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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/b2MouseJoint.cpp
parent5e2a973516e0729b225da9de0b03015dc5854ac4 (diff)
*rename
Diffstat (limited to 'Source/3rdParty/Box2D/Dynamics/Joints/b2MouseJoint.cpp')
-rw-r--r--Source/3rdParty/Box2D/Dynamics/Joints/b2MouseJoint.cpp222
1 files changed, 0 insertions, 222 deletions
diff --git a/Source/3rdParty/Box2D/Dynamics/Joints/b2MouseJoint.cpp b/Source/3rdParty/Box2D/Dynamics/Joints/b2MouseJoint.cpp
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--- a/Source/3rdParty/Box2D/Dynamics/Joints/b2MouseJoint.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/b2MouseJoint.h"
-#include "Box2D/Dynamics/b2Body.h"
-#include "Box2D/Dynamics/b2TimeStep.h"
-
-// p = attached point, m = mouse point
-// C = p - m
-// Cdot = v
-// = v + cross(w, r)
-// J = [I r_skew]
-// Identity used:
-// w k % (rx i + ry j) = w * (-ry i + rx j)
-
-b2MouseJoint::b2MouseJoint(const b2MouseJointDef* def)
-: b2Joint(def)
-{
- b2Assert(def->target.IsValid());
- b2Assert(b2IsValid(def->maxForce) && def->maxForce >= 0.0f);
- b2Assert(b2IsValid(def->frequencyHz) && def->frequencyHz >= 0.0f);
- b2Assert(b2IsValid(def->dampingRatio) && def->dampingRatio >= 0.0f);
-
- m_targetA = def->target;
- m_localAnchorB = b2MulT(m_bodyB->GetTransform(), m_targetA);
-
- m_maxForce = def->maxForce;
- m_impulse.SetZero();
-
- m_frequencyHz = def->frequencyHz;
- m_dampingRatio = def->dampingRatio;
-
- m_beta = 0.0f;
- m_gamma = 0.0f;
-}
-
-void b2MouseJoint::SetTarget(const b2Vec2& target)
-{
- if (target != m_targetA)
- {
- m_bodyB->SetAwake(true);
- m_targetA = target;
- }
-}
-
-const b2Vec2& b2MouseJoint::GetTarget() const
-{
- return m_targetA;
-}
-
-void b2MouseJoint::SetMaxForce(float32 force)
-{
- m_maxForce = force;
-}
-
-float32 b2MouseJoint::GetMaxForce() const
-{
- return m_maxForce;
-}
-
-void b2MouseJoint::SetFrequency(float32 hz)
-{
- m_frequencyHz = hz;
-}
-
-float32 b2MouseJoint::GetFrequency() const
-{
- return m_frequencyHz;
-}
-
-void b2MouseJoint::SetDampingRatio(float32 ratio)
-{
- m_dampingRatio = ratio;
-}
-
-float32 b2MouseJoint::GetDampingRatio() const
-{
- return m_dampingRatio;
-}
-
-void b2MouseJoint::InitVelocityConstraints(const b2SolverData& data)
-{
- m_indexB = m_bodyB->m_islandIndex;
- m_localCenterB = m_bodyB->m_sweep.localCenter;
- m_invMassB = m_bodyB->m_invMass;
- m_invIB = m_bodyB->m_invI;
-
- 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 qB(aB);
-
- float32 mass = m_bodyB->GetMass();
-
- // Frequency
- float32 omega = 2.0f * b2_pi * m_frequencyHz;
-
- // Damping coefficient
- float32 d = 2.0f * mass * m_dampingRatio * omega;
-
- // Spring stiffness
- float32 k = mass * (omega * omega);
-
- // magic formulas
- // gamma has units of inverse mass.
- // beta has units of inverse time.
- float32 h = data.step.dt;
- b2Assert(d + h * k > b2_epsilon);
- m_gamma = h * (d + h * k);
- if (m_gamma != 0.0f)
- {
- m_gamma = 1.0f / m_gamma;
- }
- m_beta = h * k * m_gamma;
-
- // Compute the effective mass matrix.
- m_rB = b2Mul(qB, m_localAnchorB - m_localCenterB);
-
- // K = [(1/m1 + 1/m2) * eye(2) - skew(r1) * invI1 * skew(r1) - skew(r2) * invI2 * skew(r2)]
- // = [1/m1+1/m2 0 ] + invI1 * [r1.y*r1.y -r1.x*r1.y] + invI2 * [r1.y*r1.y -r1.x*r1.y]
- // [ 0 1/m1+1/m2] [-r1.x*r1.y r1.x*r1.x] [-r1.x*r1.y r1.x*r1.x]
- b2Mat22 K;
- K.ex.x = m_invMassB + m_invIB * m_rB.y * m_rB.y + m_gamma;
- K.ex.y = -m_invIB * m_rB.x * m_rB.y;
- K.ey.x = K.ex.y;
- K.ey.y = m_invMassB + m_invIB * m_rB.x * m_rB.x + m_gamma;
-
- m_mass = K.GetInverse();
-
- m_C = cB + m_rB - m_targetA;
- m_C *= m_beta;
-
- // Cheat with some damping
- wB *= 0.98f;
-
- if (data.step.warmStarting)
- {
- m_impulse *= data.step.dtRatio;
- vB += m_invMassB * m_impulse;
- wB += m_invIB * b2Cross(m_rB, m_impulse);
- }
- else
- {
- m_impulse.SetZero();
- }
-
- data.velocities[m_indexB].v = vB;
- data.velocities[m_indexB].w = wB;
-}
-
-void b2MouseJoint::SolveVelocityConstraints(const b2SolverData& data)
-{
- b2Vec2 vB = data.velocities[m_indexB].v;
- float32 wB = data.velocities[m_indexB].w;
-
- // Cdot = v + cross(w, r)
- b2Vec2 Cdot = vB + b2Cross(wB, m_rB);
- b2Vec2 impulse = b2Mul(m_mass, -(Cdot + m_C + m_gamma * m_impulse));
-
- b2Vec2 oldImpulse = m_impulse;
- m_impulse += impulse;
- float32 maxImpulse = data.step.dt * m_maxForce;
- if (m_impulse.LengthSquared() > maxImpulse * maxImpulse)
- {
- m_impulse *= maxImpulse / m_impulse.Length();
- }
- impulse = m_impulse - oldImpulse;
-
- vB += m_invMassB * impulse;
- wB += m_invIB * b2Cross(m_rB, impulse);
-
- data.velocities[m_indexB].v = vB;
- data.velocities[m_indexB].w = wB;
-}
-
-bool b2MouseJoint::SolvePositionConstraints(const b2SolverData& data)
-{
- B2_NOT_USED(data);
- return true;
-}
-
-b2Vec2 b2MouseJoint::GetAnchorA() const
-{
- return m_targetA;
-}
-
-b2Vec2 b2MouseJoint::GetAnchorB() const
-{
- return m_bodyB->GetWorldPoint(m_localAnchorB);
-}
-
-b2Vec2 b2MouseJoint::GetReactionForce(float32 inv_dt) const
-{
- return inv_dt * m_impulse;
-}
-
-float32 b2MouseJoint::GetReactionTorque(float32 inv_dt) const
-{
- return inv_dt * 0.0f;
-}
-
-void b2MouseJoint::ShiftOrigin(const b2Vec2& newOrigin)
-{
- m_targetA -= newOrigin;
-}