godot/servers/physics/joints/hinge_joint_sw.cpp
Rémi Verschelde 5dbf1809c6 A Whole New World (clang-format edition)
I can show you the code
Pretty, with proper whitespace
Tell me, coder, now when did
You last write readable code?

I can open your eyes
Make you see your bad indent
Force you to respect the style
The core devs agreed upon

A whole new world
A new fantastic code format
A de facto standard
With some sugar
Enforced with clang-format

A whole new world
A dazzling style we all dreamed of
And when we read it through
It's crystal clear
That now we're in a whole new world of code
2017-03-05 16:44:50 +01:00

439 lines
15 KiB
C++

/*************************************************************************/
/* hinge_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 "hinge_joint_sw.h"
static void plane_space(const Vector3 &n, Vector3 &p, Vector3 &q) {
if (Math::abs(n.z) > 0.707106781186547524400844362) {
// choose p in y-z plane
real_t a = n[1] * n[1] + n[2] * n[2];
real_t k = 1.0 / Math::sqrt(a);
p = Vector3(0, -n[2] * k, n[1] * k);
// set q = n x p
q = Vector3(a * k, -n[0] * p[2], n[0] * p[1]);
} else {
// choose p in x-y plane
real_t a = n.x * n.x + n.y * n.y;
real_t k = 1.0 / Math::sqrt(a);
p = Vector3(-n.y * k, n.x * k, 0);
// set q = n x p
q = Vector3(-n.z * p.y, n.z * p.x, a * k);
}
}
HingeJointSW::HingeJointSW(BodySW *rbA, BodySW *rbB, const Transform &frameA, const Transform &frameB)
: JointSW(_arr, 2) {
A = rbA;
B = rbB;
m_rbAFrame = frameA;
m_rbBFrame = frameB;
// flip axis
m_rbBFrame.basis[0][2] *= real_t(-1.);
m_rbBFrame.basis[1][2] *= real_t(-1.);
m_rbBFrame.basis[2][2] *= real_t(-1.);
//start with free
m_lowerLimit = Math_PI;
m_upperLimit = -Math_PI;
m_useLimit = false;
m_biasFactor = 0.3f;
m_relaxationFactor = 1.0f;
m_limitSoftness = 0.9f;
m_solveLimit = false;
tau = 0.3;
m_angularOnly = false;
m_enableAngularMotor = false;
A->add_constraint(this, 0);
B->add_constraint(this, 1);
}
HingeJointSW::HingeJointSW(BodySW *rbA, BodySW *rbB, const Vector3 &pivotInA, const Vector3 &pivotInB,
const Vector3 &axisInA, const Vector3 &axisInB)
: JointSW(_arr, 2) {
A = rbA;
B = rbB;
m_rbAFrame.origin = pivotInA;
// since no frame is given, assume this to be zero angle and just pick rb transform axis
Vector3 rbAxisA1 = rbA->get_transform().basis.get_axis(0);
Vector3 rbAxisA2;
real_t projection = axisInA.dot(rbAxisA1);
if (projection >= 1.0f - CMP_EPSILON) {
rbAxisA1 = -rbA->get_transform().basis.get_axis(2);
rbAxisA2 = rbA->get_transform().basis.get_axis(1);
} else if (projection <= -1.0f + CMP_EPSILON) {
rbAxisA1 = rbA->get_transform().basis.get_axis(2);
rbAxisA2 = rbA->get_transform().basis.get_axis(1);
} else {
rbAxisA2 = axisInA.cross(rbAxisA1);
rbAxisA1 = rbAxisA2.cross(axisInA);
}
m_rbAFrame.basis = Basis(rbAxisA1.x, rbAxisA2.x, axisInA.x,
rbAxisA1.y, rbAxisA2.y, axisInA.y,
rbAxisA1.z, rbAxisA2.z, axisInA.z);
Quat rotationArc = Quat(axisInA, axisInB);
Vector3 rbAxisB1 = rotationArc.xform(rbAxisA1);
Vector3 rbAxisB2 = axisInB.cross(rbAxisB1);
m_rbBFrame.origin = pivotInB;
m_rbBFrame.basis = Basis(rbAxisB1.x, rbAxisB2.x, -axisInB.x,
rbAxisB1.y, rbAxisB2.y, -axisInB.y,
rbAxisB1.z, rbAxisB2.z, -axisInB.z);
//start with free
m_lowerLimit = Math_PI;
m_upperLimit = -Math_PI;
m_useLimit = false;
m_biasFactor = 0.3f;
m_relaxationFactor = 1.0f;
m_limitSoftness = 0.9f;
m_solveLimit = false;
tau = 0.3;
m_angularOnly = false;
m_enableAngularMotor = false;
A->add_constraint(this, 0);
B->add_constraint(this, 1);
}
bool HingeJointSW::setup(real_t p_step) {
m_appliedImpulse = 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()));
}
}
//calculate two perpendicular jointAxis, orthogonal to hingeAxis
//these two jointAxis require equal angular velocities for both bodies
//this is unused for now, it's a todo
Vector3 jointAxis0local;
Vector3 jointAxis1local;
plane_space(m_rbAFrame.basis.get_axis(2), jointAxis0local, jointAxis1local);
A->get_transform().basis.xform(m_rbAFrame.basis.get_axis(2));
Vector3 jointAxis0 = A->get_transform().basis.xform(jointAxis0local);
Vector3 jointAxis1 = A->get_transform().basis.xform(jointAxis1local);
Vector3 hingeAxisWorld = A->get_transform().basis.xform(m_rbAFrame.basis.get_axis(2));
memnew_placement(&m_jacAng[0], JacobianEntrySW(jointAxis0,
A->get_principal_inertia_axes().transposed(),
B->get_principal_inertia_axes().transposed(),
A->get_inv_inertia(),
B->get_inv_inertia()));
memnew_placement(&m_jacAng[1], JacobianEntrySW(jointAxis1,
A->get_principal_inertia_axes().transposed(),
B->get_principal_inertia_axes().transposed(),
A->get_inv_inertia(),
B->get_inv_inertia()));
memnew_placement(&m_jacAng[2], JacobianEntrySW(hingeAxisWorld,
A->get_principal_inertia_axes().transposed(),
B->get_principal_inertia_axes().transposed(),
A->get_inv_inertia(),
B->get_inv_inertia()));
// Compute limit information
real_t hingeAngle = get_hinge_angle();
//print_line("angle: "+rtos(hingeAngle));
//set bias, sign, clear accumulator
m_correction = real_t(0.);
m_limitSign = real_t(0.);
m_solveLimit = false;
m_accLimitImpulse = real_t(0.);
/*if (m_useLimit) {
print_line("low: "+rtos(m_lowerLimit));
print_line("hi: "+rtos(m_upperLimit));
}*/
//if (m_lowerLimit < m_upperLimit)
if (m_useLimit && m_lowerLimit <= m_upperLimit) {
//if (hingeAngle <= m_lowerLimit*m_limitSoftness)
if (hingeAngle <= m_lowerLimit) {
m_correction = (m_lowerLimit - hingeAngle);
m_limitSign = 1.0f;
m_solveLimit = true;
}
//else if (hingeAngle >= m_upperLimit*m_limitSoftness)
else if (hingeAngle >= m_upperLimit) {
m_correction = m_upperLimit - hingeAngle;
m_limitSign = -1.0f;
m_solveLimit = true;
}
}
//Compute K = J*W*J' for hinge axis
Vector3 axisA = A->get_transform().basis.xform(m_rbAFrame.basis.get_axis(2));
m_kHinge = 1.0f / (A->compute_angular_impulse_denominator(axisA) +
B->compute_angular_impulse_denominator(axisA));
return true;
}
void HingeJointSW::solve(real_t p_step) {
Vector3 pivotAInW = A->get_transform().xform(m_rbAFrame.origin);
Vector3 pivotBInW = B->get_transform().xform(m_rbBFrame.origin);
//real_t tau = real_t(0.3);
//linear part
if (!m_angularOnly) {
Vector3 rel_pos1 = pivotAInW - A->get_transform().origin;
Vector3 rel_pos2 = pivotBInW - B->get_transform().origin;
Vector3 vel1 = A->get_velocity_in_local_point(rel_pos1);
Vector3 vel2 = B->get_velocity_in_local_point(rel_pos2);
Vector3 vel = vel1 - vel2;
for (int i = 0; i < 3; i++) {
const Vector3 &normal = m_jac[i].m_linearJointAxis;
real_t jacDiagABInv = real_t(1.) / m_jac[i].getDiagonal();
real_t rel_vel;
rel_vel = normal.dot(vel);
//positional error (zeroth order error)
real_t depth = -(pivotAInW - pivotBInW).dot(normal); //this is the error projected on the normal
real_t impulse = depth * tau / p_step * jacDiagABInv - rel_vel * jacDiagABInv;
m_appliedImpulse += impulse;
Vector3 impulse_vector = normal * impulse;
A->apply_impulse(pivotAInW - A->get_transform().origin, impulse_vector);
B->apply_impulse(pivotBInW - B->get_transform().origin, -impulse_vector);
}
}
{
///solve angular part
// get axes in world space
Vector3 axisA = A->get_transform().basis.xform(m_rbAFrame.basis.get_axis(2));
Vector3 axisB = B->get_transform().basis.xform(m_rbBFrame.basis.get_axis(2));
const Vector3 &angVelA = A->get_angular_velocity();
const Vector3 &angVelB = B->get_angular_velocity();
Vector3 angVelAroundHingeAxisA = axisA * axisA.dot(angVelA);
Vector3 angVelAroundHingeAxisB = axisB * axisB.dot(angVelB);
Vector3 angAorthog = angVelA - angVelAroundHingeAxisA;
Vector3 angBorthog = angVelB - angVelAroundHingeAxisB;
Vector3 velrelOrthog = angAorthog - angBorthog;
{
//solve orthogonal angular velocity correction
real_t relaxation = real_t(1.);
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);
// scale for mass and relaxation
velrelOrthog *= (real_t(1.) / denom) * m_relaxationFactor;
}
//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) * relaxation;
}
A->apply_torque_impulse(-velrelOrthog + angularError);
B->apply_torque_impulse(velrelOrthog - angularError);
// solve limit
if (m_solveLimit) {
real_t amplitude = ((angVelB - angVelA).dot(axisA) * m_relaxationFactor + m_correction * (real_t(1.) / p_step) * m_biasFactor) * m_limitSign;
real_t impulseMag = amplitude * m_kHinge;
// Clamp the accumulated impulse
real_t temp = m_accLimitImpulse;
m_accLimitImpulse = MAX(m_accLimitImpulse + impulseMag, real_t(0));
impulseMag = m_accLimitImpulse - temp;
Vector3 impulse = axisA * impulseMag * m_limitSign;
A->apply_torque_impulse(impulse);
B->apply_torque_impulse(-impulse);
}
}
//apply motor
if (m_enableAngularMotor) {
//todo: add limits too
Vector3 angularLimit(0, 0, 0);
Vector3 velrel = angVelAroundHingeAxisA - angVelAroundHingeAxisB;
real_t projRelVel = velrel.dot(axisA);
real_t desiredMotorVel = m_motorTargetVelocity;
real_t motor_relvel = desiredMotorVel - projRelVel;
real_t unclippedMotorImpulse = m_kHinge * motor_relvel;
//todo: should clip against accumulated impulse
real_t clippedMotorImpulse = unclippedMotorImpulse > m_maxMotorImpulse ? m_maxMotorImpulse : unclippedMotorImpulse;
clippedMotorImpulse = clippedMotorImpulse < -m_maxMotorImpulse ? -m_maxMotorImpulse : clippedMotorImpulse;
Vector3 motorImp = clippedMotorImpulse * axisA;
A->apply_torque_impulse(motorImp + angularLimit);
B->apply_torque_impulse(-motorImp - angularLimit);
}
}
}
/*
void HingeJointSW::updateRHS(real_t timeStep)
{
(void)timeStep;
}
*/
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;
}
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 HingeJointSW::set_param(PhysicsServer::HingeJointParam p_param, real_t p_value) {
switch (p_param) {
case PhysicsServer::HINGE_JOINT_BIAS: tau = p_value; break;
case PhysicsServer::HINGE_JOINT_LIMIT_UPPER: m_upperLimit = p_value; break;
case PhysicsServer::HINGE_JOINT_LIMIT_LOWER: m_lowerLimit = p_value; break;
case PhysicsServer::HINGE_JOINT_LIMIT_BIAS: m_biasFactor = p_value; break;
case PhysicsServer::HINGE_JOINT_LIMIT_SOFTNESS: m_limitSoftness = p_value; break;
case PhysicsServer::HINGE_JOINT_LIMIT_RELAXATION: m_relaxationFactor = p_value; break;
case PhysicsServer::HINGE_JOINT_MOTOR_TARGET_VELOCITY: m_motorTargetVelocity = p_value; break;
case PhysicsServer::HINGE_JOINT_MOTOR_MAX_IMPULSE: m_maxMotorImpulse = p_value; break;
}
}
real_t HingeJointSW::get_param(PhysicsServer::HingeJointParam p_param) const {
switch (p_param) {
case PhysicsServer::HINGE_JOINT_BIAS: return tau;
case PhysicsServer::HINGE_JOINT_LIMIT_UPPER: return m_upperLimit;
case PhysicsServer::HINGE_JOINT_LIMIT_LOWER: return m_lowerLimit;
case PhysicsServer::HINGE_JOINT_LIMIT_BIAS: return m_biasFactor;
case PhysicsServer::HINGE_JOINT_LIMIT_SOFTNESS: return m_limitSoftness;
case PhysicsServer::HINGE_JOINT_LIMIT_RELAXATION: return m_relaxationFactor;
case PhysicsServer::HINGE_JOINT_MOTOR_TARGET_VELOCITY: return m_motorTargetVelocity;
case PhysicsServer::HINGE_JOINT_MOTOR_MAX_IMPULSE: return m_maxMotorImpulse;
}
return 0;
}
void HingeJointSW::set_flag(PhysicsServer::HingeJointFlag p_flag, bool p_value) {
switch (p_flag) {
case PhysicsServer::HINGE_JOINT_FLAG_USE_LIMIT: m_useLimit = p_value; break;
case PhysicsServer::HINGE_JOINT_FLAG_ENABLE_MOTOR: m_enableAngularMotor = p_value; break;
}
}
bool HingeJointSW::get_flag(PhysicsServer::HingeJointFlag p_flag) const {
switch (p_flag) {
case PhysicsServer::HINGE_JOINT_FLAG_USE_LIMIT: return m_useLimit;
case PhysicsServer::HINGE_JOINT_FLAG_ENABLE_MOTOR: return m_enableAngularMotor;
}
return false;
}