initial commit, 4.5 stable

thirdparty/jolt_physics/Jolt/Physics/Vehicle/VehicleTransmission.cpp

@@ -0,0 +1,159 @@
+// Jolt Physics Library (https://github.com/jrouwe/JoltPhysics)
+// SPDX-FileCopyrightText: 2021 Jorrit Rouwe
+// SPDX-License-Identifier: MIT
+
+#include <Jolt/Jolt.h>
+
+#include <Jolt/Physics/Vehicle/VehicleTransmission.h>
+#include <Jolt/ObjectStream/TypeDeclarations.h>
+
+JPH_NAMESPACE_BEGIN
+
+JPH_IMPLEMENT_SERIALIZABLE_NON_VIRTUAL(VehicleTransmissionSettings)
+{
+	JPH_ADD_ENUM_ATTRIBUTE(VehicleTransmissionSettings, mMode)
+	JPH_ADD_ATTRIBUTE(VehicleTransmissionSettings, mGearRatios)
+	JPH_ADD_ATTRIBUTE(VehicleTransmissionSettings, mReverseGearRatios)
+	JPH_ADD_ATTRIBUTE(VehicleTransmissionSettings, mSwitchTime)
+	JPH_ADD_ATTRIBUTE(VehicleTransmissionSettings, mClutchReleaseTime)
+	JPH_ADD_ATTRIBUTE(VehicleTransmissionSettings, mSwitchLatency)
+	JPH_ADD_ATTRIBUTE(VehicleTransmissionSettings, mShiftUpRPM)
+	JPH_ADD_ATTRIBUTE(VehicleTransmissionSettings, mShiftDownRPM)
+	JPH_ADD_ATTRIBUTE(VehicleTransmissionSettings, mClutchStrength)
+}
+
+void VehicleTransmissionSettings::SaveBinaryState(StreamOut &inStream) const
+{
+	inStream.Write(mMode);
+	inStream.Write(mGearRatios);
+	inStream.Write(mReverseGearRatios);
+	inStream.Write(mSwitchTime);
+	inStream.Write(mClutchReleaseTime);
+	inStream.Write(mSwitchLatency);
+	inStream.Write(mShiftUpRPM);
+	inStream.Write(mShiftDownRPM);
+	inStream.Write(mClutchStrength);
+}
+
+void VehicleTransmissionSettings::RestoreBinaryState(StreamIn &inStream)
+{
+	inStream.Read(mMode);
+	inStream.Read(mGearRatios);
+	inStream.Read(mReverseGearRatios);
+	inStream.Read(mSwitchTime);
+	inStream.Read(mClutchReleaseTime);
+	inStream.Read(mSwitchLatency);
+	inStream.Read(mShiftUpRPM);
+	inStream.Read(mShiftDownRPM);
+	inStream.Read(mClutchStrength);
+}
+
+void VehicleTransmission::Update(float inDeltaTime, float inCurrentRPM, float inForwardInput, bool inCanShiftUp)
+{
+	// Update current gear and calculate clutch friction
+	if (mMode == ETransmissionMode::Auto)
+	{
+		// Switch gears based on rpm
+		int old_gear = mCurrentGear;
+		if (mCurrentGear == 0 // In neutral
+			|| inForwardInput * float(mCurrentGear) < 0.0f) // Changing between forward / reverse
+		{
+			// Switch to first gear or reverse depending on input
+			mCurrentGear = inForwardInput > 0.0f? 1 : (inForwardInput < 0.0f? -1 : 0);
+		}
+		else if (mGearSwitchLatencyTimeLeft == 0.0f) // If not in the timout after switching gears
+		{
+			if (inCanShiftUp && inCurrentRPM > mShiftUpRPM)
+			{
+				if (mCurrentGear < 0)
+				{
+					// Shift up, reverse
+					if (mCurrentGear > -(int)mReverseGearRatios.size())
+						mCurrentGear--;
+				}
+				else
+				{
+					// Shift up, forward
+					if (mCurrentGear < (int)mGearRatios.size())
+						mCurrentGear++;
+				}
+			}
+			else if (inCurrentRPM < mShiftDownRPM)
+			{
+				if (mCurrentGear < 0)
+				{
+					// Shift down, reverse
+					int max_gear = inForwardInput != 0.0f? -1 : 0;
+					if (mCurrentGear < max_gear)
+						mCurrentGear++;
+				}
+				else
+				{
+					// Shift down, forward
+					int min_gear = inForwardInput != 0.0f? 1 : 0;
+					if (mCurrentGear > min_gear)
+						mCurrentGear--;
+				}
+			}
+		}
+
+		if (old_gear != mCurrentGear)
+		{
+			// We've shifted gear, start switch countdown
+			mGearSwitchTimeLeft = old_gear != 0? mSwitchTime : 0.0f;
+			mClutchReleaseTimeLeft = mClutchReleaseTime;
+			mGearSwitchLatencyTimeLeft = mSwitchLatency;
+			mClutchFriction = 0.0f;
+		}
+		else if (mGearSwitchTimeLeft > 0.0f)
+		{
+			// If still switching gears, count down
+			mGearSwitchTimeLeft = max(0.0f, mGearSwitchTimeLeft - inDeltaTime);
+			mClutchFriction = 0.0f;
+		}
+		else if (mClutchReleaseTimeLeft > 0.0f)
+		{
+			// After switching the gears we slowly release the clutch
+			mClutchReleaseTimeLeft = max(0.0f, mClutchReleaseTimeLeft - inDeltaTime);
+			mClutchFriction = 1.0f - mClutchReleaseTimeLeft / mClutchReleaseTime;
+		}
+		else
+		{
+			// Clutch has full friction
+			mClutchFriction = 1.0f;
+
+			// Count down switch latency
+			mGearSwitchLatencyTimeLeft = max(0.0f, mGearSwitchLatencyTimeLeft - inDeltaTime);
+		}
+	}
+}
+
+float VehicleTransmission::GetCurrentRatio() const
+{
+	if (mCurrentGear < 0)
+		return mReverseGearRatios[-mCurrentGear - 1];
+	else if (mCurrentGear == 0)
+		return 0.0f;
+	else
+		return mGearRatios[mCurrentGear - 1];
+}
+
+void VehicleTransmission::SaveState(StateRecorder &inStream) const
+{
+	inStream.Write(mCurrentGear);
+	inStream.Write(mClutchFriction);
+	inStream.Write(mGearSwitchTimeLeft);
+	inStream.Write(mClutchReleaseTimeLeft);
+	inStream.Write(mGearSwitchLatencyTimeLeft);
+}
+
+void VehicleTransmission::RestoreState(StateRecorder &inStream)
+{
+	inStream.Read(mCurrentGear);
+	inStream.Read(mClutchFriction);
+	inStream.Read(mGearSwitchTimeLeft);
+	inStream.Read(mClutchReleaseTimeLeft);
+	inStream.Read(mGearSwitchLatencyTimeLeft);
+}
+
+JPH_NAMESPACE_END