Function AcceptEnginePreview

src/engine.cpp:882–907

* Company \a company accepts engine \a eid for preview. * @param eid Engine being accepted (is under preview). * @param company Current company previewing the engine. * @param recursion_depth Recursion depth to avoid infinite loop. */

 * @param recursion_depth Recursion depth to avoid infinite loop.
 */
static void AcceptEnginePreview(EngineID eid, CompanyID company, int recursion_depth = 0)
{
	Engine *e = Engine::Get(eid);

	e->preview_company = CompanyID::Invalid();
	e->preview_asked.Set();

	EnableEngineForCompany(eid, company);

	/* Notify preview window, that it might want to close.
	 * Note: We cannot directly close the window.
	 *       In singleplayer this function is called from the preview window, so
	 *       we have to use the GUI-scope scheduling of InvalidateWindowData.
	 */
	InvalidateWindowData(WC_ENGINE_PREVIEW, eid);

	/* Don't search for variants to include if we are 10 levels deep already. */
	if (recursion_depth >= 10) return;

	/* Find variants to be included in preview. */
	for (Engine *ve : Engine::IterateType(e->type)) {
		if (ve->index != eid && ve->info.variant_id == eid && ve->info.extra_flags.Test(ExtraEngineFlag::JoinPreview)) {
			AcceptEnginePreview(ve->index, company, recursion_depth + 1);
		}
	}
}

/**
 * Get the best company for an engine preview.