Ktaf

A Kotlin library that provides a framework for creating text adventures and interactive stories for JVM. Ktaf is a Kotlin implementation of NetAF. Ktaf aims to provide all of the basic building blocks required to start writing simple games.

Overview

Included in the repo are example projects that show how Ktaf can be used to write games that run in a terminal window as originally intended, and also an example Swing application and an example Ktor webserver are also included that render the game in HTML.

At its core Ktaf provides simple classes for developing game elements:

Environments

Environments are broken down in to three elements - Overworld, Region and Room. An Overworld contains one or more Regions. A Region contains one or more Rooms. A Room can contain up to six exits (north, south, east, west, up and down).

Overworld
├── Region
│   ├── Room
│   ├── Room
│   ├── Room
├── Region
│   ├── Room
│   ├── Room

Exits

Rooms contain exits. Exits can be locked to block progress through the game.

// create a test room
val room = Room("Test Room", "A test room.")
        
// add an exit to the north
room.addExit(Exit(Direction.NORTH))

Items

Items add richness to a game. Items support interaction with the player, rooms, other items and NPC's. Items can morph in to other items. For example, using item A on item B may cause item B to morph into item C.

val sword = Item("Sword", "The heroes sword.")

Playable Character

Each Ktaf game has a single playable character. The game is played through the view point of the playable character.

val player = PlayableChracter("Dave", "The hero of the story.")

Non-playable Characters

Non-playable characters (NPC's) can be added to rooms and can help drive the narrative. NPC's can hold conversations, contains items, and interact with items.

val npc = NonPlayableChracter("Gary", "The antagonist of the story.")

Commands

Ktaf provides commands for interacting with game elements:

• Drop X - drop an item.
• Examine X - allows items, characters and environments to be examined.
• Take X - take an item.
• Talk to X - talk to a NPC, where X is the NPC.
• Use X on Y - use an item. Items can be used on a variety of targets. Where X is the item and Y is the target.
• N, S, E, W, U, D - traverse through the rooms in a region.

Ktaf also provides global commands to help with game flow and option management:

• About - display version information.
• CommandsOn / CommandsOff - toggle commands on/off.
• Exit - exit the game.
• Help - display the help screen.
• KeyOn / KeyOff - turn the Key on/off.
• Map - display the map.
• New - start a new game.

Custom commands can be added to games without the need to extend the existing interpretation.

Interpretation

Ktaf provides classes for handling interpretation of input. Interpretation is extensible with the ability for custom interpreters to be added outside of the core Ktaf library.

Conversations

Conversations can be held between the player and a NPC. Conversations support multiple lines of dialogue and responses.

Attributes

All game assets support customisable attributes. This provides the possibility to build systems within a game, for example adding currency and trading, adding HP to enemies, MP to your character, durability to Items etc.

Rendering

Ktaf provides frames for rendering the various game screens. These are fully extensible and customisable. These include:

• Scene frame.
• Help frame.
• Map frame.
• Title frame.
• Completion frame.
• Game over frame.
• Transition frame.
• Conversation frame.

Maps

Maps are automatically generated for regions and rooms, and can be viewed with the map command:

Maps display visited rooms, exits, player position, if an item is in a room, lower floors and more.

Dynamic Loading

Precompiled games can also be discovered and loaded from .jar files at runtime with the GameCatalogResolver.

// load a .jar file and discover all GameTemplate instances
val catalog = GameCatalogResolver.resolveCatalogFromJar(File(path))

// in this case take the first GameTemplate from the catalog
val template = catalog.get().first()

// begin execution of the game
GameExecutor.execute(gameTemplate, ioConfiguration = AnsiConsoleConfiguration)

Prerequisites

The default frame collections for rendering in a terminal assume that a terminal capable of handling ANSI is being used. If a terminal that doesn't support ANSI is used the game will still render but ANSI will also be displayed as text.

Getting Started

Clone the repo

Clone the repo to the local machine.

git clone https://github.com/benpollarduk/ktaf.git

Hello World

// create a game template. this template can be use to instantiate instances of the game
val template = object : GameTemplate() {

    override fun instantiate(ioConfiguration: IOConfiguration): Game {

        // create the player. this is the character the user plays as
        val player = PlayableCharacter("Dave", "A young boy on a quest to find the meaning of life.")

        // create region maker. the region maker simplifies creating in game regions. a region contains a series of rooms
        val regionMaker = RegionMaker("Mountain", "An imposing volcano just East of town.").also {
            // add a room to the region at position x 0, y 0, z 0
            it[0, 0, 0] = Room("Cavern", "A dark cavern set in to the base of the mountain.")
        }

        // create overworld maker. the overworld maker simplifies creating in game overworlds. an overworld contains a series or regions
        val overworldMaker = OverworldMaker("Daves World", "An ancient kingdom.", listOf(regionMaker))

        // return a new instance of the game
        return Game(
            GameInformation(
                "The Life Of Dave",
                "Dave awakes to find himself in a cavern...",
                "A very low budget adventure.",
                "Me",
            ),
            player,
            overworldMaker.make(),
            { EndCheckResult.notEnded },
            { EndCheckResult.notEnded },
        )
    }
}

// begin execution of the game. the ioConfiguration determines how input is received and output is displayed
GameExecutor.execute(template, ioConfiguration = ioConfiguration)

Tutorial

The quickest way to start getting to grips with Ktaf is to take a look at the Getting Started page.

Example game

An example game is provided in the ktaf-exmples directory and have been designed with the aim of showcasing the various features.

Running the examples

The example applications can be used to execute the example Ktaf game and demonstrate the core principals of the framework.

Example console

The example console provides a basic terminal application that can execute a Ktaf game.

• Build the example console application.

./gradlew clean :app-ktaf-example-console:build

• Run the example console application.

cd app-ktaf-example-console/build/libs
java -jar app-ktaf-example-console-all.jar

Example Swing application

The example Swing application provides a basic UI that can execute a Ktaf game.

• Build the example Swing application.

./gradlew clean :app-ktaf-example-swing:build

• Run the example Swing application.

./gradlew :app-ktaf-example-swing:run

Example Ktor web app

The example Ktor web app provides a basic web server that can host a Ktaf game and display it in the browser.

• Build the example Ktor application.

./gradlew clean :app-ktaf-example-ktor:build

• Run included ktor example webserver then navigate to localhost:8080 in browser.

./gradlew :app-ktaf-example-ktor:run

Documentation

Please visit https://benpollarduk.github.io/ktaf-docs/ to view the Ktaf documentation.

Please visit https://benpollarduk.github.io/ktaf-api-docs/ to view the Ktaf Api documentation.

For Open Questions

Visit https://github.com/benpollarduk/ktaf/issues