Kali Engine (C) Martok https://github.com/martok/kali/

For copyright information see file LICENSE.

General

Runs on Delphi 7. Newer/Older versions and FPC untested.

This engine is composed of different subsystems, each handling separate aspects. The overarching focus is on old-school graphics at very low resoulutions. It provides only the most basic functions. Most advanced techniques are left to the implementation.

While usage is best seen in the examples provided, it may be neccessary to understand the basic concepts first. The engine provides a TScreen object that is essentially a fusion of TApplication and exactly one TForm. It provides several entry points in the form of event handlers that can be used to build the implementation. The most important idea is the strict distinction between graphics and logic. This is represented by the OnTick and OnRender events. Both occur sequentially in the same loop, but you should not assume that. Future versions may further decouple them.

Ticks can be rate-limited to save computation power. In any case, the event always provides a measurement of time elapsed since the last tick, allowing for timebased movement. Render cycles are passed a Surface which can be drawn on, and should not do any logic (except maybe state-independent animations).

A similar idea applies to the server, but there is of course no Render function. The client and server use a set of Events, just like the Engine does. Communication is based on Entity Messages (notifications from server to client) and Entity Calls (commands from client to server). It is the implementations responsibility to manage entities and route messages if required. Parameters can be passed as Variant arrays, the Net subsystem takes care of converting data and transmitting/ receiving/decoding it back into Variant array form.

Usually, a client will issue a Call on user interaction. The server then processes it, updates its internal states and then sends all clients Messages notifying them of the new state if required. This allows for relatively 'stupid' clients, only holding information essential to rendering and user interaction. Only the server needs all information required for Tick processing.

Subsystems

• Engine

  The Core graphics and game engine. Provides startup code and resource loading as well as graphics and mouse/keyboard interaction.

• Net

  Client and Threaded Server base classes for an entity message based server as well as a generic Entity base class. This does the most basic tasks required for every server, such as handshaking and packet creation. It also provides server states for more high-level Lobby/In-Game distinctions.

• Sound

  OpenAL powered sound system capable of playing Wave and OGG audio on multiple 3D positioned sources.

Examples

The package provides some examples to demonstrate the general use of the engine. You'll notice a recurring theme in there, since they were all built upon the (most basic) "game" example by extending upon and stripping out of it.

The Star Wars character graphics are from a sprite collection I downloaded ages ago; if you recognise the source: please tell me, I would love to give credit!

/example/game

The most basic thing you can do. Shows setup and the logic behind seperate render and tick functions. Also, it shows key interaction for walking and rudimentary (and physically completely wrong ;-) ) jumping. Also notice the two things needed to use the VFS: including it and adding one data overlay.

/example/network

A chat client/server, also demoing the menu system. Has possibly the weirdest menu structure ever and does no error handling at all, but should show the general idea of how to use the net subsystem.

/example/complex

A more complex version of how a game could be structured, employing a "scene"-pattern to handle different views/UIs.

Externals

This engine requires the following external libraries in case the respective subsystem is to be used:

• Engine
  • GraphicEx by Mike Lische - Web Site
  • KAZip by Kiril Antonov - Web Site Direct Link
• Net
  • NarsesBFPA by Narses - Forum Post
  • MessageThread by delfiphan - Forum Post
• Sound
  • libOgg, libVorbis, Binary form taken from Audorra package.
  • ogg/vorbis header translation from FreePascal's oggvorbis package; includes several bugfixes
  • OpenAL Soft - Web Site

History

git commit information is all there is, at least for now.