Editing v0.31:Reactions

{{quality|Fine|09:41, 6 October 2010 (UTC)}}
{{av}}

Reactions are modular, editable formulas that take specific ingredients, or reagents, and use them to produce a desired item.  A lot of reactions are hardcoded - building beds or creating glass, for example -- but a few are freely editable, and it's quite simple to add additional ones.

== Reaction differences between modes ==
In [[Fortress mode]], reactions are linked to specific buildings, and must be added to a civilization's [[Entities|entity file]] to be usable by that civilization.  This has the useful effect of limiting new items and materials (such as special [[wood]] or [[metal]]) to civilizations that have the requisite reaction -- so that if you give your custom civilization a reaction to produce star metal or some other custom material, only they will be able to use it.

In [[Adventure mode]], reactions are freely available via x > create, and any adventurer character can make free use of them.  Reagents may be held in the hands or dropped on the ground, but cannot be used within a backpack or quiver.  As of .10, there are several bugs with Adventure mode reactions, chief of which is the fact that the [HAS_MATERIAL_REACTION_PRODUCT] token is completely ignored, leading to dragon eye tissue tanned hides, among other things.

Prior to version 31.10, a reaction could only result in an object of base [[quality]].  However, in .10 items produced via reactions have been observed to have quality modifiers.  The way skill factors into them has yet to be determined.

==Anatomy of a reaction==

Reactions are found within reaction_x files (such as reaction_smelter or reaction_other).  Generally speaking they adhere to the following structure:

   [REACTION:<identifier>]
      [NAME:<name>]
      [BUILDING:<BUILDING NAME>:<BUILDING KEY>]
      [REAGENT:A:150:BAR:NONE:POTASH:NONE]
      [PRODUCT:100:1:BAR:NONE:PEARLASH:NONE][PRODUCT_DIMENSION:150]
      [FUEL] 
      [SKILL:<SKILL TOKEN>]
      [AUTOMATIC]
      [ADVENTURE_MODE_ENABLED]
* ''identifier'': The internal ID of the reaction.
* ''name'': The name of the reaction, visible to the player in the Fortress mode or Adventure mode menus.
* ''building'': The building ID that the reaction uses, and the relevant keyboard shortcut.
* ''...reagents...'': Zero or more reagents (ingredients) that are required to be in stock for the reaction to be possible.
* ''...products...'': Zero or more products that are created from the reaction.
* ''fuel'': (optional) If present, the reaction requires charcoal, coke or a magma-powered workshop.
* ''skill'': (optional) The skill required and trained by the reaction.
* ''automatic'': (optional) If present, the reaction will automatically be enqueued whenever it can possibly be performed.
* ''adventure mode'': (optional) If present, the reaction is used by the player in Adventure mode instead.

=== Reaction Identifier ===

The reaction identifier may be anything, so long as it is unique within the raw data files.  A good habit to get into is to append a short prefix or suffix to each name related to the name of your mod, to ensure nobody else is going to make an identical reaction and thereby mess up the game if their mod is run alongside yours.

=== Reaction Name ===

This can be anything at all, and is usually used to describe the reaction.  '''Tan a hide'''', for example, is the name of the default leather-producing reaction.  Generally this should be written as a small descriptive verb phrase, with the first letter capitalised, for consistency with the existing reactions.

=== Building ===

[BUILDING:<BUILDING NAME>:<BUILDING KEY>]

The BUILDING NAME is the name of the building that will house this reaction, and the building key is the keyboard shortcut that will queue up the reaction.  If two reactions have the same key, then one of them will be assigned a different key, the first alphabetically available at the building.

=== Reagents ===
REAGENTs are a little bit complicated.  They are the ingredients that the reaction will use.  You can define as many as you like within a reaction.

    [REAGENT:<name>:<quantity>:<item token>:<item subtype>:<material token>:<material subtype>][...modifiers...]
* ''[[#name|name]]'': The name of the reagent, local to the reaction.
* ''[[#quantity|quantity]]'': The amount of the item that will be used in the reaction.
* ''[[#item_token_.2F_item_subtype|item token]]'': The type of the item you require.  [TODO Link to full list? Should just be based on OBJECT tokens in every raw file.]
* ''[[#item_token_.2F_item_subtype|item subtype]]'': The unique identifier of the item you require, as it appears in the corresponding raw data file, or NONE for no specific type.
* ''[[#material_token_.2F_material_subtype|material token]]'': The category of the material needed that the item should be made of, or NONE if only the ''item token'' matters.
* ''[[#material_token_.2F_material_subtype|material subtype]]'': The unique identifier of a specific material required within the ''material token'' category, or NONE if any type will do.
* ''[[#Modifiers|...modifiers...]]'': Zero or more tokens which further clarify the acceptable types when the item type and material types are insufficient to distinguish them.

==== name ====
The name field is a small string used to identify the reagent within the reaction.  The name is not visible to the player.  It is local to the reaction and does not need to be unique across all of the reactions, so you can reuse the same names over and over, although each reagent within the same individual reaction must have a different name.

Most reactions are simply named '''A''', '''B''', and so forth in default reactions, although names such as '''TOOLSTONE''' or '''FLUX''' will also work equally well.  The PRODUCT may make reference to this name &mdash; for instance, if a container '''B''' is specified as a reagent, PRODUCT_TO_CONTAINER:B specifies that container.

==== quantity ====
The quantity differs between item types.  Generally speaking, cloth, thread, powder and globs use numbers representing the size of material within one item, and everything else uses a static quantity.  While REAGENT:A:'''''10''''':'''''THREAD''''':NONE:NONE:NONE thread is an extremely tiny portion of a random spool of thread, REAGENT:A:'''''10''''':'''''TOY''''':NONE:NONE:NONE is ten unique, solid toy items.

Sometimes the quantity of product is directly connected with the quantity of reagent; it seems to be REAGENT <quantity> / 150 (rounding down) so that Reagent <quantity> of 3 gives 50 product and a <quantity> of 4 gives 37. (150/4=37.5) [List of item types this applies to? Bars, for instance.]

==== item token / item subtype ====
The item token is the type of item you require; WEAPON, TOY or SKIN_TANNED, for example.  A [[item token|full list]] is available.

The item subtype is name of the exact item that you require.  Examples are ITEM_WEAPON_SPEAR or ITEM_TOY_PUZZLEBOX.  Some items, like quivers or backpacks, or chunks of stone or metal, only require the item token to be filled in, so if you're asking for those you can leave this blank.  Subtypes are the entities defined within the local raw data files and their exact names can be referenced by looking at the corresponding file.

==== material token / material subtype ====
The material token and material subtype are frequently related.  The first indicates the category of material you want, such as INORGANIC, though it can also specify one of the hardcoded materials (see {{L|material token}} for a list).  The second indicates the specific subtype of material you want, such as OBSIDIAN or STEEL.

==== Modifiers ====
Reagents may also have extra tokens added on afterwards, placed just after the REAGENT tag.

A list of them follows:

{| {{prettytable}}
|- bgcolor="#dddddd"
! Token
! Meaning
|-
| [PRESERVE_REAGENT]
| Reagent is not destroyed, which is the normal effect, at the completion of the reaction. Typically used for containers.
|-
| [REACTION_CLASS:X]
| Detailed below the reaction anatomy section.
|-
| [HAS_MATERIAL_REACTION_PRODUCT:X]
| Detailed below the reaction anatomy section.
|-
| [UNROTTEN]
| Reagent must not be rotten, mainly for organic MATGLOSS types.
|-
| [BUILDMAT]
| Reagent is able to be used to build structures (Stone, Wood, Blocks, Bars?).
|-
| [GLASS_MATERIAL] 
| Reagent has a one of the glass MATGLOSS types.
|-
| [WORTHLESS_STONE_ONLY]
| The reagent respects allowed and forbidden economic stones from the Stone menu.
|-
| [FIRE_BUILD_SAFE]
| Reagent must be considered fire safe - ie. not wood, and not coal.
|-
| [MAGMA_BUILD_SAFE]
| Reagent must have a melting point greater than the temperature of Magma.
|-
| [CAN_USE_ARTIFACT]
| Reagent can be an Artifact.  Using [PRESERVE_REAGENT] with this is strongly advised.
|-
| [ANY_PLANT_MATERIAL] 
| Reagent MATGLOSS must be of a plant subtype.
|-
| [ANY_SILK_MATERIAL] 
| Reagent MATGLOSS must be of a silk type.
|-
| [ANY_SOAP_MATERIAL]
| Reagent MATGLOSS must be of a soap type.
|-
| [ANY_LEATHER_MATERIAL]
| Reagent MATGLOSS must be of a leather type.
|-
| [ANY_BONE_MATERIAL]
| Reagent MATGLOSS must be of a bone type.
|-
| [ANY_SHELL_MATERIAL]
| Reagent MATGLOSS must be of a shell type.
|-
| [ANY_TOOTH_MATERIAL]
| Reagent MATGLOSS must be of a tooth type.
|-
| [ANY_HORN_MATERIAL]
| Reagent MATGLOSS must be of a horn type.
|-
| [ANY_PEARL_MATERIAL]
| Reagent MATGLOSS must be of a pearl type (Excretion from sea creatures?)
|-
| [USE_BODY_COMPONENT]
| Reagent MATGLOSS must come off a creature's body.
|-
| [METAL_ORE]
| Reagent MATGLOSS must be a metal ore.
|-
| [NOT_WEB]
| States that the material cannot be web (For making only plant/adamantine thread?).
|-
| [WEB_ONLY]
| States that the material has to be web (For making only silk thread?).
|-
| [POTASHABLE]
| The reagent must be able to be turned into pot ash.
|-
| [EMPTY]
| If the reagent is a container, it must be empty.
|-
| [CONTAINS_LYE]
| If the reagent is a container, it must contain LYE.
|-
| [NOT_CONTAIN_BARREL_ITEM]
| If the reagent is a Barrel, it must not contain an item that has to reside in a barrel.  Barrel items appear to be lye and milk.  Alcohol appears to be covered as part of [EMPTY].  A reaction which places an item in a barrel should probably have both tags.
|-
| [BAG]
| Reagent has to be a bag. Intended to be used with an item type of BOX, to prevent chests, coffers, and other containers from being used instead.
|}

Generally speaking, if you set a field in a reagent to NONE, the reaction won't discriminate when it comes to that particular field.  For example, if you require a BOULDER reagent but leave the matgloss fields as NONE:NONE, it will grab any available BOULDER-type item irrespective of matgloss.

===Products===
Products are the end product of the reaction.  A reaction can have as many products as it likes.

Products are almost identical to reagents, except that they do not need to be named, can't have fields undefined, and don't use the quantity field to determine the product size.  Instead, the token PRODUCT_DIMENSION:X is tacked on after the PRODUCT token, determining the size of the product.  Products also don't use tokens like USE_ANY_BONE_MATERIAL.

Products can be produced directly to a container using the [PRODUCT_TO_CONTAINER:<IDENTIFIER>] token, where the IDENTIFIER is the name of a reagent.  This requires the reagent to have the PRESERVE_REAGENT token.

===Other tokens===
The [FUEL] token means that the reaction requires coke or charcoal to be performed, or theoretically magma, if we could build magma workshops.

The [SKILL:X] token determines what [[Skill tokens|skill]] the reaction requires and what skill it trains.  Multiple skills can be listed but only one will be used.

The [AUTOMATIC] token means that the reaction will be queued automatically if the reaction reagents are all present.

The [ADVENTURE_MODE_ENABLED] token means that this version of the reaction is not used by dwarves at home in a fortress, but rather the wanderers of Adventure Mode.  When using this token, it will be allowed for adventurers of any race, without editing Entity files.

==Material reaction products and reaction classes==

You can get a certain measure of control over very specific materials using reaction classes and material reaction products - the tokens look like this:

   [REACTION_CLASS:FAT]
   [HAS_MATERIAL_REACTION_PRODUCT:RENDER_MAT]

Reaction classes represent different classes of material - basically, the matgloss subtype of the reagent must have a REACTION_CLASS the same as the one in the reaction.

Material reaction products are similar, but are generally used more for things like different kinds of creature materials than universal materials like stone.  This token is how skin can be tanned into leather, which are two separate materials - the skin material has leather as a MATERIAL_REACTION_PRODUCT.

In short, they require the material to have a token such as 
   [MATERIAL_REACTION_PRODUCT:X:Y:Z]
...where X is the name of the reaction product that will be referred to in the reaction (RENDER_MAT, in the reaction class example, or TAN_MAT for leather), Y is the matgloss type of the desired product (such as INORGANIC or LOCAL_CREATURE_MAT) and Z is the specific material, like LEATHER or OBSIDIAN.

==Reactions and world generation==

There are several things to keep in mind when you're adding reactions to a game that already exists.

* Most entity changes require a regen, but adding PERMITTED_REACTION tokens for reactions that existed at the time of world generation to the entity file in the save directory do not.
* Adding reactions to the raws in a save directory requires you to regen the world.
* You can alter an existing reaction in any way you like without regenning the world, so long as you don't alter the reaction identifier.

[[Category:DF2010:Modding]]