RelativePath=".\..\src\ground_vehicle.cpp"

				>

			</File>

			<File

				RelativePath=".\..\src\ground_vehicle.cpp"

				>

			</File>

			<File

ground_vehicle.cpp

/* $Id$ */

/*

 * This file is part of OpenTTD.

 * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.

 * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

 * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.

 */

/** @file ground_vehicle.cpp Implementation of GroundVehicle. */

#include "stdafx.h"

#include "train.h"

#include "ground_vehicle.hpp"

#include "window_type.h"

#include "vehicle_gui.h"

#include "window_func.h"

/**

 * Recalculates the cached total power of a vehicle. Should be called when the consist is changed.

 */

template <class T, VehicleType Type>

void GroundVehicle<T, Type>::PowerChanged()

{

	assert(this->First() == this);

	const T *v = T::From(this);

	uint32 total_power = 0;

	uint32 max_te = 0;

	uint32 number_of_parts = 0;

	uint16 max_track_speed = v->GetInitialMaxSpeed();

	for (const T *u = v; u != NULL; u = u->Next()) {

		uint32 current_power = u->GetPower();

		total_power += current_power;

		/* Only powered parts add tractive effort. */

		if (current_power > 0) max_te += u->GetWeight() * u->GetTractiveEffort();

		total_power += u->GetPoweredPartPower(v);

		number_of_parts++;

		/* Get minimum max speed for this track. */

		uint16 track_speed = u->GetMaxTrackSpeed();

		if (track_speed > 0) max_track_speed = min(max_track_speed, track_speed);

	}

	this->acc_cache.cached_axle_resistance = 60 * number_of_parts;

	this->acc_cache.cached_air_drag = 20 + 3 * number_of_parts;

	max_te *= 10000; // Tractive effort in (tonnes * 1000 * 10 =) N.

	max_te /= 256;   // Tractive effort is a [0-255] coefficient.

	if (this->acc_cache.cached_power != total_power || this->acc_cache.cached_max_te != max_te) {

		/* Stop the vehicle if it has no power. */

		if (total_power == 0) this->vehstatus |= VS_STOPPED;

		this->acc_cache.cached_power = total_power;

		this->acc_cache.cached_max_te = max_te;

		SetWindowDirty(WC_VEHICLE_DETAILS, this->index);

		SetWindowWidgetDirty(WC_VEHICLE_VIEW, this->index, VVW_WIDGET_START_STOP_VEH);

	}

	this->acc_cache.cached_max_track_speed = max_track_speed;

}

/**

 * Recalculates the cached weight of a vehicle and its parts. Should be called each time the cargo on

 * the consist changes.

 */

template <class T, VehicleType Type>

void GroundVehicle<T, Type>::CargoChanged()

{

	assert(this->First() == this);

	uint32 weight = 0;

	for (T *u = T::From(this); u != NULL; u = u->Next()) {

		uint32 current_weight = u->GetWeight();

		weight += current_weight;

		u->acc_cache.cached_slope_resistance = current_weight * u->GetSlopeSteepness();

	}

	/* Store consist weight in cache. */

	this->acc_cache.cached_weight = weight;

	/* Now update vehicle power (tractive effort is dependent on weight). */

	this->PowerChanged();

}

/**

 * Calculates the acceleration of the vehicle under its current conditions.

 * @return Current acceleration of the vehicle.

 */

template <class T, VehicleType Type>

int GroundVehicle<T, Type>::GetAcceleration() const

{

	/* Templated class used for function calls for performance reasons. */

	const T *v = T::From(this);

	int32 speed = v->GetCurrentSpeed();

	/* Weight is stored in tonnes. */

	int32 mass = this->acc_cache.cached_weight;

	/* Power is stored in HP, we need it in watts. */

	int32 power = this->acc_cache.cached_power * 746;

	int32 resistance = 0;

	bool maglev = v->GetAccelerationType() == 2;

	const int area = 120;

	if (!maglev) {

		resistance = (13 * mass) / 10;

		resistance += this->acc_cache.cached_axle_resistance;

		resistance += (v->GetRollingFriction() * mass * speed) / 1000;

		resistance += (area * this->acc_cache.cached_air_drag * speed * speed) / 10000;

	} else {

		resistance += (area * this->acc_cache.cached_air_drag * speed * speed) / 20000;

	}

	resistance += v->GetSlopeResistance();

	resistance *= 4; //[N]

	/* This value allows to know if the vehicle is accelerating or braking. */

	AccelStatus mode = v->GetAccelerationStatus();

	const int max_te = this->acc_cache.cached_max_te; // [N]

	int force;

	if (speed > 0) {

		if (!maglev) {

			force = power / speed; //[N]

			force *= 22;

			force /= 10;

			if (mode == AS_ACCEL && force > max_te) force = max_te;

		} else {

			force = power / 25;

		}

	} else {

		/* "Kickoff" acceleration. */

		force = (mode == AS_ACCEL && !maglev) ? min(max_te, power) : power;

		force = max(force, (mass * 8) + resistance);

	}

	if (mode == AS_ACCEL) {

		return (force - resistance) / (mass * 2);

	} else {

		return min(-force - resistance, -10000) / mass;

	}

}

/* Instantiation for Train */

template struct GroundVehicle<Train, VEH_TRAIN>;

	void PowerChanged();

	void CargoChanged();

	int GetAcceleration() const;

	friend struct GroundVehicle<Train, VEH_TRAIN>; // GroundVehicle needs to use the acceleration functions defined at Train.