(svn r19339) -Codechange: Move acceleration functions to GroundVehicle.

1 files changed, 150 insertions, 0 deletions

diff --git a/src/ground_vehicle.cpp b/src/ground_vehicle.cpp
new file mode 100644
index 000000000..1ab6da9da
--- /dev/null
+++ b/src/ground_vehicle.cpp
@@ -0,0 +1,150 @@
+/* $Id$ */
+
+/*
+ * 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>;