Enigma Reference Manual

This manual describes the internals of Enigma, in particular how to build new levels using Lua and how to interact with the game engine. It describes Enigma version 0.90.

1. Introduction

This chapter explains how Enigma works internally and how you can create your own levels. This manual is not for users of graphical level editors, but rather for programmers of graphical level editors or users who want to use the full power of the Enigma "engine" by using the built-in scripting language.

There are two kinds of file formats you can use to build levels for Enigma. The traditional solution was to write small programs in a programming language called Lua. Although this is still possible, the preferred way is now to prepare files in a data-centric format called XML; this will be discussed in detail in chapter

Enigma's level format is extremely flexible and allows you to create very dynamic and interactive levels. Here are a few examples of levels that make heavy use of Lua, both when preparing the level and during the game:

• Flood Gates (`nat8.lua') Was one of the first levels to use Lua for more than simply building the level and then handing it over to the game engine. The flowing water is controlled by a small function written in Lua-there is no built-in suppport for flowing water in the game engine.
• Enigris (`ralf04.lua') lets you play Tetris inside Enigma.
• Mourning Palace (`ant08.lua') moving platforms, also controlled by a Lua function.
• Finally, some of the maze levels and most of the levels in the Sokoban pack are dynamically generated: They look a little different every time you play them.

Our focus is on using Lua to access Enigma's game engine, so you won't learn much about Lua as a language in this chapter. Many simple things, like function calls or if statements, will appear familiar to anyone having a little programming experience: In many ways Lua is similar to programming languages like Basic or Pascal. But for most of Lua's finer points you will have to reach for the official Lua documentation, which you can download from lua.org.

1.1 Creating New Levels

Creating a new level basically consists of the following steps

1. Writing the level description, for example a file named `daniel01.lua'.
2. Inserting the new level into a level pack of your choice
3. Creating a preview image for the level
4. Testing the level in Enigma

1.2 A Simple Level

Here is a very simple level description that can also serve as a starting-point for new landscapes. (In fact, this is the first level in Enigma, so you can try it out right away.)

 1   CreateWorld(20, 13)
 2   draw_border("st-brownie")
 3   fill_floor("fl-hay", 0,0, level_width,level_height)
 4
 5   set_stone("st-fart", level_width-1,0, {name="fart"})
 6   set_stone("st-timer", 0,0, {action="trigger", target="fart",
 7             interval=10})
 8
 9   oxyd(3,3)
10   oxyd(level_width-4,level_height-4)
11   oxyd(level_width-4, 3)
12   oxyd(3,level_height-4)
13   oxyd_shuffle()
14
15   set_actor("ac-blackball", 10,6.5)

The resulting level looks like this inside the game:

Let's now turn to a line-by-line analysis of this program:

 1   CreateWorld(20, 13)
 2   draw_border("st-brownie")
 3   fill_floor("fl-hay", 0,0, level_width,level_height)

The level begins with a call to CreateWorld, which creates a new world that is 20 blocks wide and 13 blocks high. Every block in the world can be accessed with a pair of coordinates: The upper left corner has coordinates (0,0), the lower right one has coordinates (19,12). Every block contains a floor tile, an (optional) item, and an (optional) stone.

A frame of stones is drawn around the newly created landscape with the draw_border command. Its argument, "st-brownie", is the name of a stone. By convention, all stones have "st-" prefixed to their name, similarly all item names begin with "it-" and all floor names with "fl-".

The fill_floor command in line 3 fills the complete floor with tiles of type "fl-hay". The other arguments are the upper left corner and the width and height of the rectangle to be filled.

 5   set_stone("st-fart", level_width-1,0, {name="fart"})
 6   set_stone("st-timer", 0,0, {action="trigger", target="fart",
 7             interval=10})

Lines 5 to 7 demonstrate how to create individual stones. The set_stone command takes a stone name, the desired coordinates, and an (optional) list of attributes as arguments. Note the use of curly braces {, } to enclose the attribute list.

Attributes are the key to customizing the behaviour of objects in a landscape. Here, we first give a name to the first stone we create. It's a fart stone that has the unpleasant habit of "blowing off" when triggered. Triggering this fart stone is done by the timer stone we create in line 6-7. This stone performs a predefined action at regular intervals. In this case we want to send a "trigger" message every ten seconds to the object named "fart".

 9   oxyd(3,3)
10   oxyd(level_width-4,level_height-4)
11   oxyd(level_width-4, 3)
12   oxyd(3,level_height-4)
13   oxyd_shuffle()

These commands place a couple of oxyd stones in the level. The oxyd command internally uses set_stone("st-oxyd", x,y, ...) to create the stones, but it additionally assigns sensible values to some of the oxyd stones' attributes (most notably the color). The command on line 14 permutes the colors on the oxyd stones currently in the landscape.

15   set_actor("ac-blackball", 10,6.5)

This final line creates the black marble controlled by the player. Objects that can move around freely are called "actors" in Enigma. Unlike stones and items, actors are not restricted to integer coordinates, as you can see in this example.

1.3 Registering Levels

After writing the level description you have to tell Enigma where to find your brand new landscape. That's really two separate steps:

1. Move the `.lua'-File where Enigma can find it;
2. Insert a new entry into the appropriate level index.

The `.lua'-Files and the corresponding level index usually reside in the same directory. For the levels that come with Enigma, for example, this is the `levels' directory inside. For your own levels you can either use the same directory (currently your only choice if you use the Windows version of Enigma) or the `.enigma/levels' directory in your home folder (only if you use the Unix version).

A level index is a file that contains the list of landscapes that comprise a level pack in Enigma. Here is an excerpt from `index_enigma.txt', which defines the "Enigma" level pack:

{file=welcome              name="Welcome"                        author="Daniel Heck"         }
{file=martin06             name="Is It Easy?"                    author="Martin Hawlisch"     }
{file=lasers101            name="Lasers 101"                     author="Daniel Heck"         }
{file=level3a              name="Feel Your Way"                  author="Siegfried Fennig"    }
{file=martin04             name="Sokoban Revival"                author="Martin Hawlisch"     }

Every line in this file describes one landscape in the level pack. The general format of these lines is

{ tag1=content1 tag2=content2 ... }

One line normally contains many different tag=content pairs.

If your content contains spaces, surround the content with quotes (e.g. name="Is It Easy?"). If you want the string to contain quotes, escape them with \ (e.g. author = "Petr \"ant\" Machata").

Here's a description of all supported tags:

file

Defines the file name of the level (excluding the `.lua' extension). This entry is mandatory!

name

Defines the full name of the level. This is the name the player will see in the level menu. You can leave this field empty if you prefer to leave your level unnamed.

author

Defines the name of the autor. It will be displayed together with the full name at level startup.

revision

Defines the revision number of the level (defaults to 1) When the revision number is increased, a small red ! appears in the level menu.

If you do changes to the level that affect the way the level is solved, you should increase the revision number. If you only did cosmetic changes, you should NOT increase the revision.

You should never decrease the revision number!

easymode

Set this to 1 when the level supports different difficulties.

par_time

Syntax: par_time=sec,name

sec is the par time for the level in seconds.

name is the player who did the par.

If easymode is 1 then par_time_easy and/or par_time_normal have to be used instead of par_time.

When Enigma starts up it automatically tries to load an index file called `index_user.txt', where you can store all your personal levels. This file is not included in Enigma distributions, you have to create it yourself. The levels listed in this file will show up in a new level pack called "User Levels".

1.4 Where to go from here

The example level from the first section of this chapter was hopefully enough to give you an impression how level descriptions look like in Enigma. Of course, that level was extremely simple, and most interesting levels will be more complicated. The rest of this reference manual tries to document the available game objects and how to interact with the Enigma game engine, both when preparing the level (before the game starts) and during the game.

This manual only describes the low-level interface to Enigma's game engine, which is as flexible as it is inconvenient to use by hand. Petr Machata has written a comprehensive set of helper routines that greatly simplify the creation of new levels. You can use the package by including the line Require("levels/ant.lua") in your level descriptions. There is extensive documentation for `ant.lua' in file `ant_lua.txt' in the documentation directory.

Before you read on, please be aware that this manual is far from complete. We are working on it and it will be ready for the (glorious) 1.0 release. For the moment, the available level descriptions are the best "documentation" available.

2. XML levels

Enigma is slowly moving towards a more data-centric level description format. Although the current use of small Lua scripts for this purpose makes it possible to create levels with sophisticated dynamic behavior, it is difficult to create large, complex levels by hand and even more difficult to write graphical tools that help level designers with this task. The purpose of the XML-based levle format for Enigma is to provide an extensible basis for automated processing of Enigma levels, while retaining the full expressive power of the Lua scripting language where necessary or desirable.

The general outline of an XML-style Enigma level looks like this:

<level width="20" height="13">
  <info>
     <!-- level information -->
  </info>
  <option ... />
  <actors>
     <!-- actor definitions -->
  </actors>
  <floors>
     <!-- floor definition -->
  </floors>
  <items>
     <!-- item definition -->
  </items>
  <stones>
     <!-- stone definition -->
  </stones>
  <rubberbands>
     <!-- rubberband definition -->
  </rubberbands>
  <signals>
     <!-- signal definition -->
  </signals>
  <lua>
     <!-- optional Lua code -->
  </lua>
</level>

If you are unfamiliar with XML, here are a few general notes:

• XML is a standard for representing hierarchical documents. An XML document consists of a number of arbitrarily nested segments delimited by opening tags like <level> and closing tags </level>.
• Tags can have arguments, as shown above for the level tag. Arguments have the form name="value"; note that the value must be enclosed in quotation marks.
• The empty tag <option ... /> is an abbreviation for <option ...></option>.
• Comments can be written like this <!-- blabla -->.

An Enigma level must begin with <level width="xx" height="yy">, where xx and yy are width and height of the level, and ends with </level> The following sections of this manual describe the structure of the remaining parts of a level description, in the order indicated in the above example.

2.1 Meta information

Every level should begin with a short block containing general information about the level. This can include the level name, its author and license restrictions. If you intend your level(s) to be distributed with Enigma, the following four fields are mandatory:

<info>
  <name>LEVEL NAME</name>
  <author>AUTHOR NAME</author>
  <copyright>COPYRIGHT NOTICE</copyright>
  <license>LICENSE TERMS</license>
</info>

2.2 Level options

Certain aspects of the game can be customized by changing the values of the options to be described in this section. Some of these options control general aspects, like constant force fields or whether the level automatically restarts when the marble gets destroyed, while other options provide default values for objects in the level, like the strength of magnetic fields or the look of Oxyd stones.

The following example shows the general syntax for options. Note the use of empty tags: the salient information is already contained in the attributes name and value. Boolean options are always encoded as "YES" or "NO".

<option name="shuffle" value="NO" />

Here is the table of all options available so far:

shuffle

Shuffle the colors of the Oxyd stones after before starting the game? "YES"/"NO".

oxydflavor

The look of Oxyd stones; "a"/"b"/"c"/"d". See st-oxyd: Oxyd Stones for details.

reset

Reset the level when the player dies? "YES"/"NO"

scrolling

An integer between 1 and 4 (inclusive). Determines how the screen follows the currently active ball. 1: scroll the screen, 2: flip the screen, 3: scroll but align to screens, 4: keep marble at center.

In addition, there are a few numeric options that determine the behavior of certain comon objects. These correspond to the variables desribed later in the document, see Variables for details.

brittleness

slopeforce

flatforce

frictionfactor

electricforce

bumperforce

magnetforce

magnetrange

wormholeforce

wormholerange

holeforce

2.3 Actors

Syntax:

<actors>
  <actor kind="ac-blackball" x="10.5" y="5.5" />
</actors>

<actors difficulty="hard">
  <actor kind="ac-killerball" x="3" y="4" attribs="controllers=3" />
</actors>

<actors difficulty="easy">
  <actor kind="ac-killerball" x="3" y="4" attribs="controllers=0" />
</actors>

2.4 Objects

The description of floor tiles, items, and stones in the XML level file is very similar, so we treat them here in one section. The general syntax looks like this:

<floors>
  <row y="yy"> ... </row>
  <floor kind="name" x="xx" y="yy" attribs="attriblist" />
</floor>

For items and stones, the XML tags are called <items> and <stones> respectively. As for the actor sections, you can optionally include a difficulty= option to place certain objects only in the specified difficulty level.

The <row> tag can be used to draw complete rows of objects to the screen. An example looks like this:

<floors>
  <row y="10">abyss 10 water # abyss 10 </row>
</floors>

This must be read as follows: In the tenth row, put one fl-abyss (not that the prefix is not included in the level file!), repeat it ten more times (so it's elevel abyss tiles), put one water tile, repeat it once, and then finish with another eleven abysses.

Here's another, more advanced, example for a row of items:

<items>
  <row y="10">-10 hammer - - blackbomb - # -5 3</row>
</items>

Read this as follows: skip 10 fields, put one hammer, skip two fields (you could also write -2 instead), put one black bomb, skip one field, put another black bomb, skip five fields, and finish with three more black bombs.

In general there can be five different kinds of entries in such a row description, all of them separated by spaces:

name

Put one object of the specified type at the current position, remember the object name;

#

Repeat the last named object

positive number

Repeat the last named object the specified number of times

-

Skip one field

negative number

Skip the specified number of fields

You cannot specify object attributes using <row> tags, to do this you must place objects individually, using either <floor ... />, <item ... />, or <stone ... />, for example

<stones>
  ...
  <stone kind="st-switch" x="2" y="2" attribs="action='openclose', target='door1'" />
  ...
</stones>

The attribute list looks like the one in Lua would, except for the enclosing braces {} that must be omitted in the XML level format. Please note that you must in this case use single quotes ' to enclose string attributes, double quotes would terminate the XML argument. Enigma's current XML parser unfortunately does not yet understand character entities like ", this will hopefully be fixed in future versions.

2.5 Signals

[To be written]

2.6 Rubberbands

Syntax:

<rubberbands>
  <rubberband from="objname" to="objname" strength="12" length="5" minlen="0" />
</rubberbands>

2.7 Embedded Lua code

To make XML levels every bit as expressive as the former level format, a special <lua> tag is available to carry arbitrary Lua code. Only one such tag per level is allowed, and the code it contains is executed after all other tags have been processed, immediately before handing the level over to the game engine.

Lua code blocks can be used for everything that can not be realized with the data-centric XML format, like specially crafted signal handlers, randomly generated levels or puzzles, or to access features of Enigma's game engine that are not otherwise available.

Graphical level editors are expected not to tamper with the contents of Lua code blocks when they read or write Enigma levels, i.e., neither to modify them nor to delete them without notice.

3. Objects

3.1 Floors

3.1.1 Special floor tiles

fl-abyss
fl-acblack
fl-acwhite
fl-bridge( type )
fl-bridge-closed( type )
fl-bridge-open( type )
fl-gradient( type )
fl-gradient{1..16}
fl-springboard
fl-swamp
fl-water

3.1.2 Regular floor tiles

fl-abyss_fake
fl-black
fl-bluegray
fl-bluegreen
fl-bluegreenx
fl-brick
fl-bumps
fl-concrete
fl-darkgray
fl-dummy
fl-dunes
fl-floor_001
fl-gravel
fl-gray
fl-hay
fl-himalaya
fl-ice
fl-ice_001
fl-inverse
fl-inverse2
fl-leaves
fl-leavesb
fl-leavesc{1..4}
fl-leavesd{1..4}
fl-leavese{1..4}
fl-light
fl-lightgray
fl-marble
fl-metal
fl-metal{1..6}
fl-mortar
fl-normal
fl-normal_x
fl-plank
fl-red
fl-rock
fl-rough
fl-rough-blue
fl-rough-red
fl-rough_medium
fl-rough_slow
fl-sahara
fl-samba
fl-samba1
fl-samba2
fl-sand
fl-space
fl-space-force
fl-stone
fl-stwood
fl-stwood1
fl-stwood2
fl-tigris
fl-trigger
fl-white
fl-wood
fl-woven

3.2 Items

3.2.1 Item List

it-1pkillstone
it-2pkillstone
it-abyss
it-bag
it-banana
it-blackbomb
it-blackbomb_burning
it-blocker
it-blocker-new
it-booze
it-brake
it-bridge-oxyd
it-bridge-oxyd_active
it-brush
it-burnable
it-burnable_ash
it-burnable_burning
it-burnable_fireproof
it-burnable_ignited
it-changefloor
it-cherry
it-coffee
it-coin1( value )
it-coin2( value )
it-coin4( value )
it-crack{0..3} ( type fixed brittleness )
it-cross
it-debris
it-document( text )
it-drop
it-dummy
it-dynamite
it-easykeepstone
it-easykillstone
it-explosion1
it-explosion2
it-explosion3
it-extinguisher( load )
it-extinguisher_empty( load )
it-extinguisher_medium( load )
it-extralife
it-flagblack
it-flagwhite
it-floppy
it-glasses
it-glasses-broken
it-hammer
it-hill
it-hollow
it-hstrip
it-inversesensor
it-key( keycode )
it-key_a
it-key_b
it-key_c
it-landmine
it-magicwand
it-magnet( on strength range )
it-magnet-off( on strength range )
it-magnet-on( on strength range )
it-odometer
it-oxyd5f
it-pencil
it-pin
it-pipe-e
it-pipe-es
it-pipe-h
it-pipe-n
it-pipe-ne
it-pipe-s
it-pipe-sw
it-pipe-v
it-pipe-w
it-pipe-wn
it-puller-e
it-puller-n
it-puller-s
it-puller-w
it-ring
it-rubberband( object1 object2 length strength )
it-seed
it-seed_nowood
it-seed_volcano
it-sensor
it-shogun-l
it-shogun-m
it-shogun-s
it-signalfilter0
it-signalfilter1
it-spade
it-spoon
it-spring1
it-spring2
it-springboard
it-squashed
it-surprise
it-sword
it-tinyhill
it-tinyhollow
it-trigger( invisible )
it-umbrella
it-vortex-closed( autoclose targetx targety )
it-vortex-open( autoclose targetx targety )
it-vstrip
it-weight
it-whitebomb
it-wormhole( on targetx targety strength range )
it-wormhole-off( on targetx targety strength range )
it-wrench
it-yinyang

3.2.2 it-document: Scrolls of Paper

This item looks like a piece of paper and contains text messages that can be displayed by activating the item.

Attributes

text

The message to be displayed.

Example

set_item("it-document", 1,1, {text="Hello World!"})
Document(1,1, "Hello World")

3.2.3 it-floppy: Floppy Disk

The floppy disk is needed to activate the Floppy switch (see st-floppy: Floppy Switch).

3.2.4 it-hollow: Hollows in the floor

This item creates a hollow in the floor. If all existing @ref{ac-whiteball-small} are inside hollows the level succeeds.

Attributes

essential

Whether the hollow must be filled with a whiteball to end the level (1 means 'yes').

Use this attribute if there are more holes than small whiteballs in a level and you want to determine which of the holes are needed to finish the level.

For example: If you have many holes and 3 whiteballs, then set essential=1 in 3 holes. The game will end when the 3 whiteballs are inside the 3 marked holes.

3.2.5 it-ring: Ring

When a player drops this item, the marble is teleported. The destination depends on the game mode:

Single player levels:

The marble is transported to its starting position or to the position of the last dropped @ref{it-flag}.

Multi player levels:

Both marbles exchange their positions.

3.2.6 it-vortex: Vortex

Vortices, like wormholes, can be used to teleport marbles. In the simplest case, every vortex is connected to exactly one other vortex. If there are multiple target vortices, the marble will be teleported to the first unblocked target site. Many levels in the original Oxyd games required the player to selectively block vortices to gain access to new parts of the level.

Example

This example creates three vortices. If the second vortex is blocked, a marble falling into the first one is transported to (20,1).

set_item ("it-vortex", 1, 1)
set_item ("it-vortex", 10,1)
set_item ("it-vortex", 20,1)
Signal ("it(1 1)", "it(10 1)")
Signal ("it(1 1)", "it(20 1)")
Signal ("it(10 1)", "it(1 1)")
Signal ("it(20 1)", "it(1 1)")

3.3 Stones

3.3.1 Stone List

Simple stones

The following stone types are commonly used for "decoration". They generally do not have special properties or abilities. Three types of abbreviations are used in the tables: [abc] stands for any of the characters in square brackets, <abc> stands for any subsequence of the characters between the angle brackets (in this case abc, ab, bc, a, b, c), and {1..9} indicates a sequence of numbers.

st-beads
st-bigbrick-<nesw>
st-blue-sand
st-bluegray
st-bluegray_hole
st-brick
st-brownie
st-bumps
st-dummy
st-fakeoxyd( blinking )
st-fakeoxyda
st-glass
st-glass[123]
st-glass[12]_hole
st-glass1_move
st-glass_move
st-grate{1..3}
st-greenbrown
st-greenbrown_hole
st-greenbrown_move
st-likeoxyd[abcd]
st-likeoxyd[abcd]-open
st-marble
st-marble_hole
st-marble_move
st-metal
st-plain
st-plain_hole
st-plain_move
st-rock{1..8}
st-rock[123]_hole
st-rock[13]_move
st-stone[12]
st-wood[12]
st-wood_001
st-woven
st-yellow

Special stones

The following stones types are special in the sense that they perform some action, either when hit by an actor, or all by themselves.

st-3mirror( transparent movable orientation )
st-actorimpulse
st-actorimpulse_invisible
st-black{1..4}
st-blackballs
st-block
st-blocker
st-blocker-growing
st-bolder-[ensw]
st-bombs
st-brake
st-break_acblack
st-break_acwhite
st-break_bolder
st-break_gray
st-break_invisible
st-breaking
st-brick_magic
st-bug
st-chameleon
st-chargeminus( charge )
st-chargeplus( charge )
st-chargezero( charge )
st-coffee
st-coinslot( on )
st-death
st-death_invisible
st-disco-dark
st-disco-light
st-disco-medium
st-door( type )
st-door-h( type )
st-door-h-open( type )
st-door-v( type )
st-door-v-open( type )
st-door_[abc]
st-easymode
st-explosion
st-fart
st-flash
st-floppy( on )
st-fourswitch( on )
st-greenbrown-growing
st-invisible
st-invisible_magic
st-key( on keycode )
st-key_[abc] ( on keycode )
st-knight
st-laser-[ensw]( on )
st-laserbreak
st-laserswitch
st-lasertimeswitch( delay )
st-magic
st-mail-[ensw]
st-mirror-3<
st-mirror-3<m
st-mirror-3<t
st-mirror-3<tm
st-mirror-3>
st-mirror-3>m
st-mirror-3>t
st-mirror-3>tm
st-mirror-3^
st-mirror-3^m
st-mirror-3^t
st-mirror-3^tm
st-mirror-3v
st-mirror-3vm
st-mirror-3vt
st-mirror-3vtm
st-mirror-p-
st-mirror-p-m
st-mirror-p-t
st-mirror-p-tm
st-mirror-p/
st-mirror-p/m
st-mirror-p/t
st-mirror-p/tm
st-mirror-p\
st-mirror-p\m
st-mirror-p\t
st-mirror-p\tm
st-mirror-p|
st-mirror-p|m
st-mirror-p|t
st-mirror-p|tm
st-oneway-[nesw]
st-oneway_black-[nesw]
st-oneway_white-[nesw]
st-oxyd( flavor color )
st-oxyd-0x18
st-peroxyd-0xb8
st-peroxyd-0xb9
st-plain_break
st-plain_breaking
st-plain_cracked
st-plain_falling
st-pmirror( transparent movable orientation )
st-pull
st-puzzle-hollow( oxyd )
st-puzzle-<nesw>( oxyd )
st-puzzle2-hollow( oxyd )
st-puzzle2-<nesw>( oxyd )
st-rock3_break
st-rock3_movebreak
st-rotator-left
st-rotator-right
st-rotator_move-left
st-rotator_move-right
st-rubberband( length strength )
st-scissors
st-shogun-<sml>
st-spitter
st-stone_break
st-stonebrush
st-stoneimpulse
st-stoneimpulse-hollow
st-stoneimpulse_movable
st-surprise
st-swap
st-switch( on )
st-switch_black( on )
st-switch_white( on )
st-thief
st-timer( on interval loop invisible )
st-timeswitch( delay )
st-turnstile
st-turnstile-green
st-turnstile-[ensw]
st-volcano
st-volcano-growing
st-volcano_active
st-volcano_inactive
st-white{1..4}
st-whiteballs
st-window
st-wood
st-wood-growing
st-yinyang{1..3}

3.3.2 st-actorimpulse: Bumper Stones

These stones apply an impulse to actors that touch them. The amount of force applied can be controlled by setting @ref{enigma.BumperForce} accordingly (the default is 800). Alternatively, the force attribute can be used to set this factor for individual bumper stones.

The invisible variant, @ref{st-actorimpulse_invisible} can "painted" with a @ref{it-brush}.

3.3.3 st-chameleon: Chameleon Stone

This stone takes on the look of the floor beneath it. Actors can move through it, so these stones are perfect for hiding stuff under them...

3.3.4 st-coinslot

A switch that can be activated with coins. The more coins you put in, the longer the switch will stay activated.

Attributes

target, action

As usual

3.3.5 st-death: Skull Stones

Simply kills all marbles that touch it (except when protected by an umbrella).

Variants

st-death

st-death_invisible

3.3.6 st-disco: Disco Stones

Darkens everything that is underneath the stone (much like tinted glass). Can be switched on and off (hence the name).

Messages

signal

With parameter 1, lighten the stone and (recursively) all neighboring disco stones; with parameter smaller than 1, darken them.

lighten

darken

Variants

st-disco-light

st-disco-medium

st-disco-dark

3.3.7 st-easymode: Easy Mode Stone

In easy game mode this stone converts the floor at its position to fl-normal. In normal game mode the stone removes any item at its position. The stone itself never appears in either game mode; it removes itself immediately after performing its job.

This stone is commonly used to hide danger areas (water holes, abyss) or to insert helper items (umbrellas, seeds, etc.) that make the level easier in easy game mode.

3.3.8 st-fart: Fart Stone

The fart stone has the unpleasant habit of "blowing off" when triggered (by actor hit or signal) and will close all Oxyd stones.

Messages

trigger

blow off

3.3.9 st-floppy: Floppy Switch

A switch that is activated by inserting a floppy disk (see it-floppy: Floppy Disk).

Attributes

on

1 or 0

target

action

3.3.10 st-grate: Grates

Floating grates, mainly decorative. Flying objects (jumping marbles, rotors, etc.) cannot pass, objects moving on the floor can.

Variants

st-grate1

st-grate2

st-grate3

3.3.11 st-laserswitch: Laser Switch

This switch is on while hit by a laserbeam and off when not hit by a laserbeam.

See also st-lasertimeswitch: Laser Time Switch.

Attributes

inverse=1

Inverts the on/off state of the switch (i.e on at startup and switch off with laserbeam)

target,action

as usual

3.3.12 st-lasertimeswitch: Laser Time Switch

This switch is a mix between st-laserswitch: Laser Switch and st-timeswitch: Time Switch.

3.3.13 st-oneway: One-way Stones

This stone can be passed by the marble in only one direction. (Or, to be more exact, the arrow on the stone points to the one side of the stone through which it can't be entered. Hard to explain, try it yourself :-)

There are three different variants of the one-way stone: the standard one, st-oneway, which both the black and the white marble can pass, and two colored ones, st-oneway_black and st-oneway_white, which completely block marbles of the other color.

Variants

st-oneway

st-oneway-[nesw]

st-oneway_black

st-oneway_black-[nesw]

st-oneway_white

st-oneway_white-[nesw]

Attributes

orientation

One of NORTH, EAST, SOUTH, or WEST. This determines the orientation of the stone when the level is loaded. You need to use the direction message for changing the orientation during the game. Note that it is usually easier to use one of the alternative names, like st-oneway-north instead of explicitly setting this attribute.

Messages

direction

Set the direction of the arrow during the game. Simply setting the attribute orientation is not enough, since this does not update the stone's model on the screen.

signal

flip

Both these messages flip the direction of the arrow.

3.3.14 st-oxyd: Oxyd Stones

Oxyd stones are characterized by two attributes: Their flavor and their color. The flavor only affects the visual representation of the stone; it can be either `a' (opening like a flower), `b' (displaying a fade-in animation), `c', or `d'. The color attribute determines the color on the oxyd stone.

Note: You should rarely need to create Oxyd stones manually with set_stone(). Use the predefined oxyd() function instead. It will automatically take care of creating two Oxyd stones of every color.

Attributes

flavor

`a', `b', `c', or `d'

color

a number between 0 and 7

Messages

closeall

Close all oxyd stones

shuffle

Interchange the colors of the oxyd stones in the current landscape. Use the oxyd_shuffle() function.

trigger

Open the stone (useful for opening Oxyd stones using switches)

3.3.15 st-rubberband: Rubberband Stone

If hit by a marble, this stone first removes existing connections with other rubberband stones and then attaches a new elastic between the marble and itself. Nothing happens if the marble was already attached to this particular stone.

This stone can be moved if hit with a magic wand.

Attributes

length

The natural length of the rubberband (default: 1)

strength

The strength of the rubberband (default: 10)

3.3.16 st-scissors: Scissors Stone

This stone cuts all rubber bands attached to an actor that touches it.

3.3.17 st-stone_break: Breakable Stone

This stone can be destroyed by an actor having a hammer and by laser, dynamite, bombs and bombstones.

3.3.18 st-swap: Swap Stone

This stone can exchange its position with other neighboring stones if it is hit hard enough. In a way, this makes swap stones a kind of "movable stone", except that they can be only exchanged with other stones and may not be moved on empty fields.

3.3.19 st-switch: Switches

A simple switch.

Variants

st-switch

All kinds of objects can activate this switch

st-switch_black

Only black marbles can activate this switch

st-switch_white

Only white marbles can activate this switch

Attributes

on

1 (activate) or 0 (inactive)

target, action

as usual

3.3.20 st-thief: Thief Stone

Takes one item from inventory after when hit by the player's marble. Umbrellas protect against thievery.

3.3.21 st-timer: Timer Stone

This stone can be used to trigger periodic events or to trigger one single event after a certain amount of time.

Attributes

on

1 if the timer is running

interval

number of seconds before action is performed

loop

if 1, restart the timer after performing action

action

as usual

target

as usual

invisible

if 1, stone is invisible

Messages

on

off

onoff

Example

-- activate a laser after 5 seconds
set_stone("st-laser", 10,11, {name="laser"})
set_stone("st-timer", 10,10,
          {loop=0, action="onoff", target="laser", interval=5})

3.3.22 st-timeswitch: Time Switch

When this switch is touched by an actor, it switches on for 1.8 seconds and then switches off again.

See also st-lasertimeswitch: Laser Time Switch.

Attributes

delay

The delay in seconds after which the switch goes off.

inverse=1

Inverts the on/off state of the switch.

3.3.23 st-window: Breakable Stone

Hit this window heavily with your marble to blast it into smithereens.

3.3.24 st-wood: Wooden Stone

This stone is movable. If moved into abyss, water or swamp it builds a wooden plank.

Note: There are two flavors of st-wood which may be specified by using st-wood1 or st-wood2.

3.3.25 st-yinyang: Yin-Yang Stones

Yin-Yang stones change into @ref{st-white} or @ref{st-black} if you touch them.

There are several flavors of this stone:

st-yinyang1

If touched it changes it's color to the opposite color of your marble.

st-yinyang2

If touched it changes it's color to the same color as your marble.

st-yinyang3

The Per.Oxyd compatible: You must hold @ref{it-magicwand} or @ref{it-brush} to change the color to the opposite color of your marble.

Actors get stuck inside the Yin-Yang Stone if they are starting there or when they warp there. They can be freed by changing the color of the Yin-Yang Stone to their color.

3.4 Actors

Movable objects are called "actors" in Enigma. The commonest actor is, of course, the black marble, but there are others, including the white marble, the killerball and a few more:

3.4.1 ac-blackball

mouseforce (default 1.0) color (default 0.0) blackball (default 1) player (default 0) controllers (default 1)

3.4.2 ac-whiteball

mouseforce (default 1.0) color (default 1.0) whiteball (default 1) player (default 1) controllers (default 2)

3.4.3 ac-whiteball_small

mouseforce (default 1.0) color (default 1.0) whiteball (default 1) controllers (default 3)

3.4.4 ac-killerball

mouseforce (default 2.0) color (default 1.0) whiteball (default 1) controllers (default 3)

3.4.5 ac-rotor

range (default 5.0) force (default 10.0) gohome (default 1)

3.4.6 ac-top

range (default 5.0) force (default 10.0) gohome (default 1)

3.4.7 ac-bug

3.4.8 ac-horse

force (default 10.0) target1 target2 target3 target4

3.4.9 Actor Attributes

All actors share a set of common attributes that determine their general behaviour:

player

The player "owning" this actor. This is either 0 or 1 for the first or second player respectively. Actors attached to a player can pick up items and can be respawned when they are killed.

mouseforce

A factor that determines how much the actor accelerates when the mouse is moved. Default is 1, use higher values for fast moving actors. If set to 0, the actor cannot be moved with the mouse (but external forces can still exert a force on it).

controllers

Determines which players may move this actor: 1=Player 1, 2=Player 2, 3=both. By default, ac-blackball, ac-whiteball and ac-whiteball-small have their controllers attribute set to 1,2, and 3 respectively.

essential

A non-zero value marks this actor as essential. If essential=1, the game restarts if 1 of all essential actors can't resurrect (analog for higher values). If you set the attribute for several actors, you should use the same value for all of them!

whiteball, blackball

Used by color-sensitive stones (black/white switches for example) to determine whether the actor is the black or the white marble. These attributes may disappear in future versions, please do not use them.

3.5 General object attributes

name

All objects may be given a name attribute. Such named objects can be searched using enigma.GetNamedObject.

4. Variables

This chapter describes the a few variables that can be changed from level descriptions to alter the behavior of the game engine or set default attributes for some particular objects. In the latter case, the same effect can usually be achieved by setting the corresponding object attributes directly, but being able to specify a global default value it is often more convenient. You can always override these default attribute values for specific objects by setting the appropriate object attributes.

Variable: enigma.ConserveLevel

TRUE or FALSE. If FALSE, reload the level whenever the an actor that is controlled by a player (i.e., one that has the player attribute set) dies. Often used in meditation landscapes or landscapes that are intended to be solved in one go. Default: TRUE.

Variable: enigma.ShowMoves

TRUE or FALSE. This is only used in the Sokoban level pack to display a move counter in the inventory. Default: FALSE.

Variable: enigma.Brittleness

A value between 0 and 1, denoting the probability that a brittle floor plate desintegrates further when an actor enters or leaves it. 1 means that the floor will always crack, 0 that it is indestructible. Default: 0.5.

Variable: enigma.BumperForce

The amount of force applied to an actor that hits an st-actorimpulse stone. st-actorimpulse: Bumper Stones. Default: 200.0.

Variable: enigma.ElectricForce

A force multiplier for all electric forces between actors. Default: 15.0.

Variable: enigma.FrictionFactor

All friction forces are multiplied by this value. Default: 1.0.

Variable: enigma.FlatForce

A global downward force. This is currently only applied on floors of type fl-space. Default: 0.

Variable: enigma.HoleForce

A force factor that affects the steepness of hollows and hills. Default: 1.0.

Variable: enigma.MagnetForce

A force multiplier for magnetic fields. Default: 30.0.

Variable: enigma.MagnetRange

The range of magnetic fields. Default: 10.0.

Variable: enigma.SlopeForce

A force multiplier for sloped floor tiles. Default: 25.0.

Variable: enigma.WaterSinkSpeed

How quickly balls sink in water. Default: 1000.0.

Variable: enigma.SwampSinkSpeed

How quickly balls sink in swamp. Default: 4.0.

Variable: enigma.WormholeForce

A force multiplier for wormholes. Default: 30.0.

Variable: enigma.WormholeRange

The range of worm holes. Default: 10.0.

5. Functions

5.1 AddRubberBand

Function: AddRubberBand (actor, object, strength, length)

This function connects two objects with a rubber band: The first object is always an actor, the second object can be either another actor or a stone.

The first argument actor is always a reference to an actor created earlier with the set_actor function. The second parameter object may be either an actor or a stone created earlier. The last two parameters define the properties of the rubber band: strength denotes the force factor of the elastic and length its natural length. No force is exerted on the actor if the rubber band is shorter than its natural length.

5.1.1 Example

local ac=set_actor("ac-blackball", 1.5,7.5)
local st=set_stone("st-brownie", 10,6)
AddRubberBand(ac, st, 50, 10)

5.2 CreateWorld

Function: CreateWorld (width, heigth)

This function creates a new level. Because objects can only be added to the level after CreateWorld has been called, you should usually do so near the beginning of your level description.

The width and height denote the size of the new level. All levels with only one screen have the minimum size of 20x13 blocks.

Note that level fields are indexed from zero, i.e, the field indices for a 20x13 level are in the range (0..19)x(0..12). Also note that the screens in Enigma overlap by one line or column: A level that fits on a single screen has size of 20x13, but two a level that is two screens wide 39x13 or 20x25, three screens 58x13 or 20x37.

5.3 enigma.AddConstantForce

Function: enigma.AddConstantForce (gravity_x, gravity_y)

Adds global gravity to the current level.

gravity_x

adds gravity in horizontal direction (positive means rightwards).

gravity_y

adds gravity in vertical direction (positive means downwards).

5.4 enigma.GetNamedObject

Function: enigma.GetNamedObject (objname)

This function searches for an object that has a name attribute with value objname. It returns a reference to the object or nil if none could be found.

5.4.1 Example

set_stone("st-wood", 7, 11, {name="woodie"})
...
local Woodie = enigma.GetNamedObject("woodie")

5.5 SendMessage

Function: SendMessage (object, message, data)

This function sends a message to an object.

object

The recipient of the message. Can either be the name of an object or a reference as returned by enigma.GetNamedObject.

message

The message itself (e.g. "signal") You can see which messages are understood in the documentation of the particular Objects.

data

Some specific messages expect some additional data (e.g. message "direction" expects a direction like SOUTH or WEST).

5.5.1 Examples

set_stone("st-laser-s", 2, 2, {name="laser3", on=FALSE})
...
SendMessage("laser3", "onoff")

set_stone("st-bolder", 7, 11, {name="bolder1", direction=SOUTH})
...
SendMessage("bolder1", "direction", WEST)

5.6 draw_checkerboard_floor

Function: draw_checkerboard_floor (name1, name2, x, y, w, h, attribs)

This function draws checkerboard composed of two selected floor types. name1 and name2 are names of floor objects. See @ref{set_floor} for further details.

name1, name2

Names of floor objects

x, y

Location of left top corner of checkerboard area. Note that upper left map corner is [0,0].

w, h

Size of generated checkerboard.

attribs

Table of attribute names and corresponding values: {attrib1=value1, attrib2=value2, ...}. These attributes, together with default attributes, are passed to each tile of the generated checkerboard.

5.6.1 Example

draw_checkerboard_floor("fl-abyss", "fl-rough", 2, 2, 23, 11)
draw_checkerboard_floor("fl-normal", "fl-inverse", 0, 0, levelw, levelh) -- racetrack

5.7 draw_border

Function: draw_border (stonename, x,y, w,h)

This function adds a border of stones to your level. If invoked with only one argument, this border encloses the whole level.

stonename

The name of the border stone.

x,y

(optional) Coordinates of upper-left corner. (0,0) if omitted.

w,h

(optional) Width and height of border.

5.7.1 Example

draw_border("st-marble")
draw_border("st-greenbrown", 0,5,3,3)

Index

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