Function DoCurrent

TombEngine/Objects/TR3/Vehicles/upv.cpp:386–444

	}

	static void DoCurrent(ItemInfo* UPVItem, ItemInfo* laraItem)
	{
		auto* lara = GetLaraInfo(laraItem);

		Vector3i target;

		if (!lara->Context.WaterCurrentActive)
		{
			int absVel = abs(lara->Context.WaterCurrentPull.x);
			int shift;
			if (absVel > 16)
				shift = 4;
			else if (absVel > 8)
				shift = 3;
			else
				shift = 2;

			lara->Context.WaterCurrentPull.x -= lara->Context.WaterCurrentPull.x >> shift;

			if (abs(lara->Context.WaterCurrentPull.x) < 4)
				lara->Context.WaterCurrentPull.x = 0;

			absVel = abs(lara->Context.WaterCurrentPull.z);
			if (absVel > 16)
				shift = 4;
			else if (absVel > 8)
				shift = 3;
			else
				shift = 2;

			lara->Context.WaterCurrentPull.z -= lara->Context.WaterCurrentPull.z >> shift;
			if (abs(lara->Context.WaterCurrentPull.z) < 4)
				lara->Context.WaterCurrentPull.z = 0;

			if (lara->Context.WaterCurrentPull.x == 0 && lara->Context.WaterCurrentPull.z == 0)
				return;
		}
		else
		{
			int sinkVal = lara->Context.WaterCurrentActive - 1;
			target = g_Level.Sinks[sinkVal].Position;
		
			int angle = ((Geometry::GetOrientToPoint(laraItem->Pose.Position.ToVector3(), target.ToVector3()).y) / 16) & 4095;

			int dx = target.x - laraItem->Pose.Position.x;
			int dz = target.z - laraItem->Pose.Position.z;

			int velocity = g_Level.Sinks[sinkVal].Strength;
			dx = phd_sin(angle * 16) * velocity * BLOCK(1);
			dz = phd_cos(angle * 16) * velocity * BLOCK(1);

			lara->Context.WaterCurrentPull.x += ((dx - lara->Context.WaterCurrentPull.x) / 16);
			lara->Context.WaterCurrentPull.z += ((dz - lara->Context.WaterCurrentPull.z) / 16);
		}

		lara->Context.WaterCurrentActive = 0;
		UPVItem->Pose.Position.x += lara->Context.WaterCurrentPull.x / CLICK(1);
		UPVItem->Pose.Position.z += lara->Context.WaterCurrentPull.z / CLICK(1);