+init

1 files changed, 672 insertions, 0 deletions

diff --git a/Client/ThirdParty/Box2D/src/dynamics/b2_wheel_joint.cpp b/Client/ThirdParty/Box2D/src/dynamics/b2_wheel_joint.cpp
new file mode 100644
index 0000000..c23b984
--- /dev/null
+++ b/Client/ThirdParty/Box2D/src/dynamics/b2_wheel_joint.cpp
@@ -0,0 +1,672 @@
+// 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_wheel_joint.h"
+#include "box2d/b2_time_step.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_axialMass = 0.0f;
+	m_lowerImpulse = 0.0f;
+	m_upperImpulse = 0.0f;
+	m_lowerTranslation = def->lowerTranslation;
+	m_upperTranslation = def->upperTranslation;
+	m_enableLimit = def->enableLimit;
+
+	m_maxMotorTorque = def->maxMotorTorque;
+	m_motorSpeed = def->motorSpeed;
+	m_enableMotor = def->enableMotor;
+
+	m_bias = 0.0f;
+	m_gamma = 0.0f;
+
+	m_ax.SetZero();
+	m_ay.SetZero();
+
+	m_stiffness = def->stiffness;
+	m_damping = def->damping;
+}
+
+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;
+
+	float mA = m_invMassA, mB = m_invMassB;
+	float iA = m_invIA, iB = m_invIB;
+
+	b2Vec2 cA = data.positions[m_indexA].c;
+	float aA = data.positions[m_indexA].a;
+	b2Vec2 vA = data.velocities[m_indexA].v;
+	float wA = data.velocities[m_indexA].w;
+
+	b2Vec2 cB = data.positions[m_indexB].c;
+	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);
+
+	// 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_ax = b2Mul(qA, m_localXAxisA);
+	m_sAx = b2Cross(d + rA, m_ax);
+	m_sBx = b2Cross(rB, m_ax);
+
+	const float invMass = mA + mB + iA * m_sAx * m_sAx + iB * m_sBx * m_sBx;
+	if (invMass > 0.0f)
+	{
+		m_axialMass = 1.0f / invMass;
+	}
+	else
+	{
+		m_axialMass = 0.0f;
+	}
+
+	m_springMass = 0.0f;
+	m_bias = 0.0f;
+	m_gamma = 0.0f;
+
+	if (m_stiffness > 0.0f && invMass > 0.0f)
+	{
+		m_springMass = 1.0f / invMass;
+
+		float C = b2Dot(d, m_ax);
+
+		// magic formulas
+		float h = data.step.dt;
+		m_gamma = h * (m_damping + h * m_stiffness);
+		if (m_gamma > 0.0f)
+		{
+			m_gamma = 1.0f / m_gamma;
+		}
+
+		m_bias = C * h * m_stiffness * m_gamma;
+
+		m_springMass = invMass + m_gamma;
+		if (m_springMass > 0.0f)
+		{
+			m_springMass = 1.0f / m_springMass;
+		}
+	}
+	else
+	{
+		m_springImpulse = 0.0f;
+	}
+
+	if (m_enableLimit)
+	{
+		m_translation = b2Dot(m_ax, d);
+	}
+	else
+	{
+		m_lowerImpulse = 0.0f;
+		m_upperImpulse = 0.0f;
+	}
+
+	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;
+
+		float axialImpulse = m_springImpulse + m_lowerImpulse - m_upperImpulse;
+		b2Vec2 P = m_impulse * m_ay + axialImpulse * m_ax;
+		float LA = m_impulse * m_sAy + axialImpulse * m_sAx + m_motorImpulse;
+		float LB = m_impulse * m_sBy + axialImpulse * 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;
+		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 b2WheelJoint::SolveVelocityConstraints(const b2SolverData& data)
+{
+	float mA = m_invMassA, mB = m_invMassB;
+	float iA = m_invIA, iB = m_invIB;
+
+	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;
+
+	// Solve spring constraint
+	{
+		float Cdot = b2Dot(m_ax, vB - vA) + m_sBx * wB - m_sAx * wA;
+		float impulse = -m_springMass * (Cdot + m_bias + m_gamma * m_springImpulse);
+		m_springImpulse += impulse;
+
+		b2Vec2 P = impulse * m_ax;
+		float LA = impulse * m_sAx;
+		float LB = impulse * m_sBx;
+
+		vA -= mA * P;
+		wA -= iA * LA;
+
+		vB += mB * P;
+		wB += iB * LB;
+	}
+
+	// Solve rotational motor constraint
+	{
+		float Cdot = wB - wA - m_motorSpeed;
+		float impulse = -m_motorMass * 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)
+	{
+		// Lower limit
+		{
+			float C = m_translation - m_lowerTranslation;
+			float Cdot = b2Dot(m_ax, vB - vA) + m_sBx * wB - m_sAx * 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;
+
+			b2Vec2 P = impulse * m_ax;
+			float LA = impulse * m_sAx;
+			float LB = impulse * m_sBx;
+
+			vA -= mA * P;
+			wA -= iA * LA;
+			vB += mB * P;
+			wB += iB * LB;
+		}
+
+		// 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_upperTranslation - m_translation;
+			float Cdot = b2Dot(m_ax, vA - vB) + m_sAx * wA - m_sBx * 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;
+
+			b2Vec2 P = impulse * m_ax;
+			float LA = impulse * m_sAx;
+			float LB = impulse * m_sBx;
+
+			vA += mA * P;
+			wA += iA * LA;
+			vB -= mB * P;
+			wB -= iB * LB;
+		}
+	}
+
+	// Solve point to line constraint
+	{
+		float Cdot = b2Dot(m_ay, vB - vA) + m_sBy * wB - m_sAy * wA;
+		float impulse = -m_mass * Cdot;
+		m_impulse += impulse;
+
+		b2Vec2 P = impulse * m_ay;
+		float LA = impulse * m_sAy;
+		float 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;
+	float aA = data.positions[m_indexA].a;
+	b2Vec2 cB = data.positions[m_indexB].c;
+	float aB = data.positions[m_indexB].a;
+
+	float linearError = 0.0f;
+
+	if (m_enableLimit)
+	{
+		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 ax = b2Mul(qA, m_localXAxisA);
+		float sAx = b2Cross(d + rA, m_ax);
+		float sBx = b2Cross(rB, m_ax);
+
+		float C = 0.0f;
+		float translation = b2Dot(ax, d);
+		if (b2Abs(m_upperTranslation - m_lowerTranslation) < 2.0f * b2_linearSlop)
+		{
+			C = translation;
+		}
+		else if (translation <= m_lowerTranslation)
+		{
+			C = b2Min(translation - m_lowerTranslation, 0.0f);
+		}
+		else if (translation >= m_upperTranslation)
+		{
+			C = b2Max(translation - m_upperTranslation, 0.0f);
+		}
+
+		if (C != 0.0f)
+		{
+
+			float invMass = m_invMassA + m_invMassB + m_invIA * sAx * sAx + m_invIB * sBx * sBx;
+			float impulse = 0.0f;
+			if (invMass != 0.0f)
+			{
+				impulse = -C / invMass;
+			}
+
+			b2Vec2 P = impulse * ax;
+			float LA = impulse * sAx;
+			float LB = impulse * sBx;
+
+			cA -= m_invMassA * P;
+			aA -= m_invIA * LA;
+			cB += m_invMassB * P;
+			aB += m_invIB * LB;
+
+			linearError = b2Abs(C);
+		}
+	}
+
+	// Solve perpendicular constraint
+	{
+		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);
+
+		float sAy = b2Cross(d + rA, ay);
+		float sBy = b2Cross(rB, ay);
+
+		float C = b2Dot(d, ay);
+
+		float invMass = m_invMassA + m_invMassB + m_invIA * m_sAy * m_sAy + m_invIB * m_sBy * m_sBy;
+
+		float impulse = 0.0f;
+		if (invMass != 0.0f)
+		{
+			impulse = - C / invMass;
+		}
+
+		b2Vec2 P = impulse * ay;
+		float LA = impulse * sAy;
+		float LB = impulse * sBy;
+
+		cA -= m_invMassA * P;
+		aA -= m_invIA * LA;
+		cB += m_invMassB * P;
+		aB += m_invIB * LB;
+
+		linearError = b2Max(linearError, b2Abs(C));
+	}
+
+	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 linearError <= 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(float inv_dt) const
+{
+	return inv_dt * (m_impulse * m_ay + (m_springImpulse + m_lowerImpulse - m_upperImpulse) * m_ax);
+}
+
+float b2WheelJoint::GetReactionTorque(float inv_dt) const
+{
+	return inv_dt * m_motorImpulse;
+}
+
+float 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);
+
+	float translation = b2Dot(d, axis);
+	return translation;
+}
+
+float 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;
+	float wA = bA->m_angularVelocity;
+	float wB = bB->m_angularVelocity;
+
+	float speed = b2Dot(d, b2Cross(wA, axis)) + b2Dot(axis, vB + b2Cross(wB, rB) - vA - b2Cross(wA, rA));
+	return speed;
+}
+
+float b2WheelJoint::GetJointAngle() const
+{
+	b2Body* bA = m_bodyA;
+	b2Body* bB = m_bodyB;
+	return bB->m_sweep.a - bA->m_sweep.a;
+}
+
+float b2WheelJoint::GetJointAngularSpeed() const
+{
+	float wA = m_bodyA->m_angularVelocity;
+	float wB = m_bodyB->m_angularVelocity;
+	return wB - wA;
+}
+
+bool b2WheelJoint::IsLimitEnabled() const
+{
+	return m_enableLimit;
+}
+
+void b2WheelJoint::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 b2WheelJoint::GetLowerLimit() const
+{
+	return m_lowerTranslation;
+}
+
+float b2WheelJoint::GetUpperLimit() const
+{
+	return m_upperTranslation;
+}
+
+void b2WheelJoint::SetLimits(float lower, float upper)
+{
+	b2Assert(lower <= upper);
+	if (lower != m_lowerTranslation || upper != m_upperTranslation)
+	{
+		m_bodyA->SetAwake(true);
+		m_bodyB->SetAwake(true);
+		m_lowerTranslation = lower;
+		m_upperTranslation = upper;
+		m_lowerImpulse = 0.0f;
+		m_upperImpulse = 0.0f;
+	}
+}
+
+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(float speed)
+{
+	if (speed != m_motorSpeed)
+	{
+		m_bodyA->SetAwake(true);
+		m_bodyB->SetAwake(true);
+		m_motorSpeed = speed;
+	}
+}
+
+void b2WheelJoint::SetMaxMotorTorque(float torque)
+{
+	if (torque != m_maxMotorTorque)
+	{
+		m_bodyA->SetAwake(true);
+		m_bodyB->SetAwake(true);
+		m_maxMotorTorque = torque;
+	}
+}
+
+float b2WheelJoint::GetMotorTorque(float inv_dt) const
+{
+	return inv_dt * m_motorImpulse;
+}
+
+void b2WheelJoint::SetStiffness(float stiffness)
+{
+	m_stiffness = stiffness;
+}
+
+float b2WheelJoint::GetStiffness() const
+{
+	return m_stiffness;
+}
+
+void b2WheelJoint::SetDamping(float damping)
+{
+	m_damping = damping;
+}
+
+float b2WheelJoint::GetDamping() const
+{
+	return m_damping;
+}
+
+void b2WheelJoint::Dump()
+{
+	// FLT_DECIMAL_DIG == 9
+
+	int32 indexA = m_bodyA->m_islandIndex;
+	int32 indexB = m_bodyB->m_islandIndex;
+
+	b2Dump("  b2WheelJointDef 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.localAxisA.Set(%.9g, %.9g);\n", m_localXAxisA.x, m_localXAxisA.y);
+	b2Dump("  jd.enableMotor = bool(%d);\n", m_enableMotor);
+	b2Dump("  jd.motorSpeed = %.9g;\n", m_motorSpeed);
+	b2Dump("  jd.maxMotorTorque = %.9g;\n", m_maxMotorTorque);
+	b2Dump("  jd.stiffness = %.9g;\n", m_stiffness);
+	b2Dump("  jd.damping = %.9g;\n", m_damping);
+	b2Dump("  joints[%d] = m_world->CreateJoint(&jd);\n", m_index);
+}
+
+///
+void b2WheelJoint::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);
+
+	b2Vec2 axis = b2Mul(xfA.q, m_localXAxisA);
+
+	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->DrawSegment(pA, pB, c5);
+
+	if (m_enableLimit)
+	{
+		b2Vec2 lower = pA + m_lowerTranslation * axis;
+		b2Vec2 upper = pA + m_upperTranslation * axis;
+		b2Vec2 perp = b2Mul(xfA.q, m_localYAxisA);
+		draw->DrawSegment(lower, upper, c1);
+		draw->DrawSegment(lower - 0.5f * perp, lower + 0.5f * perp, c2);
+		draw->DrawSegment(upper - 0.5f * perp, upper + 0.5f * perp, c3);
+	}
+	else
+	{
+		draw->DrawSegment(pA - 1.0f * axis, pA + 1.0f * axis, c1);
+	}
+
+	draw->DrawPoint(pA, 5.0f, c1);
+	draw->DrawPoint(pB, 5.0f, c4);
+}