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Diffstat (limited to 'src/libjin/3rdparty/Box2D/Dynamics/Joints')
24 files changed, 6123 insertions, 0 deletions
diff --git a/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2DistanceJoint.cpp b/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2DistanceJoint.cpp new file mode 100644 index 0000000..126133c --- /dev/null +++ b/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2DistanceJoint.cpp @@ -0,0 +1,260 @@ +/* +* 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/b2DistanceJoint.h" +#include "Box2D/Dynamics/b2Body.h" +#include "Box2D/Dynamics/b2TimeStep.h" + +// 1-D constrained system +// m (v2 - v1) = lambda +// v2 + (beta/h) * x1 + gamma * lambda = 0, gamma has units of inverse mass. +// x2 = x1 + h * v2 + +// 1-D mass-damper-spring system +// m (v2 - v1) + h * d * v2 + h * k * + +// C = norm(p2 - p1) - L +// u = (p2 - p1) / norm(p2 - p1) +// Cdot = dot(u, v2 + cross(w2, r2) - v1 - cross(w1, r1)) +// J = [-u -cross(r1, u) u cross(r2, u)] +// K = J * invM * JT +// = invMass1 + invI1 * cross(r1, u)^2 + invMass2 + invI2 * cross(r2, u)^2 + +void b2DistanceJointDef::Initialize(b2Body* b1, b2Body* b2, + const b2Vec2& anchor1, const b2Vec2& anchor2) +{ + bodyA = b1; + bodyB = b2; + localAnchorA = bodyA->GetLocalPoint(anchor1); + localAnchorB = bodyB->GetLocalPoint(anchor2); + b2Vec2 d = anchor2 - anchor1; + length = d.Length(); +} + +b2DistanceJoint::b2DistanceJoint(const b2DistanceJointDef* def) +: b2Joint(def) +{ + m_localAnchorA = def->localAnchorA; + m_localAnchorB = def->localAnchorB; + m_length = def->length; + m_frequencyHz = def->frequencyHz; + m_dampingRatio = def->dampingRatio; + m_impulse = 0.0f; + m_gamma = 0.0f; + m_bias = 0.0f; +} + +void b2DistanceJoint::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; + + // Handle singularity. + float32 length = m_u.Length(); + if (length > b2_linearSlop) + { + m_u *= 1.0f / length; + } + else + { + m_u.Set(0.0f, 0.0f); + } + + float32 crAu = b2Cross(m_rA, m_u); + float32 crBu = b2Cross(m_rB, m_u); + float32 invMass = m_invMassA + m_invIA * crAu * crAu + m_invMassB + m_invIB * crBu * crBu; + + // Compute the effective mass matrix. + m_mass = invMass != 0.0f ? 1.0f / invMass : 0.0f; + + if (m_frequencyHz > 0.0f) + { + float32 C = length - m_length; + + // Frequency + float32 omega = 2.0f * b2_pi * m_frequencyHz; + + // Damping coefficient + float32 d = 2.0f * m_mass * m_dampingRatio * omega; + + // Spring stiffness + float32 k = m_mass * omega * omega; + + // magic formulas + float32 h = data.step.dt; + m_gamma = h * (d + h * k); + m_gamma = m_gamma != 0.0f ? 1.0f / m_gamma : 0.0f; + m_bias = C * h * k * m_gamma; + + invMass += m_gamma; + m_mass = invMass != 0.0f ? 1.0f / invMass : 0.0f; + } + else + { + m_gamma = 0.0f; + m_bias = 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 b2DistanceJoint::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 Cdot = b2Dot(m_u, vpB - vpA); + + float32 impulse = -m_mass * (Cdot + m_bias + m_gamma * m_impulse); + m_impulse += impulse; + + 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 b2DistanceJoint::SolvePositionConstraints(const b2SolverData& data) +{ + if (m_frequencyHz > 0.0f) + { + // There is no position correction for soft distance constraints. + return true; + } + + 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_length; + C = b2Clamp(C, -b2_maxLinearCorrection, 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 b2Abs(C) < b2_linearSlop; +} + +b2Vec2 b2DistanceJoint::GetAnchorA() const +{ + return m_bodyA->GetWorldPoint(m_localAnchorA); +} + +b2Vec2 b2DistanceJoint::GetAnchorB() const +{ + return m_bodyB->GetWorldPoint(m_localAnchorB); +} + +b2Vec2 b2DistanceJoint::GetReactionForce(float32 inv_dt) const +{ + b2Vec2 F = (inv_dt * m_impulse) * m_u; + return F; +} + +float32 b2DistanceJoint::GetReactionTorque(float32 inv_dt) const +{ + B2_NOT_USED(inv_dt); + return 0.0f; +} + +void b2DistanceJoint::Dump() +{ + int32 indexA = m_bodyA->m_islandIndex; + int32 indexB = m_bodyB->m_islandIndex; + + b2Log(" b2DistanceJointDef 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.length = %.15lef;\n", m_length); + b2Log(" jd.frequencyHz = %.15lef;\n", m_frequencyHz); + b2Log(" jd.dampingRatio = %.15lef;\n", m_dampingRatio); + b2Log(" joints[%d] = m_world->CreateJoint(&jd);\n", m_index); +} diff --git a/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2DistanceJoint.h b/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2DistanceJoint.h new file mode 100644 index 0000000..ba59210 --- /dev/null +++ b/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2DistanceJoint.h @@ -0,0 +1,169 @@ +/* +* 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. +*/ + +#ifndef B2_DISTANCE_JOINT_H +#define B2_DISTANCE_JOINT_H + +#include "Box2D/Dynamics/Joints/b2Joint.h" + +/// Distance joint definition. This requires defining an +/// anchor point on both bodies and the non-zero length of the +/// distance joint. The definition uses local anchor points +/// so that the initial configuration can violate the constraint +/// slightly. This helps when saving and loading a game. +/// @warning Do not use a zero or short length. +struct b2DistanceJointDef : public b2JointDef +{ + b2DistanceJointDef() + { + type = e_distanceJoint; + localAnchorA.Set(0.0f, 0.0f); + localAnchorB.Set(0.0f, 0.0f); + length = 1.0f; + frequencyHz = 0.0f; + dampingRatio = 0.0f; + } + + /// Initialize the bodies, anchors, and length using the world + /// anchors. + void Initialize(b2Body* bodyA, b2Body* bodyB, + const b2Vec2& anchorA, const b2Vec2& anchorB); + + /// The local anchor point relative to bodyA's origin. + b2Vec2 localAnchorA; + + /// The local anchor point relative to bodyB's origin. + b2Vec2 localAnchorB; + + /// The natural length between the anchor points. + float32 length; + + /// The mass-spring-damper frequency in Hertz. A value of 0 + /// disables softness. + float32 frequencyHz; + + /// The damping ratio. 0 = no damping, 1 = critical damping. + float32 dampingRatio; +}; + +/// A distance joint constrains two points on two bodies +/// to remain at a fixed distance from each other. You can view +/// this as a massless, rigid rod. +class b2DistanceJoint : public b2Joint +{ +public: + + b2Vec2 GetAnchorA() const override; + b2Vec2 GetAnchorB() const override; + + /// Get the reaction force given the inverse time step. + /// Unit is N. + b2Vec2 GetReactionForce(float32 inv_dt) const override; + + /// Get the reaction torque given the inverse time step. + /// Unit is N*m. This is always zero for a distance joint. + float32 GetReactionTorque(float32 inv_dt) const override; + + /// The local anchor point relative to bodyA's origin. + const b2Vec2& GetLocalAnchorA() const { return m_localAnchorA; } + + /// The local anchor point relative to bodyB's origin. + const b2Vec2& GetLocalAnchorB() const { return m_localAnchorB; } + + /// Set/get the natural length. + /// Manipulating the length can lead to non-physical behavior when the frequency is zero. + void SetLength(float32 length); + float32 GetLength() const; + + /// Set/get frequency in Hz. + void SetFrequency(float32 hz); + float32 GetFrequency() const; + + /// Set/get damping ratio. + void SetDampingRatio(float32 ratio); + float32 GetDampingRatio() const; + + /// Dump joint to dmLog + void Dump() override; + +protected: + + friend class b2Joint; + b2DistanceJoint(const b2DistanceJointDef* data); + + void InitVelocityConstraints(const b2SolverData& data) override; + void SolveVelocityConstraints(const b2SolverData& data) override; + bool SolvePositionConstraints(const b2SolverData& data) override; + + float32 m_frequencyHz; + float32 m_dampingRatio; + float32 m_bias; + + // Solver shared + b2Vec2 m_localAnchorA; + b2Vec2 m_localAnchorB; + float32 m_gamma; + float32 m_impulse; + float32 m_length; + + // Solver temp + int32 m_indexA; + int32 m_indexB; + b2Vec2 m_u; + b2Vec2 m_rA; + b2Vec2 m_rB; + b2Vec2 m_localCenterA; + b2Vec2 m_localCenterB; + float32 m_invMassA; + float32 m_invMassB; + float32 m_invIA; + float32 m_invIB; + float32 m_mass; +}; + +inline void b2DistanceJoint::SetLength(float32 length) +{ + m_length = length; +} + +inline float32 b2DistanceJoint::GetLength() const +{ + return m_length; +} + +inline void b2DistanceJoint::SetFrequency(float32 hz) +{ + m_frequencyHz = hz; +} + +inline float32 b2DistanceJoint::GetFrequency() const +{ + return m_frequencyHz; +} + +inline void b2DistanceJoint::SetDampingRatio(float32 ratio) +{ + m_dampingRatio = ratio; +} + +inline float32 b2DistanceJoint::GetDampingRatio() const +{ + return m_dampingRatio; +} + +#endif diff --git a/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2FrictionJoint.cpp b/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2FrictionJoint.cpp new file mode 100644 index 0000000..cb122eb --- /dev/null +++ b/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2FrictionJoint.cpp @@ -0,0 +1,251 @@ +/* +* 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); +} diff --git a/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2FrictionJoint.h b/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2FrictionJoint.h new file mode 100644 index 0000000..d964f84 --- /dev/null +++ b/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2FrictionJoint.h @@ -0,0 +1,119 @@ +/* +* 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. +*/ + +#ifndef B2_FRICTION_JOINT_H +#define B2_FRICTION_JOINT_H + +#include "Box2D/Dynamics/Joints/b2Joint.h" + +/// Friction joint definition. +struct b2FrictionJointDef : public b2JointDef +{ + b2FrictionJointDef() + { + type = e_frictionJoint; + localAnchorA.SetZero(); + localAnchorB.SetZero(); + maxForce = 0.0f; + maxTorque = 0.0f; + } + + /// Initialize the bodies, anchors, axis, and reference angle using the world + /// anchor and world axis. + void Initialize(b2Body* bodyA, b2Body* bodyB, const b2Vec2& anchor); + + /// The local anchor point relative to bodyA's origin. + b2Vec2 localAnchorA; + + /// The local anchor point relative to bodyB's origin. + b2Vec2 localAnchorB; + + /// The maximum friction force in N. + float32 maxForce; + + /// The maximum friction torque in N-m. + float32 maxTorque; +}; + +/// Friction joint. This is used for top-down friction. +/// It provides 2D translational friction and angular friction. +class b2FrictionJoint : public b2Joint +{ +public: + b2Vec2 GetAnchorA() const override; + b2Vec2 GetAnchorB() const override; + + b2Vec2 GetReactionForce(float32 inv_dt) const override; + float32 GetReactionTorque(float32 inv_dt) const override; + + /// The local anchor point relative to bodyA's origin. + const b2Vec2& GetLocalAnchorA() const { return m_localAnchorA; } + + /// The local anchor point relative to bodyB's origin. + const b2Vec2& GetLocalAnchorB() const { return m_localAnchorB; } + + /// Set the maximum friction force in N. + void SetMaxForce(float32 force); + + /// Get the maximum friction force in N. + float32 GetMaxForce() const; + + /// Set the maximum friction torque in N*m. + void SetMaxTorque(float32 torque); + + /// Get the maximum friction torque in N*m. + float32 GetMaxTorque() const; + + /// Dump joint to dmLog + void Dump() override; + +protected: + + friend class b2Joint; + + b2FrictionJoint(const b2FrictionJointDef* def); + + void InitVelocityConstraints(const b2SolverData& data) override; + void SolveVelocityConstraints(const b2SolverData& data) override; + bool SolvePositionConstraints(const b2SolverData& data) override; + + b2Vec2 m_localAnchorA; + b2Vec2 m_localAnchorB; + + // Solver shared + b2Vec2 m_linearImpulse; + float32 m_angularImpulse; + float32 m_maxForce; + float32 m_maxTorque; + + // Solver temp + int32 m_indexA; + int32 m_indexB; + b2Vec2 m_rA; + b2Vec2 m_rB; + b2Vec2 m_localCenterA; + b2Vec2 m_localCenterB; + float32 m_invMassA; + float32 m_invMassB; + float32 m_invIA; + float32 m_invIB; + b2Mat22 m_linearMass; + float32 m_angularMass; +}; + +#endif diff --git a/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2GearJoint.cpp b/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2GearJoint.cpp new file mode 100644 index 0000000..1ce575b --- /dev/null +++ b/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2GearJoint.cpp @@ -0,0 +1,419 @@ +/* +* 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/b2GearJoint.h" +#include "Box2D/Dynamics/Joints/b2RevoluteJoint.h" +#include "Box2D/Dynamics/Joints/b2PrismaticJoint.h" +#include "Box2D/Dynamics/b2Body.h" +#include "Box2D/Dynamics/b2TimeStep.h" + +// Gear Joint: +// C0 = (coordinate1 + ratio * coordinate2)_initial +// C = (coordinate1 + ratio * coordinate2) - C0 = 0 +// J = [J1 ratio * J2] +// K = J * invM * JT +// = J1 * invM1 * J1T + ratio * ratio * J2 * invM2 * J2T +// +// Revolute: +// coordinate = rotation +// Cdot = angularVelocity +// J = [0 0 1] +// K = J * invM * JT = invI +// +// Prismatic: +// coordinate = dot(p - pg, ug) +// Cdot = dot(v + cross(w, r), ug) +// J = [ug cross(r, ug)] +// K = J * invM * JT = invMass + invI * cross(r, ug)^2 + +b2GearJoint::b2GearJoint(const b2GearJointDef* def) +: b2Joint(def) +{ + m_joint1 = def->joint1; + m_joint2 = def->joint2; + + m_typeA = m_joint1->GetType(); + m_typeB = m_joint2->GetType(); + + b2Assert(m_typeA == e_revoluteJoint || m_typeA == e_prismaticJoint); + b2Assert(m_typeB == e_revoluteJoint || m_typeB == e_prismaticJoint); + + float32 coordinateA, coordinateB; + + // TODO_ERIN there might be some problem with the joint edges in b2Joint. + + m_bodyC = m_joint1->GetBodyA(); + m_bodyA = m_joint1->GetBodyB(); + + // Get geometry of joint1 + b2Transform xfA = m_bodyA->m_xf; + float32 aA = m_bodyA->m_sweep.a; + b2Transform xfC = m_bodyC->m_xf; + float32 aC = m_bodyC->m_sweep.a; + + if (m_typeA == e_revoluteJoint) + { + b2RevoluteJoint* revolute = (b2RevoluteJoint*)def->joint1; + m_localAnchorC = revolute->m_localAnchorA; + m_localAnchorA = revolute->m_localAnchorB; + m_referenceAngleA = revolute->m_referenceAngle; + m_localAxisC.SetZero(); + + coordinateA = aA - aC - m_referenceAngleA; + } + else + { + b2PrismaticJoint* prismatic = (b2PrismaticJoint*)def->joint1; + m_localAnchorC = prismatic->m_localAnchorA; + m_localAnchorA = prismatic->m_localAnchorB; + m_referenceAngleA = prismatic->m_referenceAngle; + m_localAxisC = prismatic->m_localXAxisA; + + b2Vec2 pC = m_localAnchorC; + b2Vec2 pA = b2MulT(xfC.q, b2Mul(xfA.q, m_localAnchorA) + (xfA.p - xfC.p)); + coordinateA = b2Dot(pA - pC, m_localAxisC); + } + + m_bodyD = m_joint2->GetBodyA(); + m_bodyB = m_joint2->GetBodyB(); + + // Get geometry of joint2 + b2Transform xfB = m_bodyB->m_xf; + float32 aB = m_bodyB->m_sweep.a; + b2Transform xfD = m_bodyD->m_xf; + float32 aD = m_bodyD->m_sweep.a; + + if (m_typeB == e_revoluteJoint) + { + b2RevoluteJoint* revolute = (b2RevoluteJoint*)def->joint2; + m_localAnchorD = revolute->m_localAnchorA; + m_localAnchorB = revolute->m_localAnchorB; + m_referenceAngleB = revolute->m_referenceAngle; + m_localAxisD.SetZero(); + + coordinateB = aB - aD - m_referenceAngleB; + } + else + { + b2PrismaticJoint* prismatic = (b2PrismaticJoint*)def->joint2; + m_localAnchorD = prismatic->m_localAnchorA; + m_localAnchorB = prismatic->m_localAnchorB; + m_referenceAngleB = prismatic->m_referenceAngle; + m_localAxisD = prismatic->m_localXAxisA; + + b2Vec2 pD = m_localAnchorD; + b2Vec2 pB = b2MulT(xfD.q, b2Mul(xfB.q, m_localAnchorB) + (xfB.p - xfD.p)); + coordinateB = b2Dot(pB - pD, m_localAxisD); + } + + m_ratio = def->ratio; + + m_constant = coordinateA + m_ratio * coordinateB; + + m_impulse = 0.0f; +} + +void b2GearJoint::InitVelocityConstraints(const b2SolverData& data) +{ + m_indexA = m_bodyA->m_islandIndex; + m_indexB = m_bodyB->m_islandIndex; + m_indexC = m_bodyC->m_islandIndex; + m_indexD = m_bodyD->m_islandIndex; + m_lcA = m_bodyA->m_sweep.localCenter; + m_lcB = m_bodyB->m_sweep.localCenter; + m_lcC = m_bodyC->m_sweep.localCenter; + m_lcD = m_bodyD->m_sweep.localCenter; + m_mA = m_bodyA->m_invMass; + m_mB = m_bodyB->m_invMass; + m_mC = m_bodyC->m_invMass; + m_mD = m_bodyD->m_invMass; + m_iA = m_bodyA->m_invI; + m_iB = m_bodyB->m_invI; + m_iC = m_bodyC->m_invI; + m_iD = m_bodyD->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; + + float32 aC = data.positions[m_indexC].a; + b2Vec2 vC = data.velocities[m_indexC].v; + float32 wC = data.velocities[m_indexC].w; + + float32 aD = data.positions[m_indexD].a; + b2Vec2 vD = data.velocities[m_indexD].v; + float32 wD = data.velocities[m_indexD].w; + + b2Rot qA(aA), qB(aB), qC(aC), qD(aD); + + m_mass = 0.0f; + + if (m_typeA == e_revoluteJoint) + { + m_JvAC.SetZero(); + m_JwA = 1.0f; + m_JwC = 1.0f; + m_mass += m_iA + m_iC; + } + else + { + b2Vec2 u = b2Mul(qC, m_localAxisC); + b2Vec2 rC = b2Mul(qC, m_localAnchorC - m_lcC); + b2Vec2 rA = b2Mul(qA, m_localAnchorA - m_lcA); + m_JvAC = u; + m_JwC = b2Cross(rC, u); + m_JwA = b2Cross(rA, u); + m_mass += m_mC + m_mA + m_iC * m_JwC * m_JwC + m_iA * m_JwA * m_JwA; + } + + if (m_typeB == e_revoluteJoint) + { + m_JvBD.SetZero(); + m_JwB = m_ratio; + m_JwD = m_ratio; + m_mass += m_ratio * m_ratio * (m_iB + m_iD); + } + else + { + b2Vec2 u = b2Mul(qD, m_localAxisD); + b2Vec2 rD = b2Mul(qD, m_localAnchorD - m_lcD); + b2Vec2 rB = b2Mul(qB, m_localAnchorB - m_lcB); + m_JvBD = m_ratio * u; + m_JwD = m_ratio * b2Cross(rD, u); + m_JwB = m_ratio * b2Cross(rB, u); + m_mass += m_ratio * m_ratio * (m_mD + m_mB) + m_iD * m_JwD * m_JwD + m_iB * m_JwB * m_JwB; + } + + // Compute effective mass. + m_mass = m_mass > 0.0f ? 1.0f / m_mass : 0.0f; + + if (data.step.warmStarting) + { + vA += (m_mA * m_impulse) * m_JvAC; + wA += m_iA * m_impulse * m_JwA; + vB += (m_mB * m_impulse) * m_JvBD; + wB += m_iB * m_impulse * m_JwB; + vC -= (m_mC * m_impulse) * m_JvAC; + wC -= m_iC * m_impulse * m_JwC; + vD -= (m_mD * m_impulse) * m_JvBD; + wD -= m_iD * m_impulse * m_JwD; + } + 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; + data.velocities[m_indexC].v = vC; + data.velocities[m_indexC].w = wC; + data.velocities[m_indexD].v = vD; + data.velocities[m_indexD].w = wD; +} + +void b2GearJoint::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; + b2Vec2 vC = data.velocities[m_indexC].v; + float32 wC = data.velocities[m_indexC].w; + b2Vec2 vD = data.velocities[m_indexD].v; + float32 wD = data.velocities[m_indexD].w; + + float32 Cdot = b2Dot(m_JvAC, vA - vC) + b2Dot(m_JvBD, vB - vD); + Cdot += (m_JwA * wA - m_JwC * wC) + (m_JwB * wB - m_JwD * wD); + + float32 impulse = -m_mass * Cdot; + m_impulse += impulse; + + vA += (m_mA * impulse) * m_JvAC; + wA += m_iA * impulse * m_JwA; + vB += (m_mB * impulse) * m_JvBD; + wB += m_iB * impulse * m_JwB; + vC -= (m_mC * impulse) * m_JvAC; + wC -= m_iC * impulse * m_JwC; + vD -= (m_mD * impulse) * m_JvBD; + wD -= m_iD * impulse * m_JwD; + + data.velocities[m_indexA].v = vA; + data.velocities[m_indexA].w = wA; + data.velocities[m_indexB].v = vB; + data.velocities[m_indexB].w = wB; + data.velocities[m_indexC].v = vC; + data.velocities[m_indexC].w = wC; + data.velocities[m_indexD].v = vD; + data.velocities[m_indexD].w = wD; +} + +bool b2GearJoint::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; + b2Vec2 cC = data.positions[m_indexC].c; + float32 aC = data.positions[m_indexC].a; + b2Vec2 cD = data.positions[m_indexD].c; + float32 aD = data.positions[m_indexD].a; + + b2Rot qA(aA), qB(aB), qC(aC), qD(aD); + + float32 linearError = 0.0f; + + float32 coordinateA, coordinateB; + + b2Vec2 JvAC, JvBD; + float32 JwA, JwB, JwC, JwD; + float32 mass = 0.0f; + + if (m_typeA == e_revoluteJoint) + { + JvAC.SetZero(); + JwA = 1.0f; + JwC = 1.0f; + mass += m_iA + m_iC; + + coordinateA = aA - aC - m_referenceAngleA; + } + else + { + b2Vec2 u = b2Mul(qC, m_localAxisC); + b2Vec2 rC = b2Mul(qC, m_localAnchorC - m_lcC); + b2Vec2 rA = b2Mul(qA, m_localAnchorA - m_lcA); + JvAC = u; + JwC = b2Cross(rC, u); + JwA = b2Cross(rA, u); + mass += m_mC + m_mA + m_iC * JwC * JwC + m_iA * JwA * JwA; + + b2Vec2 pC = m_localAnchorC - m_lcC; + b2Vec2 pA = b2MulT(qC, rA + (cA - cC)); + coordinateA = b2Dot(pA - pC, m_localAxisC); + } + + if (m_typeB == e_revoluteJoint) + { + JvBD.SetZero(); + JwB = m_ratio; + JwD = m_ratio; + mass += m_ratio * m_ratio * (m_iB + m_iD); + + coordinateB = aB - aD - m_referenceAngleB; + } + else + { + b2Vec2 u = b2Mul(qD, m_localAxisD); + b2Vec2 rD = b2Mul(qD, m_localAnchorD - m_lcD); + b2Vec2 rB = b2Mul(qB, m_localAnchorB - m_lcB); + JvBD = m_ratio * u; + JwD = m_ratio * b2Cross(rD, u); + JwB = m_ratio * b2Cross(rB, u); + mass += m_ratio * m_ratio * (m_mD + m_mB) + m_iD * JwD * JwD + m_iB * JwB * JwB; + + b2Vec2 pD = m_localAnchorD - m_lcD; + b2Vec2 pB = b2MulT(qD, rB + (cB - cD)); + coordinateB = b2Dot(pB - pD, m_localAxisD); + } + + float32 C = (coordinateA + m_ratio * coordinateB) - m_constant; + + float32 impulse = 0.0f; + if (mass > 0.0f) + { + impulse = -C / mass; + } + + cA += m_mA * impulse * JvAC; + aA += m_iA * impulse * JwA; + cB += m_mB * impulse * JvBD; + aB += m_iB * impulse * JwB; + cC -= m_mC * impulse * JvAC; + aC -= m_iC * impulse * JwC; + cD -= m_mD * impulse * JvBD; + aD -= m_iD * impulse * JwD; + + data.positions[m_indexA].c = cA; + data.positions[m_indexA].a = aA; + data.positions[m_indexB].c = cB; + data.positions[m_indexB].a = aB; + data.positions[m_indexC].c = cC; + data.positions[m_indexC].a = aC; + data.positions[m_indexD].c = cD; + data.positions[m_indexD].a = aD; + + // TODO_ERIN not implemented + return linearError < b2_linearSlop; +} + +b2Vec2 b2GearJoint::GetAnchorA() const +{ + return m_bodyA->GetWorldPoint(m_localAnchorA); +} + +b2Vec2 b2GearJoint::GetAnchorB() const +{ + return m_bodyB->GetWorldPoint(m_localAnchorB); +} + +b2Vec2 b2GearJoint::GetReactionForce(float32 inv_dt) const +{ + b2Vec2 P = m_impulse * m_JvAC; + return inv_dt * P; +} + +float32 b2GearJoint::GetReactionTorque(float32 inv_dt) const +{ + float32 L = m_impulse * m_JwA; + return inv_dt * L; +} + +void b2GearJoint::SetRatio(float32 ratio) +{ + b2Assert(b2IsValid(ratio)); + m_ratio = ratio; +} + +float32 b2GearJoint::GetRatio() const +{ + return m_ratio; +} + +void b2GearJoint::Dump() +{ + int32 indexA = m_bodyA->m_islandIndex; + int32 indexB = m_bodyB->m_islandIndex; + + int32 index1 = m_joint1->m_index; + int32 index2 = m_joint2->m_index; + + b2Log(" b2GearJointDef 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.joint1 = joints[%d];\n", index1); + b2Log(" jd.joint2 = joints[%d];\n", index2); + b2Log(" jd.ratio = %.15lef;\n", m_ratio); + b2Log(" joints[%d] = m_world->CreateJoint(&jd);\n", m_index); +} diff --git a/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2GearJoint.h b/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2GearJoint.h new file mode 100644 index 0000000..53f7e58 --- /dev/null +++ b/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2GearJoint.h @@ -0,0 +1,125 @@ +/* +* 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. +*/ + +#ifndef B2_GEAR_JOINT_H +#define B2_GEAR_JOINT_H + +#include "Box2D/Dynamics/Joints/b2Joint.h" + +/// Gear joint definition. This definition requires two existing +/// revolute or prismatic joints (any combination will work). +struct b2GearJointDef : public b2JointDef +{ + b2GearJointDef() + { + type = e_gearJoint; + joint1 = nullptr; + joint2 = nullptr; + ratio = 1.0f; + } + + /// The first revolute/prismatic joint attached to the gear joint. + b2Joint* joint1; + + /// The second revolute/prismatic joint attached to the gear joint. + b2Joint* joint2; + + /// The gear ratio. + /// @see b2GearJoint for explanation. + float32 ratio; +}; + +/// A gear joint is used to connect two joints together. Either joint +/// can be a revolute or prismatic joint. You specify a gear ratio +/// to bind the motions together: +/// coordinate1 + ratio * coordinate2 = constant +/// The ratio can be negative or positive. If one joint is a revolute joint +/// and the other joint is a prismatic joint, then the ratio will have units +/// of length or units of 1/length. +/// @warning You have to manually destroy the gear joint if joint1 or joint2 +/// is destroyed. +class b2GearJoint : public b2Joint +{ +public: + b2Vec2 GetAnchorA() const override; + b2Vec2 GetAnchorB() const override; + + b2Vec2 GetReactionForce(float32 inv_dt) const override; + float32 GetReactionTorque(float32 inv_dt) const override; + + /// Get the first joint. + b2Joint* GetJoint1() { return m_joint1; } + + /// Get the second joint. + b2Joint* GetJoint2() { return m_joint2; } + + /// Set/Get the gear ratio. + void SetRatio(float32 ratio); + float32 GetRatio() const; + + /// Dump joint to dmLog + void Dump() override; + +protected: + + friend class b2Joint; + b2GearJoint(const b2GearJointDef* data); + + void InitVelocityConstraints(const b2SolverData& data) override; + void SolveVelocityConstraints(const b2SolverData& data) override; + bool SolvePositionConstraints(const b2SolverData& data) override; + + b2Joint* m_joint1; + b2Joint* m_joint2; + + b2JointType m_typeA; + b2JointType m_typeB; + + // Body A is connected to body C + // Body B is connected to body D + b2Body* m_bodyC; + b2Body* m_bodyD; + + // Solver shared + b2Vec2 m_localAnchorA; + b2Vec2 m_localAnchorB; + b2Vec2 m_localAnchorC; + b2Vec2 m_localAnchorD; + + b2Vec2 m_localAxisC; + b2Vec2 m_localAxisD; + + float32 m_referenceAngleA; + float32 m_referenceAngleB; + + float32 m_constant; + float32 m_ratio; + + float32 m_impulse; + + // Solver temp + int32 m_indexA, m_indexB, m_indexC, m_indexD; + b2Vec2 m_lcA, m_lcB, m_lcC, m_lcD; + float32 m_mA, m_mB, m_mC, m_mD; + float32 m_iA, m_iB, m_iC, m_iD; + b2Vec2 m_JvAC, m_JvBD; + float32 m_JwA, m_JwB, m_JwC, m_JwD; + float32 m_mass; +}; + +#endif diff --git a/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2Joint.cpp b/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2Joint.cpp new file mode 100644 index 0000000..8103b01 --- /dev/null +++ b/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2Joint.cpp @@ -0,0 +1,211 @@ +/* +* 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/b2Joint.h" +#include "Box2D/Dynamics/Joints/b2DistanceJoint.h" +#include "Box2D/Dynamics/Joints/b2WheelJoint.h" +#include "Box2D/Dynamics/Joints/b2MouseJoint.h" +#include "Box2D/Dynamics/Joints/b2RevoluteJoint.h" +#include "Box2D/Dynamics/Joints/b2PrismaticJoint.h" +#include "Box2D/Dynamics/Joints/b2PulleyJoint.h" +#include "Box2D/Dynamics/Joints/b2GearJoint.h" +#include "Box2D/Dynamics/Joints/b2WeldJoint.h" +#include "Box2D/Dynamics/Joints/b2FrictionJoint.h" +#include "Box2D/Dynamics/Joints/b2RopeJoint.h" +#include "Box2D/Dynamics/Joints/b2MotorJoint.h" +#include "Box2D/Dynamics/b2Body.h" +#include "Box2D/Dynamics/b2World.h" +#include "Box2D/Common/b2BlockAllocator.h" + +#include <new> + +b2Joint* b2Joint::Create(const b2JointDef* def, b2BlockAllocator* allocator) +{ + b2Joint* joint = nullptr; + + switch (def->type) + { + case e_distanceJoint: + { + void* mem = allocator->Allocate(sizeof(b2DistanceJoint)); + joint = new (mem) b2DistanceJoint(static_cast<const b2DistanceJointDef*>(def)); + } + break; + + case e_mouseJoint: + { + void* mem = allocator->Allocate(sizeof(b2MouseJoint)); + joint = new (mem) b2MouseJoint(static_cast<const b2MouseJointDef*>(def)); + } + break; + + case e_prismaticJoint: + { + void* mem = allocator->Allocate(sizeof(b2PrismaticJoint)); + joint = new (mem) b2PrismaticJoint(static_cast<const b2PrismaticJointDef*>(def)); + } + break; + + case e_revoluteJoint: + { + void* mem = allocator->Allocate(sizeof(b2RevoluteJoint)); + joint = new (mem) b2RevoluteJoint(static_cast<const b2RevoluteJointDef*>(def)); + } + break; + + case e_pulleyJoint: + { + void* mem = allocator->Allocate(sizeof(b2PulleyJoint)); + joint = new (mem) b2PulleyJoint(static_cast<const b2PulleyJointDef*>(def)); + } + break; + + case e_gearJoint: + { + void* mem = allocator->Allocate(sizeof(b2GearJoint)); + joint = new (mem) b2GearJoint(static_cast<const b2GearJointDef*>(def)); + } + break; + + case e_wheelJoint: + { + void* mem = allocator->Allocate(sizeof(b2WheelJoint)); + joint = new (mem) b2WheelJoint(static_cast<const b2WheelJointDef*>(def)); + } + break; + + case e_weldJoint: + { + void* mem = allocator->Allocate(sizeof(b2WeldJoint)); + joint = new (mem) b2WeldJoint(static_cast<const b2WeldJointDef*>(def)); + } + break; + + case e_frictionJoint: + { + void* mem = allocator->Allocate(sizeof(b2FrictionJoint)); + joint = new (mem) b2FrictionJoint(static_cast<const b2FrictionJointDef*>(def)); + } + break; + + case e_ropeJoint: + { + void* mem = allocator->Allocate(sizeof(b2RopeJoint)); + joint = new (mem) b2RopeJoint(static_cast<const b2RopeJointDef*>(def)); + } + break; + + case e_motorJoint: + { + void* mem = allocator->Allocate(sizeof(b2MotorJoint)); + joint = new (mem) b2MotorJoint(static_cast<const b2MotorJointDef*>(def)); + } + break; + + default: + b2Assert(false); + break; + } + + return joint; +} + +void b2Joint::Destroy(b2Joint* joint, b2BlockAllocator* allocator) +{ + joint->~b2Joint(); + switch (joint->m_type) + { + case e_distanceJoint: + allocator->Free(joint, sizeof(b2DistanceJoint)); + break; + + case e_mouseJoint: + allocator->Free(joint, sizeof(b2MouseJoint)); + break; + + case e_prismaticJoint: + allocator->Free(joint, sizeof(b2PrismaticJoint)); + break; + + case e_revoluteJoint: + allocator->Free(joint, sizeof(b2RevoluteJoint)); + break; + + case e_pulleyJoint: + allocator->Free(joint, sizeof(b2PulleyJoint)); + break; + + case e_gearJoint: + allocator->Free(joint, sizeof(b2GearJoint)); + break; + + case e_wheelJoint: + allocator->Free(joint, sizeof(b2WheelJoint)); + break; + + case e_weldJoint: + allocator->Free(joint, sizeof(b2WeldJoint)); + break; + + case e_frictionJoint: + allocator->Free(joint, sizeof(b2FrictionJoint)); + break; + + case e_ropeJoint: + allocator->Free(joint, sizeof(b2RopeJoint)); + break; + + case e_motorJoint: + allocator->Free(joint, sizeof(b2MotorJoint)); + break; + + default: + b2Assert(false); + break; + } +} + +b2Joint::b2Joint(const b2JointDef* def) +{ + b2Assert(def->bodyA != def->bodyB); + + m_type = def->type; + m_prev = nullptr; + m_next = nullptr; + m_bodyA = def->bodyA; + m_bodyB = def->bodyB; + m_index = 0; + m_collideConnected = def->collideConnected; + m_islandFlag = false; + m_userData = def->userData; + + m_edgeA.joint = nullptr; + m_edgeA.other = nullptr; + m_edgeA.prev = nullptr; + m_edgeA.next = nullptr; + + m_edgeB.joint = nullptr; + m_edgeB.other = nullptr; + m_edgeB.prev = nullptr; + m_edgeB.next = nullptr; +} + +bool b2Joint::IsActive() const +{ + return m_bodyA->IsActive() && m_bodyB->IsActive(); +} diff --git a/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2Joint.h b/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2Joint.h new file mode 100644 index 0000000..2ab5616 --- /dev/null +++ b/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2Joint.h @@ -0,0 +1,226 @@ +/* +* 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. +*/ + +#ifndef B2_JOINT_H +#define B2_JOINT_H + +#include "Box2D/Common/b2Math.h" + +class b2Body; +class b2Joint; +struct b2SolverData; +class b2BlockAllocator; + +enum b2JointType +{ + e_unknownJoint, + e_revoluteJoint, + e_prismaticJoint, + e_distanceJoint, + e_pulleyJoint, + e_mouseJoint, + e_gearJoint, + e_wheelJoint, + e_weldJoint, + e_frictionJoint, + e_ropeJoint, + e_motorJoint +}; + +enum b2LimitState +{ + e_inactiveLimit, + e_atLowerLimit, + e_atUpperLimit, + e_equalLimits +}; + +struct b2Jacobian +{ + b2Vec2 linear; + float32 angularA; + float32 angularB; +}; + +/// A joint edge is used to connect bodies and joints together +/// in a joint graph where each body is a node and each joint +/// is an edge. A joint edge belongs to a doubly linked list +/// maintained in each attached body. Each joint has two joint +/// nodes, one for each attached body. +struct b2JointEdge +{ + b2Body* other; ///< provides quick access to the other body attached. + b2Joint* joint; ///< the joint + b2JointEdge* prev; ///< the previous joint edge in the body's joint list + b2JointEdge* next; ///< the next joint edge in the body's joint list +}; + +/// Joint definitions are used to construct joints. +struct b2JointDef +{ + b2JointDef() + { + type = e_unknownJoint; + userData = nullptr; + bodyA = nullptr; + bodyB = nullptr; + collideConnected = false; + } + + /// The joint type is set automatically for concrete joint types. + b2JointType type; + + /// Use this to attach application specific data to your joints. + void* userData; + + /// The first attached body. + b2Body* bodyA; + + /// The second attached body. + b2Body* bodyB; + + /// Set this flag to true if the attached bodies should collide. + bool collideConnected; +}; + +/// The base joint class. Joints are used to constraint two bodies together in +/// various fashions. Some joints also feature limits and motors. +class b2Joint +{ +public: + + /// Get the type of the concrete joint. + b2JointType GetType() const; + + /// Get the first body attached to this joint. + b2Body* GetBodyA(); + + /// Get the second body attached to this joint. + b2Body* GetBodyB(); + + /// Get the anchor point on bodyA in world coordinates. + virtual b2Vec2 GetAnchorA() const = 0; + + /// Get the anchor point on bodyB in world coordinates. + virtual b2Vec2 GetAnchorB() const = 0; + + /// Get the reaction force on bodyB at the joint anchor in Newtons. + virtual b2Vec2 GetReactionForce(float32 inv_dt) const = 0; + + /// Get the reaction torque on bodyB in N*m. + virtual float32 GetReactionTorque(float32 inv_dt) const = 0; + + /// Get the next joint the world joint list. + b2Joint* GetNext(); + const b2Joint* GetNext() const; + + /// Get the user data pointer. + void* GetUserData() const; + + /// Set the user data pointer. + void SetUserData(void* data); + + /// Short-cut function to determine if either body is inactive. + bool IsActive() const; + + /// Get collide connected. + /// Note: modifying the collide connect flag won't work correctly because + /// the flag is only checked when fixture AABBs begin to overlap. + bool GetCollideConnected() const; + + /// Dump this joint to the log file. + virtual void Dump() { b2Log("// Dump is not supported for this joint type.\n"); } + + /// Shift the origin for any points stored in world coordinates. + virtual void ShiftOrigin(const b2Vec2& newOrigin) { B2_NOT_USED(newOrigin); } + +protected: + friend class b2World; + friend class b2Body; + friend class b2Island; + friend class b2GearJoint; + + static b2Joint* Create(const b2JointDef* def, b2BlockAllocator* allocator); + static void Destroy(b2Joint* joint, b2BlockAllocator* allocator); + + b2Joint(const b2JointDef* def); + virtual ~b2Joint() {} + + virtual void InitVelocityConstraints(const b2SolverData& data) = 0; + virtual void SolveVelocityConstraints(const b2SolverData& data) = 0; + + // This returns true if the position errors are within tolerance. + virtual bool SolvePositionConstraints(const b2SolverData& data) = 0; + + b2JointType m_type; + b2Joint* m_prev; + b2Joint* m_next; + b2JointEdge m_edgeA; + b2JointEdge m_edgeB; + b2Body* m_bodyA; + b2Body* m_bodyB; + + int32 m_index; + + bool m_islandFlag; + bool m_collideConnected; + + void* m_userData; +}; + +inline b2JointType b2Joint::GetType() const +{ + return m_type; +} + +inline b2Body* b2Joint::GetBodyA() +{ + return m_bodyA; +} + +inline b2Body* b2Joint::GetBodyB() +{ + return m_bodyB; +} + +inline b2Joint* b2Joint::GetNext() +{ + return m_next; +} + +inline const b2Joint* b2Joint::GetNext() const +{ + return m_next; +} + +inline void* b2Joint::GetUserData() const +{ + return m_userData; +} + +inline void b2Joint::SetUserData(void* data) +{ + m_userData = data; +} + +inline bool b2Joint::GetCollideConnected() const +{ + return m_collideConnected; +} + +#endif diff --git a/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2MotorJoint.cpp b/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2MotorJoint.cpp new file mode 100644 index 0000000..7906845 --- /dev/null +++ b/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2MotorJoint.cpp @@ -0,0 +1,309 @@ +/* +* Copyright (c) 2006-2012 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/b2MotorJoint.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) +// +// r1 = offset - c1 +// r2 = -c2 + +// Angle constraint +// Cdot = w2 - w1 +// J = [0 0 -1 0 0 1] +// K = invI1 + invI2 + +void b2MotorJointDef::Initialize(b2Body* bA, b2Body* bB) +{ + bodyA = bA; + bodyB = bB; + b2Vec2 xB = bodyB->GetPosition(); + linearOffset = bodyA->GetLocalPoint(xB); + + float32 angleA = bodyA->GetAngle(); + float32 angleB = bodyB->GetAngle(); + angularOffset = angleB - angleA; +} + +b2MotorJoint::b2MotorJoint(const b2MotorJointDef* def) +: b2Joint(def) +{ + m_linearOffset = def->linearOffset; + m_angularOffset = def->angularOffset; + + m_linearImpulse.SetZero(); + m_angularImpulse = 0.0f; + + m_maxForce = def->maxForce; + m_maxTorque = def->maxTorque; + m_correctionFactor = def->correctionFactor; +} + +void b2MotorJoint::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); + + // Compute the effective mass matrix. + m_rA = b2Mul(qA, m_linearOffset - m_localCenterA); + m_rB = b2Mul(qB, -m_localCenterB); + + // J = [-I -r1_skew I r2_skew] + // 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; + + // Upper 2 by 2 of K for point to point + 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; + } + + m_linearError = cB + m_rB - cA - m_rA; + m_angularError = aB - aA - m_angularOffset; + + 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 b2MotorJoint::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; + float32 inv_h = data.step.inv_dt; + + // Solve angular friction + { + float32 Cdot = wB - wA + inv_h * m_correctionFactor * m_angularError; + 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) + inv_h * m_correctionFactor * m_linearError; + + 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 b2MotorJoint::SolvePositionConstraints(const b2SolverData& data) +{ + B2_NOT_USED(data); + + return true; +} + +b2Vec2 b2MotorJoint::GetAnchorA() const +{ + return m_bodyA->GetPosition(); +} + +b2Vec2 b2MotorJoint::GetAnchorB() const +{ + return m_bodyB->GetPosition(); +} + +b2Vec2 b2MotorJoint::GetReactionForce(float32 inv_dt) const +{ + return inv_dt * m_linearImpulse; +} + +float32 b2MotorJoint::GetReactionTorque(float32 inv_dt) const +{ + return inv_dt * m_angularImpulse; +} + +void b2MotorJoint::SetMaxForce(float32 force) +{ + b2Assert(b2IsValid(force) && force >= 0.0f); + m_maxForce = force; +} + +float32 b2MotorJoint::GetMaxForce() const +{ + return m_maxForce; +} + +void b2MotorJoint::SetMaxTorque(float32 torque) +{ + b2Assert(b2IsValid(torque) && torque >= 0.0f); + m_maxTorque = torque; +} + +float32 b2MotorJoint::GetMaxTorque() const +{ + return m_maxTorque; +} + +void b2MotorJoint::SetCorrectionFactor(float32 factor) +{ + b2Assert(b2IsValid(factor) && 0.0f <= factor && factor <= 1.0f); + m_correctionFactor = factor; +} + +float32 b2MotorJoint::GetCorrectionFactor() const +{ + return m_correctionFactor; +} + +void b2MotorJoint::SetLinearOffset(const b2Vec2& linearOffset) +{ + if (linearOffset.x != m_linearOffset.x || linearOffset.y != m_linearOffset.y) + { + m_bodyA->SetAwake(true); + m_bodyB->SetAwake(true); + m_linearOffset = linearOffset; + } +} + +const b2Vec2& b2MotorJoint::GetLinearOffset() const +{ + return m_linearOffset; +} + +void b2MotorJoint::SetAngularOffset(float32 angularOffset) +{ + if (angularOffset != m_angularOffset) + { + m_bodyA->SetAwake(true); + m_bodyB->SetAwake(true); + m_angularOffset = angularOffset; + } +} + +float32 b2MotorJoint::GetAngularOffset() const +{ + return m_angularOffset; +} + +void b2MotorJoint::Dump() +{ + int32 indexA = m_bodyA->m_islandIndex; + int32 indexB = m_bodyB->m_islandIndex; + + b2Log(" b2MotorJointDef 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.linearOffset.Set(%.15lef, %.15lef);\n", m_linearOffset.x, m_linearOffset.y); + b2Log(" jd.angularOffset = %.15lef;\n", m_angularOffset); + b2Log(" jd.maxForce = %.15lef;\n", m_maxForce); + b2Log(" jd.maxTorque = %.15lef;\n", m_maxTorque); + b2Log(" jd.correctionFactor = %.15lef;\n", m_correctionFactor); + b2Log(" joints[%d] = m_world->CreateJoint(&jd);\n", m_index); +} diff --git a/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2MotorJoint.h b/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2MotorJoint.h new file mode 100644 index 0000000..f384f41 --- /dev/null +++ b/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2MotorJoint.h @@ -0,0 +1,133 @@ +/* +* Copyright (c) 2006-2012 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. +*/ + +#ifndef B2_MOTOR_JOINT_H +#define B2_MOTOR_JOINT_H + +#include "Box2D/Dynamics/Joints/b2Joint.h" + +/// Motor joint definition. +struct b2MotorJointDef : public b2JointDef +{ + b2MotorJointDef() + { + type = e_motorJoint; + linearOffset.SetZero(); + angularOffset = 0.0f; + maxForce = 1.0f; + maxTorque = 1.0f; + correctionFactor = 0.3f; + } + + /// Initialize the bodies and offsets using the current transforms. + void Initialize(b2Body* bodyA, b2Body* bodyB); + + /// Position of bodyB minus the position of bodyA, in bodyA's frame, in meters. + b2Vec2 linearOffset; + + /// The bodyB angle minus bodyA angle in radians. + float32 angularOffset; + + /// The maximum motor force in N. + float32 maxForce; + + /// The maximum motor torque in N-m. + float32 maxTorque; + + /// Position correction factor in the range [0,1]. + float32 correctionFactor; +}; + +/// A motor joint is used to control the relative motion +/// between two bodies. A typical usage is to control the movement +/// of a dynamic body with respect to the ground. +class b2MotorJoint : public b2Joint +{ +public: + b2Vec2 GetAnchorA() const override; + b2Vec2 GetAnchorB() const override; + + b2Vec2 GetReactionForce(float32 inv_dt) const override; + float32 GetReactionTorque(float32 inv_dt) const override; + + /// Set/get the target linear offset, in frame A, in meters. + void SetLinearOffset(const b2Vec2& linearOffset); + const b2Vec2& GetLinearOffset() const; + + /// Set/get the target angular offset, in radians. + void SetAngularOffset(float32 angularOffset); + float32 GetAngularOffset() const; + + /// Set the maximum friction force in N. + void SetMaxForce(float32 force); + + /// Get the maximum friction force in N. + float32 GetMaxForce() const; + + /// Set the maximum friction torque in N*m. + void SetMaxTorque(float32 torque); + + /// Get the maximum friction torque in N*m. + float32 GetMaxTorque() const; + + /// Set the position correction factor in the range [0,1]. + void SetCorrectionFactor(float32 factor); + + /// Get the position correction factor in the range [0,1]. + float32 GetCorrectionFactor() const; + + /// Dump to b2Log + void Dump() override; + +protected: + + friend class b2Joint; + + b2MotorJoint(const b2MotorJointDef* def); + + void InitVelocityConstraints(const b2SolverData& data) override; + void SolveVelocityConstraints(const b2SolverData& data) override; + bool SolvePositionConstraints(const b2SolverData& data) override; + + // Solver shared + b2Vec2 m_linearOffset; + float32 m_angularOffset; + b2Vec2 m_linearImpulse; + float32 m_angularImpulse; + float32 m_maxForce; + float32 m_maxTorque; + float32 m_correctionFactor; + + // Solver temp + int32 m_indexA; + int32 m_indexB; + b2Vec2 m_rA; + b2Vec2 m_rB; + b2Vec2 m_localCenterA; + b2Vec2 m_localCenterB; + b2Vec2 m_linearError; + float32 m_angularError; + float32 m_invMassA; + float32 m_invMassB; + float32 m_invIA; + float32 m_invIB; + b2Mat22 m_linearMass; + float32 m_angularMass; +}; + +#endif diff --git a/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2MouseJoint.cpp b/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2MouseJoint.cpp new file mode 100644 index 0000000..637e4cd --- /dev/null +++ b/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2MouseJoint.cpp @@ -0,0 +1,222 @@ +/* +* 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; +} diff --git a/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2MouseJoint.h b/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2MouseJoint.h new file mode 100644 index 0000000..7441978 --- /dev/null +++ b/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2MouseJoint.h @@ -0,0 +1,129 @@ +/* +* 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. +*/ + +#ifndef B2_MOUSE_JOINT_H +#define B2_MOUSE_JOINT_H + +#include "Box2D/Dynamics/Joints/b2Joint.h" + +/// Mouse joint definition. This requires a world target point, +/// tuning parameters, and the time step. +struct b2MouseJointDef : public b2JointDef +{ + b2MouseJointDef() + { + type = e_mouseJoint; + target.Set(0.0f, 0.0f); + maxForce = 0.0f; + frequencyHz = 5.0f; + dampingRatio = 0.7f; + } + + /// The initial world target point. This is assumed + /// to coincide with the body anchor initially. + b2Vec2 target; + + /// The maximum constraint force that can be exerted + /// to move the candidate body. Usually you will express + /// as some multiple of the weight (multiplier * mass * gravity). + float32 maxForce; + + /// The response speed. + float32 frequencyHz; + + /// The damping ratio. 0 = no damping, 1 = critical damping. + float32 dampingRatio; +}; + +/// A mouse joint is used to make a point on a body track a +/// specified world point. This a soft constraint with a maximum +/// force. This allows the constraint to stretch and without +/// applying huge forces. +/// NOTE: this joint is not documented in the manual because it was +/// developed to be used in the testbed. If you want to learn how to +/// use the mouse joint, look at the testbed. +class b2MouseJoint : public b2Joint +{ +public: + + /// Implements b2Joint. + b2Vec2 GetAnchorA() const override; + + /// Implements b2Joint. + b2Vec2 GetAnchorB() const override; + + /// Implements b2Joint. + b2Vec2 GetReactionForce(float32 inv_dt) const override; + + /// Implements b2Joint. + float32 GetReactionTorque(float32 inv_dt) const override; + + /// Use this to update the target point. + void SetTarget(const b2Vec2& target); + const b2Vec2& GetTarget() const; + + /// Set/get the maximum force in Newtons. + void SetMaxForce(float32 force); + float32 GetMaxForce() const; + + /// Set/get the frequency in Hertz. + void SetFrequency(float32 hz); + float32 GetFrequency() const; + + /// Set/get the damping ratio (dimensionless). + void SetDampingRatio(float32 ratio); + float32 GetDampingRatio() const; + + /// The mouse joint does not support dumping. + void Dump() override { b2Log("Mouse joint dumping is not supported.\n"); } + + /// Implement b2Joint::ShiftOrigin + void ShiftOrigin(const b2Vec2& newOrigin) override; + +protected: + friend class b2Joint; + + b2MouseJoint(const b2MouseJointDef* def); + + void InitVelocityConstraints(const b2SolverData& data) override; + void SolveVelocityConstraints(const b2SolverData& data) override; + bool SolvePositionConstraints(const b2SolverData& data) override; + + b2Vec2 m_localAnchorB; + b2Vec2 m_targetA; + float32 m_frequencyHz; + float32 m_dampingRatio; + float32 m_beta; + + // Solver shared + b2Vec2 m_impulse; + float32 m_maxForce; + float32 m_gamma; + + // Solver temp + int32 m_indexA; + int32 m_indexB; + b2Vec2 m_rB; + b2Vec2 m_localCenterB; + float32 m_invMassB; + float32 m_invIB; + b2Mat22 m_mass; + b2Vec2 m_C; +}; + +#endif diff --git a/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2PrismaticJoint.cpp b/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2PrismaticJoint.cpp new file mode 100644 index 0000000..5da19b6 --- /dev/null +++ b/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2PrismaticJoint.cpp @@ -0,0 +1,642 @@ +/* +* 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/b2PrismaticJoint.h" +#include "Box2D/Dynamics/b2Body.h" +#include "Box2D/Dynamics/b2TimeStep.h" + +// Linear constraint (point-to-line) +// d = p2 - p1 = x2 + r2 - x1 - r1 +// C = dot(perp, d) +// Cdot = dot(d, cross(w1, perp)) + dot(perp, v2 + cross(w2, r2) - v1 - cross(w1, r1)) +// = -dot(perp, v1) - dot(cross(d + r1, perp), w1) + dot(perp, v2) + dot(cross(r2, perp), v2) +// J = [-perp, -cross(d + r1, perp), perp, cross(r2,perp)] +// +// Angular constraint +// C = a2 - a1 + a_initial +// Cdot = w2 - w1 +// J = [0 0 -1 0 0 1] +// +// K = J * invM * JT +// +// J = [-a -s1 a s2] +// [0 -1 0 1] +// a = perp +// s1 = cross(d + r1, a) = cross(p2 - x1, a) +// s2 = cross(r2, a) = cross(p2 - x2, a) + + +// Motor/Limit linear constraint +// C = dot(ax1, d) +// Cdot = = -dot(ax1, v1) - dot(cross(d + r1, ax1), w1) + dot(ax1, v2) + dot(cross(r2, ax1), v2) +// J = [-ax1 -cross(d+r1,ax1) ax1 cross(r2,ax1)] + +// Block Solver +// We develop a block solver that includes the joint limit. This makes the limit stiff (inelastic) even +// when the mass has poor distribution (leading to large torques about the joint anchor points). +// +// The Jacobian has 3 rows: +// J = [-uT -s1 uT s2] // linear +// [0 -1 0 1] // angular +// [-vT -a1 vT a2] // limit +// +// u = perp +// v = axis +// s1 = cross(d + r1, u), s2 = cross(r2, u) +// a1 = cross(d + r1, v), a2 = cross(r2, v) + +// M * (v2 - v1) = JT * df +// J * v2 = bias +// +// v2 = v1 + invM * JT * df +// J * (v1 + invM * JT * df) = bias +// K * df = bias - J * v1 = -Cdot +// K = J * invM * JT +// Cdot = J * v1 - bias +// +// Now solve for f2. +// df = f2 - f1 +// K * (f2 - f1) = -Cdot +// f2 = invK * (-Cdot) + f1 +// +// Clamp accumulated limit impulse. +// lower: f2(3) = max(f2(3), 0) +// upper: f2(3) = min(f2(3), 0) +// +// Solve for correct f2(1:2) +// K(1:2, 1:2) * f2(1:2) = -Cdot(1:2) - K(1:2,3) * f2(3) + K(1:2,1:3) * f1 +// = -Cdot(1:2) - K(1:2,3) * f2(3) + K(1:2,1:2) * f1(1:2) + K(1:2,3) * f1(3) +// K(1:2, 1:2) * f2(1:2) = -Cdot(1:2) - K(1:2,3) * (f2(3) - f1(3)) + K(1:2,1:2) * f1(1:2) +// f2(1:2) = invK(1:2,1:2) * (-Cdot(1:2) - K(1:2,3) * (f2(3) - f1(3))) + f1(1:2) +// +// Now compute impulse to be applied: +// df = f2 - f1 + +void b2PrismaticJointDef::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); + referenceAngle = bodyB->GetAngle() - bodyA->GetAngle(); +} + +b2PrismaticJoint::b2PrismaticJoint(const b2PrismaticJointDef* def) +: b2Joint(def) +{ + m_localAnchorA = def->localAnchorA; + m_localAnchorB = def->localAnchorB; + m_localXAxisA = def->localAxisA; + m_localXAxisA.Normalize(); + m_localYAxisA = b2Cross(1.0f, m_localXAxisA); + m_referenceAngle = def->referenceAngle; + + m_impulse.SetZero(); + m_motorMass = 0.0f; + m_motorImpulse = 0.0f; + + m_lowerTranslation = def->lowerTranslation; + m_upperTranslation = def->upperTranslation; + m_maxMotorForce = def->maxMotorForce; + m_motorSpeed = def->motorSpeed; + m_enableLimit = def->enableLimit; + m_enableMotor = def->enableMotor; + m_limitState = e_inactiveLimit; + + m_axis.SetZero(); + m_perp.SetZero(); +} + +void b2PrismaticJoint::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); + + // Compute the effective masses. + b2Vec2 rA = b2Mul(qA, m_localAnchorA - m_localCenterA); + b2Vec2 rB = b2Mul(qB, m_localAnchorB - m_localCenterB); + b2Vec2 d = (cB - cA) + rB - rA; + + float32 mA = m_invMassA, mB = m_invMassB; + float32 iA = m_invIA, iB = m_invIB; + + // Compute motor Jacobian and effective mass. + { + m_axis = b2Mul(qA, m_localXAxisA); + m_a1 = b2Cross(d + rA, m_axis); + m_a2 = b2Cross(rB, m_axis); + + m_motorMass = mA + mB + iA * m_a1 * m_a1 + iB * m_a2 * m_a2; + if (m_motorMass > 0.0f) + { + m_motorMass = 1.0f / m_motorMass; + } + } + + // Prismatic constraint. + { + m_perp = b2Mul(qA, m_localYAxisA); + + m_s1 = b2Cross(d + rA, m_perp); + m_s2 = b2Cross(rB, m_perp); + + float32 k11 = mA + mB + iA * m_s1 * m_s1 + iB * m_s2 * m_s2; + float32 k12 = iA * m_s1 + iB * m_s2; + float32 k13 = iA * m_s1 * m_a1 + iB * m_s2 * m_a2; + float32 k22 = iA + iB; + if (k22 == 0.0f) + { + // For bodies with fixed rotation. + k22 = 1.0f; + } + float32 k23 = iA * m_a1 + iB * m_a2; + float32 k33 = mA + mB + iA * m_a1 * m_a1 + iB * m_a2 * m_a2; + + m_K.ex.Set(k11, k12, k13); + m_K.ey.Set(k12, k22, k23); + m_K.ez.Set(k13, k23, k33); + } + + // Compute motor and limit terms. + if (m_enableLimit) + { + float32 jointTranslation = b2Dot(m_axis, d); + if (b2Abs(m_upperTranslation - m_lowerTranslation) < 2.0f * b2_linearSlop) + { + m_limitState = e_equalLimits; + } + else if (jointTranslation <= m_lowerTranslation) + { + if (m_limitState != e_atLowerLimit) + { + m_limitState = e_atLowerLimit; + m_impulse.z = 0.0f; + } + } + else if (jointTranslation >= m_upperTranslation) + { + if (m_limitState != e_atUpperLimit) + { + m_limitState = e_atUpperLimit; + m_impulse.z = 0.0f; + } + } + else + { + m_limitState = e_inactiveLimit; + m_impulse.z = 0.0f; + } + } + else + { + m_limitState = e_inactiveLimit; + m_impulse.z = 0.0f; + } + + if (m_enableMotor == false) + { + m_motorImpulse = 0.0f; + } + + if (data.step.warmStarting) + { + // Account for variable time step. + m_impulse *= data.step.dtRatio; + m_motorImpulse *= data.step.dtRatio; + + b2Vec2 P = m_impulse.x * m_perp + (m_motorImpulse + m_impulse.z) * m_axis; + float32 LA = m_impulse.x * m_s1 + m_impulse.y + (m_motorImpulse + m_impulse.z) * m_a1; + float32 LB = m_impulse.x * m_s2 + m_impulse.y + (m_motorImpulse + m_impulse.z) * m_a2; + + vA -= mA * P; + wA -= iA * LA; + + vB += mB * P; + wB += iB * LB; + } + else + { + m_impulse.SetZero(); + m_motorImpulse = 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 b2PrismaticJoint::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; + + // Solve linear motor constraint. + if (m_enableMotor && m_limitState != e_equalLimits) + { + float32 Cdot = b2Dot(m_axis, vB - vA) + m_a2 * wB - m_a1 * wA; + float32 impulse = m_motorMass * (m_motorSpeed - Cdot); + float32 oldImpulse = m_motorImpulse; + float32 maxImpulse = data.step.dt * m_maxMotorForce; + m_motorImpulse = b2Clamp(m_motorImpulse + impulse, -maxImpulse, maxImpulse); + impulse = m_motorImpulse - oldImpulse; + + b2Vec2 P = impulse * m_axis; + float32 LA = impulse * m_a1; + float32 LB = impulse * m_a2; + + vA -= mA * P; + wA -= iA * LA; + + vB += mB * P; + wB += iB * LB; + } + + b2Vec2 Cdot1; + Cdot1.x = b2Dot(m_perp, vB - vA) + m_s2 * wB - m_s1 * wA; + Cdot1.y = wB - wA; + + if (m_enableLimit && m_limitState != e_inactiveLimit) + { + // Solve prismatic and limit constraint in block form. + float32 Cdot2; + Cdot2 = b2Dot(m_axis, vB - vA) + m_a2 * wB - m_a1 * wA; + b2Vec3 Cdot(Cdot1.x, Cdot1.y, Cdot2); + + b2Vec3 f1 = m_impulse; + b2Vec3 df = m_K.Solve33(-Cdot); + m_impulse += df; + + if (m_limitState == e_atLowerLimit) + { + m_impulse.z = b2Max(m_impulse.z, 0.0f); + } + else if (m_limitState == e_atUpperLimit) + { + m_impulse.z = b2Min(m_impulse.z, 0.0f); + } + + // f2(1:2) = invK(1:2,1:2) * (-Cdot(1:2) - K(1:2,3) * (f2(3) - f1(3))) + f1(1:2) + b2Vec2 b = -Cdot1 - (m_impulse.z - f1.z) * b2Vec2(m_K.ez.x, m_K.ez.y); + b2Vec2 f2r = m_K.Solve22(b) + b2Vec2(f1.x, f1.y); + m_impulse.x = f2r.x; + m_impulse.y = f2r.y; + + df = m_impulse - f1; + + b2Vec2 P = df.x * m_perp + df.z * m_axis; + float32 LA = df.x * m_s1 + df.y + df.z * m_a1; + float32 LB = df.x * m_s2 + df.y + df.z * m_a2; + + vA -= mA * P; + wA -= iA * LA; + + vB += mB * P; + wB += iB * LB; + } + else + { + // Limit is inactive, just solve the prismatic constraint in block form. + b2Vec2 df = m_K.Solve22(-Cdot1); + m_impulse.x += df.x; + m_impulse.y += df.y; + + b2Vec2 P = df.x * m_perp; + float32 LA = df.x * m_s1 + df.y; + float32 LB = df.x * m_s2 + df.y; + + 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; +} + +// A velocity based solver computes reaction forces(impulses) using the velocity constraint solver.Under this context, +// the position solver is not there to resolve forces.It is only there to cope with integration error. +// +// Therefore, the pseudo impulses in the position solver do not have any physical meaning.Thus it is okay if they suck. +// +// We could take the active state from the velocity solver.However, the joint might push past the limit when the velocity +// solver indicates the limit is inactive. +bool b2PrismaticJoint::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); + + float32 mA = m_invMassA, mB = m_invMassB; + float32 iA = m_invIA, iB = m_invIB; + + // Compute fresh Jacobians + b2Vec2 rA = b2Mul(qA, m_localAnchorA - m_localCenterA); + b2Vec2 rB = b2Mul(qB, m_localAnchorB - m_localCenterB); + b2Vec2 d = cB + rB - cA - rA; + + b2Vec2 axis = b2Mul(qA, m_localXAxisA); + float32 a1 = b2Cross(d + rA, axis); + float32 a2 = b2Cross(rB, axis); + b2Vec2 perp = b2Mul(qA, m_localYAxisA); + + float32 s1 = b2Cross(d + rA, perp); + float32 s2 = b2Cross(rB, perp); + + b2Vec3 impulse; + b2Vec2 C1; + C1.x = b2Dot(perp, d); + C1.y = aB - aA - m_referenceAngle; + + float32 linearError = b2Abs(C1.x); + float32 angularError = b2Abs(C1.y); + + bool active = false; + float32 C2 = 0.0f; + if (m_enableLimit) + { + float32 translation = b2Dot(axis, d); + if (b2Abs(m_upperTranslation - m_lowerTranslation) < 2.0f * b2_linearSlop) + { + // Prevent large angular corrections + C2 = b2Clamp(translation, -b2_maxLinearCorrection, b2_maxLinearCorrection); + linearError = b2Max(linearError, b2Abs(translation)); + active = true; + } + else if (translation <= m_lowerTranslation) + { + // Prevent large linear corrections and allow some slop. + C2 = b2Clamp(translation - m_lowerTranslation + b2_linearSlop, -b2_maxLinearCorrection, 0.0f); + linearError = b2Max(linearError, m_lowerTranslation - translation); + active = true; + } + else if (translation >= m_upperTranslation) + { + // Prevent large linear corrections and allow some slop. + C2 = b2Clamp(translation - m_upperTranslation - b2_linearSlop, 0.0f, b2_maxLinearCorrection); + linearError = b2Max(linearError, translation - m_upperTranslation); + active = true; + } + } + + if (active) + { + float32 k11 = mA + mB + iA * s1 * s1 + iB * s2 * s2; + float32 k12 = iA * s1 + iB * s2; + float32 k13 = iA * s1 * a1 + iB * s2 * a2; + float32 k22 = iA + iB; + if (k22 == 0.0f) + { + // For fixed rotation + k22 = 1.0f; + } + float32 k23 = iA * a1 + iB * a2; + float32 k33 = mA + mB + iA * a1 * a1 + iB * a2 * a2; + + b2Mat33 K; + K.ex.Set(k11, k12, k13); + K.ey.Set(k12, k22, k23); + K.ez.Set(k13, k23, k33); + + b2Vec3 C; + C.x = C1.x; + C.y = C1.y; + C.z = C2; + + impulse = K.Solve33(-C); + } + else + { + float32 k11 = mA + mB + iA * s1 * s1 + iB * s2 * s2; + float32 k12 = iA * s1 + iB * s2; + float32 k22 = iA + iB; + if (k22 == 0.0f) + { + k22 = 1.0f; + } + + b2Mat22 K; + K.ex.Set(k11, k12); + K.ey.Set(k12, k22); + + b2Vec2 impulse1 = K.Solve(-C1); + impulse.x = impulse1.x; + impulse.y = impulse1.y; + impulse.z = 0.0f; + } + + b2Vec2 P = impulse.x * perp + impulse.z * axis; + float32 LA = impulse.x * s1 + impulse.y + impulse.z * a1; + float32 LB = impulse.x * s2 + impulse.y + impulse.z * a2; + + cA -= mA * P; + aA -= iA * LA; + cB += mB * P; + aB += iB * LB; + + 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 && angularError <= b2_angularSlop; +} + +b2Vec2 b2PrismaticJoint::GetAnchorA() const +{ + return m_bodyA->GetWorldPoint(m_localAnchorA); +} + +b2Vec2 b2PrismaticJoint::GetAnchorB() const +{ + return m_bodyB->GetWorldPoint(m_localAnchorB); +} + +b2Vec2 b2PrismaticJoint::GetReactionForce(float32 inv_dt) const +{ + return inv_dt * (m_impulse.x * m_perp + (m_motorImpulse + m_impulse.z) * m_axis); +} + +float32 b2PrismaticJoint::GetReactionTorque(float32 inv_dt) const +{ + return inv_dt * m_impulse.y; +} + +float32 b2PrismaticJoint::GetJointTranslation() const +{ + b2Vec2 pA = m_bodyA->GetWorldPoint(m_localAnchorA); + b2Vec2 pB = m_bodyB->GetWorldPoint(m_localAnchorB); + b2Vec2 d = pB - pA; + b2Vec2 axis = m_bodyA->GetWorldVector(m_localXAxisA); + + float32 translation = b2Dot(d, axis); + return translation; +} + +float32 b2PrismaticJoint::GetJointSpeed() 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; + float32 wA = bA->m_angularVelocity; + float32 wB = bB->m_angularVelocity; + + float32 speed = b2Dot(d, b2Cross(wA, axis)) + b2Dot(axis, vB + b2Cross(wB, rB) - vA - b2Cross(wA, rA)); + return speed; +} + +bool b2PrismaticJoint::IsLimitEnabled() const +{ + return m_enableLimit; +} + +void b2PrismaticJoint::EnableLimit(bool flag) +{ + if (flag != m_enableLimit) + { + m_bodyA->SetAwake(true); + m_bodyB->SetAwake(true); + m_enableLimit = flag; + m_impulse.z = 0.0f; + } +} + +float32 b2PrismaticJoint::GetLowerLimit() const +{ + return m_lowerTranslation; +} + +float32 b2PrismaticJoint::GetUpperLimit() const +{ + return m_upperTranslation; +} + +void b2PrismaticJoint::SetLimits(float32 lower, float32 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_impulse.z = 0.0f; + } +} + +bool b2PrismaticJoint::IsMotorEnabled() const +{ + return m_enableMotor; +} + +void b2PrismaticJoint::EnableMotor(bool flag) +{ + if (flag != m_enableMotor) + { + m_bodyA->SetAwake(true); + m_bodyB->SetAwake(true); + m_enableMotor = flag; + } +} + +void b2PrismaticJoint::SetMotorSpeed(float32 speed) +{ + if (speed != m_motorSpeed) + { + m_bodyA->SetAwake(true); + m_bodyB->SetAwake(true); + m_motorSpeed = speed; + } +} + +void b2PrismaticJoint::SetMaxMotorForce(float32 force) +{ + if (force != m_maxMotorForce) + { + m_bodyA->SetAwake(true); + m_bodyB->SetAwake(true); + m_maxMotorForce = force; + } +} + +float32 b2PrismaticJoint::GetMotorForce(float32 inv_dt) const +{ + return inv_dt * m_motorImpulse; +} + +void b2PrismaticJoint::Dump() +{ + int32 indexA = m_bodyA->m_islandIndex; + int32 indexB = m_bodyB->m_islandIndex; + + b2Log(" b2PrismaticJointDef 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.localAxisA.Set(%.15lef, %.15lef);\n", m_localXAxisA.x, m_localXAxisA.y); + b2Log(" jd.referenceAngle = %.15lef;\n", m_referenceAngle); + b2Log(" jd.enableLimit = bool(%d);\n", m_enableLimit); + b2Log(" jd.lowerTranslation = %.15lef;\n", m_lowerTranslation); + b2Log(" jd.upperTranslation = %.15lef;\n", m_upperTranslation); + b2Log(" jd.enableMotor = bool(%d);\n", m_enableMotor); + b2Log(" jd.motorSpeed = %.15lef;\n", m_motorSpeed); + b2Log(" jd.maxMotorForce = %.15lef;\n", m_maxMotorForce); + b2Log(" joints[%d] = m_world->CreateJoint(&jd);\n", m_index); +} diff --git a/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2PrismaticJoint.h b/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2PrismaticJoint.h new file mode 100644 index 0000000..131dffd --- /dev/null +++ b/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2PrismaticJoint.h @@ -0,0 +1,196 @@ +/* +* 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. +*/ + +#ifndef B2_PRISMATIC_JOINT_H +#define B2_PRISMATIC_JOINT_H + +#include "Box2D/Dynamics/Joints/b2Joint.h" + +/// Prismatic joint definition. This requires defining a line of +/// motion using an axis and an anchor point. The definition uses local +/// anchor points and a local axis so that the initial configuration +/// can violate the constraint slightly. The joint translation is zero +/// when the local anchor points coincide in world space. Using local +/// anchors and a local axis helps when saving and loading a game. +struct b2PrismaticJointDef : public b2JointDef +{ + b2PrismaticJointDef() + { + type = e_prismaticJoint; + localAnchorA.SetZero(); + localAnchorB.SetZero(); + localAxisA.Set(1.0f, 0.0f); + referenceAngle = 0.0f; + enableLimit = false; + lowerTranslation = 0.0f; + upperTranslation = 0.0f; + enableMotor = false; + maxMotorForce = 0.0f; + motorSpeed = 0.0f; + } + + /// Initialize the bodies, anchors, axis, and reference angle using the world + /// anchor and unit world axis. + void Initialize(b2Body* bodyA, b2Body* bodyB, const b2Vec2& anchor, const b2Vec2& axis); + + /// The local anchor point relative to bodyA's origin. + b2Vec2 localAnchorA; + + /// The local anchor point relative to bodyB's origin. + b2Vec2 localAnchorB; + + /// The local translation unit axis in bodyA. + b2Vec2 localAxisA; + + /// The constrained angle between the bodies: bodyB_angle - bodyA_angle. + float32 referenceAngle; + + /// Enable/disable the joint limit. + bool enableLimit; + + /// The lower translation limit, usually in meters. + float32 lowerTranslation; + + /// The upper translation limit, usually in meters. + float32 upperTranslation; + + /// Enable/disable the joint motor. + bool enableMotor; + + /// The maximum motor torque, usually in N-m. + float32 maxMotorForce; + + /// The desired motor speed in radians per second. + float32 motorSpeed; +}; + +/// A prismatic joint. This joint provides one degree of freedom: translation +/// along an axis fixed in bodyA. Relative rotation is prevented. You can +/// use a joint limit to restrict the range of motion and a joint motor to +/// drive the motion or to model joint friction. +class b2PrismaticJoint : public b2Joint +{ +public: + b2Vec2 GetAnchorA() const override; + b2Vec2 GetAnchorB() const override; + + b2Vec2 GetReactionForce(float32 inv_dt) const override; + float32 GetReactionTorque(float32 inv_dt) const override; + + /// The local anchor point relative to bodyA's origin. + const b2Vec2& GetLocalAnchorA() const { return m_localAnchorA; } + + /// The local anchor point relative to bodyB's origin. + const b2Vec2& GetLocalAnchorB() const { return m_localAnchorB; } + + /// The local joint axis relative to bodyA. + const b2Vec2& GetLocalAxisA() const { return m_localXAxisA; } + + /// Get the reference angle. + float32 GetReferenceAngle() const { return m_referenceAngle; } + + /// Get the current joint translation, usually in meters. + float32 GetJointTranslation() const; + + /// Get the current joint translation speed, usually in meters per second. + float32 GetJointSpeed() const; + + /// Is the joint limit enabled? + bool IsLimitEnabled() const; + + /// Enable/disable the joint limit. + void EnableLimit(bool flag); + + /// Get the lower joint limit, usually in meters. + float32 GetLowerLimit() const; + + /// Get the upper joint limit, usually in meters. + float32 GetUpperLimit() const; + + /// Set the joint limits, usually in meters. + void SetLimits(float32 lower, float32 upper); + + /// Is the joint motor enabled? + bool IsMotorEnabled() const; + + /// Enable/disable the joint motor. + void EnableMotor(bool flag); + + /// Set the motor speed, usually in meters per second. + void SetMotorSpeed(float32 speed); + + /// Get the motor speed, usually in meters per second. + float32 GetMotorSpeed() const; + + /// Set the maximum motor force, usually in N. + void SetMaxMotorForce(float32 force); + float32 GetMaxMotorForce() const { return m_maxMotorForce; } + + /// Get the current motor force given the inverse time step, usually in N. + float32 GetMotorForce(float32 inv_dt) const; + + /// Dump to b2Log + void Dump() override; + +protected: + friend class b2Joint; + friend class b2GearJoint; + b2PrismaticJoint(const b2PrismaticJointDef* def); + + void InitVelocityConstraints(const b2SolverData& data) override; + void SolveVelocityConstraints(const b2SolverData& data) override; + bool SolvePositionConstraints(const b2SolverData& data) override; + + // Solver shared + b2Vec2 m_localAnchorA; + b2Vec2 m_localAnchorB; + b2Vec2 m_localXAxisA; + b2Vec2 m_localYAxisA; + float32 m_referenceAngle; + b2Vec3 m_impulse; + float32 m_motorImpulse; + float32 m_lowerTranslation; + float32 m_upperTranslation; + float32 m_maxMotorForce; + float32 m_motorSpeed; + bool m_enableLimit; + bool m_enableMotor; + b2LimitState m_limitState; + + // Solver temp + int32 m_indexA; + int32 m_indexB; + b2Vec2 m_localCenterA; + b2Vec2 m_localCenterB; + float32 m_invMassA; + float32 m_invMassB; + float32 m_invIA; + float32 m_invIB; + b2Vec2 m_axis, m_perp; + float32 m_s1, m_s2; + float32 m_a1, m_a2; + b2Mat33 m_K; + float32 m_motorMass; +}; + +inline float32 b2PrismaticJoint::GetMotorSpeed() const +{ + return m_motorSpeed; +} + +#endif diff --git a/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2PulleyJoint.cpp b/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2PulleyJoint.cpp new file mode 100644 index 0000000..1525f41 --- /dev/null +++ b/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2PulleyJoint.cpp @@ -0,0 +1,348 @@ +/* +* Copyright (c) 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/b2PulleyJoint.h" +#include "Box2D/Dynamics/b2Body.h" +#include "Box2D/Dynamics/b2TimeStep.h" + +// Pulley: +// length1 = norm(p1 - s1) +// length2 = norm(p2 - s2) +// C0 = (length1 + ratio * length2)_initial +// C = C0 - (length1 + ratio * length2) +// u1 = (p1 - s1) / norm(p1 - s1) +// u2 = (p2 - s2) / norm(p2 - s2) +// Cdot = -dot(u1, v1 + cross(w1, r1)) - ratio * dot(u2, v2 + cross(w2, r2)) +// J = -[u1 cross(r1, u1) ratio * u2 ratio * cross(r2, u2)] +// K = J * invM * JT +// = invMass1 + invI1 * cross(r1, u1)^2 + ratio^2 * (invMass2 + invI2 * cross(r2, u2)^2) + +void b2PulleyJointDef::Initialize(b2Body* bA, b2Body* bB, + const b2Vec2& groundA, const b2Vec2& groundB, + const b2Vec2& anchorA, const b2Vec2& anchorB, + float32 r) +{ + bodyA = bA; + bodyB = bB; + groundAnchorA = groundA; + groundAnchorB = groundB; + localAnchorA = bodyA->GetLocalPoint(anchorA); + localAnchorB = bodyB->GetLocalPoint(anchorB); + b2Vec2 dA = anchorA - groundA; + lengthA = dA.Length(); + b2Vec2 dB = anchorB - groundB; + lengthB = dB.Length(); + ratio = r; + b2Assert(ratio > b2_epsilon); +} + +b2PulleyJoint::b2PulleyJoint(const b2PulleyJointDef* def) +: b2Joint(def) +{ + m_groundAnchorA = def->groundAnchorA; + m_groundAnchorB = def->groundAnchorB; + m_localAnchorA = def->localAnchorA; + m_localAnchorB = def->localAnchorB; + + m_lengthA = def->lengthA; + m_lengthB = def->lengthB; + + b2Assert(def->ratio != 0.0f); + m_ratio = def->ratio; + + m_constant = def->lengthA + m_ratio * def->lengthB; + + m_impulse = 0.0f; +} + +void b2PulleyJoint::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); + + // Get the pulley axes. + m_uA = cA + m_rA - m_groundAnchorA; + m_uB = cB + m_rB - m_groundAnchorB; + + float32 lengthA = m_uA.Length(); + float32 lengthB = m_uB.Length(); + + if (lengthA > 10.0f * b2_linearSlop) + { + m_uA *= 1.0f / lengthA; + } + else + { + m_uA.SetZero(); + } + + if (lengthB > 10.0f * b2_linearSlop) + { + m_uB *= 1.0f / lengthB; + } + else + { + m_uB.SetZero(); + } + + // Compute effective mass. + float32 ruA = b2Cross(m_rA, m_uA); + float32 ruB = b2Cross(m_rB, m_uB); + + float32 mA = m_invMassA + m_invIA * ruA * ruA; + float32 mB = m_invMassB + m_invIB * ruB * ruB; + + m_mass = mA + m_ratio * m_ratio * mB; + + if (m_mass > 0.0f) + { + m_mass = 1.0f / m_mass; + } + + if (data.step.warmStarting) + { + // Scale impulses to support variable time steps. + m_impulse *= data.step.dtRatio; + + // Warm starting. + b2Vec2 PA = -(m_impulse) * m_uA; + b2Vec2 PB = (-m_ratio * m_impulse) * m_uB; + + vA += m_invMassA * PA; + wA += m_invIA * b2Cross(m_rA, PA); + vB += m_invMassB * PB; + wB += m_invIB * b2Cross(m_rB, PB); + } + 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 b2PulleyJoint::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; + + b2Vec2 vpA = vA + b2Cross(wA, m_rA); + b2Vec2 vpB = vB + b2Cross(wB, m_rB); + + float32 Cdot = -b2Dot(m_uA, vpA) - m_ratio * b2Dot(m_uB, vpB); + float32 impulse = -m_mass * Cdot; + m_impulse += impulse; + + b2Vec2 PA = -impulse * m_uA; + b2Vec2 PB = -m_ratio * impulse * m_uB; + vA += m_invMassA * PA; + wA += m_invIA * b2Cross(m_rA, PA); + vB += m_invMassB * PB; + wB += m_invIB * b2Cross(m_rB, PB); + + 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 b2PulleyJoint::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); + + // Get the pulley axes. + b2Vec2 uA = cA + rA - m_groundAnchorA; + b2Vec2 uB = cB + rB - m_groundAnchorB; + + float32 lengthA = uA.Length(); + float32 lengthB = uB.Length(); + + if (lengthA > 10.0f * b2_linearSlop) + { + uA *= 1.0f / lengthA; + } + else + { + uA.SetZero(); + } + + if (lengthB > 10.0f * b2_linearSlop) + { + uB *= 1.0f / lengthB; + } + else + { + uB.SetZero(); + } + + // Compute effective mass. + float32 ruA = b2Cross(rA, uA); + float32 ruB = b2Cross(rB, uB); + + float32 mA = m_invMassA + m_invIA * ruA * ruA; + float32 mB = m_invMassB + m_invIB * ruB * ruB; + + float32 mass = mA + m_ratio * m_ratio * mB; + + if (mass > 0.0f) + { + mass = 1.0f / mass; + } + + float32 C = m_constant - lengthA - m_ratio * lengthB; + float32 linearError = b2Abs(C); + + float32 impulse = -mass * C; + + b2Vec2 PA = -impulse * uA; + b2Vec2 PB = -m_ratio * impulse * uB; + + cA += m_invMassA * PA; + aA += m_invIA * b2Cross(rA, PA); + cB += m_invMassB * PB; + aB += m_invIB * b2Cross(rB, PB); + + 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 b2PulleyJoint::GetAnchorA() const +{ + return m_bodyA->GetWorldPoint(m_localAnchorA); +} + +b2Vec2 b2PulleyJoint::GetAnchorB() const +{ + return m_bodyB->GetWorldPoint(m_localAnchorB); +} + +b2Vec2 b2PulleyJoint::GetReactionForce(float32 inv_dt) const +{ + b2Vec2 P = m_impulse * m_uB; + return inv_dt * P; +} + +float32 b2PulleyJoint::GetReactionTorque(float32 inv_dt) const +{ + B2_NOT_USED(inv_dt); + return 0.0f; +} + +b2Vec2 b2PulleyJoint::GetGroundAnchorA() const +{ + return m_groundAnchorA; +} + +b2Vec2 b2PulleyJoint::GetGroundAnchorB() const +{ + return m_groundAnchorB; +} + +float32 b2PulleyJoint::GetLengthA() const +{ + return m_lengthA; +} + +float32 b2PulleyJoint::GetLengthB() const +{ + return m_lengthB; +} + +float32 b2PulleyJoint::GetRatio() const +{ + return m_ratio; +} + +float32 b2PulleyJoint::GetCurrentLengthA() const +{ + b2Vec2 p = m_bodyA->GetWorldPoint(m_localAnchorA); + b2Vec2 s = m_groundAnchorA; + b2Vec2 d = p - s; + return d.Length(); +} + +float32 b2PulleyJoint::GetCurrentLengthB() const +{ + b2Vec2 p = m_bodyB->GetWorldPoint(m_localAnchorB); + b2Vec2 s = m_groundAnchorB; + b2Vec2 d = p - s; + return d.Length(); +} + +void b2PulleyJoint::Dump() +{ + int32 indexA = m_bodyA->m_islandIndex; + int32 indexB = m_bodyB->m_islandIndex; + + b2Log(" b2PulleyJointDef 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.groundAnchorA.Set(%.15lef, %.15lef);\n", m_groundAnchorA.x, m_groundAnchorA.y); + b2Log(" jd.groundAnchorB.Set(%.15lef, %.15lef);\n", m_groundAnchorB.x, m_groundAnchorB.y); + 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.lengthA = %.15lef;\n", m_lengthA); + b2Log(" jd.lengthB = %.15lef;\n", m_lengthB); + b2Log(" jd.ratio = %.15lef;\n", m_ratio); + b2Log(" joints[%d] = m_world->CreateJoint(&jd);\n", m_index); +} + +void b2PulleyJoint::ShiftOrigin(const b2Vec2& newOrigin) +{ + m_groundAnchorA -= newOrigin; + m_groundAnchorB -= newOrigin; +} diff --git a/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2PulleyJoint.h b/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2PulleyJoint.h new file mode 100644 index 0000000..71c759b --- /dev/null +++ b/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2PulleyJoint.h @@ -0,0 +1,152 @@ +/* +* 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. +*/ + +#ifndef B2_PULLEY_JOINT_H +#define B2_PULLEY_JOINT_H + +#include "Box2D/Dynamics/Joints/b2Joint.h" + +const float32 b2_minPulleyLength = 2.0f; + +/// Pulley joint definition. This requires two ground anchors, +/// two dynamic body anchor points, and a pulley ratio. +struct b2PulleyJointDef : public b2JointDef +{ + b2PulleyJointDef() + { + type = e_pulleyJoint; + groundAnchorA.Set(-1.0f, 1.0f); + groundAnchorB.Set(1.0f, 1.0f); + localAnchorA.Set(-1.0f, 0.0f); + localAnchorB.Set(1.0f, 0.0f); + lengthA = 0.0f; + lengthB = 0.0f; + ratio = 1.0f; + collideConnected = true; + } + + /// Initialize the bodies, anchors, lengths, max lengths, and ratio using the world anchors. + void Initialize(b2Body* bodyA, b2Body* bodyB, + const b2Vec2& groundAnchorA, const b2Vec2& groundAnchorB, + const b2Vec2& anchorA, const b2Vec2& anchorB, + float32 ratio); + + /// The first ground anchor in world coordinates. This point never moves. + b2Vec2 groundAnchorA; + + /// The second ground anchor in world coordinates. This point never moves. + b2Vec2 groundAnchorB; + + /// The local anchor point relative to bodyA's origin. + b2Vec2 localAnchorA; + + /// The local anchor point relative to bodyB's origin. + b2Vec2 localAnchorB; + + /// The a reference length for the segment attached to bodyA. + float32 lengthA; + + /// The a reference length for the segment attached to bodyB. + float32 lengthB; + + /// The pulley ratio, used to simulate a block-and-tackle. + float32 ratio; +}; + +/// The pulley joint is connected to two bodies and two fixed ground points. +/// The pulley supports a ratio such that: +/// length1 + ratio * length2 <= constant +/// Yes, the force transmitted is scaled by the ratio. +/// Warning: the pulley joint can get a bit squirrelly by itself. They often +/// work better when combined with prismatic joints. You should also cover the +/// the anchor points with static shapes to prevent one side from going to +/// zero length. +class b2PulleyJoint : public b2Joint +{ +public: + b2Vec2 GetAnchorA() const override; + b2Vec2 GetAnchorB() const override; + + b2Vec2 GetReactionForce(float32 inv_dt) const override; + float32 GetReactionTorque(float32 inv_dt) const override; + + /// Get the first ground anchor. + b2Vec2 GetGroundAnchorA() const; + + /// Get the second ground anchor. + b2Vec2 GetGroundAnchorB() const; + + /// Get the current length of the segment attached to bodyA. + float32 GetLengthA() const; + + /// Get the current length of the segment attached to bodyB. + float32 GetLengthB() const; + + /// Get the pulley ratio. + float32 GetRatio() const; + + /// Get the current length of the segment attached to bodyA. + float32 GetCurrentLengthA() const; + + /// Get the current length of the segment attached to bodyB. + float32 GetCurrentLengthB() const; + + /// Dump joint to dmLog + void Dump() override; + + /// Implement b2Joint::ShiftOrigin + void ShiftOrigin(const b2Vec2& newOrigin) override; + +protected: + + friend class b2Joint; + b2PulleyJoint(const b2PulleyJointDef* data); + + void InitVelocityConstraints(const b2SolverData& data) override; + void SolveVelocityConstraints(const b2SolverData& data) override; + bool SolvePositionConstraints(const b2SolverData& data) override; + + b2Vec2 m_groundAnchorA; + b2Vec2 m_groundAnchorB; + float32 m_lengthA; + float32 m_lengthB; + + // Solver shared + b2Vec2 m_localAnchorA; + b2Vec2 m_localAnchorB; + float32 m_constant; + float32 m_ratio; + float32 m_impulse; + + // Solver temp + int32 m_indexA; + int32 m_indexB; + b2Vec2 m_uA; + b2Vec2 m_uB; + b2Vec2 m_rA; + b2Vec2 m_rB; + b2Vec2 m_localCenterA; + b2Vec2 m_localCenterB; + float32 m_invMassA; + float32 m_invMassB; + float32 m_invIA; + float32 m_invIB; + float32 m_mass; +}; + +#endif diff --git a/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2RevoluteJoint.cpp b/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2RevoluteJoint.cpp new file mode 100644 index 0000000..b3f7ee5 --- /dev/null +++ b/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2RevoluteJoint.cpp @@ -0,0 +1,511 @@ +/* +* 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/b2RevoluteJoint.h" +#include "Box2D/Dynamics/b2Body.h" +#include "Box2D/Dynamics/b2TimeStep.h" + +// Point-to-point constraint +// C = p2 - p1 +// 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) + +// Motor constraint +// Cdot = w2 - w1 +// J = [0 0 -1 0 0 1] +// K = invI1 + invI2 + +void b2RevoluteJointDef::Initialize(b2Body* bA, b2Body* bB, const b2Vec2& anchor) +{ + bodyA = bA; + bodyB = bB; + localAnchorA = bodyA->GetLocalPoint(anchor); + localAnchorB = bodyB->GetLocalPoint(anchor); + referenceAngle = bodyB->GetAngle() - bodyA->GetAngle(); +} + +b2RevoluteJoint::b2RevoluteJoint(const b2RevoluteJointDef* def) +: b2Joint(def) +{ + m_localAnchorA = def->localAnchorA; + m_localAnchorB = def->localAnchorB; + m_referenceAngle = def->referenceAngle; + + m_impulse.SetZero(); + m_motorImpulse = 0.0f; + + m_lowerAngle = def->lowerAngle; + m_upperAngle = def->upperAngle; + m_maxMotorTorque = def->maxMotorTorque; + m_motorSpeed = def->motorSpeed; + m_enableLimit = def->enableLimit; + m_enableMotor = def->enableMotor; + m_limitState = e_inactiveLimit; +} + +void b2RevoluteJoint::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); + + 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; + + bool fixedRotation = (iA + iB == 0.0f); + + m_mass.ex.x = mA + mB + m_rA.y * m_rA.y * iA + m_rB.y * m_rB.y * iB; + m_mass.ey.x = -m_rA.y * m_rA.x * iA - m_rB.y * m_rB.x * iB; + m_mass.ez.x = -m_rA.y * iA - m_rB.y * iB; + m_mass.ex.y = m_mass.ey.x; + m_mass.ey.y = mA + mB + m_rA.x * m_rA.x * iA + m_rB.x * m_rB.x * iB; + m_mass.ez.y = m_rA.x * iA + m_rB.x * iB; + m_mass.ex.z = m_mass.ez.x; + m_mass.ey.z = m_mass.ez.y; + m_mass.ez.z = iA + iB; + + m_motorMass = iA + iB; + if (m_motorMass > 0.0f) + { + m_motorMass = 1.0f / m_motorMass; + } + + if (m_enableMotor == false || fixedRotation) + { + m_motorImpulse = 0.0f; + } + + if (m_enableLimit && fixedRotation == false) + { + float32 jointAngle = aB - aA - m_referenceAngle; + if (b2Abs(m_upperAngle - m_lowerAngle) < 2.0f * b2_angularSlop) + { + m_limitState = e_equalLimits; + } + else if (jointAngle <= m_lowerAngle) + { + if (m_limitState != e_atLowerLimit) + { + m_impulse.z = 0.0f; + } + m_limitState = e_atLowerLimit; + } + else if (jointAngle >= m_upperAngle) + { + if (m_limitState != e_atUpperLimit) + { + m_impulse.z = 0.0f; + } + m_limitState = e_atUpperLimit; + } + else + { + m_limitState = e_inactiveLimit; + m_impulse.z = 0.0f; + } + } + else + { + m_limitState = e_inactiveLimit; + } + + if (data.step.warmStarting) + { + // Scale impulses to support a variable time step. + m_impulse *= data.step.dtRatio; + m_motorImpulse *= data.step.dtRatio; + + b2Vec2 P(m_impulse.x, m_impulse.y); + + vA -= mA * P; + wA -= iA * (b2Cross(m_rA, P) + m_motorImpulse + m_impulse.z); + + vB += mB * P; + wB += iB * (b2Cross(m_rB, P) + m_motorImpulse + m_impulse.z); + } + else + { + m_impulse.SetZero(); + m_motorImpulse = 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 b2RevoluteJoint::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; + + bool fixedRotation = (iA + iB == 0.0f); + + // Solve motor constraint. + if (m_enableMotor && m_limitState != e_equalLimits && fixedRotation == false) + { + float32 Cdot = wB - wA - m_motorSpeed; + float32 impulse = -m_motorMass * Cdot; + float32 oldImpulse = m_motorImpulse; + float32 maxImpulse = data.step.dt * m_maxMotorTorque; + m_motorImpulse = b2Clamp(m_motorImpulse + impulse, -maxImpulse, maxImpulse); + impulse = m_motorImpulse - oldImpulse; + + wA -= iA * impulse; + wB += iB * impulse; + } + + // Solve limit constraint. + if (m_enableLimit && m_limitState != e_inactiveLimit && fixedRotation == false) + { + b2Vec2 Cdot1 = vB + b2Cross(wB, m_rB) - vA - b2Cross(wA, m_rA); + float32 Cdot2 = wB - wA; + b2Vec3 Cdot(Cdot1.x, Cdot1.y, Cdot2); + + b2Vec3 impulse = -m_mass.Solve33(Cdot); + + if (m_limitState == e_equalLimits) + { + m_impulse += impulse; + } + else if (m_limitState == e_atLowerLimit) + { + float32 newImpulse = m_impulse.z + impulse.z; + if (newImpulse < 0.0f) + { + b2Vec2 rhs = -Cdot1 + m_impulse.z * b2Vec2(m_mass.ez.x, m_mass.ez.y); + b2Vec2 reduced = m_mass.Solve22(rhs); + impulse.x = reduced.x; + impulse.y = reduced.y; + impulse.z = -m_impulse.z; + m_impulse.x += reduced.x; + m_impulse.y += reduced.y; + m_impulse.z = 0.0f; + } + else + { + m_impulse += impulse; + } + } + else if (m_limitState == e_atUpperLimit) + { + float32 newImpulse = m_impulse.z + impulse.z; + if (newImpulse > 0.0f) + { + b2Vec2 rhs = -Cdot1 + m_impulse.z * b2Vec2(m_mass.ez.x, m_mass.ez.y); + b2Vec2 reduced = m_mass.Solve22(rhs); + impulse.x = reduced.x; + impulse.y = reduced.y; + impulse.z = -m_impulse.z; + m_impulse.x += reduced.x; + m_impulse.y += reduced.y; + m_impulse.z = 0.0f; + } + else + { + m_impulse += impulse; + } + } + + b2Vec2 P(impulse.x, impulse.y); + + vA -= mA * P; + wA -= iA * (b2Cross(m_rA, P) + impulse.z); + + vB += mB * P; + wB += iB * (b2Cross(m_rB, P) + impulse.z); + } + else + { + // Solve point-to-point constraint + b2Vec2 Cdot = vB + b2Cross(wB, m_rB) - vA - b2Cross(wA, m_rA); + b2Vec2 impulse = m_mass.Solve22(-Cdot); + + m_impulse.x += impulse.x; + m_impulse.y += impulse.y; + + 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 b2RevoluteJoint::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); + + float32 angularError = 0.0f; + float32 positionError = 0.0f; + + bool fixedRotation = (m_invIA + m_invIB == 0.0f); + + // Solve angular limit constraint. + if (m_enableLimit && m_limitState != e_inactiveLimit && fixedRotation == false) + { + float32 angle = aB - aA - m_referenceAngle; + float32 limitImpulse = 0.0f; + + if (m_limitState == e_equalLimits) + { + // Prevent large angular corrections + float32 C = b2Clamp(angle - m_lowerAngle, -b2_maxAngularCorrection, b2_maxAngularCorrection); + limitImpulse = -m_motorMass * C; + angularError = b2Abs(C); + } + else if (m_limitState == e_atLowerLimit) + { + float32 C = angle - m_lowerAngle; + angularError = -C; + + // Prevent large angular corrections and allow some slop. + C = b2Clamp(C + b2_angularSlop, -b2_maxAngularCorrection, 0.0f); + limitImpulse = -m_motorMass * C; + } + else if (m_limitState == e_atUpperLimit) + { + float32 C = angle - m_upperAngle; + angularError = C; + + // Prevent large angular corrections and allow some slop. + C = b2Clamp(C - b2_angularSlop, 0.0f, b2_maxAngularCorrection); + limitImpulse = -m_motorMass * C; + } + + aA -= m_invIA * limitImpulse; + aB += m_invIB * limitImpulse; + } + + // Solve point-to-point constraint. + { + qA.Set(aA); + qB.Set(aB); + b2Vec2 rA = b2Mul(qA, m_localAnchorA - m_localCenterA); + b2Vec2 rB = b2Mul(qB, m_localAnchorB - m_localCenterB); + + b2Vec2 C = cB + rB - cA - rA; + positionError = C.Length(); + + float32 mA = m_invMassA, mB = m_invMassB; + float32 iA = m_invIA, iB = m_invIB; + + b2Mat22 K; + K.ex.x = mA + mB + iA * rA.y * rA.y + iB * rB.y * rB.y; + K.ex.y = -iA * rA.x * rA.y - iB * rB.x * rB.y; + K.ey.x = K.ex.y; + K.ey.y = mA + mB + iA * rA.x * rA.x + iB * rB.x * rB.x; + + b2Vec2 impulse = -K.Solve(C); + + cA -= mA * impulse; + aA -= iA * b2Cross(rA, impulse); + + cB += mB * impulse; + aB += iB * b2Cross(rB, impulse); + } + + 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 positionError <= b2_linearSlop && angularError <= b2_angularSlop; +} + +b2Vec2 b2RevoluteJoint::GetAnchorA() const +{ + return m_bodyA->GetWorldPoint(m_localAnchorA); +} + +b2Vec2 b2RevoluteJoint::GetAnchorB() const +{ + return m_bodyB->GetWorldPoint(m_localAnchorB); +} + +b2Vec2 b2RevoluteJoint::GetReactionForce(float32 inv_dt) const +{ + b2Vec2 P(m_impulse.x, m_impulse.y); + return inv_dt * P; +} + +float32 b2RevoluteJoint::GetReactionTorque(float32 inv_dt) const +{ + return inv_dt * m_impulse.z; +} + +float32 b2RevoluteJoint::GetJointAngle() const +{ + b2Body* bA = m_bodyA; + b2Body* bB = m_bodyB; + return bB->m_sweep.a - bA->m_sweep.a - m_referenceAngle; +} + +float32 b2RevoluteJoint::GetJointSpeed() const +{ + b2Body* bA = m_bodyA; + b2Body* bB = m_bodyB; + return bB->m_angularVelocity - bA->m_angularVelocity; +} + +bool b2RevoluteJoint::IsMotorEnabled() const +{ + return m_enableMotor; +} + +void b2RevoluteJoint::EnableMotor(bool flag) +{ + if (flag != m_enableMotor) + { + m_bodyA->SetAwake(true); + m_bodyB->SetAwake(true); + m_enableMotor = flag; + } +} + +float32 b2RevoluteJoint::GetMotorTorque(float32 inv_dt) const +{ + return inv_dt * m_motorImpulse; +} + +void b2RevoluteJoint::SetMotorSpeed(float32 speed) +{ + if (speed != m_motorSpeed) + { + m_bodyA->SetAwake(true); + m_bodyB->SetAwake(true); + m_motorSpeed = speed; + } +} + +void b2RevoluteJoint::SetMaxMotorTorque(float32 torque) +{ + if (torque != m_maxMotorTorque) + { + m_bodyA->SetAwake(true); + m_bodyB->SetAwake(true); + m_maxMotorTorque = torque; + } +} + +bool b2RevoluteJoint::IsLimitEnabled() const +{ + return m_enableLimit; +} + +void b2RevoluteJoint::EnableLimit(bool flag) +{ + if (flag != m_enableLimit) + { + m_bodyA->SetAwake(true); + m_bodyB->SetAwake(true); + m_enableLimit = flag; + m_impulse.z = 0.0f; + } +} + +float32 b2RevoluteJoint::GetLowerLimit() const +{ + return m_lowerAngle; +} + +float32 b2RevoluteJoint::GetUpperLimit() const +{ + return m_upperAngle; +} + +void b2RevoluteJoint::SetLimits(float32 lower, float32 upper) +{ + b2Assert(lower <= upper); + + if (lower != m_lowerAngle || upper != m_upperAngle) + { + m_bodyA->SetAwake(true); + m_bodyB->SetAwake(true); + m_impulse.z = 0.0f; + m_lowerAngle = lower; + m_upperAngle = upper; + } +} + +void b2RevoluteJoint::Dump() +{ + int32 indexA = m_bodyA->m_islandIndex; + int32 indexB = m_bodyB->m_islandIndex; + + b2Log(" b2RevoluteJointDef 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.referenceAngle = %.15lef;\n", m_referenceAngle); + b2Log(" jd.enableLimit = bool(%d);\n", m_enableLimit); + b2Log(" jd.lowerAngle = %.15lef;\n", m_lowerAngle); + b2Log(" jd.upperAngle = %.15lef;\n", m_upperAngle); + b2Log(" jd.enableMotor = bool(%d);\n", m_enableMotor); + b2Log(" jd.motorSpeed = %.15lef;\n", m_motorSpeed); + b2Log(" jd.maxMotorTorque = %.15lef;\n", m_maxMotorTorque); + b2Log(" joints[%d] = m_world->CreateJoint(&jd);\n", m_index); +} diff --git a/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2RevoluteJoint.h b/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2RevoluteJoint.h new file mode 100644 index 0000000..06b1455 --- /dev/null +++ b/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2RevoluteJoint.h @@ -0,0 +1,204 @@ +/* +* 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. +*/ + +#ifndef B2_REVOLUTE_JOINT_H +#define B2_REVOLUTE_JOINT_H + +#include "Box2D/Dynamics/Joints/b2Joint.h" + +/// Revolute joint definition. This requires defining an +/// anchor point where the bodies are joined. The definition +/// uses local anchor points so that the initial configuration +/// can violate the constraint slightly. You also need to +/// specify the initial relative angle for joint limits. This +/// helps when saving and loading a game. +/// The local anchor points are measured from the body's origin +/// rather than the center of mass because: +/// 1. you might not know where the center of mass will be. +/// 2. if you add/remove shapes from a body and recompute the mass, +/// the joints will be broken. +struct b2RevoluteJointDef : public b2JointDef +{ + b2RevoluteJointDef() + { + type = e_revoluteJoint; + localAnchorA.Set(0.0f, 0.0f); + localAnchorB.Set(0.0f, 0.0f); + referenceAngle = 0.0f; + lowerAngle = 0.0f; + upperAngle = 0.0f; + maxMotorTorque = 0.0f; + motorSpeed = 0.0f; + enableLimit = false; + enableMotor = false; + } + + /// Initialize the bodies, anchors, and reference angle using a world + /// anchor point. + void Initialize(b2Body* bodyA, b2Body* bodyB, const b2Vec2& anchor); + + /// The local anchor point relative to bodyA's origin. + b2Vec2 localAnchorA; + + /// The local anchor point relative to bodyB's origin. + b2Vec2 localAnchorB; + + /// The bodyB angle minus bodyA angle in the reference state (radians). + float32 referenceAngle; + + /// A flag to enable joint limits. + bool enableLimit; + + /// The lower angle for the joint limit (radians). + float32 lowerAngle; + + /// The upper angle for the joint limit (radians). + float32 upperAngle; + + /// A flag to enable the joint motor. + bool enableMotor; + + /// The desired motor speed. Usually in radians per second. + float32 motorSpeed; + + /// The maximum motor torque used to achieve the desired motor speed. + /// Usually in N-m. + float32 maxMotorTorque; +}; + +/// A revolute joint constrains two bodies to share a common point while they +/// are free to rotate about the point. The relative rotation about the shared +/// point is the joint angle. You can limit the relative rotation with +/// a joint limit that specifies a lower and upper angle. You can use a motor +/// to drive the relative rotation about the shared point. A maximum motor torque +/// is provided so that infinite forces are not generated. +class b2RevoluteJoint : public b2Joint +{ +public: + b2Vec2 GetAnchorA() const override; + b2Vec2 GetAnchorB() const override; + + /// The local anchor point relative to bodyA's origin. + const b2Vec2& GetLocalAnchorA() const { return m_localAnchorA; } + + /// The local anchor point relative to bodyB's origin. + const b2Vec2& GetLocalAnchorB() const { return m_localAnchorB; } + + /// Get the reference angle. + float32 GetReferenceAngle() const { return m_referenceAngle; } + + /// Get the current joint angle in radians. + float32 GetJointAngle() const; + + /// Get the current joint angle speed in radians per second. + float32 GetJointSpeed() const; + + /// Is the joint limit enabled? + bool IsLimitEnabled() const; + + /// Enable/disable the joint limit. + void EnableLimit(bool flag); + + /// Get the lower joint limit in radians. + float32 GetLowerLimit() const; + + /// Get the upper joint limit in radians. + float32 GetUpperLimit() const; + + /// Set the joint limits in radians. + void SetLimits(float32 lower, float32 upper); + + /// Is the joint motor enabled? + bool IsMotorEnabled() const; + + /// Enable/disable the joint motor. + void EnableMotor(bool flag); + + /// Set the motor speed in radians per second. + void SetMotorSpeed(float32 speed); + + /// Get the motor speed in radians per second. + float32 GetMotorSpeed() const; + + /// Set the maximum motor torque, usually in N-m. + void SetMaxMotorTorque(float32 torque); + float32 GetMaxMotorTorque() const { return m_maxMotorTorque; } + + /// Get the reaction force given the inverse time step. + /// Unit is N. + b2Vec2 GetReactionForce(float32 inv_dt) const override; + + /// Get the reaction torque due to the joint limit given the inverse time step. + /// Unit is N*m. + float32 GetReactionTorque(float32 inv_dt) const override; + + /// Get the current motor torque given the inverse time step. + /// Unit is N*m. + float32 GetMotorTorque(float32 inv_dt) const; + + /// Dump to b2Log. + void Dump() override; + +protected: + + friend class b2Joint; + friend class b2GearJoint; + + b2RevoluteJoint(const b2RevoluteJointDef* def); + + void InitVelocityConstraints(const b2SolverData& data) override; + void SolveVelocityConstraints(const b2SolverData& data) override; + bool SolvePositionConstraints(const b2SolverData& data) override; + + // Solver shared + b2Vec2 m_localAnchorA; + b2Vec2 m_localAnchorB; + b2Vec3 m_impulse; + float32 m_motorImpulse; + + bool m_enableMotor; + float32 m_maxMotorTorque; + float32 m_motorSpeed; + + bool m_enableLimit; + float32 m_referenceAngle; + float32 m_lowerAngle; + float32 m_upperAngle; + + // Solver temp + int32 m_indexA; + int32 m_indexB; + b2Vec2 m_rA; + b2Vec2 m_rB; + b2Vec2 m_localCenterA; + b2Vec2 m_localCenterB; + float32 m_invMassA; + float32 m_invMassB; + float32 m_invIA; + float32 m_invIB; + b2Mat33 m_mass; // effective mass for point-to-point constraint. + float32 m_motorMass; // effective mass for motor/limit angular constraint. + b2LimitState m_limitState; +}; + +inline float32 b2RevoluteJoint::GetMotorSpeed() const +{ + return m_motorSpeed; +} + +#endif diff --git a/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2RopeJoint.cpp b/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2RopeJoint.cpp new file mode 100644 index 0000000..86d27e7 --- /dev/null +++ b/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2RopeJoint.cpp @@ -0,0 +1,241 @@ +/* +* 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); +} diff --git a/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2RopeJoint.h b/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2RopeJoint.h new file mode 100644 index 0000000..ef5d6f7 --- /dev/null +++ b/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2RopeJoint.h @@ -0,0 +1,114 @@ +/* +* 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. +*/ + +#ifndef B2_ROPE_JOINT_H +#define B2_ROPE_JOINT_H + +#include "Box2D/Dynamics/Joints/b2Joint.h" + +/// Rope joint definition. This requires two body anchor points and +/// a maximum lengths. +/// Note: by default the connected objects will not collide. +/// see collideConnected in b2JointDef. +struct b2RopeJointDef : public b2JointDef +{ + b2RopeJointDef() + { + type = e_ropeJoint; + localAnchorA.Set(-1.0f, 0.0f); + localAnchorB.Set(1.0f, 0.0f); + maxLength = 0.0f; + } + + /// The local anchor point relative to bodyA's origin. + b2Vec2 localAnchorA; + + /// The local anchor point relative to bodyB's origin. + b2Vec2 localAnchorB; + + /// The maximum length of the rope. + /// Warning: this must be larger than b2_linearSlop or + /// the joint will have no effect. + float32 maxLength; +}; + +/// A rope joint enforces a maximum distance between two points +/// on two bodies. It has no other effect. +/// Warning: if you attempt to change the maximum length during +/// the simulation you will get some non-physical behavior. +/// A model that would allow you to dynamically modify the length +/// would have some sponginess, so I chose not to implement it +/// that way. See b2DistanceJoint if you want to dynamically +/// control length. +class b2RopeJoint : public b2Joint +{ +public: + b2Vec2 GetAnchorA() const override; + b2Vec2 GetAnchorB() const override; + + b2Vec2 GetReactionForce(float32 inv_dt) const override; + float32 GetReactionTorque(float32 inv_dt) const override; + + /// The local anchor point relative to bodyA's origin. + const b2Vec2& GetLocalAnchorA() const { return m_localAnchorA; } + + /// The local anchor point relative to bodyB's origin. + const b2Vec2& GetLocalAnchorB() const { return m_localAnchorB; } + + /// Set/Get the maximum length of the rope. + void SetMaxLength(float32 length) { m_maxLength = length; } + float32 GetMaxLength() const; + + b2LimitState GetLimitState() const; + + /// Dump joint to dmLog + void Dump() override; + +protected: + + friend class b2Joint; + b2RopeJoint(const b2RopeJointDef* data); + + void InitVelocityConstraints(const b2SolverData& data) override; + void SolveVelocityConstraints(const b2SolverData& data) override; + bool SolvePositionConstraints(const b2SolverData& data) override; + + // Solver shared + b2Vec2 m_localAnchorA; + b2Vec2 m_localAnchorB; + float32 m_maxLength; + float32 m_length; + float32 m_impulse; + + // Solver temp + int32 m_indexA; + int32 m_indexB; + b2Vec2 m_u; + b2Vec2 m_rA; + b2Vec2 m_rB; + b2Vec2 m_localCenterA; + b2Vec2 m_localCenterB; + float32 m_invMassA; + float32 m_invMassB; + float32 m_invIA; + float32 m_invIB; + float32 m_mass; + b2LimitState m_state; +}; + +#endif diff --git a/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2WeldJoint.cpp b/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2WeldJoint.cpp new file mode 100644 index 0000000..b10cee8 --- /dev/null +++ b/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2WeldJoint.cpp @@ -0,0 +1,344 @@ +/* +* 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/b2WeldJoint.h" +#include "Box2D/Dynamics/b2Body.h" +#include "Box2D/Dynamics/b2TimeStep.h" + +// Point-to-point constraint +// C = p2 - p1 +// 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 +// C = angle2 - angle1 - referenceAngle +// Cdot = w2 - w1 +// J = [0 0 -1 0 0 1] +// K = invI1 + invI2 + +void b2WeldJointDef::Initialize(b2Body* bA, b2Body* bB, const b2Vec2& anchor) +{ + bodyA = bA; + bodyB = bB; + localAnchorA = bodyA->GetLocalPoint(anchor); + localAnchorB = bodyB->GetLocalPoint(anchor); + referenceAngle = bodyB->GetAngle() - bodyA->GetAngle(); +} + +b2WeldJoint::b2WeldJoint(const b2WeldJointDef* def) +: b2Joint(def) +{ + m_localAnchorA = def->localAnchorA; + m_localAnchorB = def->localAnchorB; + m_referenceAngle = def->referenceAngle; + m_frequencyHz = def->frequencyHz; + m_dampingRatio = def->dampingRatio; + + m_impulse.SetZero(); +} + +void b2WeldJoint::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); + + 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; + + b2Mat33 K; + K.ex.x = mA + mB + m_rA.y * m_rA.y * iA + m_rB.y * m_rB.y * iB; + K.ey.x = -m_rA.y * m_rA.x * iA - m_rB.y * m_rB.x * iB; + K.ez.x = -m_rA.y * iA - m_rB.y * iB; + K.ex.y = K.ey.x; + K.ey.y = mA + mB + m_rA.x * m_rA.x * iA + m_rB.x * m_rB.x * iB; + K.ez.y = m_rA.x * iA + m_rB.x * iB; + K.ex.z = K.ez.x; + K.ey.z = K.ez.y; + K.ez.z = iA + iB; + + if (m_frequencyHz > 0.0f) + { + K.GetInverse22(&m_mass); + + float32 invM = iA + iB; + float32 m = invM > 0.0f ? 1.0f / invM : 0.0f; + + float32 C = aB - aA - m_referenceAngle; + + // Frequency + float32 omega = 2.0f * b2_pi * m_frequencyHz; + + // Damping coefficient + float32 d = 2.0f * m * m_dampingRatio * omega; + + // Spring stiffness + float32 k = m * omega * omega; + + // magic formulas + float32 h = data.step.dt; + m_gamma = h * (d + h * k); + m_gamma = m_gamma != 0.0f ? 1.0f / m_gamma : 0.0f; + m_bias = C * h * k * m_gamma; + + invM += m_gamma; + m_mass.ez.z = invM != 0.0f ? 1.0f / invM : 0.0f; + } + else if (K.ez.z == 0.0f) + { + K.GetInverse22(&m_mass); + m_gamma = 0.0f; + m_bias = 0.0f; + } + else + { + K.GetSymInverse33(&m_mass); + m_gamma = 0.0f; + m_bias = 0.0f; + } + + if (data.step.warmStarting) + { + // Scale impulses to support a variable time step. + m_impulse *= data.step.dtRatio; + + b2Vec2 P(m_impulse.x, m_impulse.y); + + vA -= mA * P; + wA -= iA * (b2Cross(m_rA, P) + m_impulse.z); + + vB += mB * P; + wB += iB * (b2Cross(m_rB, P) + m_impulse.z); + } + else + { + m_impulse.SetZero(); + } + + 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 b2WeldJoint::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; + + if (m_frequencyHz > 0.0f) + { + float32 Cdot2 = wB - wA; + + float32 impulse2 = -m_mass.ez.z * (Cdot2 + m_bias + m_gamma * m_impulse.z); + m_impulse.z += impulse2; + + wA -= iA * impulse2; + wB += iB * impulse2; + + b2Vec2 Cdot1 = vB + b2Cross(wB, m_rB) - vA - b2Cross(wA, m_rA); + + b2Vec2 impulse1 = -b2Mul22(m_mass, Cdot1); + m_impulse.x += impulse1.x; + m_impulse.y += impulse1.y; + + b2Vec2 P = impulse1; + + vA -= mA * P; + wA -= iA * b2Cross(m_rA, P); + + vB += mB * P; + wB += iB * b2Cross(m_rB, P); + } + else + { + b2Vec2 Cdot1 = vB + b2Cross(wB, m_rB) - vA - b2Cross(wA, m_rA); + float32 Cdot2 = wB - wA; + b2Vec3 Cdot(Cdot1.x, Cdot1.y, Cdot2); + + b2Vec3 impulse = -b2Mul(m_mass, Cdot); + m_impulse += impulse; + + b2Vec2 P(impulse.x, impulse.y); + + vA -= mA * P; + wA -= iA * (b2Cross(m_rA, P) + impulse.z); + + vB += mB * P; + wB += iB * (b2Cross(m_rB, P) + impulse.z); + } + + 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 b2WeldJoint::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); + + float32 mA = m_invMassA, mB = m_invMassB; + float32 iA = m_invIA, iB = m_invIB; + + b2Vec2 rA = b2Mul(qA, m_localAnchorA - m_localCenterA); + b2Vec2 rB = b2Mul(qB, m_localAnchorB - m_localCenterB); + + float32 positionError, angularError; + + b2Mat33 K; + K.ex.x = mA + mB + rA.y * rA.y * iA + rB.y * rB.y * iB; + K.ey.x = -rA.y * rA.x * iA - rB.y * rB.x * iB; + K.ez.x = -rA.y * iA - rB.y * iB; + K.ex.y = K.ey.x; + K.ey.y = mA + mB + rA.x * rA.x * iA + rB.x * rB.x * iB; + K.ez.y = rA.x * iA + rB.x * iB; + K.ex.z = K.ez.x; + K.ey.z = K.ez.y; + K.ez.z = iA + iB; + + if (m_frequencyHz > 0.0f) + { + b2Vec2 C1 = cB + rB - cA - rA; + + positionError = C1.Length(); + angularError = 0.0f; + + b2Vec2 P = -K.Solve22(C1); + + cA -= mA * P; + aA -= iA * b2Cross(rA, P); + + cB += mB * P; + aB += iB * b2Cross(rB, P); + } + else + { + b2Vec2 C1 = cB + rB - cA - rA; + float32 C2 = aB - aA - m_referenceAngle; + + positionError = C1.Length(); + angularError = b2Abs(C2); + + b2Vec3 C(C1.x, C1.y, C2); + + b2Vec3 impulse; + if (K.ez.z > 0.0f) + { + impulse = -K.Solve33(C); + } + else + { + b2Vec2 impulse2 = -K.Solve22(C1); + impulse.Set(impulse2.x, impulse2.y, 0.0f); + } + + b2Vec2 P(impulse.x, impulse.y); + + cA -= mA * P; + aA -= iA * (b2Cross(rA, P) + impulse.z); + + cB += mB * P; + aB += iB * (b2Cross(rB, P) + impulse.z); + } + + 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 positionError <= b2_linearSlop && angularError <= b2_angularSlop; +} + +b2Vec2 b2WeldJoint::GetAnchorA() const +{ + return m_bodyA->GetWorldPoint(m_localAnchorA); +} + +b2Vec2 b2WeldJoint::GetAnchorB() const +{ + return m_bodyB->GetWorldPoint(m_localAnchorB); +} + +b2Vec2 b2WeldJoint::GetReactionForce(float32 inv_dt) const +{ + b2Vec2 P(m_impulse.x, m_impulse.y); + return inv_dt * P; +} + +float32 b2WeldJoint::GetReactionTorque(float32 inv_dt) const +{ + return inv_dt * m_impulse.z; +} + +void b2WeldJoint::Dump() +{ + int32 indexA = m_bodyA->m_islandIndex; + int32 indexB = m_bodyB->m_islandIndex; + + b2Log(" b2WeldJointDef 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.referenceAngle = %.15lef;\n", m_referenceAngle); + b2Log(" jd.frequencyHz = %.15lef;\n", m_frequencyHz); + b2Log(" jd.dampingRatio = %.15lef;\n", m_dampingRatio); + b2Log(" joints[%d] = m_world->CreateJoint(&jd);\n", m_index); +} diff --git a/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2WeldJoint.h b/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2WeldJoint.h new file mode 100644 index 0000000..81ba235 --- /dev/null +++ b/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2WeldJoint.h @@ -0,0 +1,126 @@ +/* +* 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. +*/ + +#ifndef B2_WELD_JOINT_H +#define B2_WELD_JOINT_H + +#include "Box2D/Dynamics/Joints/b2Joint.h" + +/// Weld joint definition. You need to specify local anchor points +/// where they are attached and the relative body angle. The position +/// of the anchor points is important for computing the reaction torque. +struct b2WeldJointDef : public b2JointDef +{ + b2WeldJointDef() + { + type = e_weldJoint; + localAnchorA.Set(0.0f, 0.0f); + localAnchorB.Set(0.0f, 0.0f); + referenceAngle = 0.0f; + frequencyHz = 0.0f; + dampingRatio = 0.0f; + } + + /// Initialize the bodies, anchors, and reference angle using a world + /// anchor point. + void Initialize(b2Body* bodyA, b2Body* bodyB, const b2Vec2& anchor); + + /// The local anchor point relative to bodyA's origin. + b2Vec2 localAnchorA; + + /// The local anchor point relative to bodyB's origin. + b2Vec2 localAnchorB; + + /// The bodyB angle minus bodyA angle in the reference state (radians). + float32 referenceAngle; + + /// The mass-spring-damper frequency in Hertz. Rotation only. + /// Disable softness with a value of 0. + float32 frequencyHz; + + /// The damping ratio. 0 = no damping, 1 = critical damping. + float32 dampingRatio; +}; + +/// A weld joint essentially glues two bodies together. A weld joint may +/// distort somewhat because the island constraint solver is approximate. +class b2WeldJoint : public b2Joint +{ +public: + b2Vec2 GetAnchorA() const override; + b2Vec2 GetAnchorB() const override; + + b2Vec2 GetReactionForce(float32 inv_dt) const override; + float32 GetReactionTorque(float32 inv_dt) const override; + + /// The local anchor point relative to bodyA's origin. + const b2Vec2& GetLocalAnchorA() const { return m_localAnchorA; } + + /// The local anchor point relative to bodyB's origin. + const b2Vec2& GetLocalAnchorB() const { return m_localAnchorB; } + + /// Get the reference angle. + float32 GetReferenceAngle() const { return m_referenceAngle; } + + /// Set/get frequency in Hz. + void SetFrequency(float32 hz) { m_frequencyHz = hz; } + float32 GetFrequency() const { return m_frequencyHz; } + + /// Set/get damping ratio. + void SetDampingRatio(float32 ratio) { m_dampingRatio = ratio; } + float32 GetDampingRatio() const { return m_dampingRatio; } + + /// Dump to b2Log + void Dump() override; + +protected: + + friend class b2Joint; + + b2WeldJoint(const b2WeldJointDef* def); + + void InitVelocityConstraints(const b2SolverData& data) override; + void SolveVelocityConstraints(const b2SolverData& data) override; + bool SolvePositionConstraints(const b2SolverData& data) override; + + float32 m_frequencyHz; + float32 m_dampingRatio; + float32 m_bias; + + // Solver shared + b2Vec2 m_localAnchorA; + b2Vec2 m_localAnchorB; + float32 m_referenceAngle; + float32 m_gamma; + b2Vec3 m_impulse; + + // Solver temp + int32 m_indexA; + int32 m_indexB; + b2Vec2 m_rA; + b2Vec2 m_rB; + b2Vec2 m_localCenterA; + b2Vec2 m_localCenterB; + float32 m_invMassA; + float32 m_invMassB; + float32 m_invIA; + float32 m_invIB; + b2Mat33 m_mass; +}; + +#endif diff --git a/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2WheelJoint.cpp b/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2WheelJoint.cpp new file mode 100644 index 0000000..a95311e --- /dev/null +++ b/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2WheelJoint.cpp @@ -0,0 +1,456 @@ +/* +* 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/b2WheelJoint.h" +#include "Box2D/Dynamics/b2Body.h" +#include "Box2D/Dynamics/b2TimeStep.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_maxMotorTorque = def->maxMotorTorque; + m_motorSpeed = def->motorSpeed; + m_enableMotor = def->enableMotor; + + m_frequencyHz = def->frequencyHz; + m_dampingRatio = def->dampingRatio; + + m_bias = 0.0f; + m_gamma = 0.0f; + + m_ax.SetZero(); + m_ay.SetZero(); +} + +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; + + float32 mA = m_invMassA, mB = m_invMassB; + float32 iA = m_invIA, iB = m_invIB; + + 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); + + // 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_springMass = 0.0f; + m_bias = 0.0f; + m_gamma = 0.0f; + if (m_frequencyHz > 0.0f) + { + m_ax = b2Mul(qA, m_localXAxisA); + m_sAx = b2Cross(d + rA, m_ax); + m_sBx = b2Cross(rB, m_ax); + + float32 invMass = mA + mB + iA * m_sAx * m_sAx + iB * m_sBx * m_sBx; + + if (invMass > 0.0f) + { + m_springMass = 1.0f / invMass; + + float32 C = b2Dot(d, m_ax); + + // Frequency + float32 omega = 2.0f * b2_pi * m_frequencyHz; + + // Damping coefficient + float32 damp = 2.0f * m_springMass * m_dampingRatio * omega; + + // Spring stiffness + float32 k = m_springMass * omega * omega; + + // magic formulas + float32 h = data.step.dt; + m_gamma = h * (damp + h * k); + if (m_gamma > 0.0f) + { + m_gamma = 1.0f / m_gamma; + } + + m_bias = C * h * k * m_gamma; + + m_springMass = invMass + m_gamma; + if (m_springMass > 0.0f) + { + m_springMass = 1.0f / m_springMass; + } + } + } + else + { + m_springImpulse = 0.0f; + } + + // Rotational motor + 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; + + b2Vec2 P = m_impulse * m_ay + m_springImpulse * m_ax; + float32 LA = m_impulse * m_sAy + m_springImpulse * m_sAx + m_motorImpulse; + float32 LB = m_impulse * m_sBy + m_springImpulse * 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; + } + + 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) +{ + float32 mA = m_invMassA, mB = m_invMassB; + float32 iA = m_invIA, iB = m_invIB; + + 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; + + // Solve spring constraint + { + float32 Cdot = b2Dot(m_ax, vB - vA) + m_sBx * wB - m_sAx * wA; + float32 impulse = -m_springMass * (Cdot + m_bias + m_gamma * m_springImpulse); + m_springImpulse += impulse; + + b2Vec2 P = impulse * m_ax; + float32 LA = impulse * m_sAx; + float32 LB = impulse * m_sBx; + + vA -= mA * P; + wA -= iA * LA; + + vB += mB * P; + wB += iB * LB; + } + + // Solve rotational motor constraint + { + float32 Cdot = wB - wA - m_motorSpeed; + float32 impulse = -m_motorMass * Cdot; + + float32 oldImpulse = m_motorImpulse; + float32 maxImpulse = data.step.dt * m_maxMotorTorque; + m_motorImpulse = b2Clamp(m_motorImpulse + impulse, -maxImpulse, maxImpulse); + impulse = m_motorImpulse - oldImpulse; + + wA -= iA * impulse; + wB += iB * impulse; + } + + // Solve point to line constraint + { + float32 Cdot = b2Dot(m_ay, vB - vA) + m_sBy * wB - m_sAy * wA; + float32 impulse = -m_mass * Cdot; + m_impulse += impulse; + + b2Vec2 P = impulse * m_ay; + float32 LA = impulse * m_sAy; + float32 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; + 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 d = (cB - cA) + rB - rA; + + b2Vec2 ay = b2Mul(qA, m_localYAxisA); + + float32 sAy = b2Cross(d + rA, ay); + float32 sBy = b2Cross(rB, ay); + + float32 C = b2Dot(d, ay); + + float32 k = m_invMassA + m_invMassB + m_invIA * m_sAy * m_sAy + m_invIB * m_sBy * m_sBy; + + float32 impulse; + if (k != 0.0f) + { + impulse = - C / k; + } + else + { + impulse = 0.0f; + } + + b2Vec2 P = impulse * ay; + float32 LA = impulse * sAy; + float32 LB = impulse * sBy; + + cA -= m_invMassA * P; + aA -= m_invIA * LA; + cB += m_invMassB * P; + aB += m_invIB * LB; + + 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 b2Abs(C) <= 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(float32 inv_dt) const +{ + return inv_dt * (m_impulse * m_ay + m_springImpulse * m_ax); +} + +float32 b2WheelJoint::GetReactionTorque(float32 inv_dt) const +{ + return inv_dt * m_motorImpulse; +} + +float32 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); + + float32 translation = b2Dot(d, axis); + return translation; +} + +float32 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; + float32 wA = bA->m_angularVelocity; + float32 wB = bB->m_angularVelocity; + + float32 speed = b2Dot(d, b2Cross(wA, axis)) + b2Dot(axis, vB + b2Cross(wB, rB) - vA - b2Cross(wA, rA)); + return speed; +} + +float32 b2WheelJoint::GetJointAngle() const +{ + b2Body* bA = m_bodyA; + b2Body* bB = m_bodyB; + return bB->m_sweep.a - bA->m_sweep.a; +} + +float32 b2WheelJoint::GetJointAngularSpeed() const +{ + float32 wA = m_bodyA->m_angularVelocity; + float32 wB = m_bodyB->m_angularVelocity; + return wB - wA; +} + +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(float32 speed) +{ + if (speed != m_motorSpeed) + { + m_bodyA->SetAwake(true); + m_bodyB->SetAwake(true); + m_motorSpeed = speed; + } +} + +void b2WheelJoint::SetMaxMotorTorque(float32 torque) +{ + if (torque != m_maxMotorTorque) + { + m_bodyA->SetAwake(true); + m_bodyB->SetAwake(true); + m_maxMotorTorque = torque; + } +} + +float32 b2WheelJoint::GetMotorTorque(float32 inv_dt) const +{ + return inv_dt * m_motorImpulse; +} + +void b2WheelJoint::Dump() +{ + int32 indexA = m_bodyA->m_islandIndex; + int32 indexB = m_bodyB->m_islandIndex; + + b2Log(" b2WheelJointDef 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.localAxisA.Set(%.15lef, %.15lef);\n", m_localXAxisA.x, m_localXAxisA.y); + b2Log(" jd.enableMotor = bool(%d);\n", m_enableMotor); + b2Log(" jd.motorSpeed = %.15lef;\n", m_motorSpeed); + b2Log(" jd.maxMotorTorque = %.15lef;\n", m_maxMotorTorque); + b2Log(" jd.frequencyHz = %.15lef;\n", m_frequencyHz); + b2Log(" jd.dampingRatio = %.15lef;\n", m_dampingRatio); + b2Log(" joints[%d] = m_world->CreateJoint(&jd);\n", m_index); +} diff --git a/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2WheelJoint.h b/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2WheelJoint.h new file mode 100644 index 0000000..be7ad66 --- /dev/null +++ b/src/libjin/3rdparty/Box2D/Dynamics/Joints/b2WheelJoint.h @@ -0,0 +1,216 @@ +/* +* 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. +*/ + +#ifndef B2_WHEEL_JOINT_H +#define B2_WHEEL_JOINT_H + +#include "Box2D/Dynamics/Joints/b2Joint.h" + +/// Wheel joint definition. This requires defining a line of +/// motion using an axis and an anchor point. The definition uses local +/// anchor points and a local axis so that the initial configuration +/// can violate the constraint slightly. The joint translation is zero +/// when the local anchor points coincide in world space. Using local +/// anchors and a local axis helps when saving and loading a game. +struct b2WheelJointDef : public b2JointDef +{ + b2WheelJointDef() + { + type = e_wheelJoint; + localAnchorA.SetZero(); + localAnchorB.SetZero(); + localAxisA.Set(1.0f, 0.0f); + enableMotor = false; + maxMotorTorque = 0.0f; + motorSpeed = 0.0f; + frequencyHz = 2.0f; + dampingRatio = 0.7f; + } + + /// Initialize the bodies, anchors, axis, and reference angle using the world + /// anchor and world axis. + void Initialize(b2Body* bodyA, b2Body* bodyB, const b2Vec2& anchor, const b2Vec2& axis); + + /// The local anchor point relative to bodyA's origin. + b2Vec2 localAnchorA; + + /// The local anchor point relative to bodyB's origin. + b2Vec2 localAnchorB; + + /// The local translation axis in bodyA. + b2Vec2 localAxisA; + + /// Enable/disable the joint motor. + bool enableMotor; + + /// The maximum motor torque, usually in N-m. + float32 maxMotorTorque; + + /// The desired motor speed in radians per second. + float32 motorSpeed; + + /// Suspension frequency, zero indicates no suspension + float32 frequencyHz; + + /// Suspension damping ratio, one indicates critical damping + float32 dampingRatio; +}; + +/// A wheel joint. This joint provides two degrees of freedom: translation +/// along an axis fixed in bodyA and rotation in the plane. In other words, it is a point to +/// line constraint with a rotational motor and a linear spring/damper. +/// This joint is designed for vehicle suspensions. +class b2WheelJoint : public b2Joint +{ +public: + b2Vec2 GetAnchorA() const override; + b2Vec2 GetAnchorB() const override; + + b2Vec2 GetReactionForce(float32 inv_dt) const override; + float32 GetReactionTorque(float32 inv_dt) const override; + + /// The local anchor point relative to bodyA's origin. + const b2Vec2& GetLocalAnchorA() const { return m_localAnchorA; } + + /// The local anchor point relative to bodyB's origin. + const b2Vec2& GetLocalAnchorB() const { return m_localAnchorB; } + + /// The local joint axis relative to bodyA. + const b2Vec2& GetLocalAxisA() const { return m_localXAxisA; } + + /// Get the current joint translation, usually in meters. + float32 GetJointTranslation() const; + + /// Get the current joint linear speed, usually in meters per second. + float32 GetJointLinearSpeed() const; + + /// Get the current joint angle in radians. + float32 GetJointAngle() const; + + /// Get the current joint angular speed in radians per second. + float32 GetJointAngularSpeed() const; + + /// Is the joint motor enabled? + bool IsMotorEnabled() const; + + /// Enable/disable the joint motor. + void EnableMotor(bool flag); + + /// Set the motor speed, usually in radians per second. + void SetMotorSpeed(float32 speed); + + /// Get the motor speed, usually in radians per second. + float32 GetMotorSpeed() const; + + /// Set/Get the maximum motor force, usually in N-m. + void SetMaxMotorTorque(float32 torque); + float32 GetMaxMotorTorque() const; + + /// Get the current motor torque given the inverse time step, usually in N-m. + float32 GetMotorTorque(float32 inv_dt) const; + + /// Set/Get the spring frequency in hertz. Setting the frequency to zero disables the spring. + void SetSpringFrequencyHz(float32 hz); + float32 GetSpringFrequencyHz() const; + + /// Set/Get the spring damping ratio + void SetSpringDampingRatio(float32 ratio); + float32 GetSpringDampingRatio() const; + + /// Dump to b2Log + void Dump() override; + +protected: + + friend class b2Joint; + b2WheelJoint(const b2WheelJointDef* def); + + void InitVelocityConstraints(const b2SolverData& data) override; + void SolveVelocityConstraints(const b2SolverData& data) override; + bool SolvePositionConstraints(const b2SolverData& data) override; + + float32 m_frequencyHz; + float32 m_dampingRatio; + + // Solver shared + b2Vec2 m_localAnchorA; + b2Vec2 m_localAnchorB; + b2Vec2 m_localXAxisA; + b2Vec2 m_localYAxisA; + + float32 m_impulse; + float32 m_motorImpulse; + float32 m_springImpulse; + + float32 m_maxMotorTorque; + float32 m_motorSpeed; + bool m_enableMotor; + + // Solver temp + int32 m_indexA; + int32 m_indexB; + b2Vec2 m_localCenterA; + b2Vec2 m_localCenterB; + float32 m_invMassA; + float32 m_invMassB; + float32 m_invIA; + float32 m_invIB; + + b2Vec2 m_ax, m_ay; + float32 m_sAx, m_sBx; + float32 m_sAy, m_sBy; + + float32 m_mass; + float32 m_motorMass; + float32 m_springMass; + + float32 m_bias; + float32 m_gamma; +}; + +inline float32 b2WheelJoint::GetMotorSpeed() const +{ + return m_motorSpeed; +} + +inline float32 b2WheelJoint::GetMaxMotorTorque() const +{ + return m_maxMotorTorque; +} + +inline void b2WheelJoint::SetSpringFrequencyHz(float32 hz) +{ + m_frequencyHz = hz; +} + +inline float32 b2WheelJoint::GetSpringFrequencyHz() const +{ + return m_frequencyHz; +} + +inline void b2WheelJoint::SetSpringDampingRatio(float32 ratio) +{ + m_dampingRatio = ratio; +} + +inline float32 b2WheelJoint::GetSpringDampingRatio() const +{ + return m_dampingRatio; +} + +#endif |