Function EngineCostSorter

src/build_vehicle_gui.cpp:193–202

* Determines order of engines by purchase cost * @param a first engine to compare * @param b second engine to compare * @return for descending order: returns true if a < b. Vice versa for ascending order */

 * @return for descending order: returns true if a < b. Vice versa for ascending order
 */
static bool EngineCostSorter(const GUIEngineListItem &a, const GUIEngineListItem &b)
{
	Money va = Engine::Get(a.engine_id)->GetCost();
	Money vb = Engine::Get(b.engine_id)->GetCost();
	int r = ClampTo<int32_t>(va - vb);

	/* Use EngineID to sort instead since we want consistent sorting */
	if (r == 0) return EngineNumberSorter(a, b);
	return _engine_sort_direction ? r > 0 : r < 0;
}

/**
 * Determines order of engines by speed