b2_mouse_joint.h

// MIT License
 
// Copyright (c) 2019 Erin Catto
 
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
 
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.
 
#ifndef B2_MOUSE_JOINT_H
#define B2_MOUSE_JOINT_H
 
#include "b2_api.h"
#include "b2_joint.h"
 
struct B2_API b2MouseJointDef : public b2JointDef
{
    b2MouseJointDef()
    {
        type = e_mouseJoint;
        target.Set(0.0f, 0.0f);
        maxForce = 0.0f;
        stiffness = 0.0f;
        damping = 0.0f;
    }
 
    b2Vec2 target;
 
    float maxForce;
 
    float stiffness;
 
    float damping;
};
 
class B2_API b2MouseJoint : public b2Joint
{
public:
 
    b2Vec2 GetAnchorA() const override;
 
    b2Vec2 GetAnchorB() const override;
 
    b2Vec2 GetReactionForce(float inv_dt) const override;
 
    float GetReactionTorque(float inv_dt) const override;
 
    void SetTarget(const b2Vec2& target);
    const b2Vec2& GetTarget() const;
 
    void SetMaxForce(float force);
    float GetMaxForce() const;
 
    void SetStiffness(float stiffness) { m_stiffness = stiffness; }
    float GetStiffness() const { return m_stiffness; }
 
    void SetDamping(float damping) { m_damping = damping; }
    float GetDamping() const { return m_damping; }
 
    void Dump() override { b2Log("Mouse joint dumping is not supported.\n"); }
 
    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;
    float m_stiffness;
    float m_damping;
    float m_beta;
 
    // Solver shared
    b2Vec2 m_impulse;
    float m_maxForce;
    float m_gamma;
 
    // Solver temp
    int32 m_indexA;
    int32 m_indexB;
    b2Vec2 m_rB;
    b2Vec2 m_localCenterB;
    float m_invMassB;
    float m_invIB;
    b2Mat22 m_mass;
    b2Vec2 m_C;
};
 
#endif