1Liquid War(6) Games Manual Liquid War(6)
2
6 liquidwar - a unique multiplayer wargame
7
9 liquidwar [-vh]
10
12 Liquid War is a multiplayer wargame. Its rules are very simple but yet
13 original.
14
16 -v Displays the version number.
17 -h Displays copyright and various information.
19 ...
21 There are many other command lines options, which are described fur‐
22 ther in this document.
23
25 As Liquid War is a cross-platform program (it also runs on DOS and Win‐
26 dows), I could reasonably not provide groff UNIX-style documentation to
27 Windows user. Therefore, Liquid War's documentation is available in
28 many formats, including HTML, PostScript and PDF.
29 I believe these formats are easier to read than this man page. So
30 check out the /usr/share/doc/liquidwar-doc-5.6.4 directory (from the
31 liquidwar-doc package), for this is where HTML and other documentation
32 files should be. Otherwise, if you are a die-hard man page user, you
33 may continue with this document 8-)
34
37 The Liquid War concept
38 Liquid War is a wargame. But it is different from common wargames.
39 When playing Liquid War, one has to eat one's opponent. There can be
41 from 2 to 6 players. There are no weapons, the only thing you have to
42 do is to move a cursor in a 2-D battlefield. This cursor is followed by
43 your army, which is composed by a great many little fighters. Fighters
44 are represented by small colored squares. All the fighters who have the
45 same color belong to the same team. One very often controls several
46 thousands fighters at the same time. And when fighters from different
47 teams meet, they eat each other, it is as simple as that.
48 How do teams react?
51 Teams are composed of little fighters. These fighters all act indepen‐
52 dently, so it can happen that one single fighters does something dif‐
53 ferent from what all the other do.
54 The main goal of these fighters is to reach the cursor you control. And
56 to do that, they are in a way quite clever, for they choose the short‐
57 est way to reach it. Check it if you want, but it is true, they
58 *really* choose *the* shortest way to reach the cursor. That is the
59 whole point with Liquid War.
60 But these fighters are not perfect, so when they choose this shortest
62 way, they do as if they were alone on the battlefield. That's to say
63 that if there is a fighter blocking their way, they won't have the idea
64 to choose another way, which is free from fighters but would have been
65 longer otherwise. So fighters can be blocked.
66 Who eats whom?
69 When two fighters from different team meet each other, they first try
70 to avoid fighting, and they dodge. But if there is no way for them to
71 move, they get angry and attack the guy which is blocking them. Some‐
72 times, they attack each other and both loose health. But it can happen
73 that a fighter is attacked by another one, which is himself not
74 attacked at all.
75 Here is an example of this behaviour: A blue fighter and a red fighter
77 both want to move to their right, for that would be the shortest way to
78 reach their cursor if there was nobody on the battlefield. But they are
79 blocked by other fighters. If, for instance, the red fighter is on the
80 right and the blue fighter on the left, it is the red fighter which
81 will be eaten.
82 When a fighter is attacked, he first looses health, that is to say that
84 he gets darker. When his health reaches 0, his color changes and he
85 becomes a member of the team by which he has been attacked. Therefore
86 the number of fighters on the battlefield always remains the same.
87 When fighters of a same team get stuck together and block each other,
89 then they regenerate, that is to say that they get brighter.
90 However, I think the best way for you to understand the way it works is
92 to try the game...
93 Basic strategy
96 When I play Liquid War, I always try to surround my opponents, and it
97 usually works.
98 By the way, the computer has no strategy at all, he is a poor player,
100 and if you get beaten by him, it means you have to improve yourself a
101 lot!
102 But still, the computer doesn't do one thing which I've seen many
104 beginners doing: he never keeps his cursor motionless right in the mid‐
105 dle of his own fighters, for this is the best way to loose.
106 More strategy
109 Here are some more tips, kindly submitted by Jan Samohyl.
110 * Try to cut your opponent off walls and surround him completely with
112 your troops; when trying to penetrate his forces inside a tunnel,
113 keep your troops at the wall (and force them ocassionaly to attack
114 off the wall). I think this is a biggest weakness of the computer
115 AI, that it doesn't know this.
116 * When luring your troops to outflank an enemy, always move your cur‐
118 sor through the enemy, not the other way around.
119 * To penetrate very narrow tunnels, stand back for a while and let
121 some enemy troops come from the tunnel to you. Then surround them,
122 destroy, repeat.
123 * I have observed that with more than 2 players (6), the game diffi‐
125 culty depends on the map in the following way: If the playing field
126 is completely empty, without any holes (topologically equivalent to
127 full circle), the game is the easiest, because you can just go
128 through the middle to outflank your opponent. If there is a single
129 large obstacle (ie. playfield is topologically equivalent to ring
130 (the area between two nested circles)), the game is the most diffi‐
131 cult, because you have to choose one direction for the attack, and
132 cannot simply defend the other direction. For other maps, it seems
133 to really depend on their similarity to one of these two extreme
134 situations (and army size, of course, because it changes the rela‐
135 tive size of obstacles). Also, if you would later add another cur‐
136 sor, this property would probably disappear (maybe then games with
137 n+1 obstacles would be the hardest ones with n cursors).
138 * If you want a particularly challenging computer game (at least for
140 some maps), use several players, max out attack, min out defense,
141 max out base health (opposite would be harder, but game then changes
142 to the large cloud of black troops, so you don't see anything) and
143 give winner an advantage.
144 The winner is...
148 The clever guy who has got the greatest number of fighters in his team
149 at the end of the game. Or the one who exterminates all the other
150 teams!
151
154 Thom-Thom
155 Liquid War rules have been invented by Thomas Colcombet.
156 He was trying to find algorithms to find the shortest path from one
158 point to another, and found the Liquid War algorithm. Then it came to
159 his mind that a game could be build upon this algorithm, and Liquid War
160 was born. He programmed the first two versions of Liquid War using Bor‐
161 land Pascal for DOS, and gave me some information about the algorithm
162 so that I could re-program it.
163 U-Foot
166 I'm the guy who programmed the latest versions of Liquid War. I
167 enhanced the algorithms, and did quite a bunch of work to have the game
168 playable by (almost) anyone, that's to say create a correct GUI.
169 If you want to join me, here's all the information you'll ever need:
171 Christian Mauduit
173 E-mail: ufoot@ufoot.org
175 Web site: http://www.ufoot.org
176 GnuPG public key: FD409E94 - http://www.ufoot.org/gnupg.pub
178 GnuPG fingerprint: 4762 1EBA 5FA3 E62F 299C B0BB DE3F 2BCD FD40 9E94
179 Snail mail: 32 rue Jean Moulin 95100 Argenteuil FRANCE
181 Other contributors
184 As Liquid War is now free software, protected by the GPL, anyone is
185 allowed to view, edit, modify, re-compile the source code, and distrib‐
186 ute it, as long as Liquid War is still distributed under the GPL.
187 Here's a list of the contributors:
189 * Alstar: drew a map, which is now included in the main distribution.
191 * Peter Wang: ported Liquid War to GNU/Linux.
193 * Cort Danger Stratton : helped me setting up network support.
195 * Tim Chadburn : wrote midi files for the game. His contribution has
197 been truely appreciated since it's rather hard to find GNU GPL com‐
198 pliant artwork. He also wrote documentation and helped with midi
199 support in general.
200 * Jan Gretschuskin : contributed 11 maps, and made the German transla‐
202 tion. So if you run Liquid War with German menus, you know who you
203 have to thank -> Jan! 8-) Also do not forget to visit
204 http://www.game-factor.de
205 * Mouse : contributed a map.
207 * Rene Stach : drew 3 maps.
209 * Roderick Schertler : implemented HTTP 1.1 support.
211 * Ryan D. Brown : ported Liquid War to Mac OS X.
213 * Eduard Bloch : maintained the Debian package, and helped with German
215 support.
216 * Michael Terry : provided a .desktop file for better integration with
218 Gnome, KDE and other UNIX desktop environments.
219 * Kasper Hviid : contributed many maps, with their own textures, and
221 made the Danish translation. Great work, also available on
222 http://levels.2v1.cz/index.html
223 * David Redick : wrote an external random map generator, available on
225 http://xdavidx.sqrville.org/lwmapgen/index.html
226 * Alexandre Pineau : maintains the Debian package.
228 * Michael Wagner : translated the web site in German.
230 * Peter Williams : fixed the "too many opened socket" server bug.
232 * Jan Samohyl : submitted strategy tips.
234 * Gavin : wrote the Liquid War fanfic.
236 * Dave Vasilevsky : fixed the Mac OS X port.
238 * 2 of omega : contributed a map.
240 * 666-REFIZUL-666 : created many maps (distributed separately).
242 * Thomas Klausner : fixed Makefile for FreeBSD
244 * Joan Dolc : helped with Mac OS/X port
246 Many other people helped me by submitting bug reports and patches, and
249 I want to thank them for their precious help. Thanks to all the Debian
250 people too, who nicely maintain the Liquid War .deb package.
251
254 liquidwar-user
255 Description
256 This list is for general discussions about Liquid War. Here you can
258 make suggestions, submit bug reports, ask for help, find players,
259 etc... Basically, any question or remark which concerns the game is
260 welcomed on this list.
261 Practical informations
264 You can't send messages to the list without subscribing. The only rea‐
266 son for this is that it's one of the only way to block spam effi‐
267 ciently. I first thought it could be OK to allow anyone to post, but
268 liquidwar-user seems to have be harvested by robots, so now I need to
269 restrict posters. However, I insist on the fact that anyone can sub‐
270 scribe, and the subscription to the list is not moderated. So if you
271 are a human being and not a stupid spam robot, you're welcome on the
272 list 8-)
273 Here's a list of usefull URLs:
275 * To (un)subscribe: http://mail.nongnu.org/mailman/listinfo/liquid‐
277 war-user
278 * To consult archives: http://mail.nongnu.org/pipermail/liquid‐
280 war-user/
281 * To post on the list: liquidwar-user@nongnu.org
283 Chat and IRC
288 Web-based chat-box
289 I have have set up a web-based chat-box which is accessible here:
291 http://www.ufoot.org/liquidwar/v5/metaserver.php3
292 It's not as good as a good old IRC channel but not everybody can use
294 IRC (because of firewalls and the likes), and I like the idea that peo‐
295 ple can chat and have the list of available servers in one single web
296 page.
297 IRC channels
300 I personnally spend some time on irc.freenode.net so you might use it
302 to find other players - though I'm not really an IRC addict... ...not
303 yet at least!
304 Here are the channels I recommend:
306 * #liquidwar : Liquid War dedicated channel, to find players and chat
308 while playing.
309 * #netgame_players : general channel for players who want to play
311 Internet games - Free Software and/or Open Source games of course,
312 we're on freenode.net 8-)
313
318 What's this?
319 Quoting Gavin: "I wrote a liquid war fanfic some time ago [...] I wrote
320 it after a friend claimed that there wasn't any liquid war fanfic
321 because it wasn't possible."
322 So here it is, a Liquid War fanfic, enjoy! (and special thanks to
324 Gavin)
325 The Battle of Emberlificoted
328 ...
329 The General presided over his massing army in his seat, or rather hov‐
331 ering ring, of power. It dipped slightly as he flew low over his troops
332 marching through the viscous marsh-like terrain. They were like chil‐
333 dren: obedient, loyal, and they ate a lot.
334 Glancing at the status panel mounted in front of him he grimaced; the
336 other five armies: Yellow, Green, Orange, Turquoise, and, of course,
337 Red, were also readying armies of a similar size to his own. His violet
338 clones would have to fight hard and eat well to win this day.
339 Today would not be a battle of luck, the General mused, it would be a
341 battle of tactics, of alliances, and of betrayal. Every clone was iden‐
342 tical - that was the general idea behind clones - and the terrain
343 seemed strangely symmetrical; it would not give advantage to any of the
344 six armies amassed today. Glancing at the hologram of the battlefield
345 projected in front of him the General noted that he would have to move
346 quickly, Orange and Yellow were too close for comfort, though fortu‐
347 nately Baron Red's army of eponymous coloured clones was the furthest.
348 General Violet's fingertips were sweaty even before they touched the
350 four main control keys in front of him. They were labeled 'W', 'A',
351 'D', and, of course, the full retreat button - very useful for mislead‐
352 ing foes and ambushing them as they pursued - 'S'. The keys were
353 arrange in a roughly equilateral triangular pattern; with 'S' forming
354 the base and being adjacent to both 'A' and 'D', 'W' formed the tip of
355 the triangle.
356 A long breath left his parched lips as at last he made his move.
358 ...
361 "Dammit!" he screamed moments later. He had misjudged Captain Yellow
363 and Commander Orange; he had expected one at least to attack immedi‐
364 ately, one he could have handled. They were working together - foiling
365 his attempt to shoot between them to near the center of the battlefield
366 to gain a better vantage point. Yellow had shot down towards him, cut‐
367 ting off his advance, and now Orange had sealed his escape route. "It's
368 not over yet" muttered the General. He opened a voice channel with Com‐
369 mander Orange:
370 "Very clever. Flawed, but still clever."
372 "Flawed?" came the reply.
374 "Yes flawed, when the good Captain is finished devouring my army who do
376 you think he will turn to next?", bluffed the General - his hands
377 worked quickly as he manoeuvred his hovering control ring, all that his
378 troops ever saw of him, carefully towards the weakest section of his
379 attackers. If he could just break out a few units he could soon turn
380 the tide against both Yellow and Orange.
381 "We have an alliance..." Orange's voice was unsure now.
383 Time for some sarcasm to through her even more off balance, thought the
385 General,
386 "I gathered", he spoke softly, slowly, and with too much meaning. Then
388 closing the channel he turned his attention back to his escape.
389 ...
392 "Yes!" wooped the ecstatic figure of the General. Fifty or so of his
394 troops had broken free undetected and were even now working their way
395 cautiously towards the camps of the Yellow army, only the front lines
396 were still actively fighting; this opening gambit of Yellow and Orange
397 had turned into a stale siege and Yellow's army had pitched tent.
398 General Violet steered his hovering guidance ring to the center of the
400 Yellow camp. His troops struck, both those who had got behind the lines
401 and those who were still besieged. Yellow reacted too slowly and sud‐
402 denly found that her army, was shrinking back from the onslaught. There
403 was nowhere to run to, and bye now her only ally - Commander Orange -
404 had abandoned her to her fate; he was too busy engaging Sir. Turquoise,
405 who had managed to escape from the slaughter that the Baron had caused
406 to the Turquoise ranks and was even now valiantly attacking the flanks
407 of the Orange troops.
408 A glance at the status panel showed that Yellow's life force was fading
410 quickly: 8%, 3%, 1%, Gone.
411 The General smiled, he always enjoyed getting the first kill, and by
413 now his armies life force had grown and his clones had replicated. With
414 his, now, formidable fighting force it was no problem to engulf both
415 Sir. Turquoise and Commander Orange's brawling armies and annihilate
416 them. Once again his army grew in size and power. Now if only the Baron
417 didn't notice that..., thought the General.
418 ...
421 "Too late!" yelped the General, now thrown into panic, as he saw the
423 approaching Baron. His army had also grown in size and power - having
424 fatally injured the Turquoise army within the opening moments of the
425 battle, and having finally managed to catch the elusive fleeing form
426 of, or what remained of, Emperor Green.
427 Gripping the controls harder the General thought quickly, his army
429 doesn't so completely outnumber me that this is already over, however
430 unless I can cause him to make a mistake that allows me to take the
431 upper hand then I will inevitably lose. Maybe I can...
432 This thought was terminated and replaced by another as the Baron's
434 angry red troops broke through the undergrowth that had covered their
435 movements and started to surround the General's army. The thought that
436 now throbbed through the panic-stricken mind of General Violet was sim‐
437 ply 'Run!'.
438 Even as he signaled the retreat and made for what seemed to be the only
440 possible means of escape the Baron's blood red control ring appeared at
441 the opening. The General knew it was over, even before the host of red
442 beings appeared at the opening.
443 There was no escape. His life force was almost depleted and he was sur‐
445 rounded. Then it was that the Baron decided to communicate:
446 "Too bad. It was a good game"
448 The General blinked, gaped, and was generally gobsmacked. Just before
450 his life force completely failed and his own weary eyes closed in
451 defeat he snarled,
452 "What!? This is not a game!" were the General's dying words.
454
458 Introduction
459 This section describes how the GUI works. Since programming advanced
460 GUIs with Allegro is not so easy - standard C programming definitely
461 lacks flexibility -, and also since it's somewhat hard for me to figure
462 out what is user-friendly and what's not, Liquid War's menus are not
463 always self-explanatory. I'll just try and do something better next
464 time!
465 Menus
468 Map menu
469 The map menu allows you to choose the map you are going to play on. A
471 map is defined by 3 things:
472 * A frame. The frame can be chosen with the slider which is below the
474 preview. The frames are automatically sorted by alphabetical order.
475 * A texture for walls.
477 * A texture for the zone where fighters are allowed to move.
479 In the middle of the screen, there is a preview of the level. In this
482 menu, the values of the parameters can be independently changed by:
483 * Moving a slider.
485 * Clicking on a "+" or a "-" button.
487 * Typing a number.
489 On each side of the preview, sliders allow you to choose the two tex‐
492 tures. There is also a preview of each texture. Below this preview
493 there are 128 little buttons which allow you to choose single colored
494 textures.
495 The name of the map and its resolution are displayed in the lower part
497 of the screen.
498 You'll notice that on some maps the texture selection zones simply dis‐
500 appear. This is because these maps are associated with a texture, so
501 choosing a different texture is often not recommended for it won't look
502 as nice as with the right one. If you still want to override this be‐
503 haviour you can click on the "on/off" button just right to the "Use
504 default texture" label. This is a toggle button which will allow you to
505 use your own textures even on maps that normally come with their own
506 skin.
507 You'll also notice that a "Random map" button is available. This button
509 generates a new random map using an external program, "lwmapgen",
510 developped by David Redick, available on http://www.cs.clem‐
511 son.edu/~dredick/lwmapgen/
512 This program supports many command line options, and if you want a very
514 precise control on the generated maps, you'll need to run it sepa‐
515 rately. Looking at LW's log file you should be able to see the commands
516 LW issues when calling this program, this can give you ideas on how to
517 launch it manually. Alternatively using the "--help" option (for
518 instance "liquidwar-mapgen --help" under UNIX) should describe how to
519 use it.
520 Teams menu
523 This menu allows you to choose the teams which are going to play. There
525 are 6 square zones in this menu. Each of them is associated to a team.
526 Each team can be either:
528 * Disabled ("Off")
530 * Controlled by a player ("Human")
532 * Controlled by the computer ("Cpu")
534 The computer plays poorly, so remember that Liquid War is basically a
537 multiplayer game, and that the cpu control is dedicated to beginners
538 only.
539 You can also choose the color associated to each team by clicking on
541 one of the 12 colored buttons.
542 Below the 12 colored buttons, there are four buttons which allow you to
544 choose your keys. Click on one of these buttons and then press the key
545 you want to define. Joystick movements and buttons are considered as
546 keys. You can disable the joystick with the button which is at the bot‐
547 tom left of the menu. Mouse input is also possible, and mouse movements
548 are considered as keys too. To define mouse control, click on the but‐
549 ton associated to the direction you want to control, and then move the
550 mouse. Then the button should display something like "M->". Mouse sen‐
551 sibility can be set with the little slider at the bottom right of the
552 menu.
553 Graphics menu
556 Here you can choose the graphic options of the game.
558 The "Video mode" button allows you to switch between fullscreen and
560 windowed mode. This button is not available under DOS.
561 The "Brightness" slider allows you to set the brightness of the game.
563 The "Menu res" slider allows you to set the resolution used by the
565 menus. There are currently 5 possible values, which depend on which
566 platform you're running the game on.
567 I personnaly think the menus look best with the 640x480 resolution, but
569 some may prefer higher resolutions. Lower resolutions should only be
570 used if you have problems using SVGA video modes.
571 The "Game res" slider allows you to set the resolution used during the
573 game. The allowed values are the same than those for the menus. I rec‐
574 ommend that you don't use resolution higher than 640x480, unless you
575 have a Pentium VIII running a 10GHz.
576 Page flipping can be toggled. It is up to you to decide wether you keep
578 this option or not. The main disavantage of turning page flipping off
579 is that the info bar and the battlefield can look rahter ugly if they
580 overlap. But if you turn page flipping on you will not easily reach the
581 166 frames per second I sometimes get on small levels with my K6-225. I
582 personnaly always turn page flipping off.
583 The viewport size defines how much of your screen will be used by the
585 battlefield.
586 * If you set the slider on its left position, the batllefield will not
588 be stectched at all. Or if is strechted, it will be by a x2 or a x4
589 factor. So this is the mode wich allows the fastest display.
590 * If you set the slider ont its right position, the game will run in
592 fullscreen mode.
593 * With all the other positions of the slider, the battlefield will
595 keep its general proportions but it will be stretched.
596 The "Waves" button allows you to toggle the wave effect. You can also
599 do this while playing, by simply pressing F4.
600 Sound menu
603 This section allows you to set the sound volumes. There are 4 sliders,
605 which are:
606 * "Sfx": sets the volume of all the sfx sounds, thats to say'the
608 sounds you hear when the game starts, when you loose etc...
609 * "Click": sets the volume of the click, this nasty noise you hear
611 each time your press on a button.
612 * "Game water": sets the volume of the blop blop blop sounds which are
614 played continuously while you are playing.
615 * "Menu water": the same thing than "Game water" except that it con‐
617 cerns the sounds played while your are choosing options.
618 * "Music": general music volume.
620 Rules menu
624 This menu is the one where you can change the rules of the game.
626 The "Time" slider controls the time limit. The game will stop after
628 this time is elapsed. You can pause the game by pressing the "F3" key.
629 By the way, an info bar can display the time left while you are play‐
631 ing. This info bar can be toggled during the game by pressing the "F1"
632 key, and you can change its location by pressing the "F2" key. It also
633 displays how many fighters there are in each team.
634 The "Army size" slider controls the amount of fighters there will be on
636 the battlefield. The position of the slider reflects the amount of
637 fighters of all the teams together. If there are 4 teams, then each
638 player will have half as many fighters than if there had only been 2
639 teams.
640 The "Cursor x" slider controls the speed of your cursor.
642 * If it is set on the left, the cursor goes at the same speed than the
644 fighters.
645 * If it is centered, the cursor goes twice faster than the fighters.
647 * If it is set on the right, the speed of the cursor is multiplicated
649 by 3.
650 Below is a "Min 160x100" box with a slider on its right. This means
653 that maps will automatically be magnified so that they have a size of
654 at least 160x100. Indeed, some of the maps that come with Liquid War
655 were designed in 1995 when 486 Intel computers were common. Therefore
656 the maps were smalls. Today, these maps are not really fun to play on
657 fast computers, so Thomas Harte suggested this automatic magnifying
658 feature, and that was IMHO a smart idea. You can move the slider to the
659 right to make maps use a higher resolution - ie magnify them.
660 The "Defaults" button of the "Rules" menu will reset rules to their
662 defaults. This way you can tweak rules and then come back to the
663 default rules whenever you want. Note that there's also a "Defaults"
664 button in the main "Options" menu, but it will reset *all* options,
665 including player names... The advantage of the "Defaults" button in the
666 "Rules" menu is that it will only reset rules parameters, and keep the
667 rest of your configuration options untouched.
668 Speeds menu
671 The "frames/s" slider allows you to limit the number of frames per sec‐
673 ond. If this slider is set on the left, there won't be any limit, so
674 Liquid War will repaint your screen each time the fighters move. But
675 this can be a weird behaviour if your machine is really fast, for no
676 one cares about 100 fps per second, one can not even see them... So
677 this paramters limits the refreshment rate, so that there can be sev‐
678 eral logical moves of the fichters for only one screen refreshing. If
679 it is set on its right, the display is limite to 10 fps, so you'll have
680 to find your setting. I personnally set it right in the middle, and get
681 40 fps. If you press "F5", you'll get the number of frames per second,
682 and if you press "F6", you'll get the number of logical moves per sec‐
683 ond. You can also press "F7" or "F8", and you will get the percentage
684 of time your computer spends on calculating or displaying the level.
685 The "rounds/s" slider allows you to limit the number of rounds per sec‐
687 ond. If this slider is set on the left, there won't be any limit, so
688 Liquid War will run as fast as possible. This setting will be of no use
689 if you use Liquid War on a slow computer or if you play with hudge
690 maps, but sometimes, with a high-end Pentium class computer, it's sim‐
691 ply impossible to play on small maps because things simply go too fast.
692 So this parameter is here to help you and avoid the "10000 moves per
693 sec" problem.
694 Waves menu
697 This is where the wave parameters are set. The waves are just a graphic
699 effect, which is not really usefull. I don't often use waves, but I
700 still think they can sometimes look nice. Change these parameters if
701 you really mean to do it, but if you don't understand what they mean,
702 it is really OK...
703 There are 4 different types of waves, each of them being defined by:
705 * An "Ampli" parameter, to define how big the waves have to be.
707 * A "Number" parameter, to define how many waves should be displayed
709 at the same time.
710 * A "Speed" parameter, to define how fast the waves should move.
712 If you want to undestand what the "WX", "HY", "WY", and "HX" codes
715 mean, try to pay with only one type of wave, the "Ampli" parameter of
716 the 3 other types of wave being set to 0 (that is to say the slider is
717 on its left position), and sea how it looks like.
718 The wave effects can be toggled during the game by pressing the "F4"
720 key.
721 Advanced menu
724 This menu allows the user to change the behaviour of the fighters.
726 The "Attack" slider sets the agressivity of the fighters. If it is set
728 on the right, fighters eat each other very fast. If it is set on the
729 left, it takes ages to fighters to change teams.
730 The "Defense" slider sets the capacity that the fighters have to regen‐
732 erate themselves. The more it is on the right, the faster fighters
733 regenerate.
734 The "New health" slider sets the health of the fighters which have just
736 changed teams. The more it is on the left, the weaker these fighters
737 will be.
738 The "Winner help" slider controls a parameter which causes fighters to
740 attack with various strength depending on how many fighters belong to
741 their team. Not very clear... Let's just say that:
742 * If this slider is set on the right, the more fighters you have in
744 your team, the more aggressive they will become.
745 * If it is centered, all the fighters of every team will always attack
747 with the same strength.
748 * If it is set on the left, the less fighters you have, the stronger
750 they will be. In this mode, games usually never end.
751 The "Cpu strength" parameter never makes the computer more intelligent
754 than a monkey. But if you set it on the right, it advantages the
755 machine outrageously and fighters controlled by the cpu will be really
756 strong. So to get rid of them you'll definitely need to be clever.
757 Again and again, don't forget that Liquid War was conceived as a multi‐
758 player game and that playing against the computer is not really an
759 interesting thing to do.
760 The "CPU vs human" parameter allows you to control how aggressive CPUs
762 are towards humans.
763 * If set to "Always", CPUs will always attack humans and will never
765 try to attack another CPU, unless there are no humans left. This
766 used to be the default behavior in previous Liquid War versions, but
767 some players remarked that it was rather unfair, so now this is an
768 option.
769 * If set to "Random", CPUs won't care wether their opponents are CPUs
771 or humans, they'll attack anybody. This is the default behavior.
772 * It set to "Never", CPUs will attack each other before bothering
774 human players.
775 The "Allow net bots" button can be used to allow bots to connect on
778 network games. Indeed, bots are by default disabled in network games,
779 since in this case LW assumes that bots are useless (there are already
780 several human players). However, turning this option on will allow you
781 to connect bots within the game. It's important to note that this is a
782 per client option, this means that you can't use it to forbid access to
783 bots to a given network game. This option was simply created to avoid
784 confusion when connecting on network games, while still allowing bots
785 to connects if you really want them to.
786 The "Algorithm" parameter allows you to force the algorithm to standard
788 C mode. There's no real good reason you would like to do this, since
789 the C algorithm is slower than the ASM one. Moreover, the ASM algorithm
790 is automatically disabled if you play against a computer which does not
791 have ASM enabled. Think of this as a testing/debugging option.
792 Hot keys
796 Here's a list of keys you might use while playing:
797 * F1: toggles the "info" zone where the game time and the state of
799 each team is displayed.
800 * F2: moves the "info" the zone arround, possible positions being top,
802 right, bottom and left.
803 * F3: pauses the game. This function is disabled during network games.
805 * F4: toggles the "wave effect". Without this "wave effect", which is
807 turned on ny default,the game will run faster.
808 * F5: displays the number of frames per second (*).
810 * F6: displays the number of rounds per second (*).
812 * F7: displays the precentage of CPU spent on the game logic, calcu‐
814 lating where fighters must go for instance (*).
815 * F8: displays the precentage of CPU spent on graphics (*).
817 * F9: turns on/off the "capture" mode. In this mode, screenshots of
819 each frame are taken, and written to the hard drive as bitmaps.
820 * F10: quits the game right away without any confirmation prompt, also
822 known as the "my boss is coming here!" function.
823 (*) all these figures tend to be clearly false as computer go faster
826 and faster. Basically, the time required for "logic" and "display"
827 operations is getting shorter and shorter, and the tools I use to mea‐
828 sure it are not precise enough. Therefore I get approximations which
829 might by plainly wrong.
830
833 Basics
834 Since release 5.4.0, Liquid War includes network support, that's to say
835 that people can play over a LAN (Local Area Network). However, due to
836 limitations in Liquid War's legacy code, and also because of the lack
837 of time I have, it might be a little tricky to set up a network game at
838 first. So please read this section carefully.
839 You should keep in mind that:
841 * DOS only releases of Liquid War do not include network support, only
843 Windows and GNU/Linux versions will allow you to set up a network
844 game.
845 * The game should run fine on any LAN, but there's no garantee the
847 game will be playable on the Internet. Indeed if your "ping delay"
848 is not good enough, the game will be awfully slow. Bandwidth is not
849 an issue, since Liquid War rarely needs more than 2 Kb/sec.
850 * You'll need to know what an IP address is.
852 * You don't need to set up a network game to run a multiplayer game.
854 Liquid War was originally a multiplayer game without network sup‐
855 port. Network support is here only for people who don't feel com‐
856 fortable when playing at 6 on the same keyboard 8-)
857 Getting started
861 What do you need?
862 You'll basically need 2 computers connected on the same LAN. We'll call
864 them computer A and B. You might be able to play over the Internet too,
865 but the game can be harder to set up and - which is worse - very slow.
866 You'll also need to know the IP address of computer A. Type "ipconfig"
868 under Windows or "ifconfig" as root under GNU/Linux to get this infor‐
869 mation if you don't have it.
870 Starting the server
873 Liquid War uses a very traditionnal client/server approach. Basically,
875 the server gets informations from all the clients and then dispatches
876 the collected information to everybody.
877 So you'll need to start a server on computer A by running "liquid‐
879 war-server" on GNU/Linux or "lwwinsrv.exe" on windows. This is a con‐
880 sole application, ie it does not set up any graphic mode.
881 Here's a small example of a server start on GNU/Linux:
883 $ liquidwar-server
885 How many teams will connect to this server?
886 At this point you must enter a number between 2 and 6, and then press
888 "ENTER". In this example we will answer 2. The server really needs to
889 know how many teams will be in the game: when enough teams are con‐
890 nected, the game starts. It can also be a good idea to answer 6 system‐
891 atically and then force game start by clicking the "Start now" button
892 within the client. It's possible to skip this question by typing "liq‐
893 uidwar-server -2" instead of a plain "liquidwar-server".
894 Use "-2" to get rid of this question.
896 Register on "www.ufoot.org/metaserver/" (y/n)?
897 Now if we answer "y", then the server will automatically contact the
899 "meta-server" and it will be listed on http://www.ufoot.org/liquid‐
900 war/v5/metaserver.php3
901 This can be convenient for people who want to find other gamers to play
903 with on the Net. For now, let's answer "n", we'll test this meta-server
904 stuff later 8-)
905 Use "-private" to get rid of this question.
907 2002-06-03 16:43:00: Listening on port 8035...
908 2002-06-03 16:43:00: Waiting for 2 teams...
909 Now the server is ready to accept clients. By default it listens to
911 clients on port 8035. You could change this behavior setting by calling
912 "liquidwar-server -port 8061" for instance, but let's use the default
913 port to make things easier.
914 Starting the clients
917 Start the client on computer A normally by typing "liquidwar" on
919 GNU/Linux or double-click "lwwin.exe" on Windows.
920 Go to the "Teams" menu and select 2 teams, a red human and a blue CPU
922 for instance. If you don't know how to do this, then try and play Liq‐
923 uid War on a single computer first. It's important to notice that by
924 default the "blue CPU" won't connect on the network game. It's possible
925 to allow bots to connect on network games, but they are disabled by
926 default.
927 Now come back to the main menu, and a "Net Game" button should be
929 available. Click it. Now you should be able to:
930 * Start the game.
932 * Change the IP address of the server.
934 * Change the communication port.
936 * Set a password.
938 * Search for internet games automatically.
940 Since the server is also running on the same machine (A), you can leave
943 the default IP address as is (127.0.0.1).
944 Now you are ready to start the second client on computer B. Like with
946 computer A, you'll have to:
947 * Select 2 teams, green an yellow this time.
949 * Select "Net Game" in the main menu.
951 But this time you'll also need to change the server address, since the
954 client is not running on the same computer than the server.
955 Now click on "Start game" on computer A. The server should play a "sys‐
957 tem beep", which is usefull if you run a server and want to be notified
958 of client connections without watching the console all the time, and it
959 should display messages like this:
960 2002-06-03 16:44:48: Connection from "127.0.0.1:34677"
962 2002-06-03 16:44:48: Team "Napoleon" on client "127.0.0.1:34677"
963 accepted
964 2002-06-03 16:44:49: Client "127.0.0.1:34677" accepted
965 2002-06-03 16:44:49: Waiting for 1 team...
966 And on the client you should see a screen which says "Waiting for 1
968 team(s)" with the list of connected players below (Napoleon). You do
969 not need to click on the "Start now" button.
970 Now click on "Start game" on computer B. The server should display mes‐
972 sages like this:
973 2002-06-03 16:49:14: Connection from "192.168.1.1:1098"
975 2002-06-03 16:49:14: Team "Henri IV" on client "192.168.1.1:1098"
976 accepted
977 2002-06-03 16:49:15: Client "192.168.1.1:1098" accepted
978 2002-06-03 16:49:15: Client "192.168.1.1:1098" ready
979 2002-06-03 16:49:15: Client "127.0.0.1:34677" ready
980 2002-06-03 16:49:15: Sending info to "127.0.0.1:34677"
981 2002-06-03 16:49:15: Sending info to "192.168.1.1:1098"
982 2002-06-03 16:49:16: Game start
983 And at that point, the game should start 8-)
985 Restart a new game
988 Once the game is over, you can start another network game on the
990 clients without touching the server, because the server automatically
991 restarts and waits for players to connect.
992 To stop the server - if you want to change its settings for instance -
994 just go to the console where it's running and press CTRL-C.
995 Using the meta-server
999 Basics
1000 The meta-server is a piece of software which is running on my web site,
1002 and allows servers to register themselves so that client can get a list
1003 of available servers.
1004 It's written in PHP and is _very_ basic but I believe it's enough for
1006 what has to be done: maintain a list of running servers.
1007 The source code for the meta-server is included in the source package
1009 of Liquid War, so you might run such a server yourself if you want to.
1010 However, by default, servers will register themselves on my web site,
1011 and will be listed on http://www.ufoot.org/liquidwar/v5/metaserver.php3
1012 How to register a server
1015 Launch the server, and when you get the question:
1017 Register on "www.ufoot.org/metaserver/" (y/n)?
1019 answer "y".
1021 Note that if you're behind a proxy or a firewall, the server might be
1023 unable to register itself. Clients might also have problems to connect
1024 themselves on your server if there's a machine which does NAT (Network
1025 Address Translation) between you and the meta-server.
1026 How to find a server
1029 In the main menu, click on "Net Game" and then "Search for internet
1031 games".
1032 Now you should see a list of available servers. You can click on the
1034 items in the list to get more informations about a given server. Once
1035 you have chosen a server, click on "Join now".
1036 Now you get on a "Waiting for teams" screen. You might be interested in
1038 using the "Start now" button. Indeed, if you are 4 players connected on
1039 a server that accepts up to 6 players, maybe you'll want to start the
1040 game right away without waiting for 2 more players. In this case, every
1041 player must click "Start now". A "*" character will replace the "-" in
1042 the players list when a player clicks on "Start now". When all the
1043 players are displayed with a "*a, the game starts.
1044 You can also chat with other players by entering text in the area above
1046 the "Send message" button, and then click on this button. Keep in mind
1047 that this is a very primitive chat and that the best way to chat effi‐
1048 ciently is IMHO to play in windowed mode and have an IRC client at
1049 hand.
1050 Note that you can also get the list of available servers from
1052 http://www.ufoot.org/liquidwar/v5/metaserver.php3 There you'll also
1053 find a little chat-box which will allow you to send exchange messages
1054 with other players.
1055 Options
1059 Server options
1060 You can pass options to the server using the command line. The follow‐
1062 ing parameters are accepted:
1063 * "-n" where "n" is a number between 2 and 6 : with this option you
1065 can tell the server how many teams will connect to the game. Beware,
1066 there can be several teams on the same computer, so if you want to
1067 have a computer with 2 players on it and 2 other computers with a
1068 single player, then you need to use the "-4" option.
1069 * "-lag n" where "n" is an integer : with this option, you can control
1071 the lag used at startup. Normally, Liquid War handles this parameter
1072 automatically, but you might want to force it to a given value.
1073 * "-port n" where "n" is an integer : allows you to change the IP port
1075 used by the server to listen to the clients. if you omit this param‐
1076 eter, the default port is (8035) is used.
1077 * "-log file.log" : dumps all informations in "file.log" instead of
1079 using the standard output.
1080 * "-public" : skips the "Register on ..." question, and registers the
1082 server automatically on the meta-server, so that clients can find it
1083 easily.
1084 * "-private" : skips the "Register on ..." question, and does not reg‐
1086 ister the server at all.
1087 * "-comment This_is_a_comment" : associates a comment to the server,
1089 which will be displayed by the meta-server. Note that the character
1090 "_" will be replaced by spaces. This makes command line parsing eas‐
1091 ier. I'm lazy 8-)
1092 * "-password xxx" : associates a password to the server. With this
1094 option, clients will need to give the right password to be able to
1095 connect on the server.
1096 * "-callback cmd" : with this option, the command "cmd" will be
1098 launched whenever someone connects on an empty server. For instance,
1099 if you want to run a permanent server and want to know when someone
1100 connects but do not wish to permanently keep an eye on the server's
1101 log, you might use this option and put in "cmd" a command that auto‐
1102 matically sends you a mail. You might also use a command that fires
1103 a popup window. It's up to you. 2 sample scripts are available in
1104 the "misc" directory of the Liquid War source distribution. One is
1105 "misc/liquidwar_notify.sh" and works on UNIX platforms, and the
1106 other one is "misc/lwpopup.js", which is automatically used by
1107 "misc/lwserver.bat", and works on Windows.
1108 Common options
1112 These options work on both client and server, even if they are rather
1114 "server-oriented".
1115 * "-metaserver url" : redefines the URL of the meta-server. Usefull if
1117 you want to use your own meta-server.
1118 * "-netlog" : if you use this option, the server will dump all the
1120 network traffic on the standard output. This is usefull for debug‐
1121 ging.
1122 * "-nobeep" : Disables the system beeps that the application might
1124 fire. These beeps are mostly used on the server to notify clients
1125 connections.
1126 About Liquid War's network implementation
1131 Basics
1132 Liquid War uses TCP sockets, and a single-threaded server. This implies
1134 that:
1135 * The game can sometimes get blocked if you play on Internet.
1137 * The server can't talk simultaneously with several clients.
1139 I needed to use TCP sockets, since LW's algorithm can not cope with any
1142 data loss and it's not a reasonnable to try and anticipate what the map
1143 would be like if the player did not move etc...
1144 I did not implement any complex multithreaded stuff since I'm lazy and
1146 however, clients need to have informations about all the other before
1147 something can be done. However, implementing a mutltithreaded server
1148 could have advantages over the current solution.
1149 What is this lag stuff anyway?
1152 In Liquid War, all the clients send their key presses to the server,
1154 and then the server dispatches this information to everyone. This has
1155 to be done for every round.
1156 You can easily imagine that if a player has a poor connection, with a
1158 very long "ping delay", it can take quite a long time to send the
1159 information to the server, and then get it back.
1160 So what Liquid War does is that at the beginning of the game, the
1162 server sends a couple of "blank" key strokes to the clients. This way,
1163 clients receive data from the server before thay have sent any. The
1164 number of key strokes sent at the beginning of the game is called the
1165 "lag".
1166 So if it takes 200 msec to send and then receive data from the server
1168 (approx the time returned by the "ping" command) then with a lag of 6,
1169 you can theorically play at a rate of (1/0.2)*6=30 rounds/sec.
1170 On one hand, setting the lag parameter to a high value will avoid many
1172 network errors and allow you to play at a very fast pace, but the big
1173 drawback is that there will be quite a long time between the instant
1174 you send a key stroke to the server and the moment it comes back to
1175 you. On the other hand, setting the lag to a low value will limit dras‐
1176 tically he number of rounds per second, but make the game more "respon‐
1177 sive".
1178 However, since release 5.4.1, the "lag" is modified automatically and
1180 should adapt itself to the situation. I've not been able to test it in
1181 real conditions yet, but it should work 8-)
1182 Still, setting the lag to a sensible default value can save you some
1184 trouble. Indeed, by default, Liquid War will choose a value (6), but it
1185 can not guess if you are playing on Internet or on a 100 Mbit LAN, and
1186 it can take quite a long time before Liquid War automatically finds the
1187 right value. To know the right value which should be used with the
1188 "-lag" option, simply play a few games and watch the average lag (which
1189 is displayed on the server console every minute) at the end of the
1190 game.
1191 Performance issues
1194 Liquid War uses a "light" server, and one of the advantages of this
1196 solution is that it allows you to run the server on low-end computers.
1197 I personnally run a permanent server on a 486 DX2, and it runs like a
1198 charm.
1199 The only thing you have to take care of when running a server is band‐
1201 width. Don't worry, you won't need a 10Mbit connection, basically, each
1202 clients sends and receives 12 bytes of data at each round. If you add
1203 TCP/IP headers and the facts that stuff will probably be bundled in
1204 bigger packets, a client must deliver about 15 Kbit/sec (up and down)
1205 for a game that runs at 100 frames/sec. A 56K V90 modem is enough for
1206 this.
1207 So if you run a server with 2 clients connected, the server will need
1209 to deliver 30 Kbit/sec in both ways. A 56K V90 modem _can_ do that, but
1210 your provider needs to be a good one 8-)
1211 And if you run a server with 6 clients, you simply won't be able to
1213 reach the 100 frames/sec with a 56K V90 modem. It will necessarly drop
1214 to something less than 30 frames/sec, and is likely to drop to about 15
1215 frames/sec. OK this is not a big deal, since few Internet games run at
1216 more than 30 frames/sec, but well, if the server has troubles receiv‐
1217 ing/sending data, everyone will wait, and the fun will go away.
1218 As a conclusion: if you have the choice, choose the friend who has the
1220 best bandwidth to run the server, without even considering the power of
1221 his computer.
1222 Troubleshooting
1226 General information
1227 Network support in 5.4 and 5.5 is still experimental in many ways, so
1229 you might get weird behaviors. Basically, if you have a problem, just
1230 do the following:
1231 * Stop and restart the server when something goes wrong. To stop it,
1233 use CTRL-C.
1234 * Check out that you have entered the correct IP addresses.
1236 * Try and start the client and the server using the "-netlog" option
1238 to have an idea about what's happening.
1239 Bugs in 5.4.x corrected in 5.4.2
1243 Liquid War 5.4.0 and 5.4.1 were very hard to play over the Internet.
1245 The reason is that the network routines did not do enough error check‐
1246 ing, and therefore there were very often errors when sending and/or
1247 receiving the map to the server. Hopefully, this bug should not appear
1248 anymore in 5.4.2 or any other recent release.
1249 About security
1253 Network games passwords
1254 As you might have noticed, under the box where you can enter the pass‐
1256 word, a little notice explains that you must choose a "weak" password.
1257 Now you'll tell me -> people keep on explaining me that passwords must
1258 be something complex like "aS\r!Y9p" and now I'm told to use "hello",
1259 what's up?
1260 OK, keep in mind Liquid War is a game. This password stuff is just a
1262 way to be able to play with your friends only and keep on using the
1263 meta-server's services. Liquid War does not encrypt data and I can see
1264 no good reason to do it for, so the password is stored and sent to the
1265 server in clear, as plain text.
1266 The consequence is that if you use a valuable password - for instance
1268 the one you use to log in on your computer - the guy who runs the
1269 server will see your password in the log file if he wishes to. There‐
1270 fore, use something weak, something that if someones finds out what it
1271 is, you won't really care. So "hello" is a wise choice.
1272 Is Liquid War likely to have security holes?
1275 Yes.
1277 Any program is likely to have security holes, especially when it's net‐
1279 worked. However, I have good reasons to think that Liquid War is safe
1280 enough for a game. At least I find it safe enough to run a permanent
1281 public server on my personnal computer 8-)
1282 FYI, here are some things which I think make Liquid War rather safe to
1284 run:
1285 * Liquid War does not store anything on your hard drive that would
1287 have been received from the network. The maps are kept in RAM. So
1288 you won't download any virus playing Liquid War on Internet.
1289 * Liquid War does not transmit any sort of code on the network. All
1291 the transmitted bytes represent plain data. So you're not likely to
1292 execute any arbitrary code - virus, worm - when playing on the Net.
1293 * Liquid War receives network packets in static buffers, and if the
1295 received data is too big, it is truncated. One consequence is that
1296 Liquid War has a bunch of "limits". You can't send hudge maps over
1297 the network, you can't have long nicknames, and so on. But another
1298 consequence is that if you try to send garbage in the buffer, it
1299 will be truncated. Liquid War will protest with a "network error"
1300 message and the connection will be closed, but there will be no easy
1301 exploit possible here.
1302 * Liquid War does not use the sprintf, strcpy and strcat functions,
1304 which are known as being rather unsecure since they can lead to buf‐
1305 fer overflows. Instead, it uses the equivalent functions snprintf,
1306 strncpy and strncat. On platforms where these functions are sup‐
1307 ported natively, the game will use the default system functions,
1308 otherwise it will use a free implementation by Mark Martinec. FYI,
1309 Windows does not support snprintf-like functions natively, that is,
1310 it's a piece of crap.
1311 * Liquid War is Free Software, so I'm not likely to have put backdoors
1313 in it myself, since anyone can look at the source code 8-)
1314 However, I have not - and I know nobody who has - audited Liquid War
1317 for security holes. So there might be some. Therefore you should
1318 respect a few things while running Liquid War:
1319 * Never run Liquid War as root or administrator. This is obvious but I
1321 still mention it. If you want to run a Liquid War daemon on UNIX,
1322 run it as user "nobody" or something approaching. If "root" or
1323 "administrator" does not make sense on your system (DOS, Win98...)
1324 then I assume you're not _really_ concerned about security anyway
1325 8-P
1326 * If you run a server 7/7 24/24, use the "-log" option to log every‐
1328 thing in a file. This way you'll keep a trace of network activity,
1329 and if something goes wrong, you might get a chance to see it.
1330 * If you use passwords in network games, *never* choose a valuable
1332 password. Use something simple like "hello" or "goodbye".
1333 * Keep in mind that Liquid War is a game, and not a bullet proof pro‐
1335 fessionnal server.
1336 Last point: you should be aware that version 5.4.5 of Liquid War has
1339 been proved to be vulnerable to a local buffer overflow, and one should
1340 run at least 5.5.9 to get rid of this problem. FYI by the time the
1341 exploit was found on 5.4.5, 5.5.9 was already out 8-) See
1342 http://www.securityfocus.com/bid/8629 and http://www.securityfo‐
1343 cus.com/bid/9453 for more informations.
1344 Can people cheat when playing on the Net?
1347 No.
1349 Or at least, not really. In fact, you can still find the following
1351 types of lamers:
1352 * A guy who lets the CPU play at his place. He'll loose anyway because
1354 the CPU is definitely not a great Liquid War Master 8-)
1355 * A guy who tweaks the game and gets all his bots fight anyone he
1357 wishes. That's mean.
1358 * A guy who manages to let you have a 500msec lag while he does not
1360 have any lag at all.
1361 Apart from this, I can hardly see any way to cheat. Why? Because the
1364 Liquid War server does not store any information about the game. It's
1365 not aware of who wins, who looses, it knows nothing. The only thing it
1366 does is to transmit key presses between client computers.
1367 This way, if someone plays with a tweaked release of Liquid War, think‐
1369 ing he will fool you, then he will fool you on his computer only... On
1370 your computer, everything will be fine. After some time, your screen
1371 and his screen will have nothing in common, and both players are likely
1372 to think they have won. Except the lamer will stay a lamer.
1373 This also explains why it's required to play with the very same ver‐
1375 sions of the game during network games. If you plug a 5.5.2 with a
1376 5.5.1, after a minute the screens will be completely different on each
1377 client, since there are subtle differences between the 5.5.1 and the
1378 5.5.2 engine. However, you shouldn't be able to do this, since a net‐
1379 work error will stop you before you can start to play.
1380 Additionnally, versions 5.5.5 and higher have a checksum system. Every
1382 100 rounds, each client calculates a checksum with its local map, and
1383 sends it to the server. If the checksum is incorrect, the server will
1384 log a message like:
1385 Checksum error on client "192.168.1.1:1098"
1387 If you see this, then you're in one of the following situations:
1389 * There's a bug in the game
1391 * A lamer tries to cheat
1393 FYI, all releases from 5.4.0 to 5.5.4 have a bug which causes clients
1396 to desynchronize after a while...
1397
1401 Introduction
1402 When you launch Liquid War 5, you can use command line options. If you
1403 have no problems launching Liquid War, this section should not interest
1404 you very much.
1405 You can use several options at the same time. The basic syntax for
1407 options looks like this:
1408 lw -option1 -option2 parameter2 -option3 parameter3 -option4 -option5
1410 Note that most of the options are legacy options which where usefull
1412 with the initial releases of Liquid War, when you had to run in a Win‐
1413 dows DOS box, and when there were still plenty of 486 computers with
1414 only 8Mb ram...
1415 Version checking
1418 These are basic options which can be usefull to figure out which
1419 release of Liquid War is installed.
1420 * "-v" : returns the version number of the program.
1422 * "-h" : displays a short description and copyright information.
1424 Changing default paths
1428 Very usefull options, especially if you can not install Liquid War in
1429 default directories or want to put the game in a special place.
1430 * "-cfg myconfigfile.cfg" : causes Liquid War to use the specified
1432 config file.
1433 * "-dat mydatafilefile.dat" : causes Liquid War to use the specified
1435 datafile. This might be a very interesting option if you run Liquid
1436 War on a GNU/Linux box where you do not have root access and there‐
1437 fore can not put the datafile in /usr.
1438 * "-map mycustommapdir" : causes Liquid War to use the specified
1440 directory as the user map directory. The user map directory is where
1441 you can put plain bitmaps to be used as maps.
1442 * "-tex mycustomtexturedir" : causes Liquid War to use the specified
1444 directory as the user texture directory. The user texture directory
1445 is where you can put plain bitmaps to be used as textures.
1446 * "-mid mycustommusicdir" : causes Liquid War to use the specified
1448 directory as the user music directory. Any midi file placed in this
1449 directory will be added to the list of available musics.
1450 * "-server myliquidwarserverfile" : causes Liquid War to use the spec‐
1452 ified file as the server executable. This option has no effect for
1453 now since the server is not launched by the client.
1454 * "-mapgen mylwmapgenfile" : causes Liquid War to use the specified
1456 file as the "lwmapgen" executable. "lwmapgen" is an utility by David
1457 Redick which generates random maps automatically for Liquid War. You
1458 might wish to change this option if random map generation does not
1459 work for some reason, or if you want to use your own map generator.
1460 Troubleshooting switches
1464 These options give you control on how Liquid War treats initialisation
1465 errors, how much memory it should reserve, what kind of video mode sit
1466 should not choose etc...
1467 * "-vga" : This option forces Liquid War to use your video card as if
1469 it was only a basic VGA card. This option is required if you play
1470 Liquid War from Windows NT.
1471 * "-no400300" : This option disables the VGA 400x300 video mode. I
1473 created this options for I know that some video cards/monitors don't
1474 support the 400x300 mode.
1475 * "-silent" : With this option, Liquid War will not play any sound. It
1477 will not search for any sound card. This can be interesting if you
1478 don't have any sound card or if Liquid War doesn't handle your card
1479 correctly.
1480 * "-nowater" : Causes Liquid War not to load any water sound. Use this
1482 if Liquid War runs short of memory, and you should gain about 850kb.
1483 * "-nosfx" : Causes Liquid War not to load any sound fx. Use this if
1485 Liquid War runs short of memory, and you should gain about 150kb.
1486 * "-nomusic" : Causes Liquid War not to load any midi music.
1488 * "-mem n" : The parameter "n" sets the amount of memory (in Mb) Liq‐
1490 uid War will allocate to do all its calculus. If this number is too
1491 small, you won't be able to play on all the levels. If it is too
1492 high, Liquid War may not start at all or crash while you are play‐
1493 ing. The default value is 8. If you play Liquid War from Windows and
1494 Liquid War refuses to run because this parameter is too high, then
1495 try and give more dpmi memory to Liquid War.
1496 * "-nojoy" : This option disables joystick support.
1498 * "-noback" : Causes Liquid War not to load the background image. Use
1500 this if Liquid War runs short of memory, and you should gain about
1501 300kb.
1502 * "-notex" : Causes Liquid War not to load any texture. Use this if
1504 Liquid War runs short of memory, and you should gain about 750kb.
1505 * "-auto" : If you set this option, Liquid War won't generate any
1507 error while allocating memory or loading data.
1508 * "-safe" : With this option, you will play with a very reduced ver‐
1510 sion of Liquid War. It looks rather ugly but should work in a DOS
1511 box with only 4Mb of DPMI memory. Use this if you experience serious
1512 memory or device problems. If Liquid War doesn't start with this
1513 option turned on, I really don't think I can do anything for you...
1514 * "-nice" : With this option, Liquid War will use a mode which is
1516 between the default mode and the "safe" mode.
1517 * "-check" : With this option, Liquid War will stop as soon as it
1519 detects something strange while initializing.
1520 * "-stop" : If you set this option, Liquid War will prompt you for a
1522 key when the init process is completed.
1523 * "-c" : This is a weird option, if you turn it on, the game will only
1525 use fonctions which are programmed in C langage. The default behav‐
1526 iour is to use some functions I rewrote in assembly langage, so that
1527 the game is a little faster.
1528 Debug options
1532 These options are usefull if you want to debug the game and trace
1533 what's happening.
1534 * "-netlog" : Dumps all the network traffic on the standard output.
1536 This can help finding problems when trying to connect to the server
1537 in a network game.
1538 Server options
1542 The server command line options are described in the section which
1543 deals which network games in general. IMHO you need to understand how
1544 network works in LW before trying to tweak the server 8-)
1545 Other options
1548 Everything else 8-)
1549 * "-capture" : Activates the capture mode. In this mode, the game will
1551 dump a .bmp file on the disk several times per second, which is use‐
1552 full if you want to create an mpeg movie of your game session after‐
1553 wards. You can also activate this mode interactively by pressing F9
1554 within the game.
1555 * "-metaserver url" : redefines the URL of the meta-server. Usefull if
1557 you want to use your own meta-server.
1558 * "-nobeep" : Disables the system beeps that the application might
1560 fire. These beeps are mostly used on the server to notify clients
1561 connections.
1562 * "-tombola" : Activates a special mode where scores are not displayed
1564 normally. Instead, the game displays 3 random numbers between 1 -
1565 500.
1566 lwmapgen options
1570 The external lwmapgen program by David Redick accepts a number of com‐
1571 mand line options. You can type:
1572 liquidwar-mapgen --help
1574 to get a list of all available options under UNIX. Under Windows the
1576 command would be:
1577 lwwinmap --help
1579 Note that lwmapgen is called automatically by Liquid War when you click
1581 on the "Random map" button.
1582 The idea behind lwmapgen is that you choose a function which sets the
1584 type of map generated, and then pass various arguments to this func‐
1585 tion. If you do not explicitly choose a function, one will be picked up
1586 for you randomly, and all other parameters will use default values.
1587 The most usefull and common options are:
1589 * "--help" : displays help.
1591 * "--out filename" : save bitmap to filename.
1593 * "--size n" : bitmap size (an integer between 0 and 5).
1595 * "--list" : list all available functions.
1597 * "--function function_name" : which function to use.
1599 Here's a typical use of lwmapgen:
1602 liquidwar-mapgen --size 3 --function hole --out test.bmp
1604
1607 General remarks
1608 Liquid War is now a cross-platform game, thanks to Allegro. So now you
1609 can play under different OS.
1610 The same source tree will compile on all supported platforms, but with
1612 slight differences when running. C preprocessor #defines are used to
1613 code some platform specific stuff, and in some cases there are differ‐
1614 ent files for the DOS, Windows and UNIX versions.
1615 As I said, I try to use the same code for all platforms. This is in the
1617 long term the best choice. Otherwise there would different branches of
1618 the source tree, and I don't think this is a very good solution.
1619 Therefore some optimizations that were performed in the old DOS-only
1621 version have been totally removed, for they were 100% platform depen‐
1622 dent (ie mode-X asm coding). So the new versions are all a little
1623 slower than the old 5.1 stuff, but the performance loss is only about
1624 20%, which is not significant with today's PCs. And anyways the perfor‐
1625 mance loss is most of the time limited to the goog old VGA 320x200x8
1626 mode-X, which starts being kind of obsolete.
1627 DOS
1630 This is the original version. It's the fastest one as far as I know,
1631 the safest one and it will always be I think, since Allegro was first
1632 designed for DOS, and DOS allows a full unconditionnal access to all
1633 the hardware ressources LW requires. LW doesn't use any hardware accel‐
1634 eration and it's not been designed to do so. Unfortunately there's no
1635 network support for the DOS version of Liquid War.
1636 Windows
1639 When running under a Windows box, the DOS release used to be safer than
1640 the native Windows port. Now that DOS support is getting really poor
1641 with recent versions of Windows, the native Windows release of Liquid
1642 War starts begin the good choice for Windows users. And Allegro for
1643 Windows is getting quite stable in the 4.x series.
1644 The other reason to choose this release rather than the DOS release is
1646 that it has network support.
1647 If you have problems running Liquid War under Windows, please check out
1649 the "data\lwwin.log" file which should be written each time you run the
1650 game. It contains the information which is displayed on the console
1651 under other platforms, and might give you a clue about what's going
1652 wrong.
1653 GNU/Linux
1656 This port is the most recent one, and also the one I prefer. Paths have
1657 been changed to an UNIXish style, ie the data is stored in:
1658 /usr/local/share/games/liquidwar
1660 the executable in:
1662 /usr/local/games
1664 and the configuration file is
1666 ~/.liquidwarrc
1668 Since not all GNU/Linux distributions have /usr/local/games in their
1670 path, I also put a symbolic link to the binaries in /usr/local/bin. I
1671 believe Liquid War is quite FHS compliant, so if its default directo‐
1672 ries do not match your configuration, blame your distro for not follow‐
1673 ing the standards 8-) AFAIK the only touchy directory is
1674 /usr/local/share/pixmaps which I've seen on many distribution but does
1675 not seem to be referenced in the FHS.
1676 With the latest releases of Allegro, Liquid War is becoming pretty sta‐
1678 ble under GNU/Linux. You should also know that the GNU/Linux port is
1679 usually the most up to date, since I very very seldom boot Windows at
1680 home and do most of the coding under GNU/Linux.
1681 FreeBSD
1684 This is the latest port, so I expect it to be a little touchy to
1685 install and/or run for some time.
1686 Note that to compile the game you'll need to install GNU tools like
1688 gmake and gcc. Liquid War won't compile with the genuine make and cc
1689 commands.
1690 One thing you might ask is: "why do you provide the binary as a plain
1692 .tgz file, it would be much nicer if a standard FreeBSD port was pro‐
1693 vided instead!". The answer is that the statically linked binary should
1694 work flawlessly and does not raise any dependency problem. Also I don't
1695 know how to make a BSD port and I'm not really interested in doing it.
1696 If it's easy to do, then someone can simply do it and send it back to
1697 me. If it's hard to do, then I do not really have the time nor motiva‐
1698 tion to do it. What I did is make the code and install scripts FreeBSD
1699 friendly so that it would be possible to compile the game under Free‐
1700 BSD. Packaging is another story.
1701 Mac OS X
1704 There's currently a beta version of a Mac OS X port for Liquid War.
1705 Ryan D. Brown nicely managed to compile and run the game under Mac OS
1706 X, and the latest news was that it does basically work. Still, this
1707 port did not go through intensive testing, so there might still be some
1708 bugs, expecially concerning networking.
1709 There were some byte endianess problems in previous ( <=5.5.8 )
1711 releases of LW, but I tried to fix them and they should be gone now.
1712 As of today, we're trying to find out a convenient way to package and
1714 release the Mac OS X version of LW. You can contact us on the mailing
1715 list if you're interested in this port.
1716
1719 A piece of advice
1720 You can use your own levels whith Liquid War 5. The only thing you have
1721 to do is to put your own 256-colors vbitmap files in a special direc‐
1722 tory, and the program will use them. Currently, BMP, LBM, PCX, and TGA
1723 files are supported. It is a good thing to use 256 colors bitmaps, for
1724 they waste less disk space than truecolor bitmaps, and Liquid War 5
1725 converts all bitmaps to 32 colors bitmaps. Additionnally, truecolor
1726 bitmaps might cause the DOS version to crash randomly... 2-color bit‐
1727 maps will also cause the program to crash. I warned you!
1728 The best thing you can do to create your user levels is to have a look
1730 at the few user files I put in the .zip file and try at first to do
1731 something that looks about the same!
1732 Maps
1735 Liquid War 5 does many checks on user levels and is much safer than
1736 Liquid War 3. Still, try and help the program not to crash, if possi‐
1737 ble.
1738 Liquid War considers that dark colors are walls and bright colors are
1740 associated to the playable area. So you can draw your walls in black,
1741 dark blue, etc... And the rest of the map can be of any bright color
1742 such as white or yellow.
1743 You can draw a small map on a big bitmap, as long as you use a bright
1745 background color. Liquid War will autodetect the range of your map and
1746 add the border line if necessary.
1747 Liquid War re-orders all the maps, so that the smallest ones are on the
1749 left and the most complicated ones on the right when you choose them
1750 with the slider in the "map" menu. So if you can't find the map you
1751 just draw, don't worry, it is probably just mixed with the levels from
1752 the .dat file.
1753 The default path for maps is "custom\map\" on windows, and
1755 "/usr/local/share/games/liquidwar/map" on GNU/Linux.
1756 Textures
1759 All you have to do is put a bitmap in the default directory which is
1760 "custom\texture\" on windows, and "/usr/local/share/games/liquid‐
1761 war/texture" on GNU/Linux.
1762 Textures
1765 As of Liquid War 5.6.x, it's possible to associate a map with a tex‐
1766 ture. All you need is to call the maps with the same name (case is
1767 important, lowercase recommendend...). Look at the "meditate" custom
1768 map which is shipped with Liquid War for instance.
1769 This also works with internal builtin maps (those stored in the
1771 datafile) so for instance if you name a custom texture "world1.bmp" it
1772 will automatically be associated to the builtin map world1 (to figure
1773 out internal names you have to unpack the source distribution and look
1774 in the ./data directory). This also works the other way, if you name a
1775 map "wood2.bmp" it will be automatically associated with the builtin
1776 texture wood2.
1777 Associating a texture with a map requires more work than designing a
1779 simple map, but the results is usually much nicer. See the "Kasper -
1780 ..." series of maps for instance.
1781 Send your levels
1784 Maybe you will find that the original levels are ugly and unplayable.
1785 Well, if you have made user levels and think they are great, just send
1786 them to the Liquid War user mailing list. Please use only 256 colors
1787 bitmap and zip them before sending them, or else they might be blocked
1788 by my provider...
1789 As of today, dozens of user maps have already been included in Liquid
1791 War, this is very nice for it happens that every map designer has his
1792 own personnal tastes, so the maps all look different.
1793 Still, to be included in Liquid War's mainstream distribution, your
1795 maps will need to be placed under the terms of the GNU General Public
1796 License, or at least a compatible license. You should have received a
1797 copy of this license with Liquid War anyway. Read it 8-)
1798 Of course, you can use *any* map when playing. You can even play with a
1800 bitmap you got from a proprietary source - such a proprietary game you
1801 bought for instance - but the point is that I can't - and you can't
1802 either - distribute such a map along with Liquid War.
1803 However, this is enough legal boring stuff! What you should keep in
1805 mind is that I'm always happy when I receive maps from players, and
1806 it's a pleasure for me to include them in the mainstream distribution.
1807
1810 Introduction
1811 General remarks
1812 If you have played Liquid War, you must have noticed that your army
1814 always takes the shortest way to reach the cursor. So the fundamental
1815 stuff in Liquid War is path-finding. Once you've done that the game is
1816 quite easy to code. Not harder than any other 2D game. Still the path
1817 finding algorithm is an interesting one, for it's not a common method
1818 that we used.
1819 Basically, at each round (by round I mean a game logical update, this
1821 occurs 10 or 100 times/sec depending on the level and/or your machine),
1822 the distance from all the points of the level to your cursor is calcu‐
1823 lated. Now the point is to calculate this fast, real fast. In fact, a
1824 "gradient" is calculated for all the points of the level, and the value
1825 of this gradient is the distance required for a little pixel/fighter to
1826 reach your cursor, assuming that he takes the shortest way. Liquid War
1827 does this with a 10% error tolerance, and it's enough for keeping the
1828 game interesting.
1829 Once you have this gradient calculated, it's not hard to move your
1831 fighters. Basically, you just have to move them toward the adjacent
1832 point that has the lowest gradient value, ie is the closest to your
1833 cursor.
1834 History
1837 The Liquid War algorithm has been invented by my friend Thomas Colcom‐
1839 bet In fact the Liquid War algorithm has been invented before the game
1840 itself. The game came as a consequence of the algorithm, he just
1841 thought "mmm, cool, we could make a game with that!".
1842 Later, I enhanced the algorithm, as I coded it. The consequences were a
1844 performance increase, especially on simple but big levels. I mean lev‐
1845 els with wide areas for teams to move. Still the basis of the algorithm
1846 remained the same.
1847 Pros
1850 The Liquid War algorithm for path-finding is very efficient:
1852 * When you have to move lots of different points toward one single
1854 point. Good thing that's the rule of Liquid War!
1855 * When you have no clue about how your map will look like, ie if the
1857 walls are randomly placed. The complexity of the level doesn't
1858 influence much the speed of the algorithm. The size does, but the
1859 complexity, ie the number of walls, is not so important.
1860 Cons
1864 The Liquid War algorithm is very poor compared to other algorithms
1866 when:
1867 * You have several target destinations, that's to say Liquid War would
1869 be really slow if there were 100 teams with 10 players only.
1870 * You want to move one single point only.
1872 * > You want the exact (100% sure) path. In fact, this algorithm finds
1874 solutions which approach the best one but you can never figure out
1875 if the solution you found is the best, and the algorithm never ends.
1876 In the long term, the algo will always find the best solution or
1877 something really close but I don't know any easy way to figure out
1878 when you have reached this state.
1879 Mesh
1884 Introduction
1885 The first Liquid War algorithm used to calculate the gradient (the dis‐
1887 tance from a point to your cursor) for every single point of the map.
1888 With Liquid War 5, I used a mesh system. This mesh system is a struc‐
1890 ture of squares connected together. Squares may be 1,2,4,8 or 16 units
1891 large or any nice value like that, and the gradient is only calculated
1892 once for each square. Squares have connections between them, and each
1893 connection is associated to a direction.
1894 There are 12 directions:
1896 * North-North-West (NNW)
1898 * North-West (NW)
1900 * West-North-West (WNW)
1902 * West-South-West (WSW)
1904 * South-West (SW)
1906 * South-South-West (SSW)
1908 * South-South-East (SSE)
1910 * South-East (SE)
1912 * East-South-East (ESE)
1914 * East-North-East (ENE)
1916 * North-East (NE)
1918 * North-North-East (NNE)
1920 Example
1924 Well, let me give you an example, supposing that you level structure
1926 is:
1927 **********
1929 * *
1930 * *
1931 * **
1932 * *
1933 **********
1934 The * represent walls, that's to say squares where fighters can not go.
1936 Then the mesh structure would be:
1938 **********
1940 *11112233*
1941 *11112233*
1942 *1111445**
1943 *i1114467*
1944 **********
1945 In this mesh, there are 7 zones:
1947 * zone 1 has a size of 4. It's linked with zones 2 (ENE) and 4 (ESE).
1949 * zone 2 has a size of 2. It's linked with zones 3 (ENE,ESE), 5 (SE),
1951 4 (SSE,SSW) and 1 (SW,WSW,WNW).
1952 * zone 3 has a size of 2. It's linked with zones 5 (SSW), 4 (SW) and 2
1954 (WSW,WNW).
1955 * zone 4 has a size of 2. It's linked with zones 2 (NNW,NNE), 4 (NE),
1957 5 (ENE), 6 (ESE) and 1 (WSW,WNW,NW).
1958 * zone 5 has a size of 1. It's linked with zones 3 (NNW,NNE,NE), 7
1960 (SE), 6 (SSE,SSW), 4 (SW,WSW,WNW) and 2 (NW).
1961 * zone 6 has a size of 1. It's linked with zones 5 (NNW,NNE), 7
1963 (ENE,ESE) and 4 (WSW,WNW,NW).
1964 * zone 7 has a size of 1. It's linked with zones 5 (NW) and 6
1966 (WSW,WNW).
1967 Why such a complicated structure?
1971 Because it allows the module which calculates the gradient to work much
1973 faster. With this system, the number of zones is reduced a lot, and
1974 calculus on the mesh can go very fast. At the same time, this mesh
1975 structure is complicated to understand by us humans but it's very easy
1976 for the computer.
1977 Gradient
1981 Introduction
1982 For each zone defined in the mesh, LW calculates an estimation of the
1984 distance between the cursor and this zone.
1985 The algorihm is based on the fact that to cross a zone which size is n,
1987 n movements are required. Easy, eh?
1988 Description
1991 Here's the way the algorithm works:
1993 for each turn of the game, do:
1995 * pick up a direction between the 12 defined directions. They have to
1997 be chosen is a peculiar order to avoid weird behaviors from fight‐
1998 ers, but let's suppose we just pick up the "next" direction, ie if
1999 WSW was chosen the last time, we pick up WNW.
2000 and then for each zone in the mesh, do:
2003 * Compare the potential of the current zone with that of its neighbor
2005 zone. The neighbor zone to be chosen is the one which corresponds to
2006 the direction which has been previously picked up, and by potential
2007 I mean "the distance to the cursor, estimated by the algorithm's
2008 last pass".
2009 * If potential_of_the_neighbor_zone > (potential_of_the_current_zone +
2011 size_of_the_current_zone) then potentiel_of_the_neighbor_zone =
2012 potential_of_the_current_zone + size_of_the_current_zone
2013 How can this work?
2017 Well, just ask my friend thom-Thom, he's the one who had the idea of
2019 this algorithm!
2020 The basic idea is that by applying this simple rule to all the zones,
2022 after a certain amount of time, it's impossible to find any place in
2023 the mesh where the rule is not respected. And at this time, one can
2024 consider the potiential is right in any point.
2025 Of course when the cursor moves the potential has to be recalculated,
2027 but you see, cursors move really slowly in Liquid War, so the algorithm
2028 has plenty of time to find a new stable solution...
2029 Demo
2032 It's possible to see this algorithm working by typing:
2034 ufootgrad[n]
2036 while playing, where [n] is the number of the team the gradient of
2038 which you want to view. The game is still running but you view a team's
2039 gradient being calculated in real time instead of seeing the fighters.
2040 If you type ufootgrad0 the display comes back to normal mode.
2042 Move
2046 Introduction
2047 Once the gradient is calculated for any zone on the battlefield, it's
2049 quite easy to move the fighters, hey?
2050 The following method is used to move the players:
2052 * A "main direction" is chosen for the fighter, this direction is cho‐
2054 sen using the gradient calculated on the mesh.
2055 * Knowing which direction is the main one, a "level of interest" is
2057 applied to the 12 defined directions.
2058 There are 4 "level of interest" for directions:
2061 * Main directions: the direction calculated.
2063 * Good directions: these directions should lead the fighter to the
2065 cursor.
2066 * Acceptable directions: ok, one can use this direction, since the
2068 fighter shouldn't loose any time using it.
2069 * Unpossible directions: wether there's a wall or using this direction
2071 means the fighter will be farer from his cursor than before, it
2072 always means that this direction will not be used, never.
2073 Rules
2077 The fighters will try to find any matching situation in this list, and
2079 chose the first one.
2080 * The main direction is available, no one on it, OK, let's follow it.
2082 * There's a good direction with no one on it, OK, let's follow it.
2084 * There's an acceptable direction with no one on it, OK, let's follow
2086 it.
2087 * The main direction is available, but there's an opponent on it, I
2089 attack! By attacking, one means that energy is drawned from the
2090 attacked fighter and transmitted to the attacker. When the attacked
2091 fighter dies, he belongs to the team which killed him.
2092 * A good direction is available, but there's an opponent on it, I
2094 attack!
2095 * The main direction is available, but there's a mate on it, I cure
2097 him. That's to say that energy is given to the mate. This way, when
2098 there's a big pool of fighters from the same team, they re-generate
2099 each other.
2100 * None of the previous situations found, do nothing.
2102 Tips and tricks
2106 The behavior of the armies is quite tricky to set up. I had myself to
2108 try many algorithms before I came to something nice. In fact, I had to
2109 introduce some "random" behaviors. They are not really random for I
2110 wanted the game to behave the same when given the same keyboard input,
2111 but for instance, fighters will prefer NNW to NNE sometimes, and NNE to
2112 NNW some other times. By the way, I think Liquid War could stand as a
2113 nice example of the thoery of chaos.
2114
2118 General remarks
2119 Modularity
2120 Liquid War 5 is basically a big C program. I've splitted the source
2122 code in many small files for I do not like to have to handle big mono‐
2123 lithic sources, but this does not mean Liquid War is very modular. In
2124 fact Liquid War 5 is quite bloated with global variables and other ugly
2125 stuff 8-(
2126 Coding style
2129 To be honest, it's a big mess. You won't find 2 files coded in the same
2131 maner... OK, I'm exagerating a bit. From now I try to make an effort
2132 and stick to basic rules such as:
2133 * use the GNUish-style indentation - the default Emacs mode in fact
2135 * prefix global functions / variables / constants / types with
2137 lw_<NAME_OF_THE_file>_. For instance, a "do_it" function in myfile.c
2138 will be called lw_myfile_do_it
2139 * use capitals for constants, globals and types only. All functions
2141 are in lowercase with "_" to separate words
2142 * keep on using 8.3 filenames for .c source files. This is for better
2144 DOS integration. DOS version of Liquid War is still maintained, you
2145 know 8-)
2146 * use English only for code and comments
2148 I might decide to rename and cleanup everything some day, for it would
2151 help other coders to understand what I wrote, but well, this is cer‐
2152 tainly not a thrilling task 8-/
2153 Source files organization
2157 Main game code
2158 Here you'll find the main() function, the main game loop, applica‐
2160 tion-wide constants and other global stuff.
2161 It might be a good start if you want to hack the code.
2163 * base.h: contains global constants used in many different files.
2165 * game.c / game.h: contains the main game loop.
2167 * main.c / main.h: the file where the main C function is declared.
2169 Doesn't contain much except calling init functions and running the
2170 GUI.
2171 Menus
2175 The menus are coded using the Allegro GUI system. While this system is
2177 very powerfull, it's IMHO not adapted to very complex GUIs, and one of
2178 its drawbacks is that it's not so easy to redesign something once
2179 you've coded it.
2180 Besides, when I started coding the GUI in 1998, I did it in a rather
2182 ugly way, and now I'm paying for my being lazy at that time, since I
2183 spent hours coding when I want to change something 8-/
2184 * about.c / about.h: contains the code for the about menu.
2186 * advanced.c / advanced.h: contains the GUI advanced options menu.
2188 * connect.c / connect.h: contains code for the "connect" menu which
2190 displays which players are connected to the server, before the game
2191 actually starts.
2192 * controls.c / controls.h: contains the code for the controls menu.
2194 * graphics.c / graphics.h: code for the graphic options menu.
2196 * internet.c / internet.h: contains the code for the "Search for
2198 Internet games" menu, where one can pick up a running server auto‐
2199 matically with the help of the meta-server.
2200 * language.c / language.h: contains the code for the "Language" menu.
2202 * level.c / level.h: contains code for the menu where the player can
2204 select a level and its options (texture or color).
2205 * menu.c / menu.h: contains the code for the main menu.
2207 * netgame.c / netgame.h: contains the code for the net game menu.
2209 * options.c / options.h: contains the code for the options menu.
2211 * play.c / play.h: contains the code which ties the menu to the main
2213 gameloop.
2214 * rules.c / rules.h: code for the rules menu.
2216 * score.c / score.h: functions to display the scores at the end of the
2218 game.
2219 * speeds.c / speeds.h: contains the code for the speeds menu.
2221 * team.c / team.h: code for the team menu, where one choses which
2223 teams will play.
2224 * volume.c / volume.h: code for the sound menu.
2226 * wave.c / wave.h: code for the wave menu.
2228 GUI tools
2232 These files contain various utilities which are used in the menus.
2234 * alleg2.c / alleg2.h: contains some tweaked allegro functions. I
2236 wanted to use bitmaps with sevral colors for my fonts, and change
2237 some of the allegro default behavior. So rather than modifying the
2238 allegro source code right in the library I copied it in this file
2239 and then modified it.
2240 * back.c / back.h: this modules displays the background image.
2242 * dialog.c / dialog.h: contains code for standard dialog boxes.
2244 * error.c / error.h: contains functions to display error messages once
2246 the game is in graphical mode.
2247 * help.c / help.h: generic functions to display the various help
2249 pages.
2250 Core algorithm
2254 Here's *the* interesting part. All the rest of the code is just sugar
2256 coat to display stuff, receive players commands, communicate with other
2257 computers, handle errors, etc... But the real thing is here!
2258 It's funny to note that these files have almost not been modified since
2260 Liquid War 5.0.
2261 It's also interesting to note that they represent a small percentage of
2263 the total amount of code in the game. This tends to prove - and I'm
2264 convinced of it - that game programming does not only consists in hav‐
2265 ing great ideas, but also requires a lot of "dirty" and boring work.
2266 Honestly, coding an option menu is as boring as coding Liquid War algo‐
2267 rithm is fun.
2268 * fighter.c / fighter.h: contains code to move the armies, once the
2270 gradient has been calculated.
2271 * grad.c / grad.h: this module calculates the gradient for each team.
2273 One could say it's the "kernel" of the game, since most of the CPU
2274 time is spent in this module (except if you have a slow display...).
2275 * mesh.c / mesh.h: contains code to set up a usable mesh with a map.
2277 Mesh are re-calculated at each time a new game is started, the rea‐
2278 son for this being that meshes are *very* big so it would not be
2279 reasonnable to save them directly on the HD.
2280 * monster.s / monster.h: assembly functions to speed-up the game. It's
2282 a replacement for some fighter.c functions.
2283 * spread.s / spread.h: contains assembly replacements for some func‐
2285 tions of grad.c. These replacements do the same than the original
2286 ones from grad.c, but faster. Could still be optimized.
2287 Moving cursors
2291 It looks like nothing, but moving a cursor and deciding where it should
2293 go if there's a wall in front of it is not that easy, especially if you
2294 want things to work nicely.
2295 * autoplay.c / autoplay.h: contains the code for the computer AI. This
2297 module simulates keypresses from the computer, then the computer is
2298 handled as any other player.
2299 * move.c / move.h: provides an API to move the cursors.
2301 User input
2305 Until 5.4.0, Liquid War did not have network support. As it is designed
2307 to be multiplayer, one needed to have several players on the same com‐
2308 puter. The mouse also needed to be handled in a special way since cur‐
2309 sors can *not* pass walls in Liquid War. Additionnally, I wanted all
2310 input channels (keyboard mouse and joystick) to be handled in a unified
2311 way.
2312 This explains why there's so much code for user input, when one would
2314 think at first sight that "polling the keyboard is enough".
2315 * joystick.c / joystick.h: contains code to support joystick input. It
2317 wraps joystick buttons to virtual keyboard keys, so that joystick
2318 and keyboard behave exactly the same.
2319 * keyboard.c / keyboard.h: contains code to handle key presses.
2321 * mouse.c / mouse.h: wraps the mouse movements to virtual keyboard
2323 keys. This way the mouse can be used to control the players.
2324 Initialisations
2328 These files contain functions to intialize various game components.
2330 100% boring code.
2331 * area.c / area.h: contains functions to create the game area. Basi‐
2333 cally it contains functions to create the data structures in which
2334 the level is stored during the game.
2335 * army.c / army.h: functions to create the armies, and place them on
2337 the battlefield.
2338 * asm.c / asm.h: various constants, macros and utilities to ensure
2340 that asembly code works correctly.
2341 * bigdata.c / bigdata.h: I had a really hard time with the malloc
2343 function with DJGPP under Win95 dos box. I tried to have it working
2344 for hours and hours but my program kept being buggy. So I decided to
2345 allocate the memory myself, in a memory zone I create at startup.
2346 This is what this module does: create a huge memory zone and then
2347 give parts of it to the rest of the program.
2348 * config.c / config.h: contains everything that is related to the game
2350 configuration. This module contains in global variables all the
2351 parameters that are stored in the config file.
2352 * cursor.c / cursor.h: contains the code to init the cursors and place
2354 them on the battlefield at the beginning of the game.
2355 * decal.c / decal.h: This module makes the link between teams and
2357 players. Its coding is quite ugly, for some modules in LW assume
2358 that when 2 teams are playing they are always teams 0 and 1. So when
2359 3 teams are playing are playing and the second team loses, one has
2360 to make team 2 become team 1. That's what this module is for.
2361 * exit.c / exit.h: contains code that is executed when the game ends,
2363 it shuts down Allegro and displays messages on the console.
2364 * gfxmode.c / gfxmode.h: contains code to set up the various video
2366 modes, and defines which modes are available for each platform.
2367 * init.c / init.h: contains code to initialize Allegro with proper
2369 options and analyze failures.
2370 * palette.c / palette.h: contains function to set up the current color
2372 palette. Liquid War uses different palettes, depending on what col‐
2373 ors are chosen for teams.
2374 Graphics
2378 Here lies most of the graphic functions in Liquid War. There's not that
2380 much code since Liquid War's strength is not its visual effects, but
2381 rather its gameplay.
2382 The only "funny" thing is the wave effect. I'm quite happy with it, and
2384 honestly, I do think it is rather fast, given the fact that it uses no
2385 3D hardware at all.
2386 * disp.c / disp.h: contains functions to display the battlefield.
2388 * distor.c / distor.h: this module contains code to create the "wave
2390 effect". It uses a lot of data tables, and is quite complicated to
2391 understand...
2392 * glouglou.s / glouglou.h: assembly module, it is a replacement for
2394 some functions of distor.c. It goes much faster but does the same.
2395 * info.c / info.h: contains code to display the info bar. The info bar
2397 is the bar which display the time left and the amount of players for
2398 each team while the game is running.
2399 * message.c / message.h: provides an API to display messages during
2401 the game. Very useful if you want to debug the game: you can trace
2402 and display anything.
2403 * pion.c / pion.h: contains code to display the cursors.
2405 * viewport.c / vieport.h: code to allocate and resize the zone where
2407 the map is displayed, also called "viewport".
2408 Sound and music
2412 Sound and music routines required some encapsulation, since the game
2414 must be able to run even if the sound and/or music did not load cor‐
2415 rectly.
2416 * music.c / music.h: contains the code to control MIDI playback.
2418 * sound.c / sound.h: functions to play sound.
2420 Data management
2424 These functions handle the datafile contents and also the custom data.
2426 Note that the various utilities such as liquidwarcol, liquidwarmap and
2428 liquidwartex do not share code with the main executable. This is obvi‐
2429 ously a design error, for liquidwarmap will handle maps in a very poor
2430 way and is unable to autodetect map errors, whereas the game does it
2431 rather well. Blame the programmer.
2432 * disk.c / disk.h: contains all the code to access data from the hard
2434 drive. In fact, all the HD access is done at startup.
2435 * map.c / map.h: contains code to load the maps from a datafile raw
2437 data or a user defined bitmap to a usable structure in RAM.
2438 * maptex.c / maptex.h: contains code to handle the "use default tex‐
2440 ture" option, and associate a map with a given texture automati‐
2441 cally.
2442 * texture.c / texture.h: contains code to handle textures. Textures
2444 are stored in a special format which uses 5 bits per pixel.
2445 Random map generator
2449 Liquid War has a "generate random map" feature which is available
2451 within the game and also as an external program. The source code for
2452 the external program is in ./utils/lwmapgen in Liquid War source dis‐
2453 tribution. This program has been coded by David Redick, is also avail‐
2454 able on http://www.cs.clemson.edu/~dredick/lwmapgen/ and works on
2455 GNU/Linux. Compiling this program under DOS and/or Windows is untested
2456 and unsupported.
2457 The random map generator within Liquid War - which of course works on
2459 any platform support by LW - uses for its greater part the same source
2460 code as the external lwmapgen program.
2461 * random.c / random.h: wrapper for the map generator written by David
2463 Redick. It basically does the same as ./utils/lwmapgen/main.c except
2464 that it does it within Liquid War as it is running and not in an
2465 external independant program.
2466 Time handling
2470 Time handling is fundamental in a game. Time is used for visual effects
2472 (waves...) during the game, it's used to generate some pseudo random
2473 stuff, well, it's used everywhere!
2474 Note that on the client, I use 2 "different" clocks. The first counts
2476 the "real" time, in seconds. The second one is counts "rounds" and is
2477 incremented by 1 at each game round.
2478 * srvtime.c / srvtime.h: code used to handle time on the server, where
2480 Allegro's functions are not available.
2481 * ticker.c / ticker.h: sets up a timer callback.
2483 * time.c / time.h: functions to know how long the game has been run‐
2485 ning, knowing that it can be interrupted.
2486 In-game utilities
2490 These are various utilities use to monitor and control the game while
2492 one's playing.
2493 * capture.c / capture.h: code used to capture the video output of the
2495 game and store it in .bmp files while playing.
2496 * checksum.c / checksum.h: utilities to generate a checksum from a
2498 given game state. Used in network code to make sure all the clients
2499 stay synchronized.
2500 * code.c / code.h: This file contains the code to handle key presses
2502 during the game. That's to say the pause key for instance.
2503 * profile.c / profile.h: provides tools to calculate how fast the game
2505 is runnning and what operations slow it down.
2506 * watchdog.c / watchdog.h: this module waits for "secret codes" to be
2508 typed while the game is running, and traps them.
2509 Command line handling
2513 OK, now to all the UNIX guys, I *know* there are many ways to do things
2515 in a better and simple way than I did. But keep in mind that in 1998,
2516 under DOS, I had a rotten command line and even now I need everything
2517 to work on both UNIX and Microsoft platforms.
2518 These utilities are not perfect, but they work, that's all I ask them.
2520 * basicopt.c / basicopt.h: handles basic command line parameters such
2522 as "-v" or "-h".
2523 * parser.c / parser.h: contains code to parse and analyze the command
2525 line parameters.
2526 * startup.c / startup.h: analyzes the command line parameters and
2528 stores them into global variables.
2529 Locale support
2533 Liquid War now has locale support. Basically, all the labels and texts
2535 in the UI are stored in constants. There's simply file per language.
2536 Note to translators: if you decide to translate the menus in another
2538 language, keep in mind that all the translations must fit in the vari‐
2539 ous buttons and textboxes. The best resolution to test this - the one
2540 where letters take most place - is 640x480.
2541 * lang.c / lang.h: contains code to handle language dependant stuff.
2543 * langen.c / langen.h: contains code to handle English specific stuff.
2545 * langfr.c / langfr.h: contains code to handle French specific stuff.
2547 Log and various messages
2551 OK, the API of the log routines is a piece of crap. Now I'm simply too
2553 lazy to change it. It works, that's all I ask.
2554 BTW, there's a clear advantage in using custom-made log functions
2556 instead of plain calls to "fprintf(stderr,...". It might not be obvious
2557 for UNIX users, but think about Windows. Nothing like a "tail -f"
2558 there, nor a proper output redirection system. When a user clicks on
2559 the Liquid War icon, I want "console" information to be logged in a
2560 file!
2561 * log.h: common header for logcli.c and logsrv.c.
2563 * logcli.c: contains code to display messages on the console. It's
2565 usefull for console may have different behaviors when the games is
2566 used on different platforms. This file is used to compile the
2567 client.
2568 * logsrv.c: contains code to display messages on the console. This
2570 file is used to compile the server, which does not use Allegro at
2571 all.
2572 * popupgen.h: common header for popup functions.
2574 * popupw32.c: code to handle popup on the Win32 platform. Popups are a
2576 must-have under Windows for error diagnostics, since the average
2577 Windows user never gives any look at any log file...
2578 Macros, utilities and string support
2582 As usual, I needed to prepare a small set of usefull macros.
2584 * macro.h: contains basic wrappers/macros for snprintf like functions.
2586 This mostly to ease up string manipulation which is - as always - a
2587 nightmare in standard C.
2588 * path.c / path.h: code used to handle filenames and paths, for
2590 instance remove path and file extension from a filename.
2591 It's also important to note that Liquid War uses snprintf instead of
2594 sprintf, for using the latter is very likely to cause buffer overflows.
2595 Under Linux glibc provides this function but Microsoft does not provide
2596 it natively on Windows. Therefore I used a third party snprintf imple‐
2597 mentation by Mark Martinec: http://www.ijs.si/software/snprintf/ and
2598 its source is available in the ./utils directory of Liquid War source
2599 distribution.
2600 Byte order and endianess
2603 As you might know, PC Intel based computers are "little-endian" while
2605 Sun Sparc stations and Mac computers are "big-endian". This is an issue
2606 for LW since in network games maps are transmitted in binary format.
2607 Therefore I needed to set up some (un)serialization fonctions.
2608 * serial.c / serial.h: code used to transform integers and map headers
2610 into an uniform cross-platform byte stream which is readable by both
2611 little and big endian machines.
2612 Thread support
2616 Liquid War does have thread support, but it is a "limited" thread sup‐
2618 port. I mean that the game is generally monothreaded, but a few func‐
2619 tions use threads. For instance, calls to the meta-server are done
2620 within threads.
2621 Basically, I do not really enjoy programming in a multithreaded envi‐
2623 ronnement. So when possible, I chose the monothread path, and used
2624 threads only where I simply would not be able to find another accept‐
2625 able solution.
2626 I also needed to use some mutexes to prevent crashes in the user inter‐
2628 face.
2629 * mutxdos.c: provides fake mutex support under DOS. This module is
2631 here only to make compilation easier.
2632 * mutxgen.h: header for mutxdos.c, mutxunix.c and mutxw32.c.
2634 * mutxunix.c: provides mutex support on UNIX.
2636 * mutxw32.c: provides mutex support on Win32.
2638 * thrddos.c: provides fake thread support under DOS. This module is
2640 here only to make compilation easier.
2641 * thrdgen.h: header for thrddos.c, thrdunix.c and thrdw32.c.
2643 * thrdunix.c: provides thread support on UNIX.
2645 * thrdw32.c: provides thread support on Win32.
2647 Launching external programs
2651 Liquid War might sometimes launch external programs. This is (for secu‐
2653 rity reason) not a default behavior and has to be activated and config‐
2654 ured by yourself, using the "-callback" command line option on the
2655 server for instance.
2656 * execgen.h: header for execunix.c and execw32.c.
2658 * execunix.c: code to launch external programs on UNIX.
2660 * execw32.c: code to launch external programs on Win32.
2662 * exec2.c: code to launch external programs within the client, without
2664 any interaction with the user, ie no unwanted popping window for
2665 instance.
2666 Low-level network code
2670 There are network packages for Allegro, but I decided not to use them.
2672 Socket support is not that hard to implement under UNIX and Win32 and
2673 besides, I've done it for my job recently, so I just knew how to do it.
2674 Another reason which decided me to code my own toolbox is that I did
2676 not want Liquid War to have external dependencies - except Allegro of
2677 course. This way, UNIX gamers to not have to set up and/or download a
2678 specific network library. It's also easier to integrate the game in
2679 projects like Debian if it has few dependencies.
2680 This network code is not a masterpiece, it's just a little set of tools
2682 that have proven to work. That's all.
2683 BTW, it's important to notice that when linking with Allegro, most
2685 blocking UNIX calls ("sleep" or "recv" for instance) stop working: they
2686 alwasys return immediately. This led me to implement weird ugly hacks,
2687 like calling "recv" in a loop until it gets what it wants... This is
2688 theorically and practically a performance killer, but I found no other
2689 way to fix this. And FYI, this is not an Allegro bug, it's a feature
2690 8-)
2691 * dnsutil.c / dnsutil.h: wrapper code to issue DNS requests, without
2693 having to handle the hostent struct.
2694 * sock2cli.c: sode used to wrap low-level network function on the
2696 client.
2697 * sock2gen.h: header for sock2cli.c and sock2srv.c.
2699 * sock2srv.c: code used to wrap low-level network function on the
2701 server.
2702 * sockdos.c: network API for DOS.
2704 * sockex.c: netowrk routines shared by sockunix and sockw32.
2706 * sockgen.h: header for sockdos.c, sockunix.c and sockw32.c.
2708 * sockunix.c: network API for UNIX.
2710 * sockw32.c: network API for Win32.
2712 High-level network code
2716 These files contains network utilities which are Liquid War specific.
2718 * chat.c / chat.h: functions used to handle chat messages in network
2720 games.
2721 * keyexch.c / keyexch.h: functions to send and receive keys to the
2723 server. Used on the client.
2724 * netconf.c / netconf.h: code to send and receive the config of the
2726 clients over the network.
2727 * netkey.c / netkey.h: contains some tools to manipulate key strokes
2729 over the network.
2730 * netmap.c / netmap.h: code to send and receive the maps over the net‐
2732 work.
2733 * netmess.c / netmess.h: contains a parser to interpret plain text
2735 messages. Used when exhanging information over the network.
2736 * netplay.c / netplay.h: contains the code to set up and start network
2738 games.
2739 * network.c / network.h: contains some network related functions and
2741 constants used on the client.
2742 * ping.c / ping.h: code used on the client to estimate the average
2744 ping time with a server.
2745 * protocol.c / protocol.h: contains the sequence of messages send and
2747 recevied by the client when connecting on the server.
2748 * startinf.c / startinf.h: contains struct and tools to handle some
2750 network informations while starting a network game.
2751 Communication with the meta-server
2755 The meta-server is called by both client and server. Basically, the
2757 server registers itself, and the client asks for a list of servers.
2758 The meta-server itself is just a set of simple PHP scripts with a sim‐
2760 ple MySQL database. I chose PHP because my provider allows execution of
2761 PHP pages, that's all.
2762 The protocol is *very* basic, and uses HTTP 1.0 for requests. Answers
2764 are received in plain text, with one information per line. There's no
2765 garantee that this would work with any HTTP server, but experience
2766 proved that it works with my provider 8-)
2767 * httputil.c / httputil.h: low level functions to handle http
2769 requests.
2770 * wwwcli.c / wwwcli.h: code used on the client to communicate with the
2772 meta-server.
2773 * wwwsrv.c / wwwsrv.h: code used on the server to communicate with the
2775 meta-server.
2776 Server code
2780 The Liquid War server is a rather small program. The only thing it does
2782 is accept new players, transmit map and game parameters between them,
2783 and then "replicate keys".
2784 By "replicate keys" I mean that the server asks each client what keys
2786 have been pressed during the last round, and then dispatches this
2787 informations to all clients. This implies that the server has abso‐
2788 lutely no idea of who's loosing, who's winning, etc...
2789 All the "logic" of the server is coded in these files, the rest is only
2791 utilities and helper functions.
2792 * server.c / server.h: main code for the server (equivalent of main.c
2794 for the client).
2795 * srvchan.c / srvchan.h: code used to handles channels on the server.
2797 A channel is associated to a given computer and may manage several
2798 teams.
2799 * srvcont.c / srvcont.h: global network controler used on the server.
2801 * srvteam.c / srvteam.h: code used to handle teams on the server.
2803
2808 Report a new bug
2809 If you have troubles with Liquid War 5, if you think it is a bug, and
2810 if it is not described in this file, then just send a (precise...)
2811 decription of your problem to the Liquid War user mailing list.
2812 Besides, it happens that now most bug reports come from the Debian
2814 tracking system "http://bugs.debian.org/cgi-bin/pkgreport.cgi?pkg=liq‐
2815 uidwar". Thanks to the Debian users and maintainers, it's a very valu‐
2816 able feedback source.
2817 Additionnaly, on online bug tracking system has been set up. It uses
2819 Flyspray http://flyspray.rocks.cc/. It's accessible on
2820 http://www.ufoot.org/bugtracker/ or "http://www.ufoot.org/bug‐
2821 tracker/index.php?project=2". I try to collect everything here : bugs
2822 reported on the mailing-list, bugs from Debian, and bugs I found
2823 myself. Alternatively you can report bugs directly on it 8-)
2824 Network
2827 Network support in Liquid War is far from being perfect, so there are a
2828 bunch of little problems which can appear. Basically, once the game is
2829 correctly started on a LAN, you should have no problems, but getting
2830 the game started might be difficult.
2831 Mouse does not work
2834 Some users reported that they were unable to control the Liquid War
2835 cursor with the mouse. Well, the answer is a typical Microsoftish "this
2836 ain't a bug, it's a feature!".
2837 More seriously, you're supposed to move the cursor with the keyboard in
2839 Liquid War. There's no way to handle the cursor "like a mouse pointer"
2840 (*). This is due to:
2841 * Severe limitations in the Liquid War core algorithm.
2843 * The fact that moving the cursor "too fast" would really change the
2845 gameplay of Liquid War. As a Liquid War integrist 8-) I can tell you
2846 the game would really not be the same if you could move the cursor
2847 as fast as you wish. It's part of the game that sometimes it takes
2848 you ages to recover from a strategical mistakes. You need to think
2849 twice before going to the very end of a level. That's strategy. At
2850 least that's how I view things... Anyways as I mentionned above
2851 there's a limitation in the core algorithm.
2852 (*) This is not perfectly true, there's a way to control the cursor
2855 with the mouse, but it's designed for the case "4 people want to play
2856 on the same computer and one single keyboard is not enough". Control‐
2857 ling the cursor with the mouse in Liquid War is possible but yet rather
2858 hard to master 8-/ Try it and you'll understand what I mean. This mode
2859 can be set up in the "Teams" menu.
2860 Game does not start
2863 On non UNIX platforms such as Windows or DOS, Liquid War is distributed
2864 in a .zip file. It's IMPORTANT that you unzip the .zip files with an
2865 "unzipper" which preserves the directory structure. Most install prob‐
2866 lems under Windows come from broken unzipping programs which extract
2867 all files in the same directory... WinZip 8.x or the unzip32.exe util‐
2868 ity that comes with DJGPP are both able to uncompress Liquid War .zip
2869 files correctly.
2870 On Liquid War 5.5.9 and later, the Windows version should detect this
2872 problem automatically and warn you with a message which basically says
2873 something like "Unable to load datafile. Are you sure Liquid War is
2874 correctly installed?". If you get this message, you need to reinstall
2875 the game by unzipping it with a "correct" unzipping program which does
2876 not wreck directory structrure up.
2877 Interference with other Windows programs
2880 It's been reported that Liquid War can run very slowly on Windows when
2881 some other programs (Mozilla for instance) are running. So if Liquid
2882 War's menus seem to be really really slow, then try to shut down other
2883 applications and run the game again.
2884 This problem does not seem to apply on GNU/Linux - at least if you do
2886 not run 300 daemons together on your machine 8-)
2887 Datafile bugs
2890 Sometimes there are some problems when compiling the datafile, this
2891 includes:
2892 * The liquidwarcol, liquidwarmap and liquidwartex utilities might
2894 freeze or segfault. Typing "make" again often solves the problem.
2895 * The background image sometimes ends up using the wrong palette,
2897 which has a very nasty consequence: it looks ugly.
2898 These bugs are quite hard to get rid off, since I can not reproduce
2901 them easily. The good solution would be to completely rewrite the liq‐
2902 uidwarcol, liquidwarmap and liquidwartex utilities.
2903 Midi does not work on OSS
2906 Preamble
2907 IF your midi music on Liquid War, or indeed any other Allegro game,
2909 doesn't work and you are using the OSS (Open Sound System) drivers
2910 (these are the sound drivers which come with the standard kernel dis‐
2911 tribution), this may well be because Allegro only supports "FM synthe‐
2912 sis" and not "wavetable" when it is using OSS. FM synthesis is a very
2913 old method of making sound from MIDI and has long since been replaced
2914 by wavetable synthesis, with the net result that it's quite possible
2915 you've got OSS MIDI working nicely in other applications without having
2916 FM support set up at all. This is what I found. (It has to be said that
2917 I didn't find the FM sound quality quite as bad as people have said,
2918 though).
2919 In this situation, it looks to me like you have the following choices:
2921 Hack Allegro...
2924 and for the rest of us...
2928 Use Allegro's DIGMID midi driver...
2931 Get an FM driver up and running...
2936 * Find out which FM driver is appropriate for your sound card. If you
2940 have distribution-specific tools and docs for setting up sound, try
2941 those. If not, you will need to be familiar with the knowledge in
2942 the Sound-HOWTO and Kernel-HOWTO i.e. know how to compile kernels
2943 and modules and deal with sound drivers.
2944 * Look through the OSS modules in 'make menuconfig' and see if any‐
2946 thing catches your eye. See if there is any specific documentation
2947 on your sound card on http://www.linuxdoc.org. Do a few web
2948 searches. For my AWE64, I use the OPL3 driver.
2949 * Compile and install the FM driver module, or set up your system to
2951 use the new kernel if you want to compile the driver in.
2952 * Load the module, or boot your new kernel. It is very important that
2954 you pay attention to what is said in the 'help' for your FM driver
2955 in 'make menuconfig' and read any necessary files in the Documenta‐
2956 tion/sound/ directory. For example, I just had a nice half-hour won‐
2957 dering why the hell my FM wasn't working now when it had been before
2958 - with the OPL3 driver, you have to give the option io=0x388 to ins‐
2959 mod. Which is stated nice and clear in the docs, but of course I had
2960 forgotten since then. You can prevent such happenings by recording
2961 options permanently in /etc/modules.conf - see the manpage etc.
2962 * Try the game. If it's worked you will hear particularly beepy music.
2964 Enjoy!
2965 Opl3 occult FAQ
2969 --IMPORTANT-- If you are using Liquid War, your FM will only work if
2971 you go to the map 'Elephant inside a boa' and proceed to chase each
2972 other round in circles for at least 10 minutes. This cures a bug in the
2973 design of the OPL3 interface which conflicts badly with the core Liquid
2974 War algorithms. How the hell the music hardware even knows about the
2975 core algorithms I don't know, but that's what I made of the now-defunct
2976 opl3-occult-FAQ, from which here is an excerpt:
2977 Many roads a man must take. Those with one-track minds are DOOMED, I
2979 tells ya.
2980 ---- The Liquid War algorithm calculates distances to one place, the
2982 cursor.
2983 And:
2985 Man or machine, face or code, must stand strong and solid; must not
2987 just ooze away as slime.
2988 ---- We think it might just take objection to the whole 'slimy' nature
2990 of the LW beings. As well as it being LIQUID War.
2991 So, our carefully tailored approach, is to firstly have the players
2993 going in all the possible different directions evenly by moving around
2994 the map in circles, and secondly to divert the opl3's attention from
2995 the general slimy liquidness of it all by emphasizing the solidity,
2996 reality, and natural goodness of that classic tapestry: an elephant
2997 inside a boa.
2998 That and it's a f***ing ace level.
3000 Checksum errors
3004 The Liquid War server is a "light" servers which - to some extent - has
3005 no idea about what is going on in the game. It simply replicates key
3006 strokes between clients and each client maintains its own game state.
3007 Normally, the game is designed so that given the same user input, it
3008 will behave exactly the same.
3009 However, it happens that sometimes 2 clients can behave differently,
3011 and this is a (severe) bug. One consequence is that messages reporting
3012 "Checksum errors" appear on the server's and on the client's console
3013 output. This bug appears when using non-default rules settings. Basi‐
3014 cally, if someones tweaks his rules, then the checksum errors appear.
3015 Of course I double-triple checked that options were correctly sent on
3016 the network, but, well, could not fix the bug. Yet. The short term
3017 solution seems to play with default factory settings...
3018 I'm highly interested in bug-reports concerning this problem.
3020
3023 Bug-fixing
3024 In its latest releases Liquid War is quite stable IMHO. However there
3025 are still some issues with network under Windows for instance. I'm
3026 aware of these bugs and I'm trying to fix them but this does really
3027 take time.
3028 I always welcome bug-reports and patches, as making Liquid War W 5.x.x
3030 as stable and bug-free as possible is really important to me - and most
3031 of the time players also appreciate stable programs 8-)
3032 The most important bug-fixing area is probably cross-platform support.
3034 That is, make sure that the game runs fine on every supported OS. For
3035 instance, it's quite common for Mac OS/X and/or FreeBSD users to
3036 "crash" the game. This rarely happens on GNU/Linux, just because it has
3037 been so much more tested on this platform. This applies to Liquid War
3038 itself and also, to some extent, to Allegro.
3039 New features
3042 Let's be clear: no new features in Liquid War 5. It's bloated, compli‐
3043 cated, old, uninteresting to hack. All new features should be found in
3044 Liquid War 6.
3045 Liquid War 6
3048 Since summer 2005, Liquid War 6, a complete rewrite of Liquid War, is
3049 on its way. See http://www.gnu.org/software/liquidwar6/ or
3050 http://www.ufoot.org/liquidwar/v6 for more informations.
3051
3054 Note on releases
3055 Whenever Liquid War is released, I usually pass the good news to Fresh‐
3056 meat ( http://freshmeat.net/projects/liquidwar/ ). Then all releases
3057 are accessible from the main download page, which is
3058 http://www.ufoot.org/liquidwar/v5/download.
3059 Releasing the game takes time, for I want all binaries to install prop‐
3061 erly and sources to compile cleanly. Therefore there might be some
3062 delay before the time coding is over and the time a release is actually
3063 ready. So for impatients and/or for people who need to test out the
3064 very latest versions (eg someone who wants to compile the game on a new
3065 platform), it's possible to access the source repository directly.
3066 About GNU Arch
3069 I use GNU Arch (Tom Lord's Arch in fact, http://www.gnu.org/soft‐
3070 ware/gnu-arch/ ) instead of the previously used CVS. Indeed, tla has
3071 some very fancy features such as signing patches with gpg, and I'm
3072 tired of suffering CVS limitations.
3073 So FYI the previously active CVS repositories, on Sourceforge and
3075 Savannah, are currently unmaintained.
3076 How to get latest releases
3079 * Step 1: read the excellent Arch tutorial http://reg‐
3080 exps.srparish.net/www/tutorial/html/arch.html if you are not famil‐
3081 iar with tla. I admit there's a steep learning curve, but it's yet
3082 clear and understandable.
3083 * Step 2: point on the repository, which is accessible (read-only) on
3085 http://arch.sv.gnu.org/archives/liquidwar/.
3086 A typical set of tla commands would be:
3089 tla register-archive http://arch.sv.gnu.org/archives/liquidwar
3091 tla get -A liquidwar@sv.gnu.org liquidwar6--stable
3092 If you are interested, I can open this repository in read/write mode,
3094 however one of the points of GNU Arch is that it allows cooperative
3095 developpement with multiple depots, so this isn't mandatory. And any‐
3096 ways, importing myself patches received by email has never been a real
3097 burden.
3098 Besides, most developpement is now done on Liquid War 6. See
3100 http://www.gnu.org/software/liquidwar6/ or http://www.ufoot.org/liquid‐
3101 war/v6 for more informations.
3102
3105 Liquid War is a multiplayer wargame.
3106 Copyright (C) 1998-2007 Christian Mauduit (ufoot@ufoot.org)
3108 This program is free software; you can redistribute it and/or modify it
3110 under the terms of the GNU General Public License as published by the
3111 Free Software Foundation; either version 2 of the License, or (at your
3112 option) any later version.
3113 This program is distributed in the hope that it will be useful, but
3115 WITHOUT ANY WARRANTY; without even the implied warranty of MER‐
3116 CHANTABILITY or FITNESS FOR A partICULAR PURPOSE. See the GNU General
3117 Public License for more details.
3118 You should have received a copy of the GNU General Public License along
3120 with this program; if not, write to the Free Software Foundation, Inc.,
3121 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
3122
3124 Christian Mauduit <ufoot@ufoot.org>
3125 v5.6.4 Liquid War(6)