Fix crash when setting separation mode for vehicles with no orders list.

[openttd-joker.git] / src / newgrf_engine.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 newgrf_engine.cpp NewGRF handling of engines. */

#include "stdafx.h"
#include "debug.h"
#include "train.h"
#include "roadveh.h"
#include "company_func.h"
#include "newgrf_cargo.h"
#include "newgrf_spritegroup.h"
#include "date_func.h"
#include "vehicle_func.h"
#include "core/random_func.hpp"
#include "aircraft.h"
#include "station_base.h"
#include "company_base.h"
#include "newgrf_railtype.h"
#include "ship.h"

#include "safeguards.h"

struct WagonOverride {
        EngineID *train_id;
        uint trains;
        CargoID cargo;
        const SpriteGroup *group;
};

void SetWagonOverrideSprites(EngineID engine, CargoID cargo, const SpriteGroup *group, EngineID *train_id, uint trains)
{
        Engine *e = Engine::Get(engine);
        WagonOverride *wo;

        assert(cargo < NUM_CARGO + 2); // Include CT_DEFAULT and CT_PURCHASE pseudo cargoes.

        e->overrides_count++;
        e->overrides = ReallocT(e->overrides, e->overrides_count);

        wo = &e->overrides[e->overrides_count - 1];
        wo->group = group;
        wo->cargo = cargo;
        wo->trains = trains;
        wo->train_id = MallocT<EngineID>(trains);
        memcpy(wo->train_id, train_id, trains * sizeof *train_id);
}

const SpriteGroup *GetWagonOverrideSpriteSet(EngineID engine, CargoID cargo, EngineID overriding_engine)
{
        const Engine *e = Engine::Get(engine);

        for (uint i = 0; i < e->overrides_count; i++) {
                const WagonOverride *wo = &e->overrides[i];

                if (wo->cargo != cargo && wo->cargo != CT_DEFAULT) continue;

                for (uint j = 0; j < wo->trains; j++) {
                        if (wo->train_id[j] == overriding_engine) return wo->group;
                }
        }
        return nullptr;
}

/**
 * Unload all wagon override sprite groups.
 */
void UnloadWagonOverrides(Engine *e)
{
        for (uint i = 0; i < e->overrides_count; i++) {
                WagonOverride *wo = &e->overrides[i];
                free(wo->train_id);
        }
        free(e->overrides);
        e->overrides_count = 0;
        e->overrides = nullptr;
}


void SetCustomEngineSprites(EngineID engine, byte cargo, const SpriteGroup *group)
{
        Engine *e = Engine::Get(engine);
        assert(cargo < lengthof(e->grf_prop.spritegroup));

        if (e->grf_prop.spritegroup[cargo] != nullptr) {
                grfmsg(6, "SetCustomEngineSprites: engine %d cargo %d already has group -- replacing", engine, cargo);
        }
        e->grf_prop.spritegroup[cargo] = group;
}


/**
 * Tie a GRFFile entry to an engine, to allow us to retrieve GRF parameters
 * etc during a game.
 * @param engine Engine ID to tie the GRFFile to.
 * @param file   Pointer of GRFFile to tie.
 */
void SetEngineGRF(EngineID engine, const GRFFile *file)
{
        Engine *e = Engine::Get(engine);
        e->grf_prop.grffile = file;
}


static int MapOldSubType(const Vehicle *v)
{
        switch (v->type) {
                case VEH_TRAIN:
                        if (Train::From(v)->IsEngine()) return 0;
                        if (Train::From(v)->IsFreeWagon()) return 4;
                        return 2;
                case VEH_ROAD:
                case VEH_SHIP:     return 0;
                case VEH_AIRCRAFT:
                case VEH_DISASTER: return v->subtype;
                case VEH_EFFECT:   return v->subtype << 1;
                default: NOT_REACHED();
        }
}


/* TTDP style aircraft movement states for GRF Action 2 Var 0xE2 */
enum TTDPAircraftMovementStates {
        AMS_TTDP_HANGAR,
        AMS_TTDP_TO_HANGAR,
        AMS_TTDP_TO_PAD1,
        AMS_TTDP_TO_PAD2,
        AMS_TTDP_TO_PAD3,
        AMS_TTDP_TO_ENTRY_2_AND_3,
        AMS_TTDP_TO_ENTRY_2_AND_3_AND_H,
        AMS_TTDP_TO_JUNCTION,
        AMS_TTDP_LEAVE_RUNWAY,
        AMS_TTDP_TO_INWAY,
        AMS_TTDP_TO_RUNWAY,
        AMS_TTDP_TO_OUTWAY,
        AMS_TTDP_WAITING,
        AMS_TTDP_TAKEOFF,
        AMS_TTDP_TO_TAKEOFF,
        AMS_TTDP_CLIMBING,
        AMS_TTDP_FLIGHT_APPROACH,
        AMS_TTDP_UNUSED_0x11,
        AMS_TTDP_FLIGHT_TO_TOWER,
        AMS_TTDP_UNUSED_0x13,
        AMS_TTDP_FLIGHT_FINAL,
        AMS_TTDP_FLIGHT_DESCENT,
        AMS_TTDP_BRAKING,
        AMS_TTDP_HELI_TAKEOFF_AIRPORT,
        AMS_TTDP_HELI_TO_TAKEOFF_AIRPORT,
        AMS_TTDP_HELI_LAND_AIRPORT,
        AMS_TTDP_HELI_TAKEOFF_HELIPORT,
        AMS_TTDP_HELI_TO_TAKEOFF_HELIPORT,
        AMS_TTDP_HELI_LAND_HELIPORT,
};


/**
 * Map OTTD aircraft movement states to TTDPatch style movement states
 * (VarAction 2 Variable 0xE2)
 */
static byte MapAircraftMovementState(const Aircraft *v)
{
        const Station *st = GetTargetAirportIfValid(v);
        if (st == nullptr) return AMS_TTDP_FLIGHT_TO_TOWER;

        const AirportFTAClass *afc = st->airport.GetFTA();
        uint16 amdflag = afc->MovingData(v->pos)->flag;

        switch (v->state) {
                case HANGAR:
                        /* The international airport is a special case as helicopters can land in
                         * front of the hangar. Helicopters also change their air.state to
                         * AMED_HELI_LOWER some time before actually descending. */

                        /* This condition only occurs for helicopters, during descent,
                         * to a landing by the hangar of an international airport. */
                        if (amdflag & AMED_HELI_LOWER) return AMS_TTDP_HELI_LAND_AIRPORT;

                        /* This condition only occurs for helicopters, before starting descent,
                         * to a landing by the hangar of an international airport. */
                        if (amdflag & AMED_SLOWTURN) return AMS_TTDP_FLIGHT_TO_TOWER;

                        /* The final two conditions apply to helicopters or aircraft.
                         * Has reached hangar? */
                        if (amdflag & AMED_EXACTPOS) return AMS_TTDP_HANGAR;

                        /* Still moving towards hangar. */
                        return AMS_TTDP_TO_HANGAR;

                case TERM1:
                        if (amdflag & AMED_EXACTPOS) return AMS_TTDP_TO_PAD1;
                        return AMS_TTDP_TO_JUNCTION;

                case TERM2:
                        if (amdflag & AMED_EXACTPOS) return AMS_TTDP_TO_PAD2;
                        return AMS_TTDP_TO_ENTRY_2_AND_3_AND_H;

                case TERM3:
                case TERM4:
                case TERM5:
                case TERM6:
                case TERM7:
                case TERM8:
                        /* TTDPatch only has 3 terminals, so treat these states the same */
                        if (amdflag & AMED_EXACTPOS) return AMS_TTDP_TO_PAD3;
                        return AMS_TTDP_TO_ENTRY_2_AND_3_AND_H;

                case HELIPAD1:
                case HELIPAD2:
                case HELIPAD3:
                        /* Will only occur for helicopters.*/
                        if (amdflag & AMED_HELI_LOWER) return AMS_TTDP_HELI_LAND_AIRPORT; // Descending.
                        if (amdflag & AMED_SLOWTURN)   return AMS_TTDP_FLIGHT_TO_TOWER;   // Still hasn't started descent.
                        return AMS_TTDP_TO_JUNCTION; // On the ground.

                case TAKEOFF: // Moving to takeoff position.
                        return AMS_TTDP_TO_OUTWAY;

                case STARTTAKEOFF: // Accelerating down runway.
                        return AMS_TTDP_TAKEOFF;

                case ENDTAKEOFF: // Ascent
                        return AMS_TTDP_CLIMBING;

                case HELITAKEOFF: // Helicopter is moving to take off position.
                        if (afc->delta_z == 0) {
                                return amdflag & AMED_HELI_RAISE ?
                                        AMS_TTDP_HELI_TAKEOFF_AIRPORT : AMS_TTDP_TO_JUNCTION;
                        } else {
                                return AMS_TTDP_HELI_TAKEOFF_HELIPORT;
                        }

                case FLYING:
                        return amdflag & AMED_HOLD ? AMS_TTDP_FLIGHT_APPROACH : AMS_TTDP_FLIGHT_TO_TOWER;

                case LANDING: // Descent
                        return AMS_TTDP_FLIGHT_DESCENT;

                case ENDLANDING: // On the runway braking
                        if (amdflag & AMED_BRAKE) return AMS_TTDP_BRAKING;
                        /* Landed - moving off runway */
                        return AMS_TTDP_TO_INWAY;

                case HELILANDING:
                case HELIENDLANDING: // Helicoptor is decending.
                        if (amdflag & AMED_HELI_LOWER) {
                                return afc->delta_z == 0 ?
                                        AMS_TTDP_HELI_LAND_AIRPORT : AMS_TTDP_HELI_LAND_HELIPORT;
                        } else {
                                return AMS_TTDP_FLIGHT_TO_TOWER;
                        }

                default:
                        return AMS_TTDP_HANGAR;
        }
}


/* TTDP style aircraft movement action for GRF Action 2 Var 0xE6 */
enum TTDPAircraftMovementActions {
        AMA_TTDP_IN_HANGAR,
        AMA_TTDP_ON_PAD1,
        AMA_TTDP_ON_PAD2,
        AMA_TTDP_ON_PAD3,
        AMA_TTDP_HANGAR_TO_PAD1,
        AMA_TTDP_HANGAR_TO_PAD2,
        AMA_TTDP_HANGAR_TO_PAD3,
        AMA_TTDP_LANDING_TO_PAD1,
        AMA_TTDP_LANDING_TO_PAD2,
        AMA_TTDP_LANDING_TO_PAD3,
        AMA_TTDP_PAD1_TO_HANGAR,
        AMA_TTDP_PAD2_TO_HANGAR,
        AMA_TTDP_PAD3_TO_HANGAR,
        AMA_TTDP_PAD1_TO_TAKEOFF,
        AMA_TTDP_PAD2_TO_TAKEOFF,
        AMA_TTDP_PAD3_TO_TAKEOFF,
        AMA_TTDP_HANGAR_TO_TAKOFF,
        AMA_TTDP_LANDING_TO_HANGAR,
        AMA_TTDP_IN_FLIGHT,
};


/**
 * Map OTTD aircraft movement states to TTDPatch style movement actions
 * (VarAction 2 Variable 0xE6)
 * This is not fully supported yet but it's enough for Planeset.
 */
static byte MapAircraftMovementAction(const Aircraft *v)
{
        switch (v->state) {
                case HANGAR:
                        return (v->cur_speed > 0) ? AMA_TTDP_LANDING_TO_HANGAR : AMA_TTDP_IN_HANGAR;

                case TERM1:
                case HELIPAD1:
                        return (v->current_order.IsType(OT_LOADING)) ? AMA_TTDP_ON_PAD1 : AMA_TTDP_LANDING_TO_PAD1;

                case TERM2:
                case HELIPAD2:
                        return (v->current_order.IsType(OT_LOADING)) ? AMA_TTDP_ON_PAD2 : AMA_TTDP_LANDING_TO_PAD2;

                case TERM3:
                case TERM4:
                case TERM5:
                case TERM6:
                case TERM7:
                case TERM8:
                case HELIPAD3:
                        return (v->current_order.IsType(OT_LOADING)) ? AMA_TTDP_ON_PAD3 : AMA_TTDP_LANDING_TO_PAD3;

                case TAKEOFF:      // Moving to takeoff position
                case STARTTAKEOFF: // Accelerating down runway
                case ENDTAKEOFF:   // Ascent
                case HELITAKEOFF:
                        /* @todo Need to find which terminal (or hangar) we've come from. How? */
                        return AMA_TTDP_PAD1_TO_TAKEOFF;

                case FLYING:
                        return AMA_TTDP_IN_FLIGHT;

                case LANDING:    // Descent
                case ENDLANDING: // On the runway braking
                case HELILANDING:
                case HELIENDLANDING:
                        /* @todo Need to check terminal we're landing to. Is it known yet? */
                        return (v->current_order.IsType(OT_GOTO_DEPOT)) ?
                                AMA_TTDP_LANDING_TO_HANGAR : AMA_TTDP_LANDING_TO_PAD1;

                default:
                        return AMA_TTDP_IN_HANGAR;
        }
}


/* virtual */ uint32 VehicleScopeResolver::GetRandomBits() const
{
        return this->v == nullptr ? 0 : this->v->random_bits;
}

/* virtual */ uint32 VehicleScopeResolver::GetTriggers() const
{
        return this->v == nullptr ? 0 : this->v->waiting_triggers;
}


/* virtual */ ScopeResolver *VehicleResolverObject::GetScope(VarSpriteGroupScope scope, byte relative)
{
        switch (scope) {
                case VSG_SCOPE_SELF:   return &this->self_scope;
                case VSG_SCOPE_PARENT: return &this->parent_scope;
                case VSG_SCOPE_RELATIVE: {
                        int32 count = GB(relative, 0, 4);
                        if (this->self_scope.v != nullptr && (relative != this->cached_relative_count || count == 0)) {
                                /* Note: This caching only works as long as the VSG_SCOPE_RELATIVE cannot be used in
                                 *       VarAct2 with procedure calls. */
                                if (count == 0) count = GetRegister(0x100);

                                const Vehicle *v = nullptr;
                                switch (GB(relative, 6, 2)) {
                                        default: NOT_REACHED();
                                        case 0x00: // count back (away from the engine), starting at this vehicle
                                                v = this->self_scope.v;
                                                break;
                                        case 0x01: // count forward (toward the engine), starting at this vehicle
                                                v = this->self_scope.v;
                                                count = -count;
                                                break;
                                        case 0x02: // count back, starting at the engine
                                                v = this->parent_scope.v;
                                                break;
                                        case 0x03: { // count back, starting at the first vehicle in this chain of vehicles with the same ID, as for vehicle variable 41
                                                const Vehicle *self = this->self_scope.v;
                                                for (const Vehicle *u = self->First(); u != self; u = u->Next()) {
                                                        if (u->engine_type != self->engine_type) {
                                                                v = nullptr;
                                                        } else {
                                                                if (v == nullptr) v = u;
                                                        }
                                                }
                                                if (v == nullptr) v = self;
                                                break;
                                        }
                                }
                                this->relative_scope.SetVehicle(v->Move(count));
                        }
                        return &this->relative_scope;
                }
                default: return ResolverObject::GetScope(scope, relative);
        }
}

/**
 * Determines the livery of an engine.
 *
 * This always uses dual company colours independent of GUI settings. So it is desync-safe.
 *
 * @param engine Engine type
 * @param v Vehicle, nullptr in purchase list.
 * @return Livery to use
 */
static const Livery *LiveryHelper(EngineID engine, const Vehicle *v)
{
        const Livery *l;

        if (v == nullptr) {
                if (!Company::IsValidID(_current_company)) return nullptr;
                l = GetEngineLivery(engine, _current_company, INVALID_ENGINE, nullptr, LIT_ALL);
        } else if (v->IsGroundVehicle()) {
                l = GetEngineLivery(v->engine_type, v->owner, v->GetGroundVehicleCache()->first_engine, v, LIT_ALL);
        } else {
                l = GetEngineLivery(v->engine_type, v->owner, INVALID_ENGINE, v, LIT_ALL);
        }

        return l;
}

/**
 * Helper to get the position of a vehicle within a chain of vehicles.
 * @param v the vehicle to get the position of.
 * @param consecutive whether to look at the whole chain or the vehicles
 *                    with the same 'engine type'.
 * @return the position in the chain from front and tail and chain length.
 */
static uint32 PositionHelper(const Vehicle *v, bool consecutive)
{
        const Vehicle *u;
        byte chain_before = 0;
        byte chain_after  = 0;

        for (u = v->First(); u != v; u = u->Next()) {
                chain_before++;
                if (consecutive && u->engine_type != v->engine_type) chain_before = 0;
        }

        while (u->Next() != nullptr && (!consecutive || u->Next()->engine_type == v->engine_type)) {
                chain_after++;
                u = u->Next();
        }

        return chain_before | chain_after << 8 | (chain_before + chain_after + consecutive) << 16;
}

static uint32 VehicleGetVariable(Vehicle *v, const VehicleScopeResolver *object, byte variable, uint32 parameter, bool *available)
{
        /* Calculated vehicle parameters */
        switch (variable) {
                case 0x25: // Get engine GRF ID
                        return v->GetGRFID();

                case 0x40: // Get length of consist
                        if (!HasBit(v->grf_cache.cache_valid, NCVV_POSITION_CONSIST_LENGTH)) {
                                v->grf_cache.position_consist_length = PositionHelper(v, false);
                                SetBit(v->grf_cache.cache_valid, NCVV_POSITION_CONSIST_LENGTH);
                        }
                        return v->grf_cache.position_consist_length;

                case 0x41: // Get length of same consecutive wagons
                        if (!HasBit(v->grf_cache.cache_valid, NCVV_POSITION_SAME_ID_LENGTH)) {
                                v->grf_cache.position_same_id_length = PositionHelper(v, true);
                                SetBit(v->grf_cache.cache_valid, NCVV_POSITION_SAME_ID_LENGTH);
                        }
                        return v->grf_cache.position_same_id_length;

                case 0x42: { // Consist cargo information
                        if (!HasBit(v->grf_cache.cache_valid, NCVV_CONSIST_CARGO_INFORMATION)) {
                                const Vehicle *u;
                                byte cargo_classes = 0;
                                uint8 common_cargoes[NUM_CARGO];
                                uint8 common_subtypes[256];
                                byte user_def_data = 0;
                                CargoID common_cargo_type = CT_INVALID;
                                uint8 common_subtype = 0xFF; // Return 0xFF if nothing is carried

                                /* Reset our arrays */
                                memset(common_cargoes, 0, sizeof(common_cargoes));
                                memset(common_subtypes, 0, sizeof(common_subtypes));

                                for (u = v; u != nullptr; u = u->Next()) {
                                        if (v->type == VEH_TRAIN) user_def_data |= Train::From(u)->tcache.user_def_data;

                                        /* Skip empty engines */
                                        if (!u->GetEngine()->CanCarryCargo()) continue;

                                        cargo_classes |= CargoSpec::Get(u->cargo_type)->classes;
                                        common_cargoes[u->cargo_type]++;
                                }

                                /* Pick the most common cargo type */
                                uint common_cargo_best_amount = 0;
                                for (CargoID cargo = 0; cargo < NUM_CARGO; cargo++) {
                                        if (common_cargoes[cargo] > common_cargo_best_amount) {
                                                common_cargo_best_amount = common_cargoes[cargo];
                                                common_cargo_type = cargo;
                                        }
                                }

                                /* Count subcargo types of common_cargo_type */
                                for (u = v; u != nullptr; u = u->Next()) {
                                        /* Skip empty engines and engines not carrying common_cargo_type */
                                        if (u->cargo_type != common_cargo_type || !u->GetEngine()->CanCarryCargo()) continue;

                                        common_subtypes[u->cargo_subtype]++;
                                }

                                /* Pick the most common subcargo type*/
                                uint common_subtype_best_amount = 0;
                                for (uint i = 0; i < lengthof(common_subtypes); i++) {
                                        if (common_subtypes[i] > common_subtype_best_amount) {
                                                common_subtype_best_amount = common_subtypes[i];
                                                common_subtype = i;
                                        }
                                }

                                /* Note: We have to store the untranslated cargotype in the cache as the cache can be read by different NewGRFs,
                                 *       which will need different translations */
                                v->grf_cache.consist_cargo_information = cargo_classes | (common_cargo_type << 8) | (common_subtype << 16) | (user_def_data << 24);
                                SetBit(v->grf_cache.cache_valid, NCVV_CONSIST_CARGO_INFORMATION);
                        }

                        /* The cargo translation is specific to the accessing GRF, and thus cannot be cached. */
                        CargoID common_cargo_type = (v->grf_cache.consist_cargo_information >> 8) & 0xFF;

                        /* Note:
                         *  - Unlike everywhere else the cargo translation table is only used since grf version 8, not 7.
                         *  - For translating the cargo type we need to use the GRF which is resolving the variable, which
                         *    is object->ro.grffile.
                         *    In case of CBID_TRAIN_ALLOW_WAGON_ATTACH this is not the same as v->GetGRF().
                         *  - The grffile == nullptr case only happens if this function is called for default vehicles.
                         *    And this is only done by CheckCaches().
                         */
                        const GRFFile *grffile = object->ro.grffile;
                        uint8 common_bitnum = (common_cargo_type == CT_INVALID) ? 0xFF :
                                (grffile == nullptr || grffile->grf_version < 8) ? CargoSpec::Get(common_cargo_type)->bitnum : grffile->cargo_map[common_cargo_type];

                        return (v->grf_cache.consist_cargo_information & 0xFFFF00FF) | common_bitnum << 8;
                }

                case 0x43: // Company information
                        if (!HasBit(v->grf_cache.cache_valid, NCVV_COMPANY_INFORMATION)) {
                                v->grf_cache.company_information = GetCompanyInfo(v->owner, LiveryHelper(v->engine_type, v));
                                SetBit(v->grf_cache.cache_valid, NCVV_COMPANY_INFORMATION);
                        }
                        return v->grf_cache.company_information;

                case 0x44: // Aircraft information
                        if (v->type != VEH_AIRCRAFT || !Aircraft::From(v)->IsNormalAircraft()) return UINT_MAX;

                        {
                                const Vehicle *w = v->Next();
                                uint16 altitude = ClampToU16(v->z_pos - w->z_pos); // Aircraft height - shadow height
                                byte airporttype = ATP_TTDP_LARGE;

                                const Station *st = GetTargetAirportIfValid(Aircraft::From(v));

                                if (st != nullptr && st->airport.tile != INVALID_TILE) {
                                        airporttype = st->airport.GetSpec()->ttd_airport_type;
                                }

                                return (Clamp(altitude, 0, 0xFF) << 8) | airporttype;
                        }

                case 0x45: { // Curvature info
                        /* Format: xxxTxBxF
                         * F - previous wagon to current wagon, 0 if vehicle is first
                         * B - current wagon to next wagon, 0 if wagon is last
                         * T - previous wagon to next wagon, 0 in an S-bend
                         */
                        if (!v->IsGroundVehicle()) return 0;

                        const Vehicle *u_p = v->Previous();
                        const Vehicle *u_n = v->Next();
                        DirDiff f = (u_p == nullptr) ?  DIRDIFF_SAME : DirDifference(u_p->direction, v->direction);
                        DirDiff b = (u_n == nullptr) ?  DIRDIFF_SAME : DirDifference(v->direction, u_n->direction);
                        DirDiff t = ChangeDirDiff(f, b);

                        return ((t > DIRDIFF_REVERSE ? t | 8 : t) << 16) |
                               ((b > DIRDIFF_REVERSE ? b | 8 : b) <<  8) |
                               ( f > DIRDIFF_REVERSE ? f | 8 : f);
                }

                case 0x46: // Motion counter
                        return v->motion_counter;

                case 0x47: { // Vehicle cargo info
                        /* Format: ccccwwtt
                         * tt - the cargo type transported by the vehicle,
                         *     translated if a translation table has been installed.
                         * ww - cargo unit weight in 1/16 tons, same as cargo prop. 0F.
                         * cccc - the cargo class value of the cargo transported by the vehicle.
                         */
                        const CargoSpec *cs = CargoSpec::Get(v->cargo_type);

                        /* Note:
                         * For translating the cargo type we need to use the GRF which is resolving the variable, which
                         * is object->ro.grffile.
                         * In case of CBID_TRAIN_ALLOW_WAGON_ATTACH this is not the same as v->GetGRF().
                         */
                        return (cs->classes << 16) | (cs->weight << 8) | object->ro.grffile->cargo_map[v->cargo_type];
                }

                case 0x48: return v->GetEngine()->flags; // Vehicle Type Info
                case 0x49: return v->build_year;

                case 0x4A: {
                        if (v->type != VEH_TRAIN) return 0;
                        if (Train::From(v)->IsVirtual()) return 0x1FF;
                        RailType rt = GetTileRailType(v->tile);
                        return (HasPowerOnRail(Train::From(v)->railtype, rt) ? 0x100 : 0) | GetReverseRailTypeTranslation(rt, object->ro.grffile);
                }

                case 0x4B: // Long date of last service
                        return v->date_of_last_service;

                case 0x4C: // Current maximum speed in NewGRF units
                        if (!v->IsPrimaryVehicle()) return 0;
                        return v->GetCurrentMaxSpeed();

                case 0x4D: // Position within articulated vehicle
                        if (!HasBit(v->grf_cache.cache_valid, NCVV_POSITION_IN_VEHICLE)) {
                                byte artic_before = 0;
                                for (const Vehicle *u = v; u->IsArticulatedPart(); u = u->Previous()) artic_before++;
                                byte artic_after = 0;
                                for (const Vehicle *u = v; u->HasArticulatedPart(); u = u->Next()) artic_after++;
                                v->grf_cache.position_in_vehicle = artic_before | artic_after << 8;
                                SetBit(v->grf_cache.cache_valid, NCVV_POSITION_IN_VEHICLE);
                        }
                        return v->grf_cache.position_in_vehicle;

                /* Variables which use the parameter */
                case 0x60: // Count consist's engine ID occurrence
                        if (v->type != VEH_TRAIN) return v->GetEngine()->grf_prop.local_id == parameter ? 1 : 0;

                        {
                                uint count = 0;
                                for (; v != nullptr; v = v->Next()) {
                                        if (v->GetEngine()->grf_prop.local_id == parameter) count++;
                                }
                                return count;
                        }

                case 0x61: // Get variable of n-th vehicle in chain [signed number relative to vehicle]
                        if (!v->IsGroundVehicle() || parameter == 0x61) {
                                /* Not available */
                                break;
                        }

                        /* Only allow callbacks that don't change properties to avoid circular dependencies. */
                        if (object->ro.callback == CBID_NO_CALLBACK || object->ro.callback == CBID_RANDOM_TRIGGER || object->ro.callback == CBID_TRAIN_ALLOW_WAGON_ATTACH ||
                                        object->ro.callback == CBID_VEHICLE_START_STOP_CHECK || object->ro.callback == CBID_VEHICLE_32DAY_CALLBACK || object->ro.callback == CBID_VEHICLE_COLOUR_MAPPING ||
                                        object->ro.callback == CBID_VEHICLE_SPAWN_VISUAL_EFFECT) {
                                Vehicle *u = v->Move((int32)GetRegister(0x10F));
                                if (u == nullptr) return 0; // available, but zero

                                if (parameter == 0x5F) {
                                        /* This seems to be the only variable that makes sense to access via var 61, but is not handled by VehicleGetVariable */
                                        return (u->random_bits << 8) | u->waiting_triggers;
                                } else {
                                        return VehicleGetVariable(u, object, parameter, GetRegister(0x10E), available);
                                }
                        }
                        /* Not available */
                        break;

                case 0x62: { // Curvature/position difference for n-th vehicle in chain [signed number relative to vehicle]
                        /* Format: zzyyxxFD
                         * zz - Signed difference of z position between the selected and this vehicle.
                         * yy - Signed difference of y position between the selected and this vehicle.
                         * xx - Signed difference of x position between the selected and this vehicle.
                         * F  - Flags, bit 7 corresponds to VS_HIDDEN.
                         * D  - Dir difference, like in 0x45.
                         */
                        if (!v->IsGroundVehicle()) return 0;

                        const Vehicle *u = v->Move((int8)parameter);
                        if (u == nullptr) return 0;

                        /* Get direction difference. */
                        bool prev = (int8)parameter < 0;
                        uint32 ret = prev ? DirDifference(u->direction, v->direction) : DirDifference(v->direction, u->direction);
                        if (ret > DIRDIFF_REVERSE) ret |= 0x08;

                        if (u->vehstatus & VS_HIDDEN) ret |= 0x80;

                        /* Get position difference. */
                        ret |= ((prev ? u->x_pos - v->x_pos : v->x_pos - u->x_pos) & 0xFF) << 8;
                        ret |= ((prev ? u->y_pos - v->y_pos : v->y_pos - u->y_pos) & 0xFF) << 16;
                        ret |= ((prev ? u->z_pos - v->z_pos : v->z_pos - u->z_pos) & 0xFF) << 24;

                        return ret;
                }

                case 0xFE:
                case 0xFF: {
                        uint16 modflags = 0;

                        if (v->type == VEH_TRAIN) {
                                const Train *t = Train::From(v);
                                bool is_powered_wagon = HasBit(t->flags, VRF_POWEREDWAGON);
                                const Train *u = is_powered_wagon ? t->First() : t; // for powered wagons the engine defines the type of engine (i.e. railtype)
                                bool powered = t->IsEngine() || is_powered_wagon;
                                bool has_power;
                                if (u->IsVirtual()) {
                                        has_power = true;
                                } else {
                                        RailType railtype = GetRailType(v->tile);
                                        has_power = HasPowerOnRail(u->railtype, railtype);
                                }

                                if (powered && has_power) SetBit(modflags, 5);
                                if (powered && !has_power) SetBit(modflags, 6);
                                if (HasBit(t->flags, VRF_TOGGLE_REVERSE)) SetBit(modflags, 8);
                        }
                        if (HasBit(v->vehicle_flags, VF_CARGO_UNLOADING)) SetBit(modflags, 1);
                        if (HasBit(v->vehicle_flags, VF_BUILT_AS_PROTOTYPE)) SetBit(modflags, 10);

                        return variable == 0xFE ? modflags : GB(modflags, 8, 8);
                }
        }

        /* General vehicle properties */
        switch (variable - 0x80) {
                case 0x00: return v->type + 0x10;
                case 0x01: return MapOldSubType(v);
                case 0x04: return v->index;
                case 0x05: return GB(v->index, 8, 8);
                case 0x0A: return v->current_order.MapOldOrder();
                case 0x0B: return v->current_order.GetDestination();
                case 0x0C: return v->GetNumOrders();
                case 0x0D: return v->cur_real_order_index;
                case 0x10:
                case 0x11: {
                        uint ticks;
                        if (v->current_order.IsType(OT_LOADING)) {
                                ticks = v->load_unload_ticks;
                        } else {
                                switch (v->type) {
                                        case VEH_TRAIN:    ticks = Train::From(v)->wait_counter; break;
                                        case VEH_AIRCRAFT: ticks = Aircraft::From(v)->turn_counter; break;
                                        default:           ticks = 0; break;
                                }
                        }
                        return (variable - 0x80) == 0x10 ? ticks : GB(ticks, 8, 8);
                }
                case 0x12: return Clamp(v->date_of_last_service - DAYS_TILL_ORIGINAL_BASE_YEAR, 0, 0xFFFF);
                case 0x13: return GB(Clamp(v->date_of_last_service - DAYS_TILL_ORIGINAL_BASE_YEAR, 0, 0xFFFF), 8, 8);
                case 0x14: return v->GetServiceInterval();
                case 0x15: return GB(v->GetServiceInterval(), 8, 8);
                case 0x16: return v->last_station_visited;
                case 0x17: return v->tick_counter;
                case 0x18:
                case 0x19: {
                        uint max_speed;
                        switch (v->type) {
                                case VEH_AIRCRAFT:
                                        max_speed = Aircraft::From(v)->GetSpeedOldUnits(); // Convert to old units.
                                        break;

                                default:
                                        max_speed = v->vcache.cached_max_speed;
                                        break;
                        }
                        return (variable - 0x80) == 0x18 ? max_speed : GB(max_speed, 8, 8);
                }
                case 0x1A: return v->x_pos;
                case 0x1B: return GB(v->x_pos, 8, 8);
                case 0x1C: return v->y_pos;
                case 0x1D: return GB(v->y_pos, 8, 8);
                case 0x1E: return v->z_pos;
                case 0x1F: return object->info_view ? DIR_W : v->direction;
                case 0x28: return 0; // cur_image is a potential desyncer due to Action1 in static NewGRFs.
                case 0x29: return 0; // cur_image is a potential desyncer due to Action1 in static NewGRFs.
                case 0x32: return v->vehstatus;
                case 0x33: return 0; // non-existent high byte of vehstatus
                case 0x34: return v->type == VEH_AIRCRAFT ? (v->cur_speed * 10) / 128 : v->cur_speed;
                case 0x35: return GB(v->type == VEH_AIRCRAFT ? (v->cur_speed * 10) / 128 : v->cur_speed, 8, 8);
                case 0x36: return v->subspeed;
                case 0x37: return v->acceleration;
                case 0x39: return v->cargo_type;
                case 0x3A: return v->cargo_cap;
                case 0x3B: return GB(v->cargo_cap, 8, 8);
                case 0x3C: return ClampToU16(v->cargo.StoredCount());
                case 0x3D: return GB(ClampToU16(v->cargo.StoredCount()), 8, 8);
                case 0x3E: return v->cargo.Source();
                case 0x3F: return ClampU(v->cargo.DaysInTransit(), 0, 0xFF);
                case 0x40: return ClampToU16(v->age);
                case 0x41: return GB(ClampToU16(v->age), 8, 8);
                case 0x42: return ClampToU16(v->max_age);
                case 0x43: return GB(ClampToU16(v->max_age), 8, 8);
                case 0x44: return Clamp(v->build_year, ORIGINAL_BASE_YEAR, ORIGINAL_MAX_YEAR) - ORIGINAL_BASE_YEAR;
                case 0x45: return v->unitnumber;
                case 0x46: return v->GetEngine()->grf_prop.local_id;
                case 0x47: return GB(v->GetEngine()->grf_prop.local_id, 8, 8);
                case 0x48:
                        if (v->type != VEH_TRAIN || v->spritenum != 0xFD) return v->spritenum;
                        return HasBit(Train::From(v)->flags, VRF_REVERSE_DIRECTION) ? 0xFE : 0xFD;

                case 0x49: return v->day_counter;
                case 0x4A: return v->breakdowns_since_last_service;
                case 0x4B: return v->breakdown_ctr;
                case 0x4C: return v->breakdown_delay;
                case 0x4D: return v->breakdown_chance;
                case 0x4E: return v->reliability;
                case 0x4F: return GB(v->reliability, 8, 8);
                case 0x50: return v->reliability_spd_dec;
                case 0x51: return GB(v->reliability_spd_dec, 8, 8);
                case 0x52: return ClampToI32(v->GetDisplayProfitThisYear());
                case 0x53: return GB(ClampToI32(v->GetDisplayProfitThisYear()),  8, 24);
                case 0x54: return GB(ClampToI32(v->GetDisplayProfitThisYear()), 16, 16);
                case 0x55: return GB(ClampToI32(v->GetDisplayProfitThisYear()), 24,  8);
                case 0x56: return ClampToI32(v->GetDisplayProfitLastYear());
                case 0x57: return GB(ClampToI32(v->GetDisplayProfitLastYear()),  8, 24);
                case 0x58: return GB(ClampToI32(v->GetDisplayProfitLastYear()), 16, 16);
                case 0x59: return GB(ClampToI32(v->GetDisplayProfitLastYear()), 24,  8);
                case 0x5A: return v->Next() == nullptr ? INVALID_VEHICLE : v->Next()->index;
                case 0x5C: return ClampToI32(v->value);
                case 0x5D: return GB(ClampToI32(v->value),  8, 24);
                case 0x5E: return GB(ClampToI32(v->value), 16, 16);
                case 0x5F: return GB(ClampToI32(v->value), 24,  8);
                case 0x72: return v->cargo_subtype;
                case 0x7A: return v->random_bits;
                case 0x7B: return v->waiting_triggers;
        }

        /* Vehicle specific properties */
        switch (v->type) {
                case VEH_TRAIN: {
                        Train *t = Train::From(v);
                        switch (variable - 0x80) {
                                case 0x62: return t->track;
                                case 0x66: return t->railtype;
                                case 0x73: return 0x80 + VEHICLE_LENGTH - t->gcache.cached_veh_length;
                                case 0x74: return t->gcache.cached_power;
                                case 0x75: return GB(t->gcache.cached_power,  8, 24);
                                case 0x76: return GB(t->gcache.cached_power, 16, 16);
                                case 0x77: return GB(t->gcache.cached_power, 24,  8);
                                case 0x7C: return t->First()->index;
                                case 0x7D: return GB(t->First()->index, 8, 8);
                                case 0x7F: return 0; // Used for vehicle reversing hack in TTDP
                        }
                        break;
                }

                case VEH_ROAD: {
                        RoadVehicle *rv = RoadVehicle::From(v);
                        switch (variable - 0x80) {
                                case 0x62: return rv->state;
                                case 0x64: return rv->blocked_ctr;
                                case 0x65: return GB(rv->blocked_ctr, 8, 8);
                                case 0x66: return rv->overtaking;
                                case 0x67: return rv->overtaking_ctr;
                                case 0x68: return rv->crashed_ctr;
                                case 0x69: return GB(rv->crashed_ctr, 8, 8);
                        }
                        break;
                }

                case VEH_SHIP: {
                        Ship *s = Ship::From(v);
                        switch (variable - 0x80) {
                                case 0x62: return s->state;
                        }
                        break;
                }

                case VEH_AIRCRAFT: {
                        Aircraft *a = Aircraft::From(v);
                        switch (variable - 0x80) {
                                case 0x62: return MapAircraftMovementState(a);  // Current movement state
                                case 0x63: return a->targetairport;             // Airport to which the action refers
                                case 0x66: return MapAircraftMovementAction(a); // Current movement action
                        }
                        break;
                }

                default: break;
        }

        DEBUG(grf, 1, "Unhandled vehicle variable 0x%X, type 0x%X", variable, (uint)v->type);

        *available = false;
        return UINT_MAX;
}

/* virtual */ uint32 VehicleScopeResolver::GetVariable(byte variable, uint32 parameter, bool *available) const
{
        if (this->v == nullptr) {
                /* Vehicle does not exist, so we're in a purchase list */
                switch (variable) {
                        case 0x43: return GetCompanyInfo(_current_company, LiveryHelper(this->self_type, nullptr)); // Owner information
                        case 0x46: return 0;               // Motion counter
                        case 0x47: { // Vehicle cargo info
                                const Engine *e = Engine::Get(this->self_type);
                                CargoID cargo_type = e->GetDefaultCargoType();
                                if (cargo_type != CT_INVALID) {
                                        const CargoSpec *cs = CargoSpec::Get(cargo_type);
                                        return (cs->classes << 16) | (cs->weight << 8) | this->ro.grffile->cargo_map[cargo_type];
                                } else {
                                        return 0x000000FF;
                                }
                        }
                        case 0x48: return Engine::Get(this->self_type)->flags; // Vehicle Type Info
                        case 0x49: return _cur_year; // 'Long' format build year
                        case 0x4B: return _date; // Long date of last service
                        case 0x92: return Clamp(_date - DAYS_TILL_ORIGINAL_BASE_YEAR, 0, 0xFFFF); // Date of last service
                        case 0x93: return GB(Clamp(_date - DAYS_TILL_ORIGINAL_BASE_YEAR, 0, 0xFFFF), 8, 8);
                        case 0xC4: return Clamp(_cur_year, ORIGINAL_BASE_YEAR, ORIGINAL_MAX_YEAR) - ORIGINAL_BASE_YEAR; // Build year
                        case 0xDA: return INVALID_VEHICLE; // Next vehicle
                        case 0xF2: return 0; // Cargo subtype
                }

                *available = false;
                return UINT_MAX;
        }

        return VehicleGetVariable(const_cast<Vehicle*>(this->v), this, variable, parameter, available);
}


/* virtual */ const SpriteGroup *VehicleResolverObject::ResolveReal(const RealSpriteGroup *group) const
{
        const Vehicle *v = this->self_scope.v;

        if (v == nullptr) {
                if (group->num_loading > 0) return group->loading[0];
                if (group->num_loaded  > 0) return group->loaded[0];
                return nullptr;
        }

        bool in_motion = !v->First()->current_order.IsType(OT_LOADING);

        uint totalsets = in_motion ? group->num_loaded : group->num_loading;

        if (totalsets == 0) return nullptr;

        uint set = (v->cargo.StoredCount() * totalsets) / max((uint16)1, v->cargo_cap);
        set = min(set, totalsets - 1);

        return in_motion ? group->loaded[set] : group->loading[set];
}

/**
 * Get the grf file associated with an engine type.
 * @param engine_type Engine to query.
 * @return grf file associated with the engine.
 */
static const GRFFile *GetEngineGrfFile(EngineID engine_type)
{
        const Engine *e = Engine::Get(engine_type);
        return (e != nullptr) ? e->GetGRF() : nullptr;
}

/**
 * Resolver of a vehicle (chain).
 * @param engine_type Engine type
 * @param v %Vehicle being resolved.
 * @param wagon_override Application of wagon overrides.
 * @param info_view Indicates if the item is being drawn in an info window.
 * @param callback Callback ID.
 * @param callback_param1 First parameter (var 10) of the callback.
 * @param callback_param2 Second parameter (var 18) of the callback.
 */
VehicleResolverObject::VehicleResolverObject(EngineID engine_type, const Vehicle *v, WagonOverride wagon_override, bool info_view,
                CallbackID callback, uint32 callback_param1, uint32 callback_param2)
        : ResolverObject(GetEngineGrfFile(engine_type), callback, callback_param1, callback_param2),
        self_scope(*this, engine_type, v, info_view),
        parent_scope(*this, engine_type, ((v != nullptr) ? v->First() : v), info_view),
        relative_scope(*this, engine_type, v, info_view),
        cached_relative_count(0)
{
        if (wagon_override == WO_SELF) {
                this->root_spritegroup = GetWagonOverrideSpriteSet(engine_type, CT_DEFAULT, engine_type);
        } else {
                if (wagon_override != WO_NONE && v != nullptr && v->IsGroundVehicle()) {
                        assert(v->engine_type == engine_type); // overrides make little sense with fake scopes

                        /* For trains we always use cached value, except for callbacks because the override spriteset
                         * to use may be different than the one cached. It happens for callback 0x15 (refit engine),
                         * as v->cargo_type is temporary changed to the new type */
                        if (wagon_override == WO_CACHED && v->type == VEH_TRAIN) {
                                this->root_spritegroup = Train::From(v)->tcache.cached_override;
                        } else {
                                this->root_spritegroup = GetWagonOverrideSpriteSet(v->engine_type, v->cargo_type, v->GetGroundVehicleCache()->first_engine);
                        }
                }

                if (this->root_spritegroup == nullptr) {
                        const Engine *e = Engine::Get(engine_type);
                        CargoID cargo = v != nullptr ? v->cargo_type : CT_PURCHASE;
                        assert(cargo < lengthof(e->grf_prop.spritegroup));
                        this->root_spritegroup = e->grf_prop.spritegroup[cargo] != nullptr ? e->grf_prop.spritegroup[cargo] : e->grf_prop.spritegroup[CT_DEFAULT];
                }
        }
}



void GetCustomEngineSprite(EngineID engine, const Vehicle *v, Direction direction, EngineImageType image_type, VehicleSpriteSeq *result)
{
        VehicleResolverObject object(engine, v, VehicleResolverObject::WO_CACHED, false, CBID_NO_CALLBACK);
        result->Clear();

        bool sprite_stack = HasBit(EngInfo(engine)->misc_flags, EF_SPRITE_STACK);
        uint max_stack = sprite_stack ? lengthof(result->seq) : 1;
        for (uint stack = 0; stack < max_stack; ++stack) {
                object.ResetState();
                object.callback_param1 = image_type | (stack << 8);
                const SpriteGroup *group = object.Resolve();
                uint32 reg100 = sprite_stack ? GetRegister(0x100) : 0;
                if (group != nullptr && group->GetNumResults() != 0) {
                        result->seq[result->count].sprite = group->GetResult() + (direction % group->GetNumResults());
                        result->seq[result->count].pal    = GB(reg100, 0, 16); // zero means default recolouring
                        result->count++;
                }
                if (!HasBit(reg100, 31)) break;
        }
}


void GetRotorOverrideSprite(EngineID engine, const struct Aircraft *v, bool info_view, EngineImageType image_type, VehicleSpriteSeq *result)
{
        const Engine *e = Engine::Get(engine);

        /* Only valid for helicopters */
        assert(e->type == VEH_AIRCRAFT);
        assert(!(e->u.air.subtype & AIR_CTOL));

        VehicleResolverObject object(engine, v, VehicleResolverObject::WO_SELF, info_view, CBID_NO_CALLBACK);
        result->Clear();
        uint rotor_pos = v == nullptr || info_view ? 0 : v->Next()->Next()->state;

        bool sprite_stack = HasBit(e->info.misc_flags, EF_SPRITE_STACK);
        uint max_stack = sprite_stack ? lengthof(result->seq) : 1;
        for (uint stack = 0; stack < max_stack; ++stack) {
                object.ResetState();
                object.callback_param1 = image_type | (stack << 8);
                const SpriteGroup *group = object.Resolve();
                uint32 reg100 = sprite_stack ? GetRegister(0x100) : 0;
                if (group != nullptr && group->GetNumResults() != 0) {
                        result->seq[result->count].sprite = group->GetResult() + (rotor_pos % group->GetNumResults());
                        result->seq[result->count].pal    = GB(reg100, 0, 16); // zero means default recolouring
                        result->count++;
                }
                if (!HasBit(reg100, 31)) break;
        }
}

/**
 * Check if a wagon is currently using a wagon override
 * @param v The wagon to check
 * @return true if it is using an override, false otherwise
 */
bool UsesWagonOverride(const Vehicle *v)
{
        assert(v->type == VEH_TRAIN);
        return Train::From(v)->tcache.cached_override != nullptr;
}

/**
 * Evaluate a newgrf callback for vehicles
 * @param callback The callback to evaluate
 * @param param1   First parameter of the callback
 * @param param2   Second parameter of the callback
 * @param engine   Engine type of the vehicle to evaluate the callback for
 * @param v        The vehicle to evaluate the callback for, or nullptr if it doesnt exist yet
 * @return The value the callback returned, or CALLBACK_FAILED if it failed
 */
uint16 GetVehicleCallback(CallbackID callback, uint32 param1, uint32 param2, EngineID engine, const Vehicle *v)
{
        VehicleResolverObject object(engine, v, VehicleResolverObject::WO_UNCACHED, false, callback, param1, param2);
        return object.ResolveCallback();
}

/**
 * Evaluate a newgrf callback for vehicles with a different vehicle for parent scope.
 * @param callback The callback to evaluate
 * @param param1   First parameter of the callback
 * @param param2   Second parameter of the callback
 * @param engine   Engine type of the vehicle to evaluate the callback for
 * @param v        The vehicle to evaluate the callback for, or nullptr if it doesn't exist yet
 * @param parent   The vehicle to use for parent scope
 * @return The value the callback returned, or CALLBACK_FAILED if it failed
 */
uint16 GetVehicleCallbackParent(CallbackID callback, uint32 param1, uint32 param2, EngineID engine, const Vehicle *v, const Vehicle *parent)
{
        VehicleResolverObject object(engine, v, VehicleResolverObject::WO_NONE, false, callback, param1, param2);
        object.parent_scope.SetVehicle(parent);
        return object.ResolveCallback();
}


/* Callback 36 handlers */
uint GetVehicleProperty(const Vehicle *v, PropertyID property, uint orig_value)
{
        return GetEngineProperty(v->engine_type, property, orig_value, v);
}


uint GetEngineProperty(EngineID engine, PropertyID property, uint orig_value, const Vehicle *v)
{
        uint16 callback = GetVehicleCallback(CBID_VEHICLE_MODIFY_PROPERTY, property, 0, engine, v);
        if (callback != CALLBACK_FAILED) return callback;

        return orig_value;
}


static void DoTriggerVehicle(Vehicle *v, VehicleTrigger trigger, byte base_random_bits, bool first)
{
        /* We can't trigger a non-existent vehicle... */
        assert(v != nullptr);

        VehicleResolverObject object(v->engine_type, v, VehicleResolverObject::WO_CACHED, false, CBID_RANDOM_TRIGGER);
        object.waiting_triggers = v->waiting_triggers | trigger;
        v->waiting_triggers = object.waiting_triggers; // store now for var 5F

        const SpriteGroup *group = object.Resolve();
        if (group == nullptr) return;

        /* Store remaining triggers. */
        v->waiting_triggers = object.GetRemainingTriggers();

        /* Rerandomise bits. Scopes other than SELF are invalid for rerandomisation. For bug-to-bug-compatibility with TTDP we ignore the scope. */
        byte new_random_bits = Random();
        uint32 reseed = object.GetReseedSum();
        v->random_bits &= ~reseed;
        v->random_bits |= (first ? new_random_bits : base_random_bits) & reseed;

        switch (trigger) {
                case VEHICLE_TRIGGER_NEW_CARGO:
                        /* All vehicles in chain get ANY_NEW_CARGO trigger now.
                         * So we call it for the first one and they will recurse.
                         * Indexing part of vehicle random bits needs to be
                         * same for all triggered vehicles in the chain (to get
                         * all the random-cargo wagons carry the same cargo,
                         * i.e.), so we give them all the NEW_CARGO triggered
                         * vehicle's portion of random bits. */
                        assert(first);
                        DoTriggerVehicle(v->First(), VEHICLE_TRIGGER_ANY_NEW_CARGO, new_random_bits, false);
                        break;

                case VEHICLE_TRIGGER_DEPOT:
                        /* We now trigger the next vehicle in chain recursively.
                         * The random bits portions may be different for each
                         * vehicle in chain. */
                        if (v->Next() != nullptr) DoTriggerVehicle(v->Next(), trigger, 0, true);
                        break;

                case VEHICLE_TRIGGER_EMPTY:
                        /* We now trigger the next vehicle in chain
                         * recursively.  The random bits portions must be same
                         * for each vehicle in chain, so we give them all
                         * first chained vehicle's portion of random bits. */
                        if (v->Next() != nullptr) DoTriggerVehicle(v->Next(), trigger, first ? new_random_bits : base_random_bits, false);
                        break;

                case VEHICLE_TRIGGER_ANY_NEW_CARGO:
                        /* Now pass the trigger recursively to the next vehicle
                         * in chain. */
                        assert(!first);
                        if (v->Next() != nullptr) DoTriggerVehicle(v->Next(), VEHICLE_TRIGGER_ANY_NEW_CARGO, base_random_bits, false);
                        break;

                case VEHICLE_TRIGGER_CALLBACK_32:
                        /* Do not do any recursion */
                        break;
        }
}

void TriggerVehicle(Vehicle *v, VehicleTrigger trigger)
{
        if (trigger == VEHICLE_TRIGGER_DEPOT) {
                /* store that the vehicle entered a depot this tick */
                VehicleEnteredDepotThisTick(v);
        }

        v->InvalidateNewGRFCacheOfChain();
        DoTriggerVehicle(v, trigger, 0, true);
        v->InvalidateNewGRFCacheOfChain();
}

/* Functions for changing the order of vehicle purchase lists */

struct ListOrderChange {
        EngineID engine;
        uint target;      ///< local ID
};

static SmallVector<ListOrderChange, 16> _list_order_changes;

/**
 * Record a vehicle ListOrderChange.
 * @param engine Engine to move
 * @param target Local engine ID to move \a engine in front of
 * @note All sorting is done later in CommitVehicleListOrderChanges
 */
void AlterVehicleListOrder(EngineID engine, uint target)
{
        /* Add the list order change to a queue */
        ListOrderChange *loc = _list_order_changes.Append();
        loc->engine = engine;
        loc->target = target;
}

/**
 * Comparator function to sort engines via scope-GRFID and local ID.
 * @param a left side
 * @param b right side
 * @return comparison result
 */
static int CDECL EnginePreSort(const EngineID *a, const EngineID *b)
{
        const EngineIDMapping *id_a = _engine_mngr.Get(*a);
        const EngineIDMapping *id_b = _engine_mngr.Get(*b);

        /* 1. Sort by engine type */
        if (id_a->type != id_b->type) return (int)id_a->type - (int)id_b->type;

        /* 2. Sort by scope-GRFID */
        if (id_a->grfid != id_b->grfid) return id_a->grfid < id_b->grfid ? -1 : 1;

        /* 3. Sort by local ID */
        return (int)id_a->internal_id - (int)id_b->internal_id;
}

/**
 * Deternine default engine sorting and execute recorded ListOrderChanges from AlterVehicleListOrder.
 */
void CommitVehicleListOrderChanges()
{
        /* Pre-sort engines by scope-grfid and local index */
        SmallVector<EngineID, 16> ordering;
        Engine *e;
        FOR_ALL_ENGINES(e) {
                *ordering.Append() = e->index;
        }
        QSortT(ordering.Begin(), ordering.Length(), EnginePreSort);

        /* Apply Insertion-Sort operations */
        const ListOrderChange *end = _list_order_changes.End();
        for (const ListOrderChange *it = _list_order_changes.Begin(); it != end; ++it) {
                EngineID source = it->engine;
                uint local_target = it->target;

                const EngineIDMapping *id_source = _engine_mngr.Get(source);
                if (id_source->internal_id == local_target) continue;

                EngineID target = _engine_mngr.GetID(id_source->type, local_target, id_source->grfid);
                if (target == INVALID_ENGINE) continue;

                int source_index = ordering.FindIndex(source);
                int target_index = ordering.FindIndex(target);

                assert(source_index >= 0 && target_index >= 0);
                assert(source_index != target_index);

                EngineID *list = ordering.Begin();
                if (source_index < target_index) {
                        --target_index;
                        for (int i = source_index; i < target_index; ++i) list[i] = list[i + 1];
                        list[target_index] = source;
                } else {
                        for (int i = source_index; i > target_index; --i) list[i] = list[i - 1];
                        list[target_index] = source;
                }
        }

        /* Store final sort-order */
        const EngineID *idend = ordering.End();
        uint index = 0;
        for (const EngineID *it = ordering.Begin(); it != idend; ++it, ++index) {
                Engine::Get(*it)->list_position = index;
        }

        /* Clear out the queue */
        _list_order_changes.Reset();
}

/**
 * Fill the grf_cache of the given vehicle.
 * @param v The vehicle to fill the cache for.
 */
void FillNewGRFVehicleCache(const Vehicle *v)
{
        VehicleResolverObject ro(v->engine_type, v, VehicleResolverObject::WO_NONE);

        /* These variables we have to check; these are the ones with a cache. */
        static const int cache_entries[][2] = {
                { 0x40, NCVV_POSITION_CONSIST_LENGTH },
                { 0x41, NCVV_POSITION_SAME_ID_LENGTH },
                { 0x42, NCVV_CONSIST_CARGO_INFORMATION },
                { 0x43, NCVV_COMPANY_INFORMATION },
                { 0x4D, NCVV_POSITION_IN_VEHICLE },
        };
        assert_compile(NCVV_END == lengthof(cache_entries));

        /* Resolve all the variables, so their caches are set. */
        for (size_t i = 0; i < lengthof(cache_entries); i++) {
                /* Only resolve when the cache isn't valid. */
                if (HasBit(v->grf_cache.cache_valid, cache_entries[i][1])) continue;
                bool stub;
                ro.GetScope(VSG_SCOPE_SELF)->GetVariable(cache_entries[i][0], 0, &stub);
        }

        /* Make sure really all bits are set. */
        assert(v->grf_cache.cache_valid == (1 << NCVV_END) - 1);
}