diff options
Diffstat (limited to 'Source/3rdParty/Box2D/Dynamics/Joints/b2MouseJoint.cpp')
-rw-r--r-- | Source/3rdParty/Box2D/Dynamics/Joints/b2MouseJoint.cpp | 222 |
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 deleted file mode 100644 index 637e4cd..0000000 --- a/Source/3rdParty/Box2D/Dynamics/Joints/b2MouseJoint.cpp +++ /dev/null @@ -1,222 +0,0 @@ -/* -* 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; -} |