1 files changed, 501 insertions, 0 deletions
diff --git a/Client/ThirdParty/Box2D/src/dynamics/b2_revolute_joint.cpp b/Client/ThirdParty/Box2D/src/dynamics/b2_revolute_joint.cpp
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+++ b/Client/ThirdParty/Box2D/src/dynamics/b2_revolute_joint.cpp
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+// MIT License
+
+// Copyright (c) 2019 Erin Catto
+
+// 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.
+
+#include "box2d/b2_body.h"
+#include "box2d/b2_draw.h"
+#include "box2d/b2_revolute_joint.h"
+#include "box2d/b2_time_step.h"
+
+// Point-to-point constraint
+// C = p2 - p1
+// Cdot = v2 - v1
+//      = v2 + cross(w2, r2) - v1 - cross(w1, r1)
+// J = [-I -r1_skew I r2_skew ]
+// Identity used:
+// w k % (rx i + ry j) = w * (-ry i + rx j)
+
+// Motor constraint
+// Cdot = w2 - w1
+// J = [0 0 -1 0 0 1]
+// K = invI1 + invI2
+
+void b2RevoluteJointDef::Initialize(b2Body* bA, b2Body* bB, const b2Vec2& anchor)
+{
+	bodyA = bA;
+	bodyB = bB;
+	localAnchorA = bodyA->GetLocalPoint(anchor);
+	localAnchorB = bodyB->GetLocalPoint(anchor);
+	referenceAngle = bodyB->GetAngle() - bodyA->GetAngle();
+}
+
+b2RevoluteJoint::b2RevoluteJoint(const b2RevoluteJointDef* def)
+: b2Joint(def)
+{
+	m_localAnchorA = def->localAnchorA;
+	m_localAnchorB = def->localAnchorB;
+	m_referenceAngle = def->referenceAngle;
+
+	m_impulse.SetZero();
+	m_axialMass = 0.0f;
+	m_motorImpulse = 0.0f;
+	m_lowerImpulse = 0.0f;
+	m_upperImpulse = 0.0f;
+
+	m_lowerAngle = def->lowerAngle;
+	m_upperAngle = def->upperAngle;
+	m_maxMotorTorque = def->maxMotorTorque;
+	m_motorSpeed = def->motorSpeed;
+	m_enableLimit = def->enableLimit;
+	m_enableMotor = def->enableMotor;
+
+	m_angle = 0.0f;
+}
+
+void b2RevoluteJoint::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;
+
+	float aA = data.positions[m_indexA].a;
+	b2Vec2 vA = data.velocities[m_indexA].v;
+	float wA = data.velocities[m_indexA].w;
+
+	float aB = data.positions[m_indexB].a;
+	b2Vec2 vB = data.velocities[m_indexB].v;
+	float wB = data.velocities[m_indexB].w;
+
+	b2Rot qA(aA), qB(aB);
+
+	m_rA = b2Mul(qA, m_localAnchorA - m_localCenterA);
+	m_rB = b2Mul(qB, m_localAnchorB - m_localCenterB);
+
+	// J = [-I -r1_skew I r2_skew]
+	// r_skew = [-ry; rx]
+
+	// Matlab
+	// K = [ mA+r1y^2*iA+mB+r2y^2*iB,  -r1y*iA*r1x-r2y*iB*r2x]
+	//     [  -r1y*iA*r1x-r2y*iB*r2x, mA+r1x^2*iA+mB+r2x^2*iB]
+
+	float mA = m_invMassA, mB = m_invMassB;
+	float iA = m_invIA, iB = m_invIB;
+
+	m_K.ex.x = mA + mB + m_rA.y * m_rA.y * iA + m_rB.y * m_rB.y * iB;
+	m_K.ey.x = -m_rA.y * m_rA.x * iA - m_rB.y * m_rB.x * iB;
+	m_K.ex.y = m_K.ey.x;
+	m_K.ey.y = mA + mB + m_rA.x * m_rA.x * iA + m_rB.x * m_rB.x * iB;
+
+	m_axialMass = iA + iB;
+	bool fixedRotation;
+	if (m_axialMass > 0.0f)
+	{
+		m_axialMass = 1.0f / m_axialMass;
+		fixedRotation = false;
+	}
+	else
+	{
+		fixedRotation = true;
+	}
+
+	m_angle = aB - aA - m_referenceAngle;
+	if (m_enableLimit == false || fixedRotation)
+	{
+		m_lowerImpulse = 0.0f;
+		m_upperImpulse = 0.0f;
+	}
+
+	if (m_enableMotor == false || fixedRotation)
+	{
+		m_motorImpulse = 0.0f;
+	}
+
+	if (data.step.warmStarting)
+	{
+		// Scale impulses to support a variable time step.
+		m_impulse *= data.step.dtRatio;
+		m_motorImpulse *= data.step.dtRatio;
+		m_lowerImpulse *= data.step.dtRatio;
+		m_upperImpulse *= data.step.dtRatio;
+
+		float axialImpulse = m_motorImpulse + m_lowerImpulse - m_upperImpulse;
+		b2Vec2 P(m_impulse.x, m_impulse.y);
+
+		vA -= mA * P;
+		wA -= iA * (b2Cross(m_rA, P) + axialImpulse);
+
+		vB += mB * P;
+		wB += iB * (b2Cross(m_rB, P) + axialImpulse);
+	}
+	else
+	{
+		m_impulse.SetZero();
+		m_motorImpulse = 0.0f;
+		m_lowerImpulse = 0.0f;
+		m_upperImpulse = 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 b2RevoluteJoint::SolveVelocityConstraints(const b2SolverData& data)
+{
+	b2Vec2 vA = data.velocities[m_indexA].v;
+	float wA = data.velocities[m_indexA].w;
+	b2Vec2 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;
+
+	bool fixedRotation = (iA + iB == 0.0f);
+
+	// Solve motor constraint.
+	if (m_enableMotor && fixedRotation == false)
+	{
+		float Cdot = wB - wA - m_motorSpeed;
+		float impulse = -m_axialMass * Cdot;
+		float oldImpulse = m_motorImpulse;
+		float maxImpulse = data.step.dt * m_maxMotorTorque;
+		m_motorImpulse = b2Clamp(m_motorImpulse + impulse, -maxImpulse, maxImpulse);
+		impulse = m_motorImpulse - oldImpulse;
+
+		wA -= iA * impulse;
+		wB += iB * impulse;
+	}
+
+	if (m_enableLimit && fixedRotation == false)
+	{
+		// Lower limit
+		{
+			float C = m_angle - m_lowerAngle;
+			float Cdot = wB - wA;
+			float impulse = -m_axialMass * (Cdot + b2Max(C, 0.0f) * data.step.inv_dt);
+			float oldImpulse = m_lowerImpulse;
+			m_lowerImpulse = b2Max(m_lowerImpulse + impulse, 0.0f);
+			impulse = m_lowerImpulse - oldImpulse;
+
+			wA -= iA * impulse;
+			wB += iB * impulse;
+		}
+
+		// Upper limit
+		// Note: signs are flipped to keep C positive when the constraint is satisfied.
+		// This also keeps the impulse positive when the limit is active.
+		{
+			float C = m_upperAngle - m_angle;
+			float Cdot = wA - wB;
+			float impulse = -m_axialMass * (Cdot + b2Max(C, 0.0f) * data.step.inv_dt);
+			float oldImpulse = m_upperImpulse;
+			m_upperImpulse = b2Max(m_upperImpulse + impulse, 0.0f);
+			impulse = m_upperImpulse - oldImpulse;
+
+			wA += iA * impulse;
+			wB -= iB * impulse;
+		}
+	}
+
+	// Solve point-to-point constraint
+	{
+		b2Vec2 Cdot = vB + b2Cross(wB, m_rB) - vA - b2Cross(wA, m_rA);
+		b2Vec2 impulse = m_K.Solve(-Cdot);
+
+		m_impulse.x += impulse.x;
+		m_impulse.y += impulse.y;
+
+		vA -= mA * impulse;
+		wA -= iA * b2Cross(m_rA, impulse);
+
+		vB += mB * impulse;
+		wB += iB * b2Cross(m_rB, impulse);
+	}
+
+	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 b2RevoluteJoint::SolvePositionConstraints(const b2SolverData& data)
+{
+	b2Vec2 cA = data.positions[m_indexA].c;
+	float aA = data.positions[m_indexA].a;
+	b2Vec2 cB = data.positions[m_indexB].c;
+	float aB = data.positions[m_indexB].a;
+
+	b2Rot qA(aA), qB(aB);
+
+	float angularError = 0.0f;
+	float positionError = 0.0f;
+
+	bool fixedRotation = (m_invIA + m_invIB == 0.0f);
+
+	// Solve angular limit constraint
+	if (m_enableLimit && fixedRotation == false)
+	{
+		float angle = aB - aA - m_referenceAngle;
+		float C = 0.0f;
+
+		if (b2Abs(m_upperAngle - m_lowerAngle) < 2.0f * b2_angularSlop)
+		{
+			// Prevent large angular corrections
+			C = b2Clamp(angle - m_lowerAngle, -b2_maxAngularCorrection, b2_maxAngularCorrection);
+		}
+		else if (angle <= m_lowerAngle)
+		{
+			// Prevent large angular corrections and allow some slop.
+			C = b2Clamp(angle - m_lowerAngle + b2_angularSlop, -b2_maxAngularCorrection, 0.0f);
+		}
+		else if (angle >= m_upperAngle)
+		{
+			// Prevent large angular corrections and allow some slop.
+			C = b2Clamp(angle - m_upperAngle - b2_angularSlop, 0.0f, b2_maxAngularCorrection);
+		}
+
+		float limitImpulse = -m_axialMass * C;
+		aA -= m_invIA * limitImpulse;
+		aB += m_invIB * limitImpulse;
+		angularError = b2Abs(C);
+	}
+
+	// Solve point-to-point constraint.
+	{
+		qA.Set(aA);
+		qB.Set(aB);
+		b2Vec2 rA = b2Mul(qA, m_localAnchorA - m_localCenterA);
+		b2Vec2 rB = b2Mul(qB, m_localAnchorB - m_localCenterB);
+
+		b2Vec2 C = cB + rB - cA - rA;
+		positionError = C.Length();
+
+		float mA = m_invMassA, mB = m_invMassB;
+		float iA = m_invIA, iB = m_invIB;
+
+		b2Mat22 K;
+		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;
+
+		b2Vec2 impulse = -K.Solve(C);
+
+		cA -= mA * impulse;
+		aA -= iA * b2Cross(rA, impulse);
+
+		cB += mB * impulse;
+		aB += iB * b2Cross(rB, impulse);
+	}
+
+	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 positionError <= b2_linearSlop && angularError <= b2_angularSlop;
+}
+
+b2Vec2 b2RevoluteJoint::GetAnchorA() const
+{
+	return m_bodyA->GetWorldPoint(m_localAnchorA);
+}
+
+b2Vec2 b2RevoluteJoint::GetAnchorB() const
+{
+	return m_bodyB->GetWorldPoint(m_localAnchorB);
+}
+
+b2Vec2 b2RevoluteJoint::GetReactionForce(float inv_dt) const
+{
+	b2Vec2 P(m_impulse.x, m_impulse.y);
+	return inv_dt * P;
+}
+
+float b2RevoluteJoint::GetReactionTorque(float inv_dt) const
+{
+	return inv_dt * (m_motorImpulse + m_lowerImpulse - m_upperImpulse);
+}
+
+float b2RevoluteJoint::GetJointAngle() const
+{
+	b2Body* bA = m_bodyA;
+	b2Body* bB = m_bodyB;
+	return bB->m_sweep.a - bA->m_sweep.a - m_referenceAngle;
+}
+
+float b2RevoluteJoint::GetJointSpeed() const
+{
+	b2Body* bA = m_bodyA;
+	b2Body* bB = m_bodyB;
+	return bB->m_angularVelocity - bA->m_angularVelocity;
+}
+
+bool b2RevoluteJoint::IsMotorEnabled() const
+{
+	return m_enableMotor;
+}
+
+void b2RevoluteJoint::EnableMotor(bool flag)
+{
+	if (flag != m_enableMotor)
+	{
+		m_bodyA->SetAwake(true);
+		m_bodyB->SetAwake(true);
+		m_enableMotor = flag;
+	}
+}
+
+float b2RevoluteJoint::GetMotorTorque(float inv_dt) const
+{
+	return inv_dt * m_motorImpulse;
+}
+
+void b2RevoluteJoint::SetMotorSpeed(float speed)
+{
+	if (speed != m_motorSpeed)
+	{
+		m_bodyA->SetAwake(true);
+		m_bodyB->SetAwake(true);
+		m_motorSpeed = speed;
+	}
+}
+
+void b2RevoluteJoint::SetMaxMotorTorque(float torque)
+{
+	if (torque != m_maxMotorTorque)
+	{
+		m_bodyA->SetAwake(true);
+		m_bodyB->SetAwake(true);
+		m_maxMotorTorque = torque;
+	}
+}
+
+bool b2RevoluteJoint::IsLimitEnabled() const
+{
+	return m_enableLimit;
+}
+
+void b2RevoluteJoint::EnableLimit(bool flag)
+{
+	if (flag != m_enableLimit)
+	{
+		m_bodyA->SetAwake(true);
+		m_bodyB->SetAwake(true);
+		m_enableLimit = flag;
+		m_lowerImpulse = 0.0f;
+		m_upperImpulse = 0.0f;
+	}
+}
+
+float b2RevoluteJoint::GetLowerLimit() const
+{
+	return m_lowerAngle;
+}
+
+float b2RevoluteJoint::GetUpperLimit() const
+{
+	return m_upperAngle;
+}
+
+void b2RevoluteJoint::SetLimits(float lower, float upper)
+{
+	b2Assert(lower <= upper);
+	
+	if (lower != m_lowerAngle || upper != m_upperAngle)
+	{
+		m_bodyA->SetAwake(true);
+		m_bodyB->SetAwake(true);
+		m_lowerImpulse = 0.0f;
+		m_upperImpulse = 0.0f;
+		m_lowerAngle = lower;
+		m_upperAngle = upper;
+	}
+}
+
+void b2RevoluteJoint::Dump()
+{
+	int32 indexA = m_bodyA->m_islandIndex;
+	int32 indexB = m_bodyB->m_islandIndex;
+
+	b2Dump("  b2RevoluteJointDef jd;\n");
+	b2Dump("  jd.bodyA = bodies[%d];\n", indexA);
+	b2Dump("  jd.bodyB = bodies[%d];\n", indexB);
+	b2Dump("  jd.collideConnected = bool(%d);\n", m_collideConnected);
+	b2Dump("  jd.localAnchorA.Set(%.9g, %.9g);\n", m_localAnchorA.x, m_localAnchorA.y);
+	b2Dump("  jd.localAnchorB.Set(%.9g, %.9g);\n", m_localAnchorB.x, m_localAnchorB.y);
+	b2Dump("  jd.referenceAngle = %.9g;\n", m_referenceAngle);
+	b2Dump("  jd.enableLimit = bool(%d);\n", m_enableLimit);
+	b2Dump("  jd.lowerAngle = %.9g;\n", m_lowerAngle);
+	b2Dump("  jd.upperAngle = %.9g;\n", m_upperAngle);
+	b2Dump("  jd.enableMotor = bool(%d);\n", m_enableMotor);
+	b2Dump("  jd.motorSpeed = %.9g;\n", m_motorSpeed);
+	b2Dump("  jd.maxMotorTorque = %.9g;\n", m_maxMotorTorque);
+	b2Dump("  joints[%d] = m_world->CreateJoint(&jd);\n", m_index);
+}
+
+///
+void b2RevoluteJoint::Draw(b2Draw* draw) const
+{
+	const b2Transform& xfA = m_bodyA->GetTransform();
+	const b2Transform& xfB = m_bodyB->GetTransform();
+	b2Vec2 pA = b2Mul(xfA, m_localAnchorA);
+	b2Vec2 pB = b2Mul(xfB, m_localAnchorB);
+
+	b2Color c1(0.7f, 0.7f, 0.7f);
+	b2Color c2(0.3f, 0.9f, 0.3f);
+	b2Color c3(0.9f, 0.3f, 0.3f);
+	b2Color c4(0.3f, 0.3f, 0.9f);
+	b2Color c5(0.4f, 0.4f, 0.4f);
+
+	draw->DrawPoint(pA, 5.0f, c4);
+	draw->DrawPoint(pB, 5.0f, c5);
+
+	float aA = m_bodyA->GetAngle();
+	float aB = m_bodyB->GetAngle();
+	float angle = aB - aA - m_referenceAngle;
+
+	const float L = 0.5f;
+
+	b2Vec2 r = L * b2Vec2(cosf(angle), sinf(angle));
+	draw->DrawSegment(pB, pB + r, c1);
+	draw->DrawCircle(pB, L, c1);
+
+	if (m_enableLimit)
+	{
+		b2Vec2 rlo = L * b2Vec2(cosf(m_lowerAngle), sinf(m_lowerAngle));
+		b2Vec2 rhi = L * b2Vec2(cosf(m_upperAngle), sinf(m_upperAngle));
+
+		draw->DrawSegment(pB, pB + rlo, c2);
+		draw->DrawSegment(pB, pB + rhi, c3);
+	}
+
+	b2Color color(0.5f, 0.8f, 0.8f);
+	draw->DrawSegment(xfA.p, pA, color);
+	draw->DrawSegment(pA, pB, color);
+	draw->DrawSegment(xfB.p, pB, color);
+}