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Diffstat (limited to 'Source/3rdParty/Box2D/Dynamics/Joints/b2RopeJoint.cpp')
-rw-r--r-- | Source/3rdParty/Box2D/Dynamics/Joints/b2RopeJoint.cpp | 241 |
1 files changed, 0 insertions, 241 deletions
diff --git a/Source/3rdParty/Box2D/Dynamics/Joints/b2RopeJoint.cpp b/Source/3rdParty/Box2D/Dynamics/Joints/b2RopeJoint.cpp deleted file mode 100644 index 86d27e7..0000000 --- a/Source/3rdParty/Box2D/Dynamics/Joints/b2RopeJoint.cpp +++ /dev/null @@ -1,241 +0,0 @@ -/* -* Copyright (c) 2007-2011 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/b2RopeJoint.h" -#include "Box2D/Dynamics/b2Body.h" -#include "Box2D/Dynamics/b2TimeStep.h" - - -// Limit: -// C = norm(pB - pA) - L -// u = (pB - pA) / norm(pB - pA) -// Cdot = dot(u, vB + cross(wB, rB) - vA - cross(wA, rA)) -// J = [-u -cross(rA, u) u cross(rB, u)] -// K = J * invM * JT -// = invMassA + invIA * cross(rA, u)^2 + invMassB + invIB * cross(rB, u)^2 - -b2RopeJoint::b2RopeJoint(const b2RopeJointDef* def) -: b2Joint(def) -{ - m_localAnchorA = def->localAnchorA; - m_localAnchorB = def->localAnchorB; - - m_maxLength = def->maxLength; - - m_mass = 0.0f; - m_impulse = 0.0f; - m_state = e_inactiveLimit; - m_length = 0.0f; -} - -void b2RopeJoint::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; - - 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); - - m_rA = b2Mul(qA, m_localAnchorA - m_localCenterA); - m_rB = b2Mul(qB, m_localAnchorB - m_localCenterB); - m_u = cB + m_rB - cA - m_rA; - - m_length = m_u.Length(); - - float32 C = m_length - m_maxLength; - if (C > 0.0f) - { - m_state = e_atUpperLimit; - } - else - { - m_state = e_inactiveLimit; - } - - if (m_length > b2_linearSlop) - { - m_u *= 1.0f / m_length; - } - else - { - m_u.SetZero(); - m_mass = 0.0f; - m_impulse = 0.0f; - return; - } - - // Compute effective mass. - float32 crA = b2Cross(m_rA, m_u); - float32 crB = b2Cross(m_rB, m_u); - float32 invMass = m_invMassA + m_invIA * crA * crA + m_invMassB + m_invIB * crB * crB; - - m_mass = invMass != 0.0f ? 1.0f / invMass : 0.0f; - - if (data.step.warmStarting) - { - // Scale the impulse to support a variable time step. - m_impulse *= data.step.dtRatio; - - b2Vec2 P = m_impulse * m_u; - vA -= m_invMassA * P; - wA -= m_invIA * b2Cross(m_rA, P); - vB += m_invMassB * P; - wB += m_invIB * b2Cross(m_rB, P); - } - else - { - m_impulse = 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 b2RopeJoint::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; - - // Cdot = dot(u, v + cross(w, r)) - b2Vec2 vpA = vA + b2Cross(wA, m_rA); - b2Vec2 vpB = vB + b2Cross(wB, m_rB); - float32 C = m_length - m_maxLength; - float32 Cdot = b2Dot(m_u, vpB - vpA); - - // Predictive constraint. - if (C < 0.0f) - { - Cdot += data.step.inv_dt * C; - } - - float32 impulse = -m_mass * Cdot; - float32 oldImpulse = m_impulse; - m_impulse = b2Min(0.0f, m_impulse + impulse); - impulse = m_impulse - oldImpulse; - - b2Vec2 P = impulse * m_u; - vA -= m_invMassA * P; - wA -= m_invIA * b2Cross(m_rA, P); - vB += m_invMassB * P; - wB += m_invIB * b2Cross(m_rB, P); - - 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 b2RopeJoint::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 u = cB + rB - cA - rA; - - float32 length = u.Normalize(); - float32 C = length - m_maxLength; - - C = b2Clamp(C, 0.0f, b2_maxLinearCorrection); - - float32 impulse = -m_mass * C; - b2Vec2 P = impulse * u; - - cA -= m_invMassA * P; - aA -= m_invIA * b2Cross(rA, P); - cB += m_invMassB * P; - aB += m_invIB * b2Cross(rB, P); - - 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 length - m_maxLength < b2_linearSlop; -} - -b2Vec2 b2RopeJoint::GetAnchorA() const -{ - return m_bodyA->GetWorldPoint(m_localAnchorA); -} - -b2Vec2 b2RopeJoint::GetAnchorB() const -{ - return m_bodyB->GetWorldPoint(m_localAnchorB); -} - -b2Vec2 b2RopeJoint::GetReactionForce(float32 inv_dt) const -{ - b2Vec2 F = (inv_dt * m_impulse) * m_u; - return F; -} - -float32 b2RopeJoint::GetReactionTorque(float32 inv_dt) const -{ - B2_NOT_USED(inv_dt); - return 0.0f; -} - -float32 b2RopeJoint::GetMaxLength() const -{ - return m_maxLength; -} - -b2LimitState b2RopeJoint::GetLimitState() const -{ - return m_state; -} - -void b2RopeJoint::Dump() -{ - int32 indexA = m_bodyA->m_islandIndex; - int32 indexB = m_bodyB->m_islandIndex; - - b2Log(" b2RopeJointDef 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.maxLength = %.15lef;\n", m_maxLength); - b2Log(" joints[%d] = m_world->CreateJoint(&jd);\n", m_index); -} |