Function Unit_IsValidMovementIntoStructure

src/unit.c:660–693

* Determines whether a move order into the given structure is OK for * a particular unit. * * It handles orders to invade enemy buildings as well as going into * a friendly structure (e.g. refinery, repair facility). * * @param unit The Unit to operate on. * @param s The Structure to operate on. * @return * 0 - invalid movement * 1 - valid movement, will try to get close to the structure

 * 2 - valid movement, will attempt to damage/conquer the structure
 */
uint16 Unit_IsValidMovementIntoStructure(Unit *unit, Structure *s)
{
	const StructureInfo *si;
	const UnitInfo *ui;
	uint16 unitEnc;
	uint16 structEnc;

	if (unit == NULL || s == NULL) return 0;

	si = &g_table_structureInfo[s->o.type];
	ui = &g_table_unitInfo[unit->o.type];

	unitEnc = Tools_Index_Encode(unit->o.index, IT_UNIT);
	structEnc = Tools_Index_Encode(s->o.index, IT_STRUCTURE);

	/* Movement into structure of other owner. */
	if (Unit_GetHouseID(unit) != s->o.houseID) {
		/* Saboteur can always enter houses */
		if (unit->o.type == UNIT_SABOTEUR && unit->targetMove == structEnc) return 2;
		/* Entering houses is only possible for foot-units and if the structure is conquerable.
		 * Everyone else can only move close to the building. */
		if (ui->movementType == MOVEMENT_FOOT && si->o.flags.conquerable) return unit->targetMove == structEnc ? 2 : 1;
		return 0;
	}

	/* Prevent movement if target structure does not accept the unit type. */
	if ((si->enterFilter & (1 << unit->o.type)) == 0) return 0;

	/* TODO -- Not sure. */
	if (s->o.script.variables[4] == unitEnc) return 2;

	/* Enter only if structure not linked to any other unit already. */
	return s->o.linkedID == 0xFF ? 1 : 0;
}

/**
 * Sets the destination for the given unit.