;
}
void SliderJointSW::initParams() {
m_lowerLinLimit = real_t(1.0);
m_upperLinLimit = real_t(-1.0);
m_lowerAngLimit = real_t(0.);
m_upperAngLimit = real_t(0.);
m_softnessDirLin = SLIDER_CONSTRAINT_DEF_SOFTNESS;
m_restitutionDirLin = SLIDER_CONSTRAINT_DEF_RESTITUTION;
m_dampingDirLin = real_t(0.);
m_softnessDirAng = SLIDER_CONSTRAINT_DEF_SOFTNESS;
m_restitutionDirAng = SLIDER_CONSTRAINT_DEF_RESTITUTION;
m_dampingDirAng = real_t(0.);
m_softnessOrthoLin = SLIDER_CONSTRAINT_DEF_SOFTNESS;
m_restitutionOrthoLin = SLIDER_CONSTRAINT_DEF_RESTITUTION;
m_dampingOrthoLin = SLIDER_CONSTRAINT_DEF_DAMPING;
m_softnessOrthoAng = SLIDER_CONSTRAINT_DEF_SOFTNESS;
m_restitutionOrthoAng = SLIDER_CONSTRAINT_DEF_RESTITUTION;
m_dampingOrthoAng = SLIDER_CONSTRAINT_DEF_DAMPING;
m_softnessLimLin = SLIDER_CONSTRAINT_DEF_SOFTNESS;
m_restitutionLimLin = SLIDER_CONSTRAINT_DEF_RESTITUTION;
m_dampingLimLin = SLIDER_CONSTRAINT_DEF_DAMPING;
m_softnessLimAng = SLIDER_CONSTRAINT_DEF_SOFTNESS;
m_restitutionLimAng = SLIDER_CONSTRAINT_DEF_RESTITUTION;
m_dampingLimAng = SLIDER_CONSTRAINT_DEF_DAMPING;
m_poweredLinMotor = false;
m_targetLinMotorVelocity = real_t(0.);
m_maxLinMotorForce = real_t(0.);
m_accumulatedLinMotorImpulse = real_t(0.0);
m_poweredAngMotor = false;
m_targetAngMotorVelocity = real_t(0.);
m_maxAngMotorForce = real_t(0.);
m_accumulatedAngMotorImpulse = real_t(0.0);
} // SliderJointSW::initParams()
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
SliderJointSW::SliderJointSW(BodySW *rbA, BodySW *rbB, const Transform &frameInA, const Transform &frameInB)
: JointSW(_arr, 2), m_frameInA(frameInA), m_frameInB(frameInB) {
A = rbA;
B = rbB;
A->add_constraint(this, 0);
B->add_constraint(this, 1);
initParams();
} // SliderJointSW::SliderJointSW()
//-----------------------------------------------------------------------------
bool SliderJointSW::setup(float p_step) {
//calculate transforms
m_calculatedTransformA = A->get_transform() * m_frameInA;
m_calculatedTransformB = B->get_transform() * m_frameInB;
m_realPivotAInW = m_calculatedTransformA.origin;
m_realPivotBInW = m_calculatedTransformB.origin;
m_sliderAxis = m_calculatedTransformA.basis.get_axis(0); // along X
m_delta = m_realPivotBInW - m_realPivotAInW;
m_projPivotInW = m_realPivotAInW + m_sliderAxis.dot(m_delta) * m_sliderAxis;
m_relPosA = m_projPivotInW - A->get_transform().origin;
m_relPosB = m_realPivotBInW - B->get_transform().origin;
Vector3 normalWorld;
int i;
//linear part
for (i = 0; i < 3; i++) {
normalWorld = m_calculatedTransformA.basis.get_axis(i);
memnew_placement(&m_jacLin[i], JacobianEntrySW(
A->get_transform().basis.transposed(),
B->get_transform().basis.transposed(),
m_relPosA,
m_relPosB,
normalWorld,
A->get_inv_inertia(),
A->get_inv_mass(),
B->get_inv_inertia(),
B->get_inv_mass()));
m_jacLinDiagABInv[i] = real_t(1.) / m_jacLin[i].getDiagonal();
m_depth[i] = m_delta.dot(normalWorld);
}
testLinLimits();
// angular part
for (i = 0; i < 3; i++) {
normalWorld = m_calculatedTransformA.basis.get_axis(i);
memnew_placement(&m_jacAng[i], JacobianEntrySW(
normalWorld,
A->get_transform().basis.transposed(),
B->get_transform().basis.transposed(),
A->get_inv_inertia(),
B->get_inv_inertia()));
}
testAngLimits();
Vector3 axisA = m_calculatedTransformA.basis.get_axis(0);
m_kAngle = real_t(1.0) / (A->compute_angular_impulse_denominator(axisA) + B->compute_angular_impulse_denominator(axisA));
// clear accumulator for motors
m_accumulatedLinMotorImpulse = real_t(0.0);
m_accumulatedAngMotorImpulse = real_t(0.0);
return true;
} // SliderJointSW::buildJacobianInt()
//-----------------------------------------------------------------------------
void SliderJointSW::solve(real_t p_step) {
int i;
// linear
Vector3 velA = A->get_velocity_in_local_point(m_relPosA);
Vector3 velB = B->get_velocity_in_local_point(m_relPosB);
Vector3 vel = velA - velB;
for (i = 0; i < 3; i++) {
const Vector3 &normal = m_jacLin[i].m_linearJointAxis;
real_t rel_vel = normal.dot(vel);
// calculate positional error
real_t depth = m_depth[i];
// get parameters
real_t softness = (i) ? m_softnessOrthoLin : (m_solveLinLim ? m_softnessLimLin : m_softnessDirLin);
real_t restitution = (i) ? m_restitutionOrthoLin : (m_solveLinLim ? m_restitutionLimLin : m_restitutionDirLin);
real_t damping = (i) ? m_dampingOrthoLin : (m_solveLinLim ? m_dampingLimLin : m_dampingDirLin);
// calcutate and apply impulse
real_t normalImpulse = softness * (restitution * depth / p_step - damping * rel_vel) * m_jacLinDiagABInv[i];
Vector3 impulse_vector = normal * normalImpulse;
A->apply_impulse(m_relPosA, impulse_vector);
B->apply_impulse(m_relPosB, -impulse_vector);
if (m_poweredLinMotor && (!i)) { // apply linear motor
if (m_accumulatedLinMotorImpulse < m_maxLinMotorForce) {
real_t desiredMotorVel = m_targetLinMotorVelocity;
real_t motor_relvel = desiredMotorVel + rel_vel;
normalImpulse = -motor_relvel * m_jacLinDiagABInv[i];
// clamp accumulated impulse
real_t new_acc = m_accumulatedLinMotorImpulse + Math::abs(normalImpulse);
if (new_acc > m_maxLinMotorForce) {
new_acc = m_maxLinMotorForce;
}
real_t del = new_acc - m_accumulatedLinMotorImpulse;
if (normalImpulse < real_t(0.0)) {
normalImpulse = -del;
} else {
normalImpulse = del;
}
m_accumulatedLinMotorImpulse = new_acc;
// apply clamped impulse
impulse_vector = normal * normalImpulse;
A->apply_impulse(m_relPosA, impulse_vector);
B->apply_impulse(m_relPosB, -impulse_vector);
}
}
}
// angular
// get axes in world space
Vector3 axisA = m_calculatedTransformA.basis.get_axis(0);
Vector3 axisB = m_calculatedTransformB.basis.get_axis(0);
const Vector3 &angVelA = A->get_angular_velocity();
const Vector3 &angVelB = B->get_angular_velocity();
Vector3 angVelAroundAxisA = axisA * axisA.dot(angVelA);
Vector3 angVelAroundAxisB = axisB * axisB.dot(angVelB);
Vector3 angAorthog = angVelA - angVelAroundAxisA;
Vector3 angBorthog = angVelB - angVelAroundAxisB;
Vector3 velrelOrthog = angAorthog - angBorthog;
//solve orthogonal angular velocity correction
real_t len = velrelOrthog.length();
if (len > real_t(0.00001)) {
Vector3 normal = velrelOrthog.normalized();
real_t denom = A->compute_angular_impulse_denominator(normal) + B->compute_angular_impulse_denominator(normal);
velrelOrthog *= (real_t(1.) / denom) * m_dampingOrthoAng * m_softnessOrthoAng;
}
//solve angular positional correction
Vector3 angularError = axisA.cross(axisB) * (real_t(1.) / p_step);
real_t len2 = angularError.length();
if (len2 > real_t(0.00001)) {
Vector3 normal2 = angularError.normalized();
real_t denom2 = A->compute_angular_impulse_denominator(normal2) + B->compute_angular_impulse_denominator(normal2);
angularError *= (real_t(1.) / denom2) * m_restitutionOrthoAng * m_softnessOrthoAng;
}
// apply impulse
A->apply_torque_impulse(-velrelOrthog + angularError);
B->apply_torque_impulse(velrelOrthog - angularError);
real_t impulseMag;
//solve angular limits
if (m_solveAngLim) {
impulseMag = (angVelB - angVelA).dot(axisA) * m_dampingLimAng + m_angDepth * m_restitutionLimAng / p_step;
impulseMag *= m_kAngle * m_softnessLimAng;
} else {
impulseMag = (angVelB - angVelA).dot(axisA) * m_dampingDirAng + m_angDepth * m_restitutionDirAng / p_step;
impulseMag *= m_kAngle * m_softnessDirAng;
}
Vector3 impulse = axisA * impulseMag;
A->apply_torque_impulse(impulse);
B->apply_torque_impulse(-impulse);
//apply angular motor
if (m_poweredAngMotor) {
if (m_accumulatedAngMotorImpulse < m_maxAngMotorForce) {
Vector3 velrel = angVelAroundAxisA - angVelAroundAxisB;
real_t projRelVel = velrel.dot(axisA);
real_t desiredMotorVel = m_targetAngMotorVelocity;
real_t motor_relvel = desiredMotorVel - projRelVel;
real_t angImpulse = m_kAngle * motor_relvel;
// clamp accumulated impulse
real_t new_acc = m_accumulatedAngMotorImpulse + Math::abs(angImpulse);
if (new_acc > m_maxAngMotorForce) {
new_acc = m_maxAngMotorForce;
}
real_t del = new_acc - m_accumulatedAngMotorImpulse;
if (angImpulse < real_t(0.0)) {
angImpulse = -del;
} else {
angImpulse = del;
}
m_accumulatedAngMotorImpulse = new_acc;
// apply clamped impulse
Vector3 motorImp = angImpulse * axisA;
A->apply_torque_impulse(motorImp);
B->apply_torque_impulse(-motorImp);
}
}
} // SliderJointSW::solveConstraint()
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
void SliderJointSW::calculateTransforms(void) {
m_calculatedTransformA = A->get_transform() * m_frameInA;
m_calculatedTransformB = B->get_transform() * m_frameInB;
m_realPivotAInW = m_calculatedTransformA.origin;
m_realPivotBInW = m_calculatedTransformB.origin;
m_sliderAxis = m_calculatedTransformA.basis.get_axis(0); // along X
m_delta = m_realPivotBInW - m_realPivotAInW;
m_projPivotInW = m_realPivotAInW + m_sliderAxis.dot(m_delta) * m_sliderAxis;
Vector3 normalWorld;
int i;
//linear part
for (i = 0; i < 3; i++) {
normalWorld = m_calculatedTransformA.basis.get_axis(i);
m_depth[i] = m_delta.dot(normalWorld);
}
} // SliderJointSW::calculateTransforms()
//-----------------------------------------------------------------------------
void SliderJointSW::testLinLimits(void) {
m_solveLinLim = false;
m_linPos = m_depth[0];
if (m_lowerLinLimit <= m_upperLinLimit) {
if (m_depth[0] > m_upperLinLimit) {
m_depth[0] -= m_upperLinLimit;
m_solveLinLim = true;
} else if (m_depth[0] < m_lowerLinLimit) {
m_depth[0] -= m_lowerLinLimit;
m_solveLinLim = true;
} else {
m_depth[0] = real_t(0.);
}
} else {
m_depth[0] = real_t(0.);
}
} // SliderJointSW::testLinLimits()
//-----------------------------------------------------------------------------
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()
//-----------------------------------------------------------------------------
Vector3 SliderJointSW::getAncorInA(void) {
Vector3 ancorInA;
ancorInA = m_realPivotAInW + (m_lowerLinLimit + m_upperLinLimit) * real_t(0.5) * m_sliderAxis;
ancorInA = A->get_transform().inverse().xform(ancorInA);
return ancorInA;
} // SliderJointSW::getAncorInA()
//-----------------------------------------------------------------------------
Vector3 SliderJointSW::getAncorInB(void) {
Vector3 ancorInB;
ancorInB = m_frameInB.origin;
return ancorInB;
} // SliderJointSW::getAncorInB();
void SliderJointSW::set_param(PhysicsServer::SliderJointParam p_param, float p_value) {
switch (p_param) {
case PhysicsServer::SLIDER_JOINT_LINEAR_LIMIT_UPPER: m_upperLinLimit = p_value; break;
case PhysicsServer::SLIDER_JOINT_LINEAR_LIMIT_LOWER: m_lowerLinLimit = p_value; break;
case PhysicsServer::SLIDER_JOINT_LINEAR_LIMIT_SOFTNESS: m_softnessLimLin = p_value; break;
case PhysicsServer::SLIDER_JOINT_LINEAR_LIMIT_RESTITUTION: m_restitutionLimLin = p_value; break;
case PhysicsServer::SLIDER_JOINT_LINEAR_LIMIT_DAMPING: m_dampingLimLin = p_value; break;
case PhysicsServer::SLIDER_JOINT_LINEAR_MOTION_SOFTNESS: m_softnessDirLin = p_value; break;
case PhysicsServer::SLIDER_JOINT_LINEAR_MOTION_RESTITUTION: m_restitutionDirLin = p_value; break;
case PhysicsServer::SLIDER_JOINT_LINEAR_MOTION_DAMPING: m_dampingDirLin = p_value; break;
case PhysicsServer::SLIDER_JOINT_LINEAR_ORTHOGONAL_SOFTNESS: m_softnessOrthoLin = p_value; break;
case PhysicsServer::SLIDER_JOINT_LINEAR_ORTHOGONAL_RESTITUTION: m_restitutionOrthoLin = p_value; break;
case PhysicsServer::SLIDER_JOINT_LINEAR_ORTHOGONAL_DAMPING: m_dampingOrthoLin = p_value; break;
case PhysicsServer::SLIDER_JOINT_ANGULAR_LIMIT_UPPER: m_upperAngLimit = p_value; break;
case PhysicsServer::SLIDER_JOINT_ANGULAR_LIMIT_LOWER: m_lowerAngLimit = p_value; break;
case PhysicsServer::SLIDER_JOINT_ANGULAR_LIMIT_SOFTNESS: m_softnessLimAng = p_value; break;
case PhysicsServer::SLIDER_JOINT_ANGULAR_LIMIT_RESTITUTION: m_restitutionLimAng = p_value; break;
case PhysicsServer::SLIDER_JOINT_ANGULAR_LIMIT_DAMPING: m_dampingLimAng = p_value; break;
case PhysicsServer::SLIDER_JOINT_ANGULAR_MOTION_SOFTNESS: m_softnessDirAng = p_value; break;
case PhysicsServer::SLIDER_JOINT_ANGULAR_MOTION_RESTITUTION: m_restitutionDirAng = p_value; break;
case PhysicsServer::SLIDER_JOINT_ANGULAR_MOTION_DAMPING: m_dampingDirAng = p_value; break;
case PhysicsServer::SLIDER_JOINT_ANGULAR_ORTHOGONAL_SOFTNESS: m_softnessOrthoAng = p_value; break;
case PhysicsServer::SLIDER_JOINT_ANGULAR_ORTHOGONAL_RESTITUTION: m_restitutionOrthoAng = p_value; break;
case PhysicsServer::SLIDER_JOINT_ANGULAR_ORTHOGONAL_DAMPING: m_dampingOrthoAng = p_value; break;
}
}
float SliderJointSW::get_param(PhysicsServer::SliderJointParam p_param) const {
switch (p_param) {
case PhysicsServer::SLIDER_JOINT_LINEAR_LIMIT_UPPER: return m_upperLinLimit;
case PhysicsServer::SLIDER_JOINT_LINEAR_LIMIT_LOWER: return m_lowerLinLimit;
case PhysicsServer::SLIDER_JOINT_LINEAR_LIMIT_SOFTNESS: return m_softnessLimLin;
case PhysicsServer::SLIDER_JOINT_LINEAR_LIMIT_RESTITUTION: return m_restitutionLimLin;
case PhysicsServer::SLIDER_JOINT_LINEAR_LIMIT_DAMPING: return m_dampingLimLin;
case PhysicsServer::SLIDER_JOINT_LINEAR_MOTION_SOFTNESS: return m_softnessDirLin;
case PhysicsServer::SLIDER_JOINT_LINEAR_MOTION_RESTITUTION: return m_restitutionDirLin;
case PhysicsServer::SLIDER_JOINT_LINEAR_MOTION_DAMPING: return m_dampingDirLin;
case PhysicsServer::SLIDER_JOINT_LINEAR_ORTHOGONAL_SOFTNESS: return m_softnessOrthoLin;
case PhysicsServer::SLIDER_JOINT_LINEAR_ORTHOGONAL_RESTITUTION: return m_restitutionOrthoLin;
case PhysicsServer::SLIDER_JOINT_LINEAR_ORTHOGONAL_DAMPING: return m_dampingOrthoLin;
case PhysicsServer::SLIDER_JOINT_ANGULAR_LIMIT_UPPER: return m_upperAngLimit;
case PhysicsServer::SLIDER_JOINT_ANGULAR_LIMIT_LOWER: return m_lowerAngLimit;
case PhysicsServer::SLIDER_JOINT_ANGULAR_LIMIT_SOFTNESS: return m_softnessLimAng;
case PhysicsServer::SLIDER_JOINT_ANGULAR_LIMIT_RESTITUTION: return m_restitutionLimAng;
case PhysicsServer::SLIDER_JOINT_ANGULAR_LIMIT_DAMPING: return m_dampingLimAng;
case PhysicsServer::SLIDER_JOINT_ANGULAR_MOTION_SOFTNESS: return m_softnessDirAng;
case PhysicsServer::SLIDER_JOINT_ANGULAR_MOTION_RESTITUTION: return m_restitutionDirAng;
case PhysicsServer::SLIDER_JOINT_ANGULAR_MOTION_DAMPING: return m_dampingDirAng;
case PhysicsServer::SLIDER_JOINT_ANGULAR_ORTHOGONAL_SOFTNESS: return m_softnessOrthoAng;
case PhysicsServer::SLIDER_JOINT_ANGULAR_ORTHOGONAL_RESTITUTION: return m_restitutionOrthoAng;
case PhysicsServer::SLIDER_JOINT_ANGULAR_ORTHOGONAL_DAMPING: return m_dampingOrthoAng;
}
return 0;
}