= Open Adventure Maintainer's Notes =
by Eric S. Raymond
+// SPDX-FileCopyrightText: (C) Eric S. Raymond <esr@thyrsus.com>
+// SPDX-License-Identifier: CC-BY-4.0
In which we explain what has been done to this code since Don Woods
authorized us to ship it under an open-source license. There's a
Ninneman. Eric received Don Woods's encouragement to update and ship
the game; Jason signed on early in the process to help. The assistance
of Peje Nilsson in restructuring some particularly grotty gotos is
-gratefully acknowledged. Petr Voropaev contributed fuzz testing. Aaron
-Traas did a lot of painstaking work to improve test coverage.
+gratefully acknowledged. Petr Voropaev contributed fuzz testing and
+code cleanups. Aaron Traas did a lot of painstaking work to improve
+test coverage, and factored out the last handful of gotos. Ryan
+Sarson nudged us into fixing a longstannding minor bug in the
+handling of incorrect magic-word sequebcesm,
== Nomenclature ==
Extreme care has been taken not to make changes that would alter the
logic of the game as we received it from Don Woods, except to fix
glitches that were clearly bugs. By policy, all user-visible
-changes must be revertible with the -o (oldstyle) option.
+changes to gameplay must be revertible with the -o (oldstyle) option.
It is a goal of this project to exactly preserve the *intended
behavior* of 430-point Adventure, but the implementation of it is fair
future languages. It has already survived a move from FORTRAN to C; a
future as a Python or Go translation seems possible, even probable.
+Compatibility with the 2.5 source we found has been checked by
+building a version patched minimally to support the seed command and
+running it against the entire test suite, which has 100% code
+coverage.
+
== Functional changes ==
Bug fixes:
+* The caged bird used to be counted as two items in your inventory.
+
* Reading the relocated Witt's End sign in the endgame didn't work right.
-* Behavior when saying the giant's magic words outside his room wasn't
- quite correct - the game responded as though the player were in
- the room.
-
-* Attempting to extinguish an unlit urn caused it to lose its oil.
+* Oyster was readable after first gotten even when not carried.
+
+* Response to an attempt to unlock the oyster while carrying it was incorrect.
+
+* Behavior when saying the giant's magic words before having seen them
+ wasn't quite correct - the game responded as though the player had
+ already read them ("...can't you read?"). The new message is "Well,
+ that was remarkably pointless!" The -o option reverts this change.
-* Unrecognized words are no longer truncated to 5 characters and
- uppercased when they are echoed.
+* Attempting to extinguish an unlit urn caused it to lose its oil.
* "A crystal bridge now spans the fissure." (progressive present) was
incorrect most places it appeared and has been replaced by "A crystal
bridge spans the fissure." (timeless present).
+* A few minor typos have been corrected: absence of capitalization on
+ "Swiss" and "Persian", inconsistent spelling of "imbedded" vs. "embedded",
+ "eying" for "eyeing", "thresholds" for "threshholds".
+
+* Under odd circumstances (dropping rug or vase outdoors) the game could
+ formerly say "floor" when it should say "ground" (or "dirt", or something).
+
+Enhancements:
+
By default, advent issues "> " as a command prompt. This feature
became common in many variants after the original 350-point version,
but was never backported into Crowther & Woods's main line before now.
alias collides with 'd' for 'down', but the others have been implemented.
The "-o" (oldstyle) option disables them.
+Unrecognized words are no longer truncated to 5 characters and
+uppercased when they are echoed. The "-o" (oldstyle) option restores
+this behavior.
+
A "seed" command has been added. This is not intended for human use
but as a way for game logs to set the PRNG (pseudorandom-number generator) so
that random events (dwarf & pirate appearances, the bird's magic word)
will be reproducible.
+A "version" command has been added. This has no effect on gameplay.
+
+The text displayed by the "news" command has been updated.
+
A -l command-line option has been added. When this is given (with a
file path argument) each command entered will be logged to the
specified file. Additionally, a generated "seed" command will be put
functions; without C's fread(3)/fwrite() and structs it was
necessarily pretty ugly by modern standards. Encryption and
checksumming have been discarded - it's pointless to try
-tamper-proofing saves when everyone has the source code.
+tamper-proofing saves when everyone has the source code. However
+the game still integrity-checks savefiles on resume, including an
+abort if the endianness of the restoring machine does not match that of
+the saving machine. There is a magic-cookie header on the saves so
+in theory they could be identified by programs like file(1).
+
+Save and resume filenames are stripped of leading and trailing
+whitespace before processing.
+
+A -r command-line option has been added. When it is given (with a file
+path argument) it is functionally equivalent to a RESTORE command.
+
+An -a command-line option has been added (conditionally on
+ADVENT_AUTOSAVE) for use in BBS door systems. When this option is
+given, the game roads from the specified filename argument on startup
+and saves to it on quit or a received signal. There is a new nmessage
+to inform the user about this.
-A -r command-line been added. When it is given (with a file path
-argument) it is functionally equivalent to a RESTORE command.
+The game can be built in a mode that entirely disables save/resume
+(-DADVENT_NOSAVE). If the game had been built this way, a diagnostic is
+emitted if you try to save or resume.
== Translation ==
Jason Ninneman and I have moved it to what is almost, but not quite,
idiomatic modern C. We refactored the right way, checking correctness
against a comprehensive test suite that we built first and verified
-with coverage tools (we have over 95% coverage, with the remaining
-confined to exception cases that are very difficult to reach). This is
+with coverage tools (there is effectively 100% code coverage). This is
what you are running when you do "make check".
The move to modern C entailed some structural changes. The most
that was performed because the FORTRAN it was written in had no string
type. Text from the adventure.text file was compiled into sequences
of sixbit code points in a restricted character set, packed 5 to a
-32-bit word (it seems clear from the code that words were originally
+32-bit word (and it seems clear from the code that words were originally
*6* chars each packed into a PDP-10 36-bit word). A command noun or
verb was one of these words, and what would be string operations in a
more recent language were all done on sequences of these words.
our new code (which occasionally uses malloc(3)), but none as yet
in Don's old code (which didn't).
+After version 1.11, correctness was carefully checked against the
+behavior of a binary from before the big refactoring.
+
The code falls short of being fully modern C in the following
ways:
and the choice to refrain will make forward translation into future
languages easier.
-* There are a few gotos left that resist restructuring; all are in the
- principal command interpreter function implementing its state
- machine.
-
* Linked lists (for objects at a location) are implemented using an array
of link indices. This is a surviving FORTRANism that is quite unlike
normal practice in C or any more modern language. We have not tried
arrays are a cell larger than they strictly need to be and cell 0 is
unused.
-* The code is still mostly typeless, slinging around machine longs
- like a FORTRAN or BCPL program. Some (incomplete) effort has been made
- to introduce semantic types.
-
We have made exactly one minor architectural change. In addition to the
old code's per-object state-description messages, we now have a per-object
message series for state *changes*. This makes it possible to pull a fair
amount of text out of the arbitrary-messages list and associate those
-mesages with the objects that conceptually own them.
+messages with the objects that conceptually own them.
+
+== Development status ==
+
+We consider this project finished. All issues and TODOs have been
+cleared, behavior has been carefully checked against original ADVENT,
+no future demand for new features is expected, and the test suite has
+100% code coverage. If new bugs appear as the toolchain bit-rots out
+from under underneath, we will fix those problems.
// end
projects / open-adventure.git / blobdiff