Guard Turfs

I've hacked together the beginnings of guard turf. The idea of turf is to have some areas of the map in which the player can move unmolested so long as he doesn't do anything suspicious. Here's a quick visualization of the turfs (click to enlarge):



Different guards have different turfs: the bank guards care about the cyan building in the upper right, for instance. This is likely overkill; I will probably be able to cut it down to a guarded/unguarded designation, or break it down by a handful of factions.

As an initial test I just made it so that guards can't see you if they are patrolling and you're not in their turf. This is not a terribly satisfactory solution, though.

I also did a quick experiment in loiter detection. I thought it might be interesting if the street guards would harass you if they thought you were hanging around somewhere you ought to be moving along. When I mentioned this to my wife she laughed and said that the Supreme Court has had its hands full slapping down anti-loitering legislation. Loiter detection in real life is tricky at best, often amounting to an excuse for police to arrest black men driving with white women and that sort of thing. Apparently Mayor Daley of Chicago has tried several times to pass laws prohibiting gang members from loitering on the streets.

Fortunately I don't care if my guards are just or not, so long as they act believably. I have tried summing the player's movements over a window of a few turns and if the resulting vector falls below a threshold he's considered to be loitering. I think this might work out OK.

I'm still pondering whether the addition of turfs is a good design decision. One goal is to add relatively safe areas from which to reconnoiter the guarded areas, looking for good ways in. Another goal is to have accessible public areas. I plan to do some experiments with overheard speech soon, and would like to have safe areas in which to listen. Also I'd like to have non-guard people walking the streets. These goals could also be met to some extent by providing appropriate cover or darkness within guarded territory, but I think the turfs will provide an additional layer of control and believability.

Bump To Use

Continuing last week's thought, I tried out bump-to-use and really like it.

Formerly when you would attempt to move into a usable object (a door, lamp, or switch, say), you'd get a message saying something like “Press Ctrl-left to open the door.” Thus, you'd learn what something was by bumping it, then use a Ctrl-dir key chord to actually use it.

Following a tester suggestion, I tried switching it so that you don't have to press Ctrl-dir to use most things. Instead you just bump them directly and they get used.

This makes the game feel a lot more fluid, which is good. Most usable objects are fairly self-explanatory, and the ones that aren't were not getting well explained under the old system, anyway. The big puzzle for me is how to allow players to shut doors. At the moment this is accomplished by aiming a Ctrl-dir combo at an open door while standing next to it.

At the moment I have status-bar messages that indicate what happened when you use something. This is all right but I think I can pare it down to be even less obtrusive. I'm going to try allocating a field on the status bar for indicating the “current thing.” Normally this will be the terrain underneath the player, but when you use something or bump something it will describe that thing instead, so after opening a door it would say door on the status bar.

I also spent several hours writing some dialog for the captain of the protagonist's ship, which in the test level serves as home base. The ship captain is my first attempt at a friendly character. By having him guard his ship I hoped to introduce the player to the mechanics of guards in a safe environment. He says most of the same things as regular guards, until he recognizes his passenger. “Using” him triggers a series of lines. (Our hero is currently the classic silent player-character whose reticence provokes monologues from everyone he meets.)

I've been mulling over whether the game design has room for sidekicks; the ship captain is kind of a prototype. They have the potential to add a lot more interest to the story since they'd each have their own agendas. However, it's important that they not take away any of the fun of the game. None of them should steal any loot that you can, for instance.

Miscellaneous interface tests

Another update for my turn-based, ASCII rendition of Thief.

I've decided to shelve random level construction for a bit and return to AI and gameplay development, where things were going well. To warm up I tried a couple of things I've been intending to for a long time. Neither worked out, but I'm glad to have seen them on-screen.

Status bar terrain description

At the moment the game requires a Ctrl-plus-direction key chord to use objects in the environment. If the player bumps into one of these objects using normal movement, the game gives them a prompt along the lines of “Press Ctrl-Up to open the door.”

This works pretty well for unobtrusively teaching the player what all the usable things are. Unfortunately it doesn't provide any way to teach the player about the terrain types under their feet.

As an experiment I added a phrase to the status bar that described the currently-occupied square. Something like “On a creaky floorboard&rdquo or “Under a table.” It feels a bit too overbearing to me, though, so I'm trying to think of alternatives.

Prohibit movement while speech is on-screen

The other problem I tried to solve is that the player can be holding down a movement key and miss the speech balloons flashing by when other characters talk. I did a quick experiment to require the player to press Space to clear the speech balloons before moving. That turns out to be incredibly onerous. If you aren't interested in what people are saying you should be able to just go about your business.

I think the correct solution for missed messages will be undo/redo. This will allow players to back up time a few moves to see dialog they missed. I've started looking at applications' undo/redo interfaces.

The Microsoft apps all seem to use Ctrl-Z and Ctrl-Y for undo and redo. I'm not sure how Ctrl-Y got chosen; it is not reachable with the same hand that's doing the undo operations. Perhaps undo predated redo by a few years and all the nearby keys were already taken by that time.

Maya (a 3D modeling package I use at work) uses Ctrl-Z and Shift-Z for undo/redo. This allow for easy motion in both directions. I think I have also used an application that paired Ctrl-Z with Ctrl-Shift-Z.

In addition to undo/redo I think I'm going to want a hotkey for jumping straight to the end of the timeline. I could envision Ctrl-Shift-Y under the Microsoft scheme, or perhaps Ctrl-Shift-Z under the Maya scheme.

Another key pair might be Space/Backspace, since they are natural antitheses. Space already does duty for clearing status-bar messages and speech balloons, though (as in most other Roguelikes), so that might not work. Backspace/Enter could work, too, but both of these ideas are pretty nonstandard.

Other Ideas

One of my testing complaints was that it was a bit cumbersome to have to use Ctrl-dir to open doors. I've been thinking about ways I could turn using into normal movement. For the most part it would just work. The interface would be slightly more risky for a couple of reasons: the player has to try an unfamiliar object to see what it does, rather than getting a bump message; and cruising along by holding down a key could result in using something when the player collided with it.

I'm not too worried about the learning aspect; I can put up a message on the status bar following the use saying what the player just did. A certain amount of experimentation is fun.

The accidental uses due to holding down keys could be reduced by not allowing a held key to use; you'd have to let up on the key and press it again.

The other thing I haven't figured out with a non-Ctrl-based use is how to close open doors. Open doors currently have no physical presence so they can't be bumped. In that way they are unique so they have always troubled me.

Open doors could be made into a physical presence. They would sit off to one side of the open doorway; stepping on one would close it. I think I'll try this out to see how it feels.

Nothing done

I was in Portland/Vancouver all weekend (plus Friday) at a wedding so I've gotten very little done. More later, hopefully.

The wedding was at Marshall House, named after George Marshall (he of the Plan). I think Queen Anne Victorian is my style.

Had some superb biscuits and gravy at Bread and Ink Cafe in Portland's Hawthorne district. I've eaten there several times over the past decade and it's always been good. They've got some sort of walk-up waffle window now which we didn't get a chance to try.

Review: Gravitron 2

Gravitron 2 is a retro-style arcade shooter in the vein of Gravitar and Thrust. You fly a rocket to a series of tiny planet surfaces, where you must destroy one or more reactors and then make your escape before the entire planet blows up. In addition to flying and shooting, the ship is capable of landing on any flat surface, which is useful for rescuing engineers. Each rescued engineer repairs a bit of hull damage as well as adding a bonus to your score for the level.

The ship controls are a slight update to the Lunar Lander family. The mouse's X axis directly orients the ship, and there is a button each for thrusting, firing, and shields. Thrusting and shields expend fuel, which can be replenished by landing or hovering near fuel depots in the levels.

The game has a nice variety of enemies. Levels often contain moving parts. There are occasionally gates with switches, and destructible trees. Each level has a checkpoint; when you first touch the checkpoint, it snapshots the enemies alive at that time. When you die the game restarts you at the checkpoint with the snapshotted enemies. Thus there is an incentive to try and clear as big a swath of the level as possible before touching the checkpoint, which is risky.

I have not finished the game; I think I'm about twenty levels in. I don't think the difficulty curve is as smooth as it ought to be (I'm reviewing version 1.5). Gravitron 2 is brutally hard in places; I've played some levels dozens of times to get through. I have a dormant game project that uses almost this exact interface, so I was already quite good at flying the rocket, and it is still really hard for me. In general the game does a good job of encouraging “Just one more try” gameplay, though. My two-year-old daughter likes watching the game; when I die she tells me “We have to try again!”

I was just over at the Chipmunk physics library page and noticed the game author's handle in the forums, so I wouldn't be surprised if Gravitron 2 makes use of the Chipmunk library for its physics. In general the game's physics is impressive, but there does seem to be some inconsistency in how much damage collisions with the environment do. I also wish the rocket didn't bounce quite so much off of walls.

There's a free demo available with the first five levels. If you like it, the full game only costs $5 (at this writing) so it's not a difficult purchase to justify. In terms of hours of gameplay per dollar this is a great value.

Ron “X-Out” Bunce has since updated his game to version 1.7, fixing several minor interface quirks and an instant-death physics bug. Give it a try!

Villa Creation (first steps)

Andrea Palladio published his Four Books of Architecture in 1570. He designed villas for wealthy people who lived in and around Venice.



Palladio was one of the earliest Neoclassicists. You don't have to read him very far to find out that he was heavily influenced by Roman architecture, in particular by the only surviving book by a Roman architect, Vitruvius' Ten Books on Architecture.

Palladio's villas were an attempt to recreate Roman style in the 16th century. His books were eventually translated to English and because of them Neoclassicism swept 18th-century England. Thomas Jefferson was a fan, and used Palladio's blueprints as a starting point for designing his home Monticello.

I had gotten the impression that Palladio's books might have given some rules for laying out his villas, but that turns out not to be the case. He does give a whole bunch of floor-plans in Book Two, though, which are quite instructive.

In 1978 Stiny and Mitchell developed a shape grammar by looking at Palladio's blueprints (“The Palladian Grammar,” Environment and Planning B 5). I have not been able to get a copy of this paper so I don't know whether it's worth anything.

Vitruvius's books are interesting in their own right. For instance, the section about where to locate the temples for the various deities is interesting. Apparently the worship of Vulcan involves lots of fire, so you want his temple well outside the city. The worship of Venus involves rites that prove distracting to upright young men, so Vitruvius recommends putting Venus's temple outside the city as well. Near the harbor, if you've got one.

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I have turned from whole-city layout to the layout of individual buildings. It seems wiser to work bottom-up from a single piece of gameplay (the burgling of a building) rather than top-down.

My initial steps for randomly constructing a building are not very impressive. I am using an adaptation of the algorithm I used for laying out alleys. The rooms of the house are laid out on a grid. The walls of the grid are then given random offsets. Finally, the random offsets are made to match in either the horizontal or vertical direction (randomly chosen) at each junction, to ensure that rooms don't overlap or leave gaps. Additionally I impose a line of symmetry on the house. Here's what I've got so far:



To ensure that all rooms are connected by doors, I use a breadth-first search to flood-fill connections from the front door. Then I go through and randomly add other door connections.



The problem with the grid-based approach is that it is hard to have rooms that vary significantly in size. For instance, a lot of urban Roman houses have a central courtyard (to admit light) surrounded by a whole bunch of little rooms.



Still, having something is better than having nothing. I'm going to throw in some loot and guard patrols and see how it plays, and then try to think about how to give the houses more realism and character.

Science!

I'm having trouble getting back up to speed on my programming project, as no doubt is clear. Today I'm going to stop by the library to pick up Andrea Palladio's 16th century book on architecture. I've heard that it lays out a shape grammar for villas which would be useful in my project. That may be a 20th century paper by Mitchell and somebody else, though; I won't know until I can get my hands on some of it.

In the meantime science marches on:

Epazote: My wife tried making identical batches of pinto beans, one with epazote and one without. I could not really tell a difference, so either we had weak epazote or it doesn't add significantly to the flavor of beans. At least not in an unmistakable way like, say, chorizo.

Head On: A product with one of the most memorable no-budget TV advertising campaigns in recent history. We picked up a small tube the other day when we were at the pharmacy. It turns out to be a homeopathic headache remedy! Who knew? Of course it's got menthol in it: that's how you know it's working. I have an idea for a product of my own: a special lamp with a row of switches for enabling various rays which will cure headaches, insomnia, constipation, etc. It would make use of advanced LED technology and the unseen portions of the electromagnetic spectrum.

Cheesy Chipotle Chicken Chorizo Chili: How does this sound for a Taco Bell special?

Avatar, the last Airbender: I stayed away from this Nickelodeon series for a long time because of the cheesy name and four-elements premise (don't get me started on the four elements!) but enough people sang its praises that I finally borrowed the first season from the DVD library at work. It's a great show!