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diff --git a/src/3rdparty/Box2D/Dynamics/Joints/b2WheelJoint.cpp b/src/3rdparty/Box2D/Dynamics/Joints/b2WheelJoint.cpp
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+/*
+* Copyright (c) 2006-2007 Erin Catto http://www.box2d.org
+*
+* This software is provided 'as-is', without any express or implied
+* warranty. In no event will the authors be held liable for any damages
+* arising from the use of this software.
+* Permission is granted to anyone to use this software for any purpose,
+* including commercial applications, and to alter it and redistribute it
+* freely, subject to the following restrictions:
+* 1. The origin of this software must not be misrepresented; you must not
+* claim that you wrote the original software. If you use this software
+* in a product, an acknowledgment in the product documentation would be
+* appreciated but is not required.
+* 2. Altered source versions must be plainly marked as such, and must not be
+* misrepresented as being the original software.
+* 3. This notice may not be removed or altered from any source distribution.
+*/
+
+#include "Box2D/Dynamics/Joints/b2WheelJoint.h"
+#include "Box2D/Dynamics/b2Body.h"
+#include "Box2D/Dynamics/b2TimeStep.h"
+
+// Linear constraint (point-to-line)
+// d = pB - pA = xB + rB - xA - rA
+// C = dot(ay, d)
+// Cdot = dot(d, cross(wA, ay)) + dot(ay, vB + cross(wB, rB) - vA - cross(wA, rA))
+// = -dot(ay, vA) - dot(cross(d + rA, ay), wA) + dot(ay, vB) + dot(cross(rB, ay), vB)
+// J = [-ay, -cross(d + rA, ay), ay, cross(rB, ay)]
+
+// Spring linear constraint
+// C = dot(ax, d)
+// Cdot = = -dot(ax, vA) - dot(cross(d + rA, ax), wA) + dot(ax, vB) + dot(cross(rB, ax), vB)
+// J = [-ax -cross(d+rA, ax) ax cross(rB, ax)]
+
+// Motor rotational constraint
+// Cdot = wB - wA
+// J = [0 0 -1 0 0 1]
+
+void b2WheelJointDef::Initialize(b2Body* bA, b2Body* bB, const b2Vec2& anchor, const b2Vec2& axis)
+{
+ bodyA = bA;
+ bodyB = bB;
+ localAnchorA = bodyA->GetLocalPoint(anchor);
+ localAnchorB = bodyB->GetLocalPoint(anchor);
+ localAxisA = bodyA->GetLocalVector(axis);
+}
+
+b2WheelJoint::b2WheelJoint(const b2WheelJointDef* def)
+: b2Joint(def)
+{
+ m_localAnchorA = def->localAnchorA;
+ m_localAnchorB = def->localAnchorB;
+ m_localXAxisA = def->localAxisA;
+ m_localYAxisA = b2Cross(1.0f, m_localXAxisA);
+
+ m_mass = 0.0f;
+ m_impulse = 0.0f;
+ m_motorMass = 0.0f;
+ m_motorImpulse = 0.0f;
+ m_springMass = 0.0f;
+ m_springImpulse = 0.0f;
+
+ m_maxMotorTorque = def->maxMotorTorque;
+ m_motorSpeed = def->motorSpeed;
+ m_enableMotor = def->enableMotor;
+
+ m_frequencyHz = def->frequencyHz;
+ m_dampingRatio = def->dampingRatio;
+
+ m_bias = 0.0f;
+ m_gamma = 0.0f;
+
+ m_ax.SetZero();
+ m_ay.SetZero();
+}
+
+void b2WheelJoint::InitVelocityConstraints(const b2SolverData& data)
+{
+ m_indexA = m_bodyA->m_islandIndex;
+ m_indexB = m_bodyB->m_islandIndex;
+ m_localCenterA = m_bodyA->m_sweep.localCenter;
+ m_localCenterB = m_bodyB->m_sweep.localCenter;
+ m_invMassA = m_bodyA->m_invMass;
+ m_invMassB = m_bodyB->m_invMass;
+ m_invIA = m_bodyA->m_invI;
+ m_invIB = m_bodyB->m_invI;
+
+ float32 mA = m_invMassA, mB = m_invMassB;
+ float32 iA = m_invIA, iB = m_invIB;
+
+ b2Vec2 cA = data.positions[m_indexA].c;
+ float32 aA = data.positions[m_indexA].a;
+ b2Vec2 vA = data.velocities[m_indexA].v;
+ float32 wA = data.velocities[m_indexA].w;
+
+ b2Vec2 cB = data.positions[m_indexB].c;
+ float32 aB = data.positions[m_indexB].a;
+ b2Vec2 vB = data.velocities[m_indexB].v;
+ float32 wB = data.velocities[m_indexB].w;
+
+ b2Rot qA(aA), qB(aB);
+
+ // Compute the effective masses.
+ b2Vec2 rA = b2Mul(qA, m_localAnchorA - m_localCenterA);
+ b2Vec2 rB = b2Mul(qB, m_localAnchorB - m_localCenterB);
+ b2Vec2 d = cB + rB - cA - rA;
+
+ // Point to line constraint
+ {
+ m_ay = b2Mul(qA, m_localYAxisA);
+ m_sAy = b2Cross(d + rA, m_ay);
+ m_sBy = b2Cross(rB, m_ay);
+
+ m_mass = mA + mB + iA * m_sAy * m_sAy + iB * m_sBy * m_sBy;
+
+ if (m_mass > 0.0f)
+ {
+ m_mass = 1.0f / m_mass;
+ }
+ }
+
+ // Spring constraint
+ m_springMass = 0.0f;
+ m_bias = 0.0f;
+ m_gamma = 0.0f;
+ if (m_frequencyHz > 0.0f)
+ {
+ m_ax = b2Mul(qA, m_localXAxisA);
+ m_sAx = b2Cross(d + rA, m_ax);
+ m_sBx = b2Cross(rB, m_ax);
+
+ float32 invMass = mA + mB + iA * m_sAx * m_sAx + iB * m_sBx * m_sBx;
+
+ if (invMass > 0.0f)
+ {
+ m_springMass = 1.0f / invMass;
+
+ float32 C = b2Dot(d, m_ax);
+
+ // Frequency
+ float32 omega = 2.0f * b2_pi * m_frequencyHz;
+
+ // Damping coefficient
+ float32 damp = 2.0f * m_springMass * m_dampingRatio * omega;
+
+ // Spring stiffness
+ float32 k = m_springMass * omega * omega;
+
+ // magic formulas
+ float32 h = data.step.dt;
+ m_gamma = h * (damp + h * k);
+ if (m_gamma > 0.0f)
+ {
+ m_gamma = 1.0f / m_gamma;
+ }
+
+ m_bias = C * h * k * m_gamma;
+
+ m_springMass = invMass + m_gamma;
+ if (m_springMass > 0.0f)
+ {
+ m_springMass = 1.0f / m_springMass;
+ }
+ }
+ }
+ else
+ {
+ m_springImpulse = 0.0f;
+ }
+
+ // Rotational motor
+ if (m_enableMotor)
+ {
+ m_motorMass = iA + iB;
+ if (m_motorMass > 0.0f)
+ {
+ m_motorMass = 1.0f / m_motorMass;
+ }
+ }
+ else
+ {
+ m_motorMass = 0.0f;
+ m_motorImpulse = 0.0f;
+ }
+
+ if (data.step.warmStarting)
+ {
+ // Account for variable time step.
+ m_impulse *= data.step.dtRatio;
+ m_springImpulse *= data.step.dtRatio;
+ m_motorImpulse *= data.step.dtRatio;
+
+ b2Vec2 P = m_impulse * m_ay + m_springImpulse * m_ax;
+ float32 LA = m_impulse * m_sAy + m_springImpulse * m_sAx + m_motorImpulse;
+ float32 LB = m_impulse * m_sBy + m_springImpulse * m_sBx + m_motorImpulse;
+
+ vA -= m_invMassA * P;
+ wA -= m_invIA * LA;
+
+ vB += m_invMassB * P;
+ wB += m_invIB * LB;
+ }
+ else
+ {
+ m_impulse = 0.0f;
+ m_springImpulse = 0.0f;
+ m_motorImpulse = 0.0f;
+ }
+
+ data.velocities[m_indexA].v = vA;
+ data.velocities[m_indexA].w = wA;
+ data.velocities[m_indexB].v = vB;
+ data.velocities[m_indexB].w = wB;
+}
+
+void b2WheelJoint::SolveVelocityConstraints(const b2SolverData& data)
+{
+ float32 mA = m_invMassA, mB = m_invMassB;
+ float32 iA = m_invIA, iB = m_invIB;
+
+ b2Vec2 vA = data.velocities[m_indexA].v;
+ float32 wA = data.velocities[m_indexA].w;
+ b2Vec2 vB = data.velocities[m_indexB].v;
+ float32 wB = data.velocities[m_indexB].w;
+
+ // Solve spring constraint
+ {
+ float32 Cdot = b2Dot(m_ax, vB - vA) + m_sBx * wB - m_sAx * wA;
+ float32 impulse = -m_springMass * (Cdot + m_bias + m_gamma * m_springImpulse);
+ m_springImpulse += impulse;
+
+ b2Vec2 P = impulse * m_ax;
+ float32 LA = impulse * m_sAx;
+ float32 LB = impulse * m_sBx;
+
+ vA -= mA * P;
+ wA -= iA * LA;
+
+ vB += mB * P;
+ wB += iB * LB;
+ }
+
+ // Solve rotational motor constraint
+ {
+ float32 Cdot = wB - wA - m_motorSpeed;
+ float32 impulse = -m_motorMass * Cdot;
+
+ float32 oldImpulse = m_motorImpulse;
+ float32 maxImpulse = data.step.dt * m_maxMotorTorque;
+ m_motorImpulse = b2Clamp(m_motorImpulse + impulse, -maxImpulse, maxImpulse);
+ impulse = m_motorImpulse - oldImpulse;
+
+ wA -= iA * impulse;
+ wB += iB * impulse;
+ }
+
+ // Solve point to line constraint
+ {
+ float32 Cdot = b2Dot(m_ay, vB - vA) + m_sBy * wB - m_sAy * wA;
+ float32 impulse = -m_mass * Cdot;
+ m_impulse += impulse;
+
+ b2Vec2 P = impulse * m_ay;
+ float32 LA = impulse * m_sAy;
+ float32 LB = impulse * m_sBy;
+
+ vA -= mA * P;
+ wA -= iA * LA;
+
+ vB += mB * P;
+ wB += iB * LB;
+ }
+
+ data.velocities[m_indexA].v = vA;
+ data.velocities[m_indexA].w = wA;
+ data.velocities[m_indexB].v = vB;
+ data.velocities[m_indexB].w = wB;
+}
+
+bool b2WheelJoint::SolvePositionConstraints(const b2SolverData& data)
+{
+ b2Vec2 cA = data.positions[m_indexA].c;
+ float32 aA = data.positions[m_indexA].a;
+ b2Vec2 cB = data.positions[m_indexB].c;
+ float32 aB = data.positions[m_indexB].a;
+
+ b2Rot qA(aA), qB(aB);
+
+ b2Vec2 rA = b2Mul(qA, m_localAnchorA - m_localCenterA);
+ b2Vec2 rB = b2Mul(qB, m_localAnchorB - m_localCenterB);
+ b2Vec2 d = (cB - cA) + rB - rA;
+
+ b2Vec2 ay = b2Mul(qA, m_localYAxisA);
+
+ float32 sAy = b2Cross(d + rA, ay);
+ float32 sBy = b2Cross(rB, ay);
+
+ float32 C = b2Dot(d, ay);
+
+ float32 k = m_invMassA + m_invMassB + m_invIA * m_sAy * m_sAy + m_invIB * m_sBy * m_sBy;
+
+ float32 impulse;
+ if (k != 0.0f)
+ {
+ impulse = - C / k;
+ }
+ else
+ {
+ impulse = 0.0f;
+ }
+
+ b2Vec2 P = impulse * ay;
+ float32 LA = impulse * sAy;
+ float32 LB = impulse * sBy;
+
+ cA -= m_invMassA * P;
+ aA -= m_invIA * LA;
+ cB += m_invMassB * P;
+ aB += m_invIB * LB;
+
+ data.positions[m_indexA].c = cA;
+ data.positions[m_indexA].a = aA;
+ data.positions[m_indexB].c = cB;
+ data.positions[m_indexB].a = aB;
+
+ return b2Abs(C) <= b2_linearSlop;
+}
+
+b2Vec2 b2WheelJoint::GetAnchorA() const
+{
+ return m_bodyA->GetWorldPoint(m_localAnchorA);
+}
+
+b2Vec2 b2WheelJoint::GetAnchorB() const
+{
+ return m_bodyB->GetWorldPoint(m_localAnchorB);
+}
+
+b2Vec2 b2WheelJoint::GetReactionForce(float32 inv_dt) const
+{
+ return inv_dt * (m_impulse * m_ay + m_springImpulse * m_ax);
+}
+
+float32 b2WheelJoint::GetReactionTorque(float32 inv_dt) const
+{
+ return inv_dt * m_motorImpulse;
+}
+
+float32 b2WheelJoint::GetJointTranslation() const
+{
+ b2Body* bA = m_bodyA;
+ b2Body* bB = m_bodyB;
+
+ b2Vec2 pA = bA->GetWorldPoint(m_localAnchorA);
+ b2Vec2 pB = bB->GetWorldPoint(m_localAnchorB);
+ b2Vec2 d = pB - pA;
+ b2Vec2 axis = bA->GetWorldVector(m_localXAxisA);
+
+ float32 translation = b2Dot(d, axis);
+ return translation;
+}
+
+float32 b2WheelJoint::GetJointLinearSpeed() const
+{
+ b2Body* bA = m_bodyA;
+ b2Body* bB = m_bodyB;
+
+ b2Vec2 rA = b2Mul(bA->m_xf.q, m_localAnchorA - bA->m_sweep.localCenter);
+ b2Vec2 rB = b2Mul(bB->m_xf.q, m_localAnchorB - bB->m_sweep.localCenter);
+ b2Vec2 p1 = bA->m_sweep.c + rA;
+ b2Vec2 p2 = bB->m_sweep.c + rB;
+ b2Vec2 d = p2 - p1;
+ b2Vec2 axis = b2Mul(bA->m_xf.q, m_localXAxisA);
+
+ b2Vec2 vA = bA->m_linearVelocity;
+ b2Vec2 vB = bB->m_linearVelocity;
+ float32 wA = bA->m_angularVelocity;
+ float32 wB = bB->m_angularVelocity;
+
+ float32 speed = b2Dot(d, b2Cross(wA, axis)) + b2Dot(axis, vB + b2Cross(wB, rB) - vA - b2Cross(wA, rA));
+ return speed;
+}
+
+float32 b2WheelJoint::GetJointAngle() const
+{
+ b2Body* bA = m_bodyA;
+ b2Body* bB = m_bodyB;
+ return bB->m_sweep.a - bA->m_sweep.a;
+}
+
+float32 b2WheelJoint::GetJointAngularSpeed() const
+{
+ float32 wA = m_bodyA->m_angularVelocity;
+ float32 wB = m_bodyB->m_angularVelocity;
+ return wB - wA;
+}
+
+bool b2WheelJoint::IsMotorEnabled() const
+{
+ return m_enableMotor;
+}
+
+void b2WheelJoint::EnableMotor(bool flag)
+{
+ if (flag != m_enableMotor)
+ {
+ m_bodyA->SetAwake(true);
+ m_bodyB->SetAwake(true);
+ m_enableMotor = flag;
+ }
+}
+
+void b2WheelJoint::SetMotorSpeed(float32 speed)
+{
+ if (speed != m_motorSpeed)
+ {
+ m_bodyA->SetAwake(true);
+ m_bodyB->SetAwake(true);
+ m_motorSpeed = speed;
+ }
+}
+
+void b2WheelJoint::SetMaxMotorTorque(float32 torque)
+{
+ if (torque != m_maxMotorTorque)
+ {
+ m_bodyA->SetAwake(true);
+ m_bodyB->SetAwake(true);
+ m_maxMotorTorque = torque;
+ }
+}
+
+float32 b2WheelJoint::GetMotorTorque(float32 inv_dt) const
+{
+ return inv_dt * m_motorImpulse;
+}
+
+void b2WheelJoint::Dump()
+{
+ int32 indexA = m_bodyA->m_islandIndex;
+ int32 indexB = m_bodyB->m_islandIndex;
+
+ b2Log(" b2WheelJointDef jd;\n");
+ b2Log(" jd.bodyA = bodies[%d];\n", indexA);
+ b2Log(" jd.bodyB = bodies[%d];\n", indexB);
+ b2Log(" jd.collideConnected = bool(%d);\n", m_collideConnected);
+ b2Log(" jd.localAnchorA.Set(%.15lef, %.15lef);\n", m_localAnchorA.x, m_localAnchorA.y);
+ b2Log(" jd.localAnchorB.Set(%.15lef, %.15lef);\n", m_localAnchorB.x, m_localAnchorB.y);
+ b2Log(" jd.localAxisA.Set(%.15lef, %.15lef);\n", m_localXAxisA.x, m_localXAxisA.y);
+ b2Log(" jd.enableMotor = bool(%d);\n", m_enableMotor);
+ b2Log(" jd.motorSpeed = %.15lef;\n", m_motorSpeed);
+ b2Log(" jd.maxMotorTorque = %.15lef;\n", m_maxMotorTorque);
+ b2Log(" jd.frequencyHz = %.15lef;\n", m_frequencyHz);
+ b2Log(" jd.dampingRatio = %.15lef;\n", m_dampingRatio);
+ b2Log(" joints[%d] = m_world->CreateJoint(&jd);\n", m_index);
+}