Rename Box2D folder to box2d

src/libraries/box2d/b2_motor_joint.h

@@ -0,0 +1,137 @@
+// 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_MOTOR_JOINT_H
+#define B2_MOTOR_JOINT_H
+
+#include "b2_joint.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.
+	float angularOffset;
+	
+	/// The maximum motor force in N.
+	float maxForce;
+
+	/// The maximum motor torque in N-m.
+	float maxTorque;
+
+	/// Position correction factor in the range [0,1].
+	float 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(float inv_dt) const override;
+	float GetReactionTorque(float 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(float angularOffset);
+	float GetAngularOffset() const;
+
+	/// Set the maximum friction force in N.
+	void SetMaxForce(float force);
+
+	/// Get the maximum friction force in N.
+	float GetMaxForce() const;
+
+	/// Set the maximum friction torque in N*m.
+	void SetMaxTorque(float torque);
+
+	/// Get the maximum friction torque in N*m.
+	float GetMaxTorque() const;
+
+	/// Set the position correction factor in the range [0,1].
+	void SetCorrectionFactor(float factor);
+
+	/// Get the position correction factor in the range [0,1].
+	float 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;
+	float m_angularOffset;
+	b2Vec2 m_linearImpulse;
+	float m_angularImpulse;
+	float m_maxForce;
+	float m_maxTorque;
+	float 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;
+	float m_angularError;
+	float m_invMassA;
+	float m_invMassB;
+	float m_invIA;
+	float m_invIB;
+	b2Mat22 m_linearMass;
+	float m_angularMass;
+};
+
+#endif