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

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3.8 KiB
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// 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/LinearCurve.h>
#include <Jolt/Core/StreamIn.h>
#include <Jolt/Core/StreamOut.h>
#include <Jolt/Physics/StateRecorder.h>
JPH_NAMESPACE_BEGIN
#ifdef JPH_DEBUG_RENDERER
class DebugRenderer;
#endif // JPH_DEBUG_RENDERER
/// Generic properties for a vehicle engine
class JPH_EXPORT VehicleEngineSettings
{
JPH_DECLARE_SERIALIZABLE_NON_VIRTUAL(JPH_EXPORT, VehicleEngineSettings)
public:
/// Constructor
VehicleEngineSettings();
/// 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);
float mMaxTorque = 500.0f; ///< Max amount of torque (Nm) that the engine can deliver
float mMinRPM = 1000.0f; ///< Min amount of revolutions per minute (rpm) the engine can produce without stalling
float mMaxRPM = 6000.0f; ///< Max amount of revolutions per minute (rpm) the engine can generate
LinearCurve mNormalizedTorque; ///< Y-axis: Curve that describes a ratio of the max torque the engine can produce (0 = 0, 1 = mMaxTorque). X-axis: the fraction of the RPM of the engine (0 = mMinRPM, 1 = mMaxRPM)
float mInertia = 0.5f; ///< Moment of inertia (kg m^2) of the engine
float mAngularDamping = 0.2f; ///< Angular damping factor of the wheel: dw/dt = -c * w
};
/// Runtime data for engine
class JPH_EXPORT VehicleEngine : public VehicleEngineSettings
{
public:
/// Multiply an angular velocity (rad/s) with this value to get rounds per minute (RPM)
static constexpr float cAngularVelocityToRPM = 60.0f / (2.0f * JPH_PI);
/// Clamp the RPM between min and max RPM
inline void ClampRPM() { mCurrentRPM = Clamp(mCurrentRPM, mMinRPM, mMaxRPM); }
/// Current rotation speed of engine in rounds per minute
float GetCurrentRPM() const { return mCurrentRPM; }
/// Update rotation speed of engine in rounds per minute
void SetCurrentRPM(float inRPM) { mCurrentRPM = inRPM; ClampRPM(); }
/// Get current angular velocity of the engine in radians / second
inline float GetAngularVelocity() const { return mCurrentRPM / cAngularVelocityToRPM; }
/// Get the amount of torque (N m) that the engine can supply
/// @param inAcceleration How much the gas pedal is pressed [0, 1]
float GetTorque(float inAcceleration) const { return inAcceleration * mMaxTorque * mNormalizedTorque.GetValue(mCurrentRPM / mMaxRPM); }
/// Apply a torque to the engine rotation speed
/// @param inTorque Torque in N m
/// @param inDeltaTime Delta time in seconds
void ApplyTorque(float inTorque, float inDeltaTime);
/// Update the engine RPM for damping
/// @param inDeltaTime Delta time in seconds
void ApplyDamping(float inDeltaTime);
#ifdef JPH_DEBUG_RENDERER
// Function that converts RPM to an angle in radians for debugging purposes
float ConvertRPMToAngle(float inRPM) const { return (-0.75f + 1.5f * inRPM / mMaxRPM) * JPH_PI; }
/// Debug draw a RPM meter
void DrawRPM(DebugRenderer *inRenderer, RVec3Arg inPosition, Vec3Arg inForward, Vec3Arg inUp, float inSize, float inShiftDownRPM, float inShiftUpRPM) const;
#endif // JPH_DEBUG_RENDERER
/// If the engine is idle we allow the vehicle to sleep
bool AllowSleep() const { return mCurrentRPM <= 1.01f * mMinRPM; }
/// Saving state for replay
void SaveState(StateRecorder &inStream) const;
void RestoreState(StateRecorder &inStream);
private:
float mCurrentRPM = mMinRPM; ///< Current rotation speed of engine in rounds per minute
};
JPH_NAMESPACE_END