The ancients designed interception dead simple: when you overfly a
sector, you get intercepted by the sector owner. Fine print
interception rules govern which planes intercept.
Then complexity got piled on top of it.
Chainsaw 2 added an extra interception by surface ship owners, in the
target sector only.
Chainsaw 3 added an extra interception by land unit owners, in the
target sector only (Empire 4 later merged this extra land unit
interception with the extra surface ship interception).
Chainsaw 3 added an entirely separate kind of interception: air
defense missions. When you enter a sector in some air defense op
area, you get intercepted. Fine print air defense rules govern which
planes intercept. These rules differ significantly from the
interception fine print.
Additional complexity comes from these facts:
* Air defense mission interception happens in addition to non-mission
interception. You can boost your total interception by setting up
air defense. Which means you must set it up, or forgo an advantage.
* Air defense planes are not available for non-mission interception
duty. You need to decide on a split.
* In contrast to non-mission interception, interceptors flying air
defense get intercepted.
Moreover, the air defense code breaks one of the plane code's design
assumptions, namely that just one plane sortie is active at a time.
The air defense sortie runs while the sortie it intercepts is in
progress. This leads to two interceptions being active at the same
time: the one intercepting the original sortie, and the one
intercepting the air defense sortie. The same plane can fly in both
interceptions, and damage received in the interception of the air
defense sortie is wiped out, triggering a seqno mismatch oops.
The previous commit already simplified non-mission interception: you
get intercepted by anyone who owns the sector, or a surface ship or a
land unit there, whether it's the target sector or not.
Now simplify mission interception, by merging air defense back into
ordinary interception: when you overfly a sector, you get intercepted
by anyone who owns the sector, or a surface ship or land unit there,
or has an air defense mission covering the sector. That's all. No
multiple interceptions, no separate air defense rules.
Remove air_defense(). Simplify ac_encounter() and sam_intercept()
accordingly; both lose their last parameter.
Change sam_intercept() and ac_intercept() to intercept in mission op
areas. New parameter only_mission to suppress non-mission
interception. Pass zero when the intercepting country owns the sector
or a surface ship or land unit in the sector.
ac_encounter() can't efficiently predict whether a country intercepts,
so it needs to call ac_intercept() unconditionally. This kills the
optimization to collect interceptors only when needed; simplify
accordingly, replacing getilist() by getilists().
--- How to build the info pages ---
Make remakes info pages, table of contents and index automatically.
This requires Perl 5 and troff. To remake just formatted info pages,
run make info.
To remake HTML info, run make html. This is not done by default. The
recommended start page is TOP.html, but you may also like all.html.
--- How to add a new info page ---
To create a new info page, follow these steps:
1. Decide which chapter to put your info page in:
Commands - Empire Commands
Concepts - Game concepts
Introduction - General info about playing Empire
Server - Info about the server
2. Decide what to call your info page:
- If it's an Empire command, give it the same name as the command
as listed in lib/player/empmod.c
- Info names are case-insensitive. Make sure there isn't another
one that differs only in case.
- Make sure your info page doesn't have the same name as an existing
subject or chapter.
3. Format your info page.
The file name for a page NAME must be NAME.t. It's easiest to start
with an existing file.
The first line must be a title header:
.TH arg1 arg2
- arg1 should be the chapter, one of: Command, Concept,
Introduction, Server
- arg2 is the title of your page. If it contains more than one
word, make sure it's in double quotes
- if the info page is for an Empire command, then arg2 must be the
command name in ALL UPPERCASE.
The second line must be a name header:
.NA arg1 arg2
- arg1 must be the name
- arg2 is a one-line description of the info page which will be
put on the Subject page that your info page belongs to. It should
be in double quotes
The third line must be a level header:
.LV arg
- arg must be a level, one of Basic, Expert
The last line should be a see also:
.SA "item1, item2, ..., subject1, subject2"
- the stuff in quotes is a list of other info pages which are
related to this page and info Subjects to which this page belongs.
- the stuff in quotes must all be on the same line
- You must include at least one subject (see the Subjects
subdirectory) in the list (at the end of the list by convention).
The lines in between can contain troff requests. The following
additional requests are available:
Empire command syntax:
.SY "command <ARGS>"
An Empire command example:
.EX "command args"
No Formatting:
.NF
this stuff
won't be formatted
.FI
Begin paragraph:
.s1
Item in a description:
.L
Fancy troff magic is prone to break HTML output.
4. Format your info page, update table of contents and index
Run make info html. If it fails, peruse the error messages and fix
your info page.
==APPENDIX A - What exactly the Perl scripts do==
The scripts read all of the info pages and create a two-level table of
contents for them, organized by subject. An info page belongs to a
subject if that subject appears as an entry in the .SA ("SEE ALSO")
field of the info page _and_ that entry is not the name of another
info page.
For example, the .SA field of headlines.t contains the entries
"newspaper" and "Communication". Since there's already an info page
called "newspaper.t", but there is no "Communication" info page, then
the headlines info page is considered to be a member of the
Communication
subject.
The output of these script is a bunch of .t files. The file TOP.t is
the top-level table of contents and lists all of the subjects. Then
for each SUBJECT, a SUBJECT.t file is created, listing all of the info
pages that belong to it.
==APPENDIX B - The checklist.pl script==
FIXME This does not work at the moment
This little perl script compares the "list" of legal Empire commands
in your server with the Empire commands documented in info. To run
it, login to your game and type:
[##:##]% list > list.out
Then, move the list.out file to this directory and run checklist.pl.
Markus Armbruster
6564ff2240