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

117 lines
4.5 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/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