G'Day....

I have been working on a text adventure game. You can follow my progress on my Blog (link in signature at bottom of post) Anyway, I have been chugging through the, frankly, tedious work of building my word lists and stuff as well as competing the 1st step in the phraser.. which is single command recognition and execution.  The problem I am running into is how do I go about implementing area specific code and conditions, in my very generic and general purpose classes.

Class Structure As it is Now

(Obviously I have striped this list to make my problem clearer)

• Level Class - Contains a variable List<Area> Level [][]. This is a 2 dimensional array creating a X/Y reference values for any given spot on the array.
• Player Class - Contains a variable PosX and PosY... these are modified by movement and on .getPosition() returns the value of List<Area>[][]. This is how I am acessing the correct place in my game world based on the player position.
• Area Class - This contains a given area. These are placed inside the List<Area>[][].
• Item Class -  This contains individual items sitting in the level to be interacted with.

So a Level -> Area -> Items.

The Problem

The problem I have having is I can not work out how to go about having unique things inside these Areas and Items. Like for example a Ball can not be opened but a box can. So they need a different variable. I can not use the same class for both Box and Sphere. An area might have nothing in it, but it also may have a table that needs a ball put on it and then something is activated.

What I am getting at here is that the structure is basically working using these generic classes but I am not sure how I can code exciting and interesting unique things in these areas or on these items with out fundamentally changing things, or adding a mass of variables to the cases that are only used in some cases.

Say I have a Box in the scene.

I want the players to see it, and then try to pick it up.. but they can't. So the examine it more closely and find that it is actually got a button on it. The press it and something happens.

The questions is where are the methods to do these unique things and edit the item parameters going to be put. If I put them in the Item or Area sections I need to basically have a unique class for everyone .. maybe that is what I am supposed to do. Thing is I wrote a really handy data txt file importer for areas and files that I do not want to scrap. That only really works on these generic ideas. To get really interesting events and natural language responses there needs to be a ton of unique things going on ... but I have kinda designed everything to be very generic.

Possible Solution

I know that a List<type> can contain classes as long as all the classes in the list are inherited form the same base class. So I was thinking of a new class that populates a simular kind of list to Level<area>[][]. This will be something like List<gameLogic>[][]. In here I put a all the methods for the individual areas. The Key values like the other list is pulled form the player positions. So if I need a unique method I could call it from Player.GetPostions().gameLogic.SetOpen();... this then would trigger bools and change description text and stuff in the more generic objects. The problem with this is I still need a series of generic method calls. So far example area.item[9] might be a Hat... if I type GETHAT it trigges a generic get() method on the hat, that ALL items have.. but it then actually dose a unique bit of logic in the logic class for that specific room.. so item.get(prams) triggers gameLogic.get(prams).. and those prams allow me to do specific "gets" per-object..

Is that making any sense?

So yeah.. I'm kinda stuck

Yeah.. so I am kinda stuck here about what to do. The crux of my issue is that I have a game loop and a series of objects.. level, areas in the level and items in the area. These are all generic so the I can be easily build the level during initiation of the game with out tons of unique code making editing and changes hard. So the exact way to continue these simple loops, but access unique code is confusing me. I mean as long as everything was very simple I could get wawya with it. but as I wanted to add more complex stuff I was finding the need for additional variables and checks.

Any thoughts? (sorry if I am not clear)

Quick demo of you... this shows the start screen and the first room. (pressing spacebar skips the text printout to finished)

So the very first time the game loops and finds you in a area it tests a variable in that area to see if you have ever been there before.. if not it prints a "cinematic".. witch is a long story focused text description, that you only see once. (it is also added to a log for reading latter). Then if you type the look command... it finds the area look description and adds it to the print buffer, then finds all the items (there are only two at the moment) and appends their descriptions and then prints out that look.

All pretty cool and I ma happy with it.

This is just to show something in the thread.. I seem to have noticed anything with a youtube video in it gets way more comments hahaah

I'm no expert in formal methodologies but I like to think about the data itself before I try to think about things as individual objects(classes).

So, as I understand it(hopefully correctly) it seems you are having trouble deciding how to organize the item data that you are needing to store and access. 

Let me throw a dart at the board across the room:

You're writing a text/phrase parser are you not?

Why not include a small array/list of item attributes in string form into your Item class?

You could have one for descriptive info: "type:box", "color:blue"

You could have another for actionable attributes: "opens:front","button:top","explodes:30"

This would then be a blue box that has a button on top and opens in the front, which explodes 30 seconds after opening...

Hope it helps!

This would require you expanding the functionality of your parser to perform game-logic tasks not related directly to user-input.  Like deciphering what an object is and determining how to describe it to the player, but that might be beneficial to your process, and the development of the parser itself.   It could also make it easier to save and load(to/from file) objects using JSON or some other simple serialization method.

Again, this is mostly a shot in the dark.  Hope it helps somewhat.

Maybe talking about the specifics of my program was confusing the question... I may edit the OP.

What I am asking is how do you insert unique code into a gameloop that uses generic classes... like at what point do you start using unique classes and how do these get incorporated. 

I'm just having a hard time working out a way to put unique checks and events into scenes.

I'd like to thank everyone that has been chatting in this thread. I only haven't responded as I didn't want to stifle  any responses.

On 1/18/2019 at 10:08 PM, wurstbrot said:

I agree with Irusan, and I'd like to go into a little more detail about his suggestion. It's one of my favorite topics in game dev, the entity component system (ECS) pattern - an incredibly simple yet powerful approach to solve exactly the sort of problem as you have it in a very elegant way.

I think for my particular case this "esc" pattern is really interesting, but might be to advanced for me right now as well as kinda requiring me to rewrite the entire project in a new and unfamiliar way. I ordered a book from ebay called "Game Engine Architecture" which was recommended in a number of threads and stackexchanges and stuff I read while googling this thing.

15 hours ago, Alberth said:

One way to go about it is to code what to do when the user enters a verb in a separate object, a Behavior object. Such a behavior object decides what should be done for a single item. Each item thus has a behavior object for each verb it responds to.

If the user types "open chest", the system looks for an 'open' behavior object in the chest item, and runs it if it exists. One Behavior class may always open the item, while another class would first look for a key Item in the inventory, for example.

This makes a lot of sense to me and also sounds like it can be done without making massive modifications to what I have already got. It is kinda a better version of my basic idea of having a "gameLogic" class as I spoke of above. 

It also occurs to me that this might have been what Irusan was saying at the start but the chat

On 1/18/2019 at 5:49 PM, Irusan, son of Arusan said:

I suggest making your item class a container for behaviours and then make these behaviours your unique classes.

Each behaviour would have verbs (look, take, open, etc) that determine how the player interacts with it. The box would then have a "container" behaviour that lets it be opened/closed and items taken in or out of it.

I am not sure why I didn't understand him. Maybe it was the talk of design patterns and stuff that confused me. Not that wurstbot didn't give good points, but my googling sent me to very complex idea used in large programs.

15 hours ago, Alberth said:

Thus if you give the Chest Item a AlwaysOpenBehavior object, it would always open, while if you give it a OpenWithKeyBehavior object, you will need a key to open the chest item. This means that for every kind of 'open' you need to code a class, but that's unavoidable anyway (somewhere you do have to specify all possible variations that you want to have), but for different items with the same open behavior, you can re-use the same behavior class to make another 'open' object.

The next puzzle you'll run into is that you want to have a zillion items, each with a zillion behaviors. I would suggest you store such information in a textfile, so you can easily edit it, At startup, you load the textfile into the program, and build all items with the correct behaviors into your Level/Area.

I have already written a working text file importer. I am using it at the mo to build the area's and items as well as setting some variables like bools and text descriptions and stuff. For example in the area file I have a list of item names, these names are read and used as file name to load data txt files for items and then they are read into a item class and that class is added to a list<Items> in the area. 

One of the goals of my project was to be able tom "write" the text adventure in text file with out editing individual code.

//--AREA_NAME: CommandTestRoom

//LIST_OF_ITEMS_IN_AREA--START
item1
item2
item3
item4
item5
//LIST_OF_ITEMS_IN_AREA--END

Basically the data reader takes lines from the txt file, reads a start and end line (I'm calling brackets) and then reads each individual line between those lines. I also built a way to read a single line with a keyword at the start. So in the example above it retrieves just "CommandTestRoom" and "item1" "item2" etc etc.

TL:DR

The question is how do I define "behaviour" classes in a text file? I can retrieve "names" from a file with the code I have in the datareader, but not sure how to translate that as "behaviours"

What I am thinking at the moment is a extension to the data reader for behaviours that is basically a giant switch statement. that adds different "behaviour" classes based on what string it is reading. 

So player types "open box"... the command processor sees that OPEN is available on that object, but when it triggers that particular item's "open" it is loading a unique behaviour.

So this would require an interface ... so I have to boil down all actions into some kind of base action.. like Open, Move, Take and stuff, and those actions trigger but are picking up unique code instead of all the same open code.

This might not be the best way I only thought this up as I wrote this post... I'm open to suggestions.