// Jolt Physics Library (https://github.com/jrouwe/JoltPhysics) // SPDX-FileCopyrightText: 2021 Jorrit Rouwe // SPDX-License-Identifier: MIT #pragma once #include #include JPH_NAMESPACE_BEGIN /// Gear constraint settings class JPH_EXPORT GearConstraintSettings final : public TwoBodyConstraintSettings { JPH_DECLARE_SERIALIZABLE_VIRTUAL(JPH_EXPORT, GearConstraintSettings) public: // See: ConstraintSettings::SaveBinaryState virtual void SaveBinaryState(StreamOut &inStream) const override; /// Create an instance of this constraint. virtual TwoBodyConstraint * Create(Body &inBody1, Body &inBody2) const override; /// Defines the ratio between the rotation of both gears /// The ratio is defined as: Gear1Rotation(t) = -ratio * Gear2Rotation(t) /// @param inNumTeethGear1 Number of teeth that body 1 has /// @param inNumTeethGear2 Number of teeth that body 2 has void SetRatio(int inNumTeethGear1, int inNumTeethGear2) { mRatio = float(inNumTeethGear2) / float(inNumTeethGear1); } /// This determines in which space the constraint is setup, all properties below should be in the specified space EConstraintSpace mSpace = EConstraintSpace::WorldSpace; /// Body 1 constraint reference frame (space determined by mSpace). Vec3 mHingeAxis1 = Vec3::sAxisX(); /// Body 2 constraint reference frame (space determined by mSpace) Vec3 mHingeAxis2 = Vec3::sAxisX(); /// Ratio between both gears, see SetRatio. float mRatio = 1.0f; protected: // See: ConstraintSettings::RestoreBinaryState virtual void RestoreBinaryState(StreamIn &inStream) override; }; /// A gear constraint constrains the rotation of body1 to the rotation of body 2 using a gear. /// Note that this constraint needs to be used in conjunction with a two hinge constraints. class JPH_EXPORT GearConstraint final : public TwoBodyConstraint { public: JPH_OVERRIDE_NEW_DELETE /// Construct gear constraint GearConstraint(Body &inBody1, Body &inBody2, const GearConstraintSettings &inSettings); // Generic interface of a constraint virtual EConstraintSubType GetSubType() const override { return EConstraintSubType::Gear; } virtual void NotifyShapeChanged(const BodyID &inBodyID, Vec3Arg inDeltaCOM) override { /* Do nothing */ } virtual void SetupVelocityConstraint(float inDeltaTime) override; virtual void ResetWarmStart() override; virtual void WarmStartVelocityConstraint(float inWarmStartImpulseRatio) override; virtual bool SolveVelocityConstraint(float inDeltaTime) override; virtual bool SolvePositionConstraint(float inDeltaTime, float inBaumgarte) override; #ifdef JPH_DEBUG_RENDERER virtual void DrawConstraint(DebugRenderer *inRenderer) const override; #endif // JPH_DEBUG_RENDERER virtual void SaveState(StateRecorder &inStream) const override; virtual void RestoreState(StateRecorder &inStream) override; virtual Ref GetConstraintSettings() const override; // See: TwoBodyConstraint virtual Mat44 GetConstraintToBody1Matrix() const override; virtual Mat44 GetConstraintToBody2Matrix() const override; /// The constraints that constrain both gears (2 hinges), optional and used to calculate the rotation error and fix numerical drift. void SetConstraints(const Constraint *inGear1, const Constraint *inGear2) { mGear1Constraint = inGear1; mGear2Constraint = inGear2; } ///@name Get Lagrange multiplier from last physics update (the angular impulse applied to satisfy the constraint) inline float GetTotalLambda() const { return mGearConstraintPart.GetTotalLambda(); } private: // Internal helper function to calculate the values below void CalculateConstraintProperties(Mat44Arg inRotation1, Mat44Arg inRotation2); // CONFIGURATION PROPERTIES FOLLOW // Local space hinge axis for body 1 Vec3 mLocalSpaceHingeAxis1; // Local space hinge axis for body 2 Vec3 mLocalSpaceHingeAxis2; // Ratio between gear 1 and 2 float mRatio; // The constraints that constrain both gears (2 hinges), optional and used to calculate the rotation error and fix numerical drift. RefConst mGear1Constraint; RefConst mGear2Constraint; // RUN TIME PROPERTIES FOLLOW // World space hinge axis for body 1 Vec3 mWorldSpaceHingeAxis1; // World space hinge axis for body 2 Vec3 mWorldSpaceHingeAxis2; // The constraint parts GearConstraintPart mGearConstraintPart; }; JPH_NAMESPACE_END