summaryrefslogtreecommitdiff
path: root/Source/3rdParty/Box2D/Dynamics/Joints/b2FrictionJoint.cpp
diff options
context:
space:
mode:
authorchai <chaifix@163.com>2019-03-19 23:06:27 +0800
committerchai <chaifix@163.com>2019-03-19 23:06:27 +0800
commit1497dccd63a84b7ee2b229b1ad9c5c02718f2a78 (patch)
treef8d1bff50da13e126d08c7345653e002e293202d /Source/3rdParty/Box2D/Dynamics/Joints/b2FrictionJoint.cpp
parent5e2a973516e0729b225da9de0b03015dc5854ac4 (diff)
*rename
Diffstat (limited to 'Source/3rdParty/Box2D/Dynamics/Joints/b2FrictionJoint.cpp')
-rw-r--r--Source/3rdParty/Box2D/Dynamics/Joints/b2FrictionJoint.cpp251
1 files changed, 0 insertions, 251 deletions
diff --git a/Source/3rdParty/Box2D/Dynamics/Joints/b2FrictionJoint.cpp b/Source/3rdParty/Box2D/Dynamics/Joints/b2FrictionJoint.cpp
deleted file mode 100644
index cb122eb..0000000
--- a/Source/3rdParty/Box2D/Dynamics/Joints/b2FrictionJoint.cpp
+++ /dev/null
@@ -1,251 +0,0 @@
-/*
-* Copyright (c) 2006-2011 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/b2FrictionJoint.h"
-#include "Box2D/Dynamics/b2Body.h"
-#include "Box2D/Dynamics/b2TimeStep.h"
-
-// Point-to-point constraint
-// 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)
-
-// Angle constraint
-// Cdot = w2 - w1
-// J = [0 0 -1 0 0 1]
-// K = invI1 + invI2
-
-void b2FrictionJointDef::Initialize(b2Body* bA, b2Body* bB, const b2Vec2& anchor)
-{
- bodyA = bA;
- bodyB = bB;
- localAnchorA = bodyA->GetLocalPoint(anchor);
- localAnchorB = bodyB->GetLocalPoint(anchor);
-}
-
-b2FrictionJoint::b2FrictionJoint(const b2FrictionJointDef* def)
-: b2Joint(def)
-{
- m_localAnchorA = def->localAnchorA;
- m_localAnchorB = def->localAnchorB;
-
- m_linearImpulse.SetZero();
- m_angularImpulse = 0.0f;
-
- m_maxForce = def->maxForce;
- m_maxTorque = def->maxTorque;
-}
-
-void b2FrictionJoint::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 aA = data.positions[m_indexA].a;
- b2Vec2 vA = data.velocities[m_indexA].v;
- float32 wA = data.velocities[m_indexA].w;
-
- 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 mass matrix.
- m_rA = b2Mul(qA, m_localAnchorA - m_localCenterA);
- m_rB = b2Mul(qB, m_localAnchorB - m_localCenterB);
-
- // J = [-I -r1_skew I r2_skew]
- // [ 0 -1 0 1]
- // r_skew = [-ry; rx]
-
- // Matlab
- // K = [ mA+r1y^2*iA+mB+r2y^2*iB, -r1y*iA*r1x-r2y*iB*r2x, -r1y*iA-r2y*iB]
- // [ -r1y*iA*r1x-r2y*iB*r2x, mA+r1x^2*iA+mB+r2x^2*iB, r1x*iA+r2x*iB]
- // [ -r1y*iA-r2y*iB, r1x*iA+r2x*iB, iA+iB]
-
- float32 mA = m_invMassA, mB = m_invMassB;
- float32 iA = m_invIA, iB = m_invIB;
-
- b2Mat22 K;
- K.ex.x = mA + mB + iA * m_rA.y * m_rA.y + iB * m_rB.y * m_rB.y;
- K.ex.y = -iA * m_rA.x * m_rA.y - iB * m_rB.x * m_rB.y;
- K.ey.x = K.ex.y;
- K.ey.y = mA + mB + iA * m_rA.x * m_rA.x + iB * m_rB.x * m_rB.x;
-
- m_linearMass = K.GetInverse();
-
- m_angularMass = iA + iB;
- if (m_angularMass > 0.0f)
- {
- m_angularMass = 1.0f / m_angularMass;
- }
-
- if (data.step.warmStarting)
- {
- // Scale impulses to support a variable time step.
- m_linearImpulse *= data.step.dtRatio;
- m_angularImpulse *= data.step.dtRatio;
-
- b2Vec2 P(m_linearImpulse.x, m_linearImpulse.y);
- vA -= mA * P;
- wA -= iA * (b2Cross(m_rA, P) + m_angularImpulse);
- vB += mB * P;
- wB += iB * (b2Cross(m_rB, P) + m_angularImpulse);
- }
- else
- {
- m_linearImpulse.SetZero();
- m_angularImpulse = 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 b2FrictionJoint::SolveVelocityConstraints(const b2SolverData& data)
-{
- 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;
-
- float32 mA = m_invMassA, mB = m_invMassB;
- float32 iA = m_invIA, iB = m_invIB;
-
- float32 h = data.step.dt;
-
- // Solve angular friction
- {
- float32 Cdot = wB - wA;
- float32 impulse = -m_angularMass * Cdot;
-
- float32 oldImpulse = m_angularImpulse;
- float32 maxImpulse = h * m_maxTorque;
- m_angularImpulse = b2Clamp(m_angularImpulse + impulse, -maxImpulse, maxImpulse);
- impulse = m_angularImpulse - oldImpulse;
-
- wA -= iA * impulse;
- wB += iB * impulse;
- }
-
- // Solve linear friction
- {
- b2Vec2 Cdot = vB + b2Cross(wB, m_rB) - vA - b2Cross(wA, m_rA);
-
- b2Vec2 impulse = -b2Mul(m_linearMass, Cdot);
- b2Vec2 oldImpulse = m_linearImpulse;
- m_linearImpulse += impulse;
-
- float32 maxImpulse = h * m_maxForce;
-
- if (m_linearImpulse.LengthSquared() > maxImpulse * maxImpulse)
- {
- m_linearImpulse.Normalize();
- m_linearImpulse *= maxImpulse;
- }
-
- impulse = m_linearImpulse - oldImpulse;
-
- 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 b2FrictionJoint::SolvePositionConstraints(const b2SolverData& data)
-{
- B2_NOT_USED(data);
-
- return true;
-}
-
-b2Vec2 b2FrictionJoint::GetAnchorA() const
-{
- return m_bodyA->GetWorldPoint(m_localAnchorA);
-}
-
-b2Vec2 b2FrictionJoint::GetAnchorB() const
-{
- return m_bodyB->GetWorldPoint(m_localAnchorB);
-}
-
-b2Vec2 b2FrictionJoint::GetReactionForce(float32 inv_dt) const
-{
- return inv_dt * m_linearImpulse;
-}
-
-float32 b2FrictionJoint::GetReactionTorque(float32 inv_dt) const
-{
- return inv_dt * m_angularImpulse;
-}
-
-void b2FrictionJoint::SetMaxForce(float32 force)
-{
- b2Assert(b2IsValid(force) && force >= 0.0f);
- m_maxForce = force;
-}
-
-float32 b2FrictionJoint::GetMaxForce() const
-{
- return m_maxForce;
-}
-
-void b2FrictionJoint::SetMaxTorque(float32 torque)
-{
- b2Assert(b2IsValid(torque) && torque >= 0.0f);
- m_maxTorque = torque;
-}
-
-float32 b2FrictionJoint::GetMaxTorque() const
-{
- return m_maxTorque;
-}
-
-void b2FrictionJoint::Dump()
-{
- int32 indexA = m_bodyA->m_islandIndex;
- int32 indexB = m_bodyB->m_islandIndex;
-
- b2Log(" b2FrictionJointDef 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.maxForce = %.15lef;\n", m_maxForce);
- b2Log(" jd.maxTorque = %.15lef;\n", m_maxTorque);
- b2Log(" joints[%d] = m_world->CreateJoint(&jd);\n", m_index);
-}