static struct RealSpriteGroup *

ResolveVehicleSpriteGroup(struct SpriteGroup *spritegroup, struct Vehicle *veh)

{

	switch (spritegroup->type) {

		case SGT_REAL:

			return &spritegroup->g.real;

		case SGT_DETERMINISTIC: {

			struct DeterministicSpriteGroup *dsg = &spritegroup->g.determ;

			struct SpriteGroup *target;

			int value = -1;

			//debug("[%p] Having fun resolving variable %x", dsg->variable);

			if ((dsg->variable >> 6) == 0) {

				/* General property */

				value = GetDeterministicSpriteValue(dsg->variable);

			} else {

				/* Station-specific property. */

				if (dsg->var_scope == VSG_SCOPE_PARENT) {

					/* First engine in the vehicle chain */

					if (veh != NULL && veh->type == VEH_Train)

						veh = GetFirstVehicleInChain(veh);

				}

				if (dsg->variable == 0x40) {

					if (veh && veh->type == VEH_Train) {

						Vehicle *u = GetFirstVehicleInChain(veh);

						byte chain_before = 0, chain_after = 0;

						while (u != veh) {

							u = u->next;

							chain_before++;

						}

						while (u->next != NULL) {

							u = u->next;

							chain_after++;

						};

						value = chain_before << 16 | chain_after << 8

						        | (chain_before + chain_after + 1);

					} else {

						value = 1; /* 1 vehicle in the chain */

					}

				} else {

					// TTDPatch runs on little-endian arch;

					// Variable is 0x80 + offset in TTD's vehicle structure

					switch (dsg->variable - 0x80) {

#define veh_prop(id_, value_) case id_: if (veh != NULL) value = value_; break /* XXX factorise "if" */

						veh_prop(0x00, veh->type);

						veh_prop(0x01, veh->subtype);

						veh_prop(0x04, veh->index);

						veh_prop(0x05, veh->index & 0xFF);

						/* XXX? Is THIS right? */

						veh_prop(0x0A, veh->next_order_param << 8 | veh->next_order);

						veh_prop(0x0B, veh->next_order);

						veh_prop(0x0C, veh->num_orders);

						veh_prop(0x0D, veh->cur_order_index);

						veh_prop(0x10, veh->load_unload_time_rem);

						veh_prop(0x11, veh->load_unload_time_rem & 0xFF);

						veh_prop(0x12, veh->date_of_last_service);

						veh_prop(0x13, veh->date_of_last_service & 0xFF);

						veh_prop(0x14, veh->service_interval);

						veh_prop(0x15, veh->service_interval & 0xFF);

						veh_prop(0x16, veh->last_station_visited);

						veh_prop(0x17, veh->tick_counter);

						veh_prop(0x18, veh->max_speed);

						veh_prop(0x19, veh->max_speed & 0xFF);

						veh_prop(0x1F, veh->direction);

						veh_prop(0x28, veh->cur_image);

						veh_prop(0x29, veh->cur_image & 0xFF);

						veh_prop(0x32, veh->vehstatus);

						veh_prop(0x33, veh->vehstatus);

						veh_prop(0x34, veh->cur_speed);

						veh_prop(0x35, veh->cur_speed & 0xFF);

						veh_prop(0x36, veh->subspeed);

						veh_prop(0x37, veh->acceleration);

						veh_prop(0x39, veh->cargo_type);

						veh_prop(0x3A, veh->cargo_cap);

						veh_prop(0x3B, veh->cargo_cap & 0xFF);

						veh_prop(0x3C, veh->cargo_count);

						veh_prop(0x3D, veh->cargo_count & 0xFF);

						veh_prop(0x3E, veh->cargo_source); // Probably useless; so what

						veh_prop(0x3F, veh->cargo_days);

						veh_prop(0x40, veh->age);

						veh_prop(0x41, veh->age & 0xFF);

						veh_prop(0x42, veh->max_age);

						veh_prop(0x43, veh->max_age & 0xFF);

						veh_prop(0x44, veh->build_year);

						veh_prop(0x45, veh->unitnumber);

						veh_prop(0x46, veh->engine_type);

						veh_prop(0x47, veh->engine_type & 0xFF);

						veh_prop(0x48, veh->spritenum);

						veh_prop(0x49, veh->day_counter);

						veh_prop(0x4A, veh->breakdowns_since_last_service);

						veh_prop(0x4B, veh->breakdown_ctr);

						veh_prop(0x4C, veh->breakdown_delay);

						veh_prop(0x4D, veh->breakdown_chance);

						veh_prop(0x4E, veh->reliability);

						veh_prop(0x4F, veh->reliability & 0xFF);

						veh_prop(0x50, veh->reliability_spd_dec);

						veh_prop(0x51, veh->reliability_spd_dec & 0xFF);

						veh_prop(0x52, veh->profit_this_year);

						veh_prop(0x53, veh->profit_this_year & 0xFFFFFF);

						veh_prop(0x54, veh->profit_this_year & 0xFFFF);

						veh_prop(0x55, veh->profit_this_year & 0xFF);

						veh_prop(0x56, veh->profit_last_year);

						veh_prop(0x57, veh->profit_last_year & 0xFF);

						veh_prop(0x58, veh->profit_last_year);

						veh_prop(0x59, veh->profit_last_year & 0xFF);

						veh_prop(0x5A, veh->next_in_chain_old);

						veh_prop(0x5B, veh->next_in_chain_old & 0xFF);

						veh_prop(0x5C, veh->value);

						veh_prop(0x5D, veh->value & 0xFFFFFF);

						veh_prop(0x5E, veh->value & 0xFFFF);

						veh_prop(0x5F, veh->value & 0xFF);

						veh_prop(0x60, veh->string_id);

						veh_prop(0x61, veh->string_id & 0xFF);

						/* 00h..07h=sub image? 40h=in tunnel; actually some kind of status

						 * aircraft: >=13h when in flight

						 * train, ship: 80h=in depot

						 * rv: 0feh=in depot */

						/* TODO veh_prop(0x62, veh->???); */

						/* TODO: The rest is per-vehicle, I hope no GRF file looks so far.

						 * But they won't let us have an easy ride so surely *some* GRF

						 * file does. So someone needs to do this too. --pasky */

#undef veh_prop

					}

				}

			}

			target = value != -1 ? EvalDeterministicSpriteGroup(dsg, value) : dsg->default_group;

			//debug("Resolved variable %x: %d", dsg->variable, value);

			return ResolveVehicleSpriteGroup(target, veh);

		}

		default:

		case SGT_RANDOM:

			error("I don't know how to handle random spritegroups yet!");

			return NULL;

	}

}

	rsg = ResolveVehicleSpriteGroup(group, v);

	if (rsg->sprites_per_set == 0 && cargo != 29) { /* XXX magic number */

		rsg = ResolveVehicleSpriteGroup(&_engine_custom_sprites[engine][29], v);

						// TTDPatch runs on little-endian arch;

						// Variable is 0x70 + offset in the TTD's station structure

								if (stat) value = stat->airport_flags & 0xFF;