godot-module-template/engine/thirdparty/jolt_physics/Jolt/Physics/Constraints/RackAndPinionConstraint.h

119 lines
4.9 KiB
C++

// 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/RackAndPinionConstraintPart.h>
JPH_NAMESPACE_BEGIN
/// Rack and pinion constraint (slider & gear) settings
class JPH_EXPORT RackAndPinionConstraintSettings final : public TwoBodyConstraintSettings
{
JPH_DECLARE_SERIALIZABLE_VIRTUAL(JPH_EXPORT, RackAndPinionConstraintSettings)
public:
// See: ConstraintSettings::SaveBinaryState
virtual void SaveBinaryState(StreamOut &inStream) const override;
/// Create an instance of this constraint.
/// Body1 should be the pinion (gear) and body 2 the rack (slider).
virtual TwoBodyConstraint * Create(Body &inBody1, Body &inBody2) const override;
/// Defines the ratio between the rotation of the pinion and the translation of the rack.
/// The ratio is defined as: PinionRotation(t) = ratio * RackTranslation(t)
/// @param inNumTeethRack Number of teeth that the rack has
/// @param inRackLength Length of the rack
/// @param inNumTeethPinion Number of teeth the pinion has
void SetRatio(int inNumTeethRack, float inRackLength, int inNumTeethPinion)
{
mRatio = 2.0f * JPH_PI * inNumTeethRack / (inRackLength * inNumTeethPinion);
}
/// This determines in which space the constraint is setup, all properties below should be in the specified space
EConstraintSpace mSpace = EConstraintSpace::WorldSpace;
/// Body 1 (pinion) constraint reference frame (space determined by mSpace).
Vec3 mHingeAxis = Vec3::sAxisX();
/// Body 2 (rack) constraint reference frame (space determined by mSpace)
Vec3 mSliderAxis = Vec3::sAxisX();
/// Ratio between the rack and pinion, see SetRatio.
float mRatio = 1.0f;
protected:
// See: ConstraintSettings::RestoreBinaryState
virtual void RestoreBinaryState(StreamIn &inStream) override;
};
/// A rack and pinion constraint constrains the rotation of body1 to the translation of body 2.
/// Note that this constraint needs to be used in conjunction with a hinge constraint for body 1 and a slider constraint for body 2.
class JPH_EXPORT RackAndPinionConstraint final : public TwoBodyConstraint
{
public:
JPH_OVERRIDE_NEW_DELETE
/// Construct gear constraint
RackAndPinionConstraint(Body &inBody1, Body &inBody2, const RackAndPinionConstraintSettings &inSettings);
// Generic interface of a constraint
virtual EConstraintSubType GetSubType() const override { return EConstraintSubType::RackAndPinion; }
virtual void NotifyShapeChanged(const BodyID &inBodyID, Vec3Arg inDeltaCOM) override { /* 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 the rack and pinion (a slider and a hinge), optional and used to calculate the position error and fix numerical drift.
void SetConstraints(const Constraint *inPinion, const Constraint *inRack) { mPinionConstraint = inPinion; mRackConstraint = inRack; }
///@name Get Lagrange multiplier from last physics update (the linear/angular impulse applied to satisfy the constraint)
inline float GetTotalLambda() const { return mRackAndPinionConstraintPart.GetTotalLambda(); }
private:
// Internal helper function to calculate the values below
void CalculateConstraintProperties(Mat44Arg inRotation1, Mat44Arg inRotation2);
// CONFIGURATION PROPERTIES FOLLOW
// Local space hinge axis
Vec3 mLocalSpaceHingeAxis;
// Local space sliding direction
Vec3 mLocalSpaceSliderAxis;
// Ratio between rack and pinion
float mRatio;
// The constraints that constrain the rack and pinion (a slider and a hinge), optional and used to calculate the position error and fix numerical drift.
RefConst<Constraint> mPinionConstraint;
RefConst<Constraint> mRackConstraint;
// RUN TIME PROPERTIES FOLLOW
// World space hinge axis
Vec3 mWorldSpaceHingeAxis;
// World space sliding direction
Vec3 mWorldSpaceSliderAxis;
// The constraint parts
RackAndPinionConstraintPart mRackAndPinionConstraintPart;
};
JPH_NAMESPACE_END