3.26. Directions

| Chapter 3: Things |

| 3.26. Directions

"Direction" is a kind which is quite unlike most of those seen so far. While it has to do with the physical world, a direction does not exactly belong to it. One cannot find "southeast" sitting on a shelf. "Direction" is not a kind of thing, nor a kind of room: it is a kind in its own right.

Every direction has an "opposite" property, which is always another direction. These occur in matched pairs. The opposite of north is south, just as the opposite of south is north. The opposite of southeast is northwest, the opposite of inside is outside, and so on. When Inform reads a sentence like...

> Bangkok is south of Nakhon Sawan.

...it assumes that the opposite map connection is probably also valid, so that

> Nakhon Sawan is north of Bangkok.

The chapter began with the twelve directions built into Inform:

> north, northeast, east, southeast, south, southwest, west, northwest, up, down, inside, outside

But the built-in set is not always appropriate. Sometimes this is too many; if we wanted to write about a Flatland, for instance, then up and down ought to go. But in practice it is better not to abolish them as directions but instead to forbid travelling in them. (See the Recipe Book for examples.)

But away from our familiar Earth, the usual frame of reference loses its meaning. Terry Pratchett's "Discworld" comedies, set on a rotating disc, use the directions turnwise, widdershins, hubwards and rimwards. On board a Zeppelin airship, which constantly changes its course, the cockpit has no fixed compass bearing from the passenger cabin: it is not very naturally "north". In zero gravity, there is no up or down. Mars does not have a magnetic core, so a compass doesn't work there.

New directions must always be created in opposing pairs, and each must be declared with a clear simple sentence of the form "X is a direction." For instance:

> Turnwise is a direction. The opposite of turnwise is widdershins.
> Widdershins is a direction. The opposite of widdershins is turnwise.
> Hubwards is a direction. The opposite of hubwards is rimwards.
> Rimwards is a direction. The opposite of rimwards is hubwards.

It is then possible to write, say, that:

> Ankh-Morpork is hubwards of Lancre and turnwise from Borogravia.

Of course the World page of the Index for the project normally draws a map based on compass bearings, so it will get a little befuddled by this. But the map drawn in the Index can be given hints to improve its legibility. More on this later, but for now note that

> Index map with turnwise mapped as east.

maps turnwise directions as if they were east, that is, pointing rightwards on the page. (This has no effect on the story file produced; it does not mean turnwise is simply a new name for east; it affects only the look of the Index map, which is only a convenience for the author in any case.)

At one time, directions had to have shortish names (up to three words only), but that's no longer true:

> Just the tiniest smidge off magnetic north is a direction. The opposite of
> just the tiniest smidge off magnetic north is just the tiniest smidge
> off magnetic south.
> Just the tiniest smidge off magnetic south is a direction. The opposite of
> just the tiniest smidge off magnetic south is just the tiniest smidge
> off magnetic north.

38
| Example Prisoner's Dilemma A button that causes a previously non-existent exit to come into being. |
RB

39
| Example The World of Charles S. Roberts Replacing the ordinary compass bearings with a set of six directions to impose a hexagonal rather than square grid on the landscape. |
RB

40
| Example Fore Understand "fore", "aft", "port", and "starboard", but only when the player is on a vessel. |
RB

Suppose we want to understand shipboard directions, but only when the player is aboard a vessel. "Fore" Section 1 - Procedure The starboard is a direction. The starboard has opposite port. Understand "s" as starboard when the location is nautical. The port is a direction. The port has opposite starboard. Understand "p" as port when the location is nautical. The fore is a direction. The fore has opposite aft. Understand "f" as fore when the location is nautical. The aft is a direction. The aft has opposite fore. Understand "a" as aft when the location is nautical. Does the player mean going a nautical direction when the location is nautical: it is very likely. Index map with fore mapped as north. Index map with aft mapped as south. Index map with port mapped as west. Index map with starboard mapped as east. And we can even add new ways to talk about the ways things are mapped, borrowing from the Relations chapter. The following will allow us to us "is abaft of" as well as "is aft of": [The verb to be abaft of implies the mapped-aft-of relation.] Now, to prevent the player from using NORTH onboard ship, or AFT on land: A room can be nautical or earthbound. A room is usually not nautical. A direction can be nautical or earthbound. A direction is usually not nautical. Starboard, port, fore, aft, up, down, the inside and the outside are nautical. Before going a nautical direction when the location is not nautical, say "Nautical directions can only be used on board ship." Before going an earthbound direction when the location is nautical, say "Compass directions make no sense on board ship, but you can use [list of nautical directions] instead." instead. Section 2 - Scenario The Fish Room is aft of the Spirit Room. Starboard of the Fish Room is the After Powder Magazine. The Bread Room is aft of the After Powder Magazine. The Fish Room, the Spirit Room, the Bread Room, and the After Powder Magazine are nautical. The description of the Fish Room is "Absurd quantities of salt fish are kept here, and periodically visited by the cook or someone serving him. It is otherwise an unexceptional little chamber, so far below the waterline that there are no portholes and no external light of any kind. [paragraph break]A narrow doorway leads forward into the Spirit Room, and the After Powder Magazine is starboard." The description of the Spirit Room is "Despite its ghostly name, this is little more than a closet down at the very navel of the ship, in which alcohol is kept: both for purifying wounds and for drinking. Under normal circumstances there is a guard posted here at every hour, lest anyone take to raiding the larder. The current absence of the guard marine strikes you as a very bad sign indeed. [paragraph break]The only way out is aft." The description of the Bread Room is "The Bread Room is not only tiny from side to side and front to back: it is also about half the height of a proper room, and the floor slopes up very steeply with the curve of the hull. [paragraph break]What is kept here would not, on land, be dignified by the name of bread: it's hard tack, punishing to the teeth, dry on the tongue, and usually a home to weevils before half the journey is done. [paragraph break]More headroom, and access to the rest of the ship, lies fore through the After Powder Magazine." The description of the After Powder Magazine is "Kept in near darkness because no one with any sense would bring a naked flame down here: when necessary, it can be lit with a single small lantern made of very thick glass and sealed to keep the sparks within. Sacks of powder are passed up into the higher levels of the ship by the scrubby little boys called 'powder monkeys' -- but none such are here now." Test me with "north / aft / fore".

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