godot-module-template/engine/thirdparty/jolt_physics/Jolt/Physics/Vehicle/VehicleTransmission.h

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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/ObjectStream/SerializableObject.h>
#include <Jolt/Core/StreamIn.h>
#include <Jolt/Core/StreamOut.h>
#include <Jolt/Physics/StateRecorder.h>
JPH_NAMESPACE_BEGIN
/// How gears are shifted
enum class ETransmissionMode : uint8
{
Auto, ///< Automatically shift gear up and down
Manual, ///< Manual gear shift (call SetTransmissionInput)
};
/// Configuration for the transmission of a vehicle (gear box)
class JPH_EXPORT VehicleTransmissionSettings
{
JPH_DECLARE_SERIALIZABLE_NON_VIRTUAL(JPH_EXPORT, VehicleTransmissionSettings)
public:
/// Saves the contents in binary form to inStream.
void SaveBinaryState(StreamOut &inStream) const;
/// Restores the contents in binary form to inStream.
void RestoreBinaryState(StreamIn &inStream);
ETransmissionMode mMode = ETransmissionMode::Auto; ///< How to switch gears
Array<float> mGearRatios { 2.66f, 1.78f, 1.3f, 1.0f, 0.74f }; ///< Ratio in rotation rate between engine and gear box, first element is 1st gear, 2nd element 2nd gear etc.
Array<float> mReverseGearRatios { -2.90f }; ///< Ratio in rotation rate between engine and gear box when driving in reverse
float mSwitchTime = 0.5f; ///< How long it takes to switch gears (s), only used in auto mode
float mClutchReleaseTime = 0.3f; ///< How long it takes to release the clutch (go to full friction), only used in auto mode
float mSwitchLatency = 0.5f; ///< How long to wait after releasing the clutch before another switch is attempted (s), only used in auto mode
float mShiftUpRPM = 4000.0f; ///< If RPM of engine is bigger then this we will shift a gear up, only used in auto mode
float mShiftDownRPM = 2000.0f; ///< If RPM of engine is smaller then this we will shift a gear down, only used in auto mode
float mClutchStrength = 10.0f; ///< Strength of the clutch when fully engaged. Total torque a clutch applies is Torque = ClutchStrength * (Velocity Engine - Avg Velocity Wheels At Clutch) (units: k m^2 s^-1)
};
/// Runtime data for transmission
class JPH_EXPORT VehicleTransmission : public VehicleTransmissionSettings
{
public:
/// Set input from driver regarding the transmission (only relevant when transmission is set to manual mode)
/// @param inCurrentGear Current gear, -1 = reverse, 0 = neutral, 1 = 1st gear etc.
/// @param inClutchFriction Value between 0 and 1 indicating how much friction the clutch gives (0 = no friction, 1 = full friction)
void Set(int inCurrentGear, float inClutchFriction) { mCurrentGear = inCurrentGear; mClutchFriction = inClutchFriction; }
/// Update the current gear and clutch friction if the transmission is in auto mode
/// @param inDeltaTime Time step delta time in s
/// @param inCurrentRPM Current RPM for engine
/// @param inForwardInput Hint if the user wants to drive forward (> 0) or backwards (< 0)
/// @param inCanShiftUp Indicates if we want to allow the transmission to shift up (e.g. pass false if wheels are slipping)
void Update(float inDeltaTime, float inCurrentRPM, float inForwardInput, bool inCanShiftUp);
/// Current gear, -1 = reverse, 0 = neutral, 1 = 1st gear etc.
int GetCurrentGear() const { return mCurrentGear; }
/// Value between 0 and 1 indicating how much friction the clutch gives (0 = no friction, 1 = full friction)
float GetClutchFriction() const { return mClutchFriction; }
/// If the auto box is currently switching gears
bool IsSwitchingGear() const { return mGearSwitchTimeLeft > 0.0f; }
/// Return the transmission ratio based on the current gear (ratio between engine and differential)
float GetCurrentRatio() const;
/// Only allow sleeping when the transmission is idle
bool AllowSleep() const { return mGearSwitchTimeLeft <= 0.0f && mClutchReleaseTimeLeft <= 0.0f && mGearSwitchLatencyTimeLeft <= 0.0f; }
/// Saving state for replay
void SaveState(StateRecorder &inStream) const;
void RestoreState(StateRecorder &inStream);
private:
int mCurrentGear = 0; ///< Current gear, -1 = reverse, 0 = neutral, 1 = 1st gear etc.
float mClutchFriction = 1.0f; ///< Value between 0 and 1 indicating how much friction the clutch gives (0 = no friction, 1 = full friction)
float mGearSwitchTimeLeft = 0.0f; ///< When switching gears this will be > 0 and will cause the engine to not provide any torque to the wheels for a short time (used for automatic gear switching only)
float mClutchReleaseTimeLeft = 0.0f; ///< After switching gears this will be > 0 and will cause the clutch friction to go from 0 to 1 (used for automatic gear switching only)
float mGearSwitchLatencyTimeLeft = 0.0f; ///< After releasing the clutch this will be > 0 and will prevent another gear switch (used for automatic gear switching only)
};
JPH_NAMESPACE_END