Function GetPreviewCompany

src/engine.cpp:914–939

* Get the best company for an engine preview. * @param e Engine to preview. * @return Best company if it exists, #CompanyID::Invalid() otherwise. */

 * @return Best company if it exists, #CompanyID::Invalid() otherwise.
 */
static CompanyID GetPreviewCompany(Engine *e)
{
	CompanyID best_company = CompanyID::Invalid();

	/* For trains the cargomask has no useful meaning, since you can attach other wagons */
	CargoTypes cargomask = e->type != VEH_TRAIN ? GetUnionOfArticulatedRefitMasks(e->index, true) : ALL_CARGOTYPES;

	int32_t best_hist = -1;
	for (const Company *c : Company::Iterate()) {
		if (c->block_preview == 0 && !e->preview_asked.Test(c->index) &&
				c->old_economy[0].performance_history > best_hist) {

			/* Check whether the company uses similar vehicles */
			for (const Vehicle *v : Vehicle::Iterate()) {
				if (v->owner != c->index || v->type != e->type) continue;
				if (!v->GetEngine()->CanCarryCargo() || !HasBit(cargomask, v->cargo_type)) continue;

				best_hist = c->old_economy[0].performance_history;
				best_company = c->index;
				break;
			}
		}
	}

	return best_company;
}

/**
 * Checks if a vehicle type is disabled for all/ai companies.