Changes between Version 1 and Version 2 of WikiStart

Timestamp:

Jul 20, 2023, 6:56:58 PM (11 months ago)

Author:

pulkomandy

Comment:

--

WikiStart

@@ -1 @@
-= Welcome to Trac
+= Readingame
 
-Trac is a '''minimalistic''' approach to '''web-based''' management of
-'''software projects'''. Its goal is to simplify effective tracking and
-handling of software issues, enhancements and overall progress.
+My notes about rewriting an engine for the Lectures Enjeu game.
 
-All aspects of Trac have been designed with the single goal to
-'''help developers write great software''' while '''staying out of the way'''
-and imposing as little as possible on a team's established process and
-culture.
+This is a "choose your adventure" game (in French) designed for teaching kids how to learn.
 
-As all Wiki pages, this page is editable, this means that you can
-modify the contents of this page simply by using your
-web-browser. Simply click on the "Edit this page" link at the bottom
-of the page. WikiFormatting will give you a detailed description of
-available Wiki formatting commands.
+Some of the adventures were initially published as books by schoolchildren, and adapted into electronic versions here.
 
-"[wiki:TracAdmin trac-admin] ''yourenvdir'' initenv" created
-a new Trac environment, containing a default set of wiki pages and some sample
-data. This newly created environment also contains
-[wiki:TracGuide documentation] to help you get started with your project.
+I remember playing this at school as a kid, and recently I decided to take a closer look at how it works. Maybe I will get as far as rewriting an engine for it so the games can be played on modern systems?
 
-You can use [wiki:TracAdmin trac-admin] to configure
-[http://trac.edgewall.org/ Trac] to better fit your project, especially in
-regard to ''components'', ''versions'' and ''milestones''.
+== Game files
 
+Each game scenario is made of INIT.DAT, MSG.DAT, MSGGEN.DAT, CONDGALE.DAT, CONDSAL.DAT, CONDULTI.DAT.
 
-TracGuide is a good place to start.
+All files are generally composed of chunks starting with a 16-bit size (self-including) followed by some data. A 16-bit 0 serves as a terminator chunk. The cunks do not appear to have an explicit type marker.
 
-Enjoy! [[BR]]
-''The Trac Team''
+== Message files
 
-== Starting Points
+These two files contain the various messages that can be displayed during the adventure.
 
- * TracGuide --  Built-in Documentation
- * [http://trac.edgewall.org/ The Trac project] -- Trac Open Source Project
- * [http://trac.edgewall.org/wiki/TracFaq Trac FAQ] -- Frequently Asked Questions
- * TracSupport --  Trac Support
+The messages are split by "room" chunks.
 
-For a complete list of local wiki pages, see TitleIndex.
+The first 16-bit word indicate the "room" chunk size
+
+The single-page messages chunks are made of a size, followed by a NULL terminated string.
+
+The complex messages chunks are made of a size, followed by more sub-chunks. Each sub-chunk is itself a size + a null terminated string.
+
+The strings can contain various escape sequences:
+
+{{{
+%p - Replaced by the player's first name
+%b - To insert an inline button (followed by a button ID)
+\o - Insert an "Ok" button centered on the last line. Can be followed by an ASCII-encoded digit, possibly indicating which message to show next
+[NSome text] - Hyperlinks, where N is an identifier for the link (it's not a room number, since it can trigger other actions, picking items, moving to subrooms, ...)
+{%f3|%m2~%m3} - Conditionals, if variable f3 is 0, show m2, else show m3
+{%f6|%m6~\o1} - The contents of the condition doesn't have to be a message
+{%c1|%m1|%m2|%m3~%m4} - Show message 1 if c1 is 0, message 2 if it is 1, etc.
+}}}
+
+This tells us a few things:
+
+- %m variables refer to submessages in a complex message
+- %f variables refer to boolean flags (such as owning or not owning an object)
+- %c variables refer to counters (such as health points)
+
+MSGGEN.DAT is similar, but contains a single "room" with global ("general") messages that can be triggered from any room (such as global buttons or using objects).
+
+Here is a rehex script to parse these files:
+
+{{{
+LittleEndian();
+
+// Simple string chunks are defined by a size (self-including) and a
+// string (NULL terminated)
+struct lenstring
+{
+        uint16_t len;
+        local uint16_t realLen = len - 2;
+        char string[realLen];
+};
+
+// Room chunks have a size and are filled by string chunks
+struct ROOM
+{
+        local uint16_t start = FTell();
+
+        uint16_t sizeInBytes;
+
+        struct lenstring substrings[0];
+        while (FTell() - start < sizeInBytes)
+        {
+                ArrayExtend(substrings);
+        }
+};
+
+struct ROOM rooms[0];
+
+while(!FEof())
+{
+        ArrayExtend(rooms);
+}
+}}}