View source for Level specification

== Introduction ==

This document presents the specification of level files (.lev). You will not learn how to make a level here. This will present you documentation that teaches you how Open Surge levels work and how can you use them to make your own games.

'''ATTENTION!''' If you just want to learn how to make a level, follow this link: [[How to make a level]]. Also read [[Level Design Document]] for tips on how to make great levels.

== Definition ==

In Open Surge, a level is a scene. Usually, levels are playable: they have scenery and the player controls the heroes. This, however, is not a strict requirement: one may create a level that is actually a cutscene. Or perhaps a special menu. Or a bonus level. You decide.

Levels are represented by .lev files stored in the '''levels/''' subdirectory, which is located inside the game folder. Level files are human-readable. You may open them with a simple text editor such as: Notepad, gedit, vim, etc.

If you want to play in a specific level of your choice, open the game, go to the options screen and enter in the '''STAGE SELECT''' area. Alternatively, you can save some time by using the command line:

Under Linux / OSX,

''./opensurge --level levels/template.lev''

Under Windows,

''opensurge.exe --level levels/template.lev''

And here's a secret for the initiates: as soon as you run the engine, you'll see the Open Surge Engine splash screen. Press RIGHT 3 times to enter the ''developer mode''. From there, you'll be able to enter on any .lev file.

== Level elements ==

=== Level objects ===

Levels objects are basically of two types:
* bricks
* entities

==== Bricks ====

Bricks are level objects that are static: they can be platforms, walls, decorative objects (like trees or plants), breakable walls, and so on.

A detailed documentation about bricks can be found at: [[Bricksets]].

==== Entities ====

Entities are level objects created via scripting. You can create pretty much anything your imagination tells you to: new items, new enemies, bosses, CPU-controlled agents, non-playable-characters, etc.

To create new entities, [http://docs.opensurge2d.org learn SurgeScript].

=== Other elements ===

==== Backgrounds ====

A background is some image or animation that is displayed behind everything else. It could be some nice mountains in a far distance, a city with falling snow, or some nice moving texture for a menu screen.

Backgrounds have their own [[Backgrounds|specification]].

==== Groups of objects ====

In order to make level design simpler, we have invented the concept of groups of objects. You can pack up many level objects together and work with them in the level editor as if they were one.

Read more about groups of objects at [[Groups]].

=== Legacy elements ===

The elements below were used in legacy versions of the engine, such as 0.2.0. They are no longer used.

==== Built-in items ====

Built-in items are "hard-coded" objects. These items are native to the engine. Examples of built-in items include: a life box, a checkpoint, a spring, spikes, etc. These objects allow no customization. The best you can do is to modify their sprites, but you should really use them the way they are.

==== Custom objects ====

Custom objects allow you to create pretty much anything your imagination tells you to - within the boundaries of the engine, of course. No, you can't create a last-generation MMORPG, but you can make pretty much anything "reasonable": different kinds of items, new enemies, bosses, cutscenes, special effects, simple intelligent CPU-controlled agents, non-playable-characters, menus, etc.

Custom objects are created via [[Introduction to objects|scripting]].

== The built-in level editor ==
[[File:Editor.png|200px|thumb|right|Level Editor: click to resize]]
The Open Surge Engine was not always very modifiable. In the beginning, the most you could do was to create simple levels using built-in features of the engine. The built-in level editor was used to make levels.

Nowadays the Open Surge Engine is much more customizable, and the built-in level editor has gained much power. However, it has retained its principles: it is still very simple to learn and to use.

Whenever you're playing on any level, press F12 to activate/deactivate the editor. See also: [[How to make a level]].

== Commands ==

As we have already said, levels are represented by .lev files stored in the '''levels/''' folder. .lev files are human-readable, that is, you can open them with a simple text editor like Notepad and understand what is written.

=== General properties ===

==== name ====

'''Syntax:''' ''name name_of_the_level''

'''Available since:''' 0.1.0

Specifies the name of your level. Example:

 name "Sunshine Paradise"

==== author ====

'''Syntax:''' ''author level_author''

'''Available since:''' 0.1.0

Name of the person/people who made the level.

 author "Your name"

==== license ====

'''Syntax:''' ''license license_name''

'''Available since:''' 0.5.0

The license of the level file (.lev). You may pick any license you'd like. Examples: CC-BY-SA 3.0, CC-BY 3.0, CC-0 (public domain).

 license "CC-BY 3.0"

==== requires ====

'''Syntax:''' ''requires engine_version''

'''Available since:''' 0.1.0

Specifies the minimum engine version your user has to have in order to play the level. You should not specify this property yourself: once you save the level using the built-in editor, the engine will assume that ''engine_version'' is the engine version you use. This guarantees that any engine features you use will also be available to your target player. Example:

 requires "0.5.0"

==== act ====

'''Syntax:''' ''act number''

'''Available since:''' 0.1.0

Specifies the act number (usually 1, 2 or 3). This property, an optional one, only makes sense for playable levels. Example:

 name "Sunshine Paradise Boss"
 act 3

==== spawn_point ====

'''Syntax:''' ''spawn_point xpos ypos''

'''Available since:''' 0.1.0

(''xpos'', ''ypos'') denotes the initial position of the player. Both ''xpos'' and ''ypos'' must be non-negative integers. (0,0) is the top-left corner of the level. This only makes sense on playable levels. Example:

 spawn_point 40 5700

==== readonly ====

'''Syntax:''' ''readonly''

'''Available since:''' 0.1.0

If the level is set to ''readonly'', the user will not be able to access the level editor.

 readonly

=== Look and feel ===

==== theme ====

'''Syntax:''' ''theme path_to_brk_file''

'''Available since:''' 0.1.0

Tells the engine which [[Bricksets|brickset]] to use in this level. Example:

 theme "themes/template.brk"

==== bgtheme ====

'''Syntax:''' ''bgtheme path_to_bg_file''

'''Available since:''' 0.1.0

Tells the engine which [[Backgrounds|background theme]] to use in this level. Example:

 bgtheme "themes/template.bg"

==== music ====

'''Syntax:''' ''music path_to_ogg_song''

'''Available since:''' 0.1.2

This property is optional. If you specify it, the engine will play the specified song, looping it when it's over. [[Musics]] must be in the [http://en.wikipedia.org/wiki/Ogg .ogg] format. Example:

 music "musics/title.ogg"

=== Setup & players ===

==== setup ====

'''Syntax:''' ''setup object1 [object2 [object3 ... [objectN] ... ]]''

'''Available since:''' 0.5.0

The ''setup'' command takes one or more object names as parameters. It simply creates the objects specified in the list when the level loads. If no ''setup'' command is specified, then an object named '''Default Setup''' will be created by default.

The '''Default Setup''' object takes care of basic game elements such as: pause, quit, default camera and displaying the HUD (Heads-Up Display). Therefore, it should be specified in the setup list in most cases (unless you want to change these basic elements).

Examples:

1) create only the '''Default Setup''' object (the default)

 setup "Default Setup"

2) create two setup objects

 setup "Default Setup" "Example Setup"

'''Note:''' in version 0.2.0 of the engine, this command was available under the name ''startup''. Setup objects created with the legacy scripting system must specify the [[API Reference#always_active|always_active]] flag.

==== players ====

'''Syntax:''' ''players player1 [player2 [player3 ... [playerN] ... ]]''

'''Available since:''' 0.2.0

The ''players'' command takes one or more parameters. It will create the list of [[Characters|characters]] specified on the list. If no ''players'' command is specified, then Surge, Neon and Charge will be spawned by default.

Examples:

1) regular team-play with Surge, Neon and Charge

 players "Surge" "Neon" "Charge"

2) a Surge-only level

 players "Surge"

3) [http://en.wikipedia.org/wiki/Tux Tux the Penguin]

 players "Tux"

4) no players

 // None is a special character that does not move and does not appear in the screen
 players "None"

=== Level objects ===

You should not worry about specifying the level objects manually. Let the Level Editor take care of them for you.

==== brick ====

'''Syntax:''' ''brick brick_id xpos ypos [layer] [flip]''

'''Available since:''' 0.1.0

Creates brick ''brick_id'' at the specified position. Example:

 brick 101 6917 1316

If a [[layer]] is specified, the brick will appear in that layer (green or yellow):

 brick 101 6917 1316 green
 brick 221 7212 3281 yellow

If flip is specified, the brick will be flipped. The possible values for flip are: noflip, hflip, vflip, vhflip.

 brick 101 6917 1316 hflip
 brick 101 6917 1316 green hflip

'''Note:''' the optional layer parameter is available since 0.2.0. The optional flip parameter, since 0.5.0.

==== entity ====

'''Syntax:''' ''entity entity_name xpos ypos [entity_id]''

'''Available since:''' 0.5.0

Spawns the specified entity at world position (''xpos'', ''ypos''). Parameter ''entity_id'' is an optional hexadecimal code that is used to uniquely identify the entity in the level. Example:

 entity "Collectible" 240 9936 "be647e181fcd7513"

=== Water ===

==== waterlevel ====

'''Syntax:''' ''waterlevel ycoord''

'''Available since:''' 0.2.0

Specifies that there should be water at every point with y-coordinate greater or equal than ycoord. Example:

 // at y-position 6410 and below, there is water
 waterlevel 6410

==== watercolor ====

'''Syntax:''' ''watercolor red green blue [alpha]''

'''Available since:''' 0.2.0

Specifies the color of the water, where 0 <= red, green, blue, alpha <= 255. Please see the [[Colors]] page for more information.

'''Note:''' property alpha is available since Open Surge 0.6.0. It's used to control the opacity of the water: 255 means fully opaque and 0 means fully transparent. It's an optional property. If left unspecified, value 128 is used by default.

Example:

 // the water should start at y-coord 6410 and it must be green
 waterlevel 6410
 watercolor 0 192 0

=== Legacy ===

The commands below were used in previous versions of the engine. '''You must no longer use them.''' They have been kept in this page for historical purposes.

==== item ====

'''Syntax:''' ''item builtin_item_id xpos ypos''

'''Available since:''' 0.1.0

'''Deprecated since:''' 0.5.0

Creates ''builtin_item_id'' at the specified position. Example:

 item 0 3322 774

==== object ====

'''Syntax:''' ''object object_name xpos ypos''

'''Available since:''' 0.1.0 | 0.1.4

'''Deprecated since:''' 0.5.0

Creates ''object_name'' at the specified position. Note that this refers to custom objects (created with scripting), not to built-in items! Example:

 object "Basic Pipe System: Pipe Master" 831 2046

Objects created with legacy scripting whose name start with a "." (examples: ''.hidden'', ''.secret'', ''.internal'') will not be available for selection in the built-in level editor. This is useful to make objects that are only supposed to be spawned by other objects.

'''Note:''' in versions prior to 0.1.4, this command was called ''enemy''.

==== grouptheme ====

'''Syntax:''' ''grouptheme path_to_grp_file''

'''Available since:''' 0.1.3

'''Deprecated since:''' 0.5.0

Tells the engine which [[Groups|group collection]] to use in this level. Example:

 grouptheme "themes/template.grp"

==== dialogbox ====

'''Syntax:''' ''dialogbox xpos ypos width height title message''

'''Available since:''' 0.1.0

'''Deprecated since:''' 0.5.0

Whenever the player enters in the rectangle described by ''xpos'', ''ypos'', ''width'' and ''height'', the engine will show a message box with the given parameters: ''title'' and ''message''. Example:

 dialogbox 190 2400 200 200 "WELCOME" "Welcome to the Dark Forest, a place where everybody enters but nobody leaves."

'''Note:''' use an Event Trigger to display a message instead. Native message boxes are not as flexible as what you can do with scripting nowadays. With the dialogbox command, you can only create dialog boxes, but with Event Triggers you can do much more, due to the fact that they are more flexible.

[[Category:MODs]]
[[Category:Level specification]]