View source for NML:Industries

{{NMLNavPropVarCB}}

This page contains information on industry properties, variables and callbacks. [[NML:IndustryTiles|Industry tiles]] are closely related.

== Industry ID allocation ==
Industry IDs are local to the NewGRF, you are free to choose any ID in the 0..127-range. You should start your item definition with the 'substitute'-property, which allocates a new industry. The value of this property should be the ID of a [[IndustryDefaultProps|default industry]], which will be used instead of your item if it is not available for whatever reason (for example, missing NewGRF). 

Furthermore, you can set the 'override'-property, which will cause the existing industry to be replaced with your item. You should use this if you are for example defining a coal mine which changes production more dynamically. If your type is not a direct replacement of an existing item, don't set this property.

==Industry properties==

Industry properties. Default industry type numbers can be found at [[NML:Default industries|default industries]].

{| class="wikitable sortable"
! property
! value range
! comment
|-
| substitute
| industry type
| Number of the original industry type that replaces this one, should it not be available for some reason (e.g. missing NewGRF). '''This property ''must'' be set first, before any other properties or graphics.''' All properties of the old type are copied to your new industry.
|-
| override
| industry type
| Number of the original industry type overridden. This will cause other grfs / industries to consider your industry type the same as the old type. Only set this property if your type is (more or less) the same as the old type.
|-
| layouts
| Array of tilelayouts
|
See [[NML:Tilelayout|Tilelayout]] syntax.
|-
| life_type
| One of IND_LIFE_TYPE_XXX, XXX = BLACK_HOLE <nowiki>|</nowiki> EXTRACTIVE <nowiki>|</nowiki> ORGANIC <nowiki>|</nowiki> PROCESSING
| The generic type of industry. This determines the production changes that occur by default (when not using the callback). Examples are respectively power plants, coal mines, forests en steel mills.
|-
| closure_msg
| string
|
Message displayed when the industry announces closure. Use a custom string or one of the [[NML:Default TTD strings|default TTD strings]].
|-
| prod_increase_msg
| string
|
Message displayed when industry increases production. Use a custom string or one of the [[NML:Default TTD strings|default TTD strings]].
|-
| prod_decrease_msg
| string
|
Message displayed when industry decreases production. Use a custom string or one of the [[NML:Default TTD strings|default TTD strings]].
|-
| fund_cost_multiplier
| 0..255
| Fund cost multiplier. Note that in OpenTTD the unmodified base cost is 8x higher for building (not prospecting) raw (=extractive / organic, see life_type) industries.
|-
| cargo_types
| array of accept_cargo(input, outputs...) and produce_cargo(output, level) expressions
| {{nml|0.5}} {{ottd|1.9}} Types of cargo accepted and produced by the industry, and their production levels and production multipliers. See [[#Cargo_types_array|cargo types array]] below.
|-
| prod_cargo_types
| array of up to 2 ints
| {{nml|0.4}} Types of cargo produced. Use the cargotype(&lt;label&gt;) built-in function to specify a label from the cargotable. {{nml|0.5}} Removed, use cargo_types instead.
|-
| accept_cargo_types
| array of up to 3 ints
| {{nml|0.4}} Types of cargo accepted. Use the cargotype(&lt;label&gt;) built-in function to specify a label from the cargotable. {{nml|0.5}} Removed, use cargo_types instead.
|-
| prod_multiplier
| array of up to 2 ints (0..255)
| {{nml|0.4}} Amount of each output cargo to produce every 256 ticks (8 or 9 times a month) {{nml|0.5}} Removed, use cargo_types instead.
|-
| min_cargo_distr
| 0..255
| Minimal amount of cargo before transporting to stations.
|-
| random_sound_effects
| array of ints
| Sound effect numbers that are played some times.
|-
| conflicting_ind_types
| array of up to 3x industry_type(IND_TYPE_OLD <nowiki>|</nowiki> IND_TYPE_NEW, id)
|
Three industry types that should not be nearby. Use the [[NML:Builtin functions|builtin function]] <code style="color:darkgreen">industry_type(..)</code> to define either an old industry (using the global ID) or a new industry from your grf (using the grf-local ID).
|-
| prob_random
| 0..255
| (up to NML v5796-418, use prob_map_gen otherwise) Probability of occurring while generating initial industries. If the random game probability value is nonzero and IND_FLAG_DO_NOT_FORCE_INSTANCE_AT_MAP_GENERATION is not set, at least one instance of this type is guaranteed to appear on the map.
|-
| prob_map_gen
| 0..255
| (NML v5796-418 or newer) Probability of occurring while generating initial industries. If the random game probability value is nonzero and IND_FLAG_DO_NOT_FORCE_INSTANCE_AT_MAP_GENERATION is not set, at least one instance of this type is guaranteed to appear on the map.
|-
| prob_in_game
| 0..255
| Probability of occurring while creating industries during the game.
|-
| map_colour
| 0..255
|
Colour index from the [[NML:Graphic files|DOS palette]] to use on the minimap for this industry.
|-
| spec_flags
| bitmask(flags)
|
for flag values see [[#industry_special_flags|Industry special flags]]
|-
| new_ind_msg
| string
| Message displayed when industry gets built during game play.
|-
| input_multiplier_1
| array of up to 2 floats (0..255)
| {{nml|0.4}} Output cargo multiplication factors for getting a unit of the first accepted cargo. {{nml|0.5}} Removed, use cargo_types instead.
|-
| input_multiplier_2
| array of up to 2 floats (0..255)
| {{nml|0.4}} Output cargo multiplication factors for getting a unit of the second accepted cargo. {{nml|0.5}} Removed, use cargo_types instead.
|-
| input_multiplier_3
| array of up to 2 floats (0..255)
| {{nml|0.4}} Output cargo multiplication factors for getting a unit of the third accepted cargo. {{nml|0.5}} Removed, use cargo_types instead.
|-
| name
| string
|
Name of the industry, use a custom string or one of the [[NML:Default TTD strings|default TTD strings]].
|-
| prospect_chance
| 0 .. 1 (float)
| Chance of successful prospecting.
|-
| callback_flags
| bitmask(flags)
|
Do not set this, unless you use [[NML:Old style callbacks|old-style callbacks]].
|-
| remove_cost_multiplier
| int
| Cost multiplier for removing the industry (currently only possible with magic bulldozer).
|-
| nearby_station_name
| string
| Default name for a nearby station.
To follow the "<Town Name> <Industry Name>" convention, the string should include a "{STRING}" at the position the town name shall be inserted. For example:
 STR_HARBOR_NEARBY_NAME   :{STRING} water side
|}

===Cargo types array===
The ''cargo_types'' property takes an array of accept_cargo and produce_cargo expressions. This array is used to define which cargo types the industry accepts, which it produces, and how much cargo is produced on production ticks and on delivery. All cargo types the industry handles must be mentioned in its ''cargo_types'' property even when they are handled by production callbacks.

The following is an example of a ''cargo_types'' property:

 cargo_types: [
   produce_cargo("GOOD", 4),
   accept_cargo("PASS"),
   produce_cargo("PASS", 0),
   accept_cargo("IORE", produce_cargo("STEL", 1), produce_cargo("SLAG", 0.25))
 ]

The above example has four items in its ''cargo_types'' array, two produce_cargo expressions and two accept_cargo expressions.

# <code>produce_cargo("GOOD", 4)</code> specifies the industry produces GOOD at a rate of 4 every production tick (256 game ticks), this production rate is scaled by the industry's production level.
# <code>accept_cargo("PASS")</code> specifies the industry accepts PASS as a "black hole", that is no cargo is produced when PASS is delivered. If you have a production callback that consumes a cargo you will also need to specify that cargo in this way.
# <code>produce_cargo("PASS", 0)</code> specifies the industry produces PASS but not on the production ticks as usual. Specifying a production rate of zero is only useful for cargo types you produce via a production callback.
# <code>accept_cargo("IORE", produce_cargo(...), ...)</code> specifies the industry produces the listed cargo types every time IORE is delivered. In the example above, delivering one IORE will result in one STEL produced and no SLAG produced (because 1*0.25 is zero after rounding down), and delivering 4 IORE will result in 4 STEL and 1 SLAG produced.

At most 16 different cargo labels may appear in accept_cargo and at most 16 different cargo labels in produce_cargo, for a single industry. The same cargo label can be used in as many accept_cargo or produce_cargo as necessary.

More complex production rules can be set up via the production callbacks, see [[#Industry_callbacks|callbacks]] below.

===Industry special flags===

{| class="wikitable sortable"
! flag
! meaning
|-
| IND_FLAG_PLANT_FIELDS_PERIODICALLY
| The industry periodically plants fields around itself (temperate and arctic farms)
|-
| IND_FLAG_CUT_TREES
| The industry cuts trees around itself and produces its first output cargo from them (lumber mill)
|-
| IND_FLAG_BUILT_ON_WATER
| The industry is built on water (oil rig)
|-
| IND_FLAG_ONLY_IN_LARGE_TOWNS
| The industry can only be built in towns (i.e. it has to replace houses) with population larger than 1200 (temperate bank)
|-
| IND_FLAG_ONLY_IN_TOWNS
| The industry can only be built in towns (i.e. it has to replace houses) (arctic and tropic banks, water tower)
|-
| IND_FLAG_BUILT_NEAR_TOWN
| The industry is always built near towns (i.e. near town sign; additionally the industry is allowed to replace houses) (toy shop)
|-
| IND_FLAG_PLANT_FIELDS_WHEN_BUILT
| Fields are planted around the industry when it's built (all farms)
|-
| IND_FLAG_NO_PRODUCTION_INCREASE
| The industry cannot increase its production on the temperate climate (oil wells)
|-
| IND_FLAG_BUILT_ONLY_BEFORE_1950
| The industry is built only before 1950 (oil wells)
|-
| IND_FLAG_BUILT_ONLY_AFTER_1960
| The industry is built only after 1960 (oil rig)
|-
| IND_FLAG_AI_CREATES_AIR_AND_SHIP_ROUTES
| AI players will attempt to establish air and ship routes going to this industry (oil rig)
|-
| IND_FLAG_MILITARY_AIRPLANE_CAN_EXPLODE
| The industry can be exploded by a military airplane (oil refinery)
|-
| IND_FLAG_MILITARY_HELICOPTER_CAN_EXPLODE
| The industry can be exploded by a military helicopter (factory)
|-
| IND_FLAG_CAN_CAUSE_SUBSIDENCE
| The industry can cause a subsidence (coal mine)
|-
| IND_FLAG_AUTOMATIC_PRODUCTION_MULTIPLIER
| Automatic production multiplier handing (No industry has this bit set by default.).
|-
| IND_FLAG_RANDOM_BITS_IN_PRODUCTION_CALLBACK
| The production callback needs random bits in var. 10 (No industry has this bit set by default.)
|-
| IND_FLAG_DO_NOT_FORCE_INSTANCE_AT_MAP_GENERATION
| Do not force one instance of this type to appear during initial map generation (No industry has this bit set by default.)
|-
| IND_FLAG_ALLOW_CLOSING_LAST_INSTANCE
| Allow closing down the last instance of this type (No industry has this bit set by default.)
|-
| IND_FLAG_LONG_CARGO_TYPE_LISTS
| New format for callbacks <code>callbacks cargo_subtype_display</code>, <code>cargo_input</code>, <code> cargo_output</code> to support more input/output cargos. See the callbacks for details.
|-
| IND_FLAG_DO_NOT_CLAMP_PASSENGER_PRODUCTION
| {{nml|0.7}} {{ottd|1.11}} By default OpenTTD's smooth economy clamps the production of passenger (like for oil rigs). This flag disables the clamping.
|}

{{NML:IndustryCommonVariables}}

==Industry variables==

{| class="wikitable sortable"
! name
! value range
! comment
|-
| production_level
| 0, or 4 .. 128
| Current production level of the industry. Usually in range 4 .. 128, default starting level is 16. A level of 0 indicates imminent closure.
|-
| waiting_cargo_1
| 0..65535
| If any of the production callbacks is enabled, this variable will contain the amount of the first cargo type awaiting to be processed. {{nml|0.5}} Removed.  Use <code>incoming_cargo_waiting</code> instead.
|-
| waiting_cargo_2
| 0..65535
| If any of the production callbacks is enabled, this variable will contain the amount of the second cargo type awaiting to be processed. {{nml|0.5}} Removed.  Use <code>incoming_cargo_waiting</code> instead.
|-
| waiting_cargo_3
| 0..65535
| If any of the production callbacks is enabled, this variable will contain the amount of the third cargo type awaiting to be processed. {{nml|0.5}} Removed.  Use <code>incoming_cargo_waiting</code> instead.
|-
| produced_cargo_waiting_1 
| 0..65535
| The amount of produced 'output cargo type 1' that this waiting to be transported. {{nml|0.5}} Removed. Use <code>produced_cargo_waiting</code> instead.
|-
| produced_cargo_waiting_2
| 0..65535
| The amount of produced 'output cargo type 2' that this waiting to be transported. {{nml|0.5}} Removed. Use <code>produced_cargo_waiting</code> instead.
|-
| produced_this_month_1
| 0..65535
| The amount of 'output cargo type 1' that was produced this month. {{nml|0.5}} Removed.  Use <code>this_month_production</code> instead.
|-
| produced_this_month_2
| 0..65535
| The amount of 'output cargo type 2' that was produced this month. {{nml|0.5}} Removed.  Use <code>this_month_production</code> instead.
|-
| produced_last_month_1
| 0..65535
| The amount of 'output cargo type 1' that was produced last month. {{nml|0.5}} Removed.  Use <code>last_month_production</code> instead.
|-
| produced_last_month_2
| 0..65535
| The amount of 'output cargo type 2' that was produced last month. {{nml|0.5}} Removed.  Use <code>last_month_production</code> instead.
|-
| transported_this_month_1
| 0..65535
| The amount of 'output cargo type 1' that was transported this month. {{nml|0.5}} Removed.  Use <code>this_month_transported</code> instead.
|-
| transported_this_month_2
| 0..65535
| The amount of 'output cargo type 2' that was transported this month. {{nml|0.5}} Removed.  Use <code>this_month_transported</code> instead.
|-
| transported_last_month_1
| 0..65535
| The amount of 'output cargo type 1' that was produced last month. {{nml|0.5}} Removed.  Use <code>last_month_transported</code> instead.
|-
| transported_last_month_2
| 0..65535
| The amount of 'output cargo type 2' that was produced last month. {{nml|0.5}} Removed.   Use <code>last_month_transported</code> instead.
|-
| transported_last_month_pct_1
| 0..100
| Percentage of produced 'output cargo type 1' that was transported last month. {{nml|0.5}} Removed.  Use <code>transported_last_month_pct</code> instead.
|-
| transported_last_month_pct_2
| 0..100
| Percentage of produced 'output cargo type 2' that was transported last month.  {{nml|0.5}} Removed.  Use <code>transported_last_month_pct</code> instead.
|-
| production_rate_1
| 0..255
| {{nml|0.3}} Amount of 'output cargo type 1' that is produced every 256 ticks. Initial value from the <code>prod_multiplier</code>-property, but it will change accordingly when the production level changes.  {{nml|0.5}} Removed.  Use <code>production_rate</code> instead.
|-
| production_rate_2
| 0..255
| {{nml|0.3}} Amount of 'output cargo type 2' that is produced every 256 ticks. Initial value from the <code>prod_multiplier</code>-property, but it will change accordingly when the production level changes.  {{nml|0.5}} Removed.  Use <code>production_rate</code> instead.
|-
| water_distance
| Distance to the tile
| If the industry is built on water, this variable gives the distance of the closest dry land tile, otherwise it gives the distance of the closest water tile.
|-
| layout_num
| 1..255
| Number of the layout being used by the industry.
|-
| founder
| 0..16
| Company number of the industry founder. It will be FOUNDER_GAME (=16) if the industry was generated randomly. TTDPatch only supports up to 8 companies (0..7).
|-
| founder_type
| PLAYERTYPE_XX
| PLAYERTYPE_HUMAN, PLAYERTYPE_AI, PLAYERTYPE_HUMAN_IN_AI (human managing AI company) or PLAYERTYPE_AI_IN_HUMAN (AI managing human company). OpenTTD only uses PLAYERTYPE_HUMAN and PLAYERTYPE_AI. If you cheat yourself to be part of an AI company OpenTTD will still report PLAYERTYPE_AI for the company with yourself and the AI and it'll report PLAYERTYPE_HUMAN for the now uncontrolled company.
|-
| founder_colour1
| COLOUR_XXX
|
Index of founding company's first colour. 0 if not founded by a company. Refer to the table [[NML:List of default colour translation palettes#Company colour helper functions|here]] for possible values.
|-
| founder_colour2
| COLOUR_XXX
|
Index of founding company's second colour. It's the same as company_colour1, if no second company colour is chosen. 0 if not founded by a company. Refer to the table [[NML:List of default colour translation palettes#Company colour helper functions|here]] for possible values.
|-
| colour
| COLOUR_XXX
|
Random colour for this industry. Refer to the table [[NML:List of default colour translation palettes#Company colour helper functions|here]] for possible values.
|-
| build_date
| 0..1826212865
| Date of the industry foundation in days since year 0.
|-
| build_type
| BUILDTYPE_XX
| BUILDTYPE_UNKNOWN (if created in an old version or with newindustries disabled), BUILDTYPE_GAMEPLAY (if founded or created by the in-game random industry generator), BUILDTYPE_GENERATION (if created during random map generation) or BUILDTYPE_EDITOR (if created with the scenario editor).
|-
| counter
| 0..65535
| Decremented every tick, used to time primary industry production in TTD.
|-
| last_accept_date
| date(year, month, day)
| Date when cargo was accepted for the last time. Not valid before 1920 and after 2090.
|-
| random_bits
| 0 ... 65535
| Random data that can be used to randomize certain descisions. (see [[NML:Random_switch|Random switch]]) (NML r1666)
|
|-
| gs_disallows_prod_decrease
| [0 <nowiki>|</nowiki> 1]
| {{nml|0.7}}{{ottd|1.11}} GameScript can optionally set a property that to indicate that production should not decrease at this industry. This will be automatically applied for organic and extractive industries, *if* the NewGRF industry production callback is *not* used *and* smooth economy is enabled.  In other cases, NewGRF industries can provide behaviour as requested by the GameScript by reading this variable during production callbacks.
|
|-
| gs_disallows_prod_increase
| [0 <nowiki>|</nowiki> 1]
| {{nml|0.7}}{{ottd|1.11}} GameScript can optionally set a property that to indicate that production should not increase at this industry. This will be automatically applied for organic and extractive industries, *if* the NewGRF industry production callback is *not* used *and* smooth economy is enabled.  In other cases, NewGRF industries can provide behaviour as requested by the GameScript by reading this variable during production callbacks.
|
|-
| gs_disallows_closure
| [0 <nowiki>|</nowiki> 1]
| {{nml|0.7}}{{ottd|1.11}} GameScript can optionally set a property that to indicate that this industry should not close. NewGRF industries can use this variable to read the property set by GameScript and provide the appropriate closure behaviour. Any closure already scheduled will still take place.
|}

<br /> Variables that require some parameters.

{| class="wikitable sortable"
! name
! arguments
! comment
|-
| industry_count
| industry_type, grfid = -1
|
The value of this variable is the number of industries of a given type that are currently on the map. industry_type is either the ID of an industry. GRFid is the grf in which the industry was defined. The default value is -1, which means current newgrf. A grfid of 0 lets you check the number of default industries of a given type. Use the [[NML:Builtin functions|builtin function]] <code style="color:darkgreen">str2number()</code> to convert a grfid to its numeric representation.<br />''Warning: using this variable trashes the contents of temporary storage register 0x100''
|-
| industry_distance
| industry_type, grfid = -1
| The value of this variable is the manhattan distance the closest instance of the given industry or 0xFFFF if not applicable. See industry_count for a description of the parameters.<br />''Warning: using this variable trashes the contents of temporary storage register 0x100.''
|-
| industry_layout_count / industry_layout_distance
| industry_type, layout, grfid = -1.
| See industry_count / industry_distance for description of industry_type, grfid and return value. The results are filtered to industries that have the given layout number.<br />''Warning: using this variable trashes the contents of temporary storage registers 0x100 and 0x101.''
|-
| industry_town_count
| industry_type, grfid = -1.
| See industry_count / industry_distance for description of industry_type, grfid and return value. The results are filtered to industries that have the same town than the current industry.<br />''Warning: using this variable trashes the contents of temporary storage registers 0x100 and 0x101.''
|-
| town_manhattan_dist
| x, y
| Parameters indicate a signed offset relative to the northern tile. Returns the Manhattan distance (dx + dy) from the selected tile to the closest town
|-
| town_euclidean_dist
| x, y
| Parameters indicate a signed offset relative to the northern tile. Returns the squared Eucleidean distance (dx^2 + dy^2) from the selected tile to the closest town.
|-
| town_zone
| x, y
|
Parameters indicate a signed offset relative to the northern tile. Returns the [[NML:List of town zones|town zone]] that the selected tile is in.
|-
| nearby_tile_random_bits
| x, y
| Parameters indicate an unsigned offset relative to the northern tile. Returns the random bits of the selected industry tile, or 0 if it is not an industry tile that's part of this industry.
|-
| incoming_cargo_waiting
| cargo label from the cargotable
| {{nml|0.5}} If any of the production callbacks is enabled, this variable will contain the amount of the cargo type waiting to be processed.  Returns 0..65535.  Example: <code>incoming_cargo_waiting("FOOD")</code>.
|-
| produced_cargo_waiting
| cargo label from the cargotable
| {{nml|0.5}} For the given cargo label, the amount of produced cargo that this waiting to be transported.  Returns 0..65535.  Example: <code>produced_cargo_waiting("GOOD")</code>.
|-
| this_month_production
| cargo label from the cargotable
| {{nml|0.5}} For the given cargo label, amount of cargo that was produced this month.  Returns 0..65535.  Example: <code>this_month_production("COAL")</code>.
|-
| last_month_production
| cargo label from the cargotable
| {{nml|0.5}} For the given cargo label, amount of cargo that was produced last month.  Returns 0..65535.  Example: <code>last_month_production("WOOD")</code>.
|-
| this_month_transported
| cargo label from the cargotable
| {{nml|0.5}} For the given cargo label, amount of produced cargo that was transported this month.  Returns 0..65535.  Example: <code>this_month_transported("IORE")</code>.
|-
| last_month_transported
| cargo label from the cargotable
| {{nml|0.5}} For the given cargo label, amount of produced cargo that was transported last month.  Returns 0..65535.  Example: <code>last_month_transported("PAPR")</code>. 
|-
| transported_last_month_pct
| cargo label from the cargotable
| {{nml|0.5}} For the given cargo label, percentage of produced cargo that was transported last month.  Returns 0..100.  Example: <code>transported_last_month_pct("BATT")</code>. 
|-
| production_rate
| cargo label from the cargotable
| {{nml|0.5}} For the given cargo label, amount of output cargo that is produced every 256 ticks. Initial value from the <code>cargo_types</code> property, but it will change accordingly when the production level changes.  Returns 0..255.  Example: <code>production_rate("SUGR")</code>. 
|}

==Industry callbacks==

{| class="wikitable sortable"
! callback
! return value
! comment
|-
| default
| varies
| Any unhandled callbacks. Generally this doesn't need to be used, except for old-style callbacks.
|-
| produce_cargo_arrival
| [[NML:Produce|Produce-block]]
| Called to produce cargo when it arrives.
|-
| produce_256_ticks
| [[NML:Produce|Produce-block]]
| Called to produce cargo every 256 ticks.
|-
| availability
| CB_RESULT_IND_ALLOW or CB_RESULT_IND_DISALLOW
|
{{nml|0.2}} Only available in NML 0.2 or earlier. Called when the game needs to know if the industry type is available. It is limited to the type as a whole, so you can't access industry-specific variables. <code style="color:darkgreen">extra_callback_info2</code> contains the [[#Industry creation types|creation type]].
|-
| construction_probability
| CB_RESULT_IND_NO_CONSTRUCTION, CB_RESULT_IND_PROBABILITY_FROM_PROPERTY or a relative probability 0..255
|
{{nml|0.3}}. Called when the game needs to know if the industry type is available. It is limited to the type as a whole, so you can't access industry-specific variables.
* <code style="color:darkgreen">getbits(extra_callback_info2, 0, 8)</code>: The [[#Industry creation types|creation type]].
If you return CB_RESULT_IND_NO_CONSTRUCTION or 0 the industry won't be build. If you return CB_RESULT_IND_PROBABILITY_FROM_PROPERTY it'll be build according to the relative probability as defined in the <code style="color:darkgreen">prob_random</code> or <code style="color:darkgreen">prob_in_game</code> properties, otherwise it'll use the value as returned as relative probability.
|-
| location_check
|
See the [[#Location check results|table]] below.
|
Called to check if a location is suitable.
* <code style="color:darkgreen">getbits(extra_callback_info2, 0, 8)</code>: The [[#Industry creation types|creation type]].
Since the industry isn't built yet, industry variables aren't available. If this callback is not implemented or fails, constructing the industry will be allowed. Construction might also be prevented via the <code style="color:darkgreen">tile_check</code> industry tile callback, though.
|-
| monthly_prod_change
|
See [[#Production change callback results|below]]
| Called each month to (possibly) change the industry production.
* <code style="color:darkgreen">extra_callback_info2</code>: 32 random bits.
|-
| random_prod_change
|
See [[#Production change callback results|below]]
| Works exactly the same as <code style="color:darkgreen">monthly_prod_change</code>, except that it's only called when TTD selects this industry for a random production change.
|-
| build_prod_change
| Value in range 4-128
| {{ottd|1.3|r24186}} Called when an industry is constructed.  Return value is production level (default 16).  Can also be used to initialise permanent storage when an industry is constructed.
|-
| cargo_subtype_display
| String, CB_RESULT_NO_TEXT or CB_RESULT_IND_NO_TEXT_NO_AMOUNT
| This callback allows displaying some text after a cargo name. Returning
* CB_RESULT_NO_TEXT displays only waiting amount of cargo,
* CB_RESULT_IND_NO_TEXT_NO_AMOUNT displays only the cargotype.

Note: To remove cargo waiting text, return <code style="color:darkgreen">0x3800 + string(STR_EMPTY)</code> where STR_EMPTY is an empty string in your lang file.

If IND_FLAG_LONG_CARGO_TYPE_LISTS is not set:
* <code style="color:darkgreen">getbits(extra_callback_info2, 0, 8)</code>: 0 .. 2 to get texts for the first .. third accepted cargo type, and 3 .. 4 for the first ... second produced cargo type.
* <code style="color:darkgreen">getbits(extra_callback_info2, 8, 8)</code>: 0 when getting a string for the buy menu (no industry variables available!), 1 when for the industry window and 2 for the industry directory window.

If IND_FLAG_LONG_CARGO_TYPE_LISTS is set:
* <code style="color:darkgreen">getbits(extra_callback_info2, 0, 8)</code>: 0 for output cargos, 1 for input cargos.
* <code style="color:darkgreen">getbits(extra_callback_info2, 8, 8)</code>: 0 when getting a string for the buy menu (no industry variables available!), 1 when for the industry window and 2 for the industry directory window.
* <code style="color:darkgreen">getbits(extra_callback_info2, 16, 8)</code>: Cargo type.

|-
| extra_text_industry
| String
| Show extra text in the industry window.
|-
| extra_text_fund
| String
| Show extra text in the fund window. Since the industry isn't built, no industry variables are available.
|-
| control_special
| 0 or 1
| Called to control various effects from the <code style="color:darkgreen">spec_flags</code> property. Currently only works for the first two (plant fields / cut trees). Return 1 to execute the action or 0 to not do so.
* <code style="color:darkgreen">extra_callback_info1</code>: 32 random bits.
* <code style="color:darkgreen">getbits(extra_callback_info2, 0, 8)</code>: Queried effect.
The default (if the flag is enabled, of course) is to plant fields with 1/8th chance every 256 ticks, and to cut trees every 512 ticks.
|-
| stop_accept_cargo
| 0 or 1
| With this callback, you can temporarily refuse accepting a certain cargo, for example because the stockpile is full. Return 1 to accept or 0 to refuse. Make sure to synchronize this callback with the <code style="color:darkgreen">cargo_amount_accept</code> callback for industry tiles.
* <code style="color:darkgreen">getbits(extra_callback_info2, 0, 8)</code> The cargo type to accept or not.
|-
| colour
| COLOUR_XXX
| Called after constructing the industry. The <code style="color:darkgreen">colour</code> variable is set to a random value at this point, you can use this callback to change this.
|-
| cargo_input
| Cargo type, or 0xFF
| Decide the input cargo types, called when the industry is built. Called repeatedly until 0xFF is returned, although currently not more than three times. Do not rely on this limitation, though.
* <code style="color:darkgreen">getbits(extra_callback_info1, 0, 8)</code>: Starts at 0 and is incremented for every iteration.
Return a cargo type (from the table) or 0xFF to stop.
|-
| cargo_output
| Cargo type, or 0xFF
| Same as <code style="color:darkgreen">cargo_input</code> above, except that it is applied to the output cargo types and currently not called more than twice.
|}

{{NML:LocationCheckResults}}

===Production change callback results===

{| class="wikitable sortable"
! value
! meaning
|-
| CB_RESULT_IND_PROD_NO_CHANGE
| Do not change industry production
|-
| CB_RESULT_IND_PROD_HALF
| Half industry production. If production goes below a quarter of default, the industry closes.
|-
| CB_RESULT_IND_PROD_DOUBLE
| Double production if it's not 8x default yet.
|-
| CB_RESULT_IND_PROD_CLOSE
| Announce closure and remove the industry next month.
|-
| CB_RESULT_IND_PROD_RANDOM
| Do a random production change, as if the industry is a primary one.
|-
| CB_RESULT_IND_PROD_DIVIDE_BY_4
| Divide production by 4
|-
| CB_RESULT_IND_PROD_DIVIDE_BY_8
| Divide production by 8
|-
| CB_RESULT_IND_PROD_DIVIDE_BY_16
| Divide production by 16
|-
| CB_RESULT_IND_PROD_DIVIDE_BY_32
| Divide production by 32
|-
| CB_RESULT_IND_PROD_MULTIPLY_BY_4
| Multiply production by 4
|-
| CB_RESULT_IND_PROD_MULTIPLY_BY_8
| Multiply production by 8
|-
| CB_RESULT_IND_PROD_MULTIPLY_BY_16
| Multiply production by 16
|-
| CB_RESULT_IND_PROD_MULTIPLY_BY_32
| Multiply production by 32
|-
| CB_RESULT_IND_PROD_DECREMENT_BY_1
| Decrement production by 1
|-
| CB_RESULT_IND_PROD_INCREMENT_BY_1
| Increment production by 1
|-
| CB_RESULT_IND_PROD_SET_BY_0x100
| Set the production level to the value in bits 16 .. 23 of register 0x100.
|}

Setting bit 7 of the result disables the associated news message.<br /> Setting bit 8 replaces the news message with a custom message, read from register 0x100 bits 0 .. 15.

===Industry creation types===

{| class="wikitable sortable"
! value
! meaning
|-
| IND_CREATION_GENERATION
| Industry is created during map generation, or when building 'many random industries' in the scenario editor.
|-
| IND_CREATION_RANDOM
| Industry is randomly generated during gameplay
|-
| IND_CREATION_FUND
| Industry is funded by the player (in game or scenario editor)
|-
| IND_CREATION_PROSPECT
| Industry is prospected by the player
|}