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Diffstat (limited to 'ThirdParty/Box2D/Dynamics/Joints/b2PrismaticJoint.h')
| -rw-r--r-- | ThirdParty/Box2D/Dynamics/Joints/b2PrismaticJoint.h | 196 |
1 files changed, 196 insertions, 0 deletions
diff --git a/ThirdParty/Box2D/Dynamics/Joints/b2PrismaticJoint.h b/ThirdParty/Box2D/Dynamics/Joints/b2PrismaticJoint.h new file mode 100644 index 0000000..131dffd --- /dev/null +++ b/ThirdParty/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 |