Function Structure_FindFreePosition

src/structure.c:1253–1299

* Find a free spot for units next to a structure. * @param s Structure that needs a free spot. * @param checkForSpice Spot should be as close to spice as possible. * @return Position of the free spot, or \c 0 if no free spot available. */

 * @return Position of the free spot, or \c 0 if no free spot available.
 */
uint16 Structure_FindFreePosition(Structure *s, bool checkForSpice)
{
	const StructureInfo *si;
	uint16 packed;
	uint16 spicePacked;  /* Position of the spice, or 0 if not used or if no spice. */
	uint16 bestPacked;
	uint16 bestDistance; /* If > 0, distance to the spice from bestPacked. */
	uint16 i, j;

	if (s == NULL) return 0;

	si = &g_table_structureInfo[s->o.type];
	packed = Tile_PackTile(Tile_Center(s->o.position));

	spicePacked = (checkForSpice) ? Map_SearchSpice(packed, 10) : 0;
	bestPacked = 0;
	bestDistance = 0;

	i = Tools_Random_256() & 0xF;
	for (j = 0; j < 16; j++, i = (i + 1) & 0xF) {
		uint16 offset;
		uint16 curPacked;
		uint16 type;
		Tile *t;

		offset = g_table_structure_layoutTilesAround[si->layout][i];
		if (offset == 0) continue;

		curPacked = packed + offset;
		if (!Map_IsValidPosition(curPacked)) continue;

		type = Map_GetLandscapeType(curPacked);
		if (type == LST_WALL || type == LST_ENTIRELY_MOUNTAIN || type == LST_PARTIAL_MOUNTAIN) continue;

		t = &g_map[curPacked];
		if (t->hasUnit || t->hasStructure) continue;

		if (!checkForSpice) return curPacked;

		if (bestDistance == 0 || Tile_GetDistancePacked(curPacked, spicePacked) < bestDistance) {
			bestPacked = curPacked;
			bestDistance = Tile_GetDistancePacked(curPacked, spicePacked);
		}
	}

	return bestPacked;
}

/**
 * Remove the structure from the map, free it, and clean up after it.