initial commit, 4.5 stable

thirdparty/jolt_physics/Jolt/Physics/Constraints/GearConstraint.h

@@ -0,0 +1,116 @@
+// Jolt Physics Library (https://github.com/jrouwe/JoltPhysics)
+// SPDX-FileCopyrightText: 2021 Jorrit Rouwe
+// SPDX-License-Identifier: MIT
+
+#pragma once
+
+#include <Jolt/Physics/Constraints/TwoBodyConstraint.h>
+#include <Jolt/Physics/Constraints/ConstraintPart/GearConstraintPart.h>
+
+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<ConstraintSettings> 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<Constraint>		mGear1Constraint;
+	RefConst<Constraint>		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