A Python module and demonstration programs for modding a classic computer RPG
INSTALLING / USING
python setup.py install
(You will need to run it as root, e.g. "sudo python setup.py install". You can also use "python setup.py develop" if you anticipate modifying the program.)
WHAT IS delv FOR?
delv is a Python module that allows users to manipulate the archives of games based on the "Delver" engine, written 1995-1999 by Glenn Andreas. It was only used, as far as is known, in the 1999 game "Cythera," published by Ambrosia Software, inc. ("Cythera" and "Delver" are trademarks of Ambrosia Software inc or Glenn Andreas.)
Extensive technical documentation of this engine and game, which were used to produce delv, can be found at http://www.ferazelhosting.net/wiki/Cythera
The wiki page for delv itself is http://www.ferazelhosting.net/wiki/delv
WHO WROTE delv AND HOW?
delv was originally written by Bryce Schroeder, bryce.schroeder@gmail.com
Website: http://www.bryce.pw
Prior work by various persons over the years and various technical information published by the author of the engine have been used in the Technical Documentation Project supporting delv, but mainly the game has been documented through meticulous black-box reverse engineering. For example, the graphics format was successfully interpreted through systematic "mutation experiments" on the graphics resources. (The notes run to about 40 pages of screenshots and comments.) In other cases, simple observation has sufficed; for example, the essentials of the Delver Archive format are almost immediately evident by inspection with a hex editor.
Cythera's license agreement does not appear to purport to forbid reverse engineering, and if it did, reverse engineering for interoperability is allowed in the United States and many other countries in any case. (delv is based heavily on the facilities offered by modern dynamic programming languages and probably would not benefit much from the specific, highly optmized techniques of implementation that are likely used in Delver anyway.)
WHAT IS THE PURPOSE OF delv?
Self-evidently, you could use it to make a third-party RPG editor suite that is interoperable with a Delver engine based game like Cythera. Another application would, e.g. be map viewers or dynamic walkthrough/guide websites for the game.
Several examples and utilties are provided to showcase the usage of delv.
WHAT CAN I DO WITH delv?
Anything permitted by the GPL version 3, ~but we ask you to please not attempt to use it to circumvent Cythera's shareware restrictions~ (Update: Ambrosia is apparently defunct now. I can't give you permission to do this, of course, but I am no longer making this polite request), and not to distribute any modified versions of "Cythera Data" (i.e. the scenario file). This latter action at least would violate Ambrosia Software's copyright (and the Cythera EULA, as it permits only redistribution of the unmodified and complete game.)
Speaking of which, here is the unmodified and complete game: https://www.bryce.pw/Cythera.bin
Here's an example of something to do with delv: Custom player character portraits in Cythera: http://ferazelhosting.net/~bryce/making_a_custom_portrait_with_redelv/tutorial.html
HOW IS delv DOCUMENTED?
Most of the classes and methods have docstrings. An overview is presented here:
delv.archive - Reads and writes Delver Archives (e.g. "Cythera Data")
delv.colormap - Contains the palette of indexed colors used by Cythera. You may need to access this if you are undertaking to display graphics.
delv.graphics - Handles the Delver Engine's custom compressed graphics format, and also the uncompressed icon graphics.
delv.monster - Handles the special monster stats resource. (Note that in the course of the game, the scripting system would normally access this itself and interpret it without any special help; this module is provided for the convenience of editors. How monsters defined is, in principle, scenario dependent.)
delv.script - Assembles, disassembles, and (in principle) executes scripts, including virtual machine scripts and AI-type scripts.
delv.sound - Handles sound and music resources.
delv.store - Utility functions for editing various kinds of binary storage formats used by Delver, such as symbol lists and serialized scripting system objects.
delv.tile - Handles graphical tiles and their renderer / engine properties (movement obstruction, vision blocking, light source specifications, etc.)
delv.util - Utilities for other delv modules, but you can use the public functions and classes if you like.
GETTING AT SOUNDS AND GRAPHICS
Multimedia formats are provided in reasonably universal formats, e.g. arrays; you will probably have to write glue code if you want to display them as PNG, use them with pygame, or whatever. delv couldn't practically support all the different ways of getting multimedia to the output device using python, and it would introduce huge testing complexity and lots of dependencies for something that is intended to also make simple command line tools and maybe even run in a browser-based python implementation someday. Sorry about that.
EXAMPLE PROGRAMS
delv comes with some examples. Probably, it'll come with more someday. You will need to install delv (python setup.py install) before they will work. All of them are, unsurprisingly, in the examples/ directory.
"archive_example.py" - Shows how one can load, modify, and save archives.
"dcg_encoder.py" - Saves .png images (n.b. with correct color maps) to the Delver Compressed Graphics format. Requires the Python Imaging Library.
"dcg_view.py" - Simple viewer for Delver Compressed Graphics. It can view them in archives or as single files, and save them to PNG. Requires the Python Imaging Library.
"delvpack.py" - This just converts Delver Archives back and forth between archive files and unpacked directories. First arguement is source, second is destination, it'll figure out what needs to happen. Very simple.
"icon_view.py" - Views uncompressed icons (Resources 8Axx / subindex 137.)
"mag.py" - Command-line tool for creating and applying patches. (It can apply patches created for the first-party patch manager Magpie, and create patches that it can apply, but it can't create patches that can be applied by Magpie.)
"tileshow.py" - Shows tiles from their tile ID (i.e. the ID used in maps.)
FUTURE DIRECTIONS
Resolve the remaining scripts that don't disassemble/assemble properly
Editors for various static data records
A nice map/proplist integrated editor