Method ConsistChanged

src/train_cmd.cpp:107–251

* Recalculates the cached stuff of a train. Should be called each time a vehicle is added * to/removed from the chain, and when the game is loaded. * Note: this needs to be called too for 'wagon chains' (in the depot, without an engine) * @param allowed_changes Stuff that is allowed to change. */

 * @param allowed_changes Stuff that is allowed to change.
 */
void Train::ConsistChanged(ConsistChangeFlags allowed_changes)
{
	uint16_t max_speed = UINT16_MAX;

	assert(this->IsFrontEngine() || this->IsFreeWagon());

	const RailVehicleInfo *rvi_v = RailVehInfo(this->engine_type);
	EngineID first_engine = this->IsFrontEngine() ? this->engine_type : EngineID::Invalid();
	this->gcache.cached_total_length = 0;
	this->compatible_railtypes = {};

	bool train_can_tilt = true;
	int16_t min_curve_speed_mod = INT16_MAX;

	for (Train *u = this; u != nullptr; u = u->Next()) {
		const RailVehicleInfo *rvi_u = RailVehInfo(u->engine_type);

		/* Check the this->first cache. */
		assert(u->First() == this);

		/* update the 'first engine' */
		u->gcache.first_engine = this == u ? EngineID::Invalid() : first_engine;
		u->railtypes = rvi_u->railtypes;

		if (u->IsEngine()) first_engine = u->engine_type;

		/* Set user defined data to its default value */
		u->tcache.user_def_data = rvi_u->user_def_data;
		this->InvalidateNewGRFCache();
		u->InvalidateNewGRFCache();
	}

	for (Train *u = this; u != nullptr; u = u->Next()) {
		/* Update user defined data (must be done before other properties) */
		u->tcache.user_def_data = GetVehicleProperty(u, PROP_TRAIN_USER_DATA, u->tcache.user_def_data);
		this->InvalidateNewGRFCache();
		u->InvalidateNewGRFCache();
	}

	for (Train *u = this; u != nullptr; u = u->Next()) {
		const Engine *e_u = u->GetEngine();
		const RailVehicleInfo *rvi_u = &e_u->VehInfo<RailVehicleInfo>();

		if (!e_u->info.misc_flags.Test(EngineMiscFlag::RailTilts)) train_can_tilt = false;
		min_curve_speed_mod = std::min(min_curve_speed_mod, u->GetCurveSpeedModifier());

		/* Cache wagon override sprite group. nullptr is returned if there is none */
		u->tcache.cached_override = GetWagonOverrideSpriteSet(u->engine_type, u->cargo_type, u->gcache.first_engine);

		/* Reset colour map */
		u->colourmap = PAL_NONE;

		/* Update powered-wagon-status and visual effect */
		u->UpdateVisualEffect(true);

		if (rvi_v->pow_wag_power != 0 && rvi_u->railveh_type == RAILVEH_WAGON &&
				UsesWagonOverride(u) && !HasBit(u->vcache.cached_vis_effect, VE_DISABLE_WAGON_POWER)) {
			/* wagon is powered */