Minetest Lua Modding API Reference 0.4.10 ======================================== More information at http://www.minetest.net/ Developer Wiki: http://dev.minetest.net/ Introduction ------------- Content and functionality can be added to Minetest 0.4 by using Lua scripting in run-time loaded mods. A mod is a self-contained bunch of scripts, textures and other related things that is loaded by and interfaces with Minetest. Mods are contained and ran solely on the server side. Definitions and media files are automatically transferred to the client. If you see a deficiency in the API, feel free to attempt to add the functionality in the engine and API. You can send such improvements as source code patches to . Programming in Lua ------------------- If you have any difficulty in understanding this, please read: http://www.lua.org/pil/ Startup -------- Mods are loaded during server startup from the mod load paths by running the init.lua scripts in a shared environment. Paths ----- RUN_IN_PLACE=1: (Windows release, local build) $path_user: Linux: Windows: $path_share: Linux: Windows: RUN_IN_PLACE=0: (Linux release) $path_share: Linux: /usr/share/minetest Windows: /minetest-0.4.x $path_user: Linux: ~/.minetest Windows: C:/users//AppData/minetest (maybe) Games ----- Games are looked up from: $path_share/games/gameid/ $path_user/games/gameid/ where gameid is unique to each game. The game directory contains the file game.conf, which contains these fields: name = e.g. name = Minetest The game directory can contain the file minetest.conf, which will be used to set default settings when running the particular game. Mod load path ------------- Generic: $path_share/games/gameid/mods/ $path_share/mods/ $path_user/games/gameid/mods/ $path_user/mods/ <-- User-installed mods $worldpath/worldmods/ In a run-in-place version (e.g. the distributed windows version): minetest-0.4.x/games/gameid/mods/ minetest-0.4.x/mods/ <-- User-installed mods minetest-0.4.x/worlds/worldname/worldmods/ On an installed version on Linux: /usr/share/minetest/games/gameid/mods/ ~/.minetest/mods/ <-- User-installed mods ~/.minetest/worlds/worldname/worldmods Mod load path for world-specific games -------------------------------------- It is possible to include a game in a world; in this case, no mods or games are loaded or checked from anywhere else. This is useful for e.g. adventure worlds. This happens if the following directory exists: $world/game/ Mods should be then be placed in: $world/game/mods/ Modpack support ---------------- Mods can be put in a subdirectory, if the parent directory, which otherwise should be a mod, contains a file named modpack.txt. This file shall be empty, except for lines starting with #, which are comments. Mod directory structure ------------------------ mods |-- modname | |-- depends.txt | |-- screenshot.png | |-- description.txt | |-- init.lua | |-- textures | | |-- modname_stuff.png | | `-- modname_something_else.png | |-- sounds | |-- media | `-- `-- another modname: The location of this directory can be fetched by using minetest.get_modpath(modname) depends.txt: List of mods that have to be loaded before loading this mod. A single line contains a single modname. Optional dependencies can be defined by appending a question mark to a single modname. Their meaning is that if the specified mod is missing, that does not prevent this mod from being loaded. screenshot.png: A screenshot shown in modmanager within mainmenu. description.txt: File containing description to be shown within mainmenu. init.lua: The main Lua script. Running this script should register everything it wants to register. Subsequent execution depends on minetest calling the registered callbacks. minetest.setting_get(name) and minetest.setting_getbool(name) can be used to read custom or existing settings at load time, if necessary. textures, sounds, media: Media files (textures, sounds, whatever) that will be transferred to the client and will be available for use by the mod. Naming convention for registered textual names ---------------------------------------------- Registered names should generally be in this format: "modname:" ( can have characters a-zA-Z0-9_) This is to prevent conflicting names from corrupting maps and is enforced by the mod loader. Example: mod "experimental", ideal item/node/entity name "tnt": -> the name should be "experimental:tnt". Enforcement can be overridden by prefixing the name with ":". This can be used for overriding the registrations of some other mod. Example: Any mod can redefine experimental:tnt by using the name ":experimental:tnt" when registering it. (also that mod is required to have "experimental" as a dependency) The ":" prefix can also be used for maintaining backwards compatibility. Aliases ------- Aliases can be added by using minetest.register_alias(name, convert_to) This will make Minetest to convert things called name to things called convert_to. This can be used for maintaining backwards compatibility. This can be also used for setting quick access names for things, e.g. if you have an item called epiclylongmodname:stuff, you could do minetest.register_alias("stuff", "epiclylongmodname:stuff") and be able to use "/giveme stuff". Textures -------- Mods should generally prefix their textures with modname_, e.g. given the mod name "foomod", a texture could be called "foomod_foothing.png" Textures are referred to by their complete name, or alternatively by stripping out the file extension: e.g. foomod_foothing.png e.g. foomod_foothing Texture modifiers ----------------- There are various texture modifiers that can be used to generate textures on-the-fly. Texture overlaying: Textures can be overlaid by putting a ^ between them. Example: default_dirt.png^default_grass_side.png default_grass_side.png is overlayed over default_dirt.png Texture grouping: Textures can be grouped together by enclosing them in ( and ). Example: cobble.png^(thing1.png^thing2.png) A texture for 'thing1.png^thing2.png' is created and the resulting texture is overlaid over cobble.png. Advanced texture modifiers: [crack::

n = animation frame count, p = current animation frame Draw a step of the crack animation on the texture. Example: default_cobble.png^[crack:10:1 [combine:x:,=:,= w = width, h = height, x1/x2 = x position, y1/y1 = y position, file1/file2 = texture to combine Create a texture of size x and blit to (,) and blit to (,). Example: [combine:16x32:0,0=default_cobble.png:0,16=default_wood.png [brighten Brightens the texture. Example: tnt_tnt_side.png^[brighten [noalpha Makes the texture completely opaque. Example: default_leaves.png^[noalpha [makealpha:,, Convert one color to transparency. Example: default_cobble.png^[makealpha:128,128,128 [transform t = transformation(s) to apply Rotates and/or flips the image. can be a number (between 0 and 7) or a transform name. Rotations are counter-clockwise. 0 I identity 1 R90 rotate by 90 degrees 2 R180 rotate by 180 degrees 3 R270 rotate by 270 degrees 4 FX flip X 5 FXR90 flip X then rotate by 90 degrees 6 FY flip Y 7 FYR90 flip Y then rotate by 90 degrees Example: default_stone.png^[transformFXR90 [inventorycube{{{ '^' is replaced by '&' in texture names Create an inventory cube texture using the side textures. Example: [inventorycube{grass.png{dirt.png&grass_side.png{dirt.png&grass_side.png Creates an inventorycube with 'grass.png', 'dirt.png^grass_side.png' and 'dirt.png^grass_side.png' textures [lowpart:: Blit the lower % part of on the texture: Example: base.png^[lowpart:25:overlay.png [verticalframe:: t = animation frame count, n = current animation frame Crops the texture to a frame of a vertical animation. Example: default_torch_animated.png^[verticalframe:16:8 [mask: Apply a mask to the base image. The mask is applied using binary AND. Sounds ------- Only OGG Vorbis files are supported. For positional playing of sounds, only single-channel (mono) files are supported. Otherwise OpenAL will play them non-positionally. Mods should generally prefix their sounds with modname_, e.g. given the mod name "foomod", a sound could be called "foomod_foosound.ogg" Sounds are referred to by their name with a dot, a single digit and the file extension stripped out. When a sound is played, the actual sound file is chosen randomly from the matching sounds. When playing the sound "foomod_foosound", the sound is chosen randomly from the available ones of the following files: foomod_foosound.ogg foomod_foosound.0.ogg foomod_foosound.1.ogg ... foomod_foosound.9.ogg Examples of sound parameter tables: -- Play location-less on all clients { gain = 1.0, -- default } -- Play location-less to a player { to_player = name, gain = 1.0, -- default } -- Play in a location { pos = {x=1,y=2,z=3}, gain = 1.0, -- default max_hear_distance = 32, -- default } -- Play connected to an object, looped { object = , gain = 1.0, -- default max_hear_distance = 32, -- default loop = true, -- only sounds connected to objects can be looped } SimpleSoundSpec: e.g. "" e.g. "default_place_node" e.g. {} e.g. {name="default_place_node"} e.g. {name="default_place_node", gain=1.0} Registered definitions of stuff -------------------------------- Anything added using certain minetest.register_* functions get added to the global minetest.registered_* tables. minetest.register_entity(name, prototype table) -> minetest.registered_entities[name] minetest.register_node(name, node definition) -> minetest.registered_items[name] -> minetest.registered_nodes[name] minetest.register_tool(name, item definition) -> minetest.registered_items[name] minetest.register_craftitem(name, item definition) -> minetest.registered_items[name] Note that in some cases you will stumble upon things that are not contained in these tables (e.g. when a mod has been removed). Always check for existence before trying to access the fields. Example: If you want to check the drawtype of a node, you could do: local function get_nodedef_field(nodename, fieldname) if not minetest.registered_nodes[nodename] then return nil end return minetest.registered_nodes[nodename][fieldname] end local drawtype = get_nodedef_field(nodename, "drawtype") Example: minetest.get_item_group(name, group) has been implemented as: function minetest.get_item_group(name, group) if not minetest.registered_items[name] or not minetest.registered_items[name].groups[group] then return 0 end return minetest.registered_items[name].groups[group] end Nodes ------ Nodes are the bulk data of the world: cubes and other things that take the space of a cube. Huge amounts of them are handled efficiently, but they are quite static. The definition of a node is stored and can be accessed by name in minetest.registered_nodes[node.name] See "Registered definitions of stuff". Nodes are passed by value between Lua and the engine. They are represented by a table: {name="name", param1=num, param2=num} param1 and param2 are 8 bit integers. The engine uses them for certain automated functions. If you don't use these functions, you can use them to store arbitrary values. The functions of param1 and param2 are determined by certain fields in the node definition: param1 is reserved for the engine when paramtype != "none": paramtype = "light" ^ The value stores light with and without sun in it's upper and lower 4 bits. param2 is reserved for the engine when any of these are used: liquidtype == "flowing" ^ The level and some flags of the liquid is stored in param2 drawtype == "flowingliquid" ^ The drawn liquid level is read from param2 drawtype == "torchlike" drawtype == "signlike" paramtype2 == "wallmounted" ^ The rotation of the node is stored in param2. You can make this value by using minetest.dir_to_wallmounted(). paramtype2 == "facedir" ^ The rotation of the node is stored in param2. Furnaces and chests are rotated this way. Can be made by using minetest.dir_to_facedir(). Values range 0 - 23 facedir modulo 4 = axisdir 0 = y+ 1 = z+ 2 = z- 3 = x+ 4 = x- 5 = y- facedir's two less significant bits are rotation around the axis paramtype2 == "leveled" ^ The drawn node level is read from param2, like flowingliquid Nodes can also contain extra data. See "Node Metadata". Node drawtypes --------------- There are a bunch of different looking node types. Look for examples in games/minimal or games/minetest_game. - normal - airlike - liquid - flowingliquid - glasslike - glasslike_framed - glasslike_framed_optional - allfaces - allfaces_optional - torchlike - signlike - plantlike - firelike - fencelike - raillike - nodebox -- See below. EXPERIMENTAL *_optional drawtypes need less rendering time if deactivated (always client side) Node boxes ----------- Node selection boxes are defined using "node boxes" The "nodebox" node drawtype allows defining visual of nodes consisting of arbitrary number of boxes. It allows defining stuff like stairs. Only the "fixed" and "leveled" box type is supported for these. ^ Please note that this is still experimental, and may be incompatibly changed in the future. A nodebox is defined as any of: { -- A normal cube; the default in most things type = "regular" } { -- A fixed box (facedir param2 is used, if applicable) type = "fixed", fixed = box OR {box1, box2, ...} } { -- A box like the selection box for torches -- (wallmounted param2 is used, if applicable) type = "wallmounted", wall_top = box, wall_bottom = box, wall_side = box } A box is defined as: {x1, y1, z1, x2, y2, z2} A box of a regular node would look like: {-0.5, -0.5, -0.5, 0.5, 0.5, 0.5}, type = "leveled" is same as "fixed", but y2 will be automatically set to level from param2 Ore types --------------- These tell in what manner the ore is generated. All default ores are of the uniformly-distributed scatter type. - scatter Randomly chooses a location and generates a cluster of ore. If noise_params is specified, the ore will be placed if the 3d perlin noise at that point is greater than the noise_threshold, giving the ability to create a non-equal distribution of ore. - sheet Creates a sheet of ore in a blob shape according to the 2d perlin noise described by noise_params. The relative height of the sheet can be controlled by the same perlin noise as well, by specifying a non-zero 'scale' parameter in noise_params. IMPORTANT: The noise is not transformed by offset or scale when comparing against the noise threshold, but scale is used to determine relative height. The height of the blob is randomly scattered, with a maximum height of clust_size. clust_scarcity and clust_num_ores are ignored. This is essentially an improved version of the so-called "stratus" ore seen in some unofficial mods. - claylike - NOT YET IMPLEMENTED Places ore if there are no more than clust_scarcity number of specified nodes within a Von Neumann neighborhood of clust_size radius. Ore attributes ------------------- See section Flag Specifier Format. Currently supported flags: absheight - absheight Also produce this same ore between the height range of -height_max and -height_min. Useful for having ore in sky realms without having to duplicate ore entries. Decoration types ------------------- The varying types of decorations that can be placed. The default value is simple, and is currently the only type supported. - simple Creates a 1xHx1 column of a specified node (or a random node from a list, if a decoration list is specified). Can specify a certain node it must spawn next to, such as water or lava, for example. Can also generate a decoration of random height between a specified lower and upper bound. This type of decoration is intended for placement of grass, flowers, cacti, papyrus, and so on. - schematic Copies a box of MapNodes from a specified schematic file (or raw description). Can specify a probability of a node randomly appearing when placed. This decoration type is intended to be used for multi-node sized discrete structures, such as trees, cave spikes, rocks, and so on. Schematic specifier -------------------- A schematic specifier identifies a schematic by either a filename to a Minetest Schematic file (.mts) or through raw data supplied through Lua, in the form of a table. This table must specify two fields: - The 'size' field is a 3d vector containing the dimensions of the provided schematic. - The 'data' field is a flat table of MapNodes making up the schematic, in the order of [z [y [x]]]. Important: The default value for param1 in MapNodes here is 255, which represents "always place". In the bulk MapNode data, param1, instead of the typical light values, instead represents the probability of that node appearing in the structure. When passed to minetest.create_schematic, probability is an integer value ranging from 0 to 255: - A probability value of 0 means that node will never appear (0% chance). - A probability value of 255 means the node will always appear (100% chance). - If the probability value p is greater than 0, then there is a (p / 256 * 100)% chance that node will appear when the schematic is placed on the map. Important note: Node aliases cannot be used for a raw schematic provided when registering as a decoration. Schematic attributes --------------------- See section Flag Specifier Format. Currently supported flags: place_center_x, place_center_y, place_center_z - place_center_x Placement of this decoration is centered along the X axis. - place_center_y Placement of this decoration is centered along the Y axis. - place_center_z Placement of this decoration is centered along the Z axis. HUD element types ------------------- The position field is used for all element types. To account for differing resolutions, the position coordinates are the percentage of the screen, ranging in value from 0 to 1. The name field is not yet used, but should contain a description of what the HUD element represents. The direction field is the direction in which something is drawn. 0 draws from left to right, 1 draws from right to left, 2 draws from top to bottom, and 3 draws from bottom to top. The alignment field specifies how the item will be aligned. It ranges from -1 to 1, with 0 being the center, -1 is moved to the left/up, and 1 is to the right/down. Fractional values can be used. The offset field specifies a pixel offset from the position. Contrary to position, the offset is not scaled to screen size. This allows for some precisely-positioned items in the HUD. Note offset WILL adapt to screen dpi as well as user defined scaling factor! Below are the specific uses for fields in each type; fields not listed for that type are ignored. Note: Future revisions to the HUD API may be incompatible; the HUD API is still in the experimental stages. - image Displays an image on the HUD. - scale: The scale of the image, with 1 being the original texture size. Only the X coordinate scale is used (positive values) Negative values represent that percentage of the screen it should take; e.g. x=-100 means 100% (width) - text: The name of the texture that is displayed. - alignment: The alignment of the image. - offset: offset in pixels from position. - text Displays text on the HUD. - scale: Defines the bounding rectangle of the text. A value such as {x=100, y=100} should work. - text: The text to be displayed in the HUD element. - number: An integer containing the RGB value of the color used to draw the text. Specify 0xFFFFFF for white text, 0xFF0000 for red, and so on. - alignment: The alignment of the text. - offset: offset in pixels from position. - statbar Displays a horizontal bar made up of half-images. - text: The name of the texture that is used. - number: The number of half-textures that are displayed. If odd, will end with a vertically center-split texture. - direction - offset: offset in pixels from position. - size: If used will force full-image size to this value (override texture pack image size) - inventory - text: The name of the inventory list to be displayed. - number: Number of items in the inventory to be displayed. - item: Position of item that is selected. - direction - waypoint Displays distance to selected world position. - name: The name of the waypoint. - text: Distance suffix. Can be blank. - number: An integer containing the RGB value of the color used to draw the text. - world_pos: World position of the waypoint. Representations of simple things -------------------------------- Position/vector: {x=num, y=num, z=num} For helper functions see "Vector helpers". pointed_thing: {type="nothing"} {type="node", under=pos, above=pos} {type="object", ref=ObjectRef} Flag Specifier Format ----------------------- Flags using the standardized flag specifier format can be specified in either of two ways, by string or table. The string format is a comma-delimited set of flag names; whitespace and unrecognized flag fields are ignored. Specifying a flag in the string sets the flag, and specifying a flag prefixed by the string "no" explicitly clears the flag from whatever the default may be. In addition to the standard string flag format, the schematic flags field can also be a table of flag names to boolean values representing whether or not the flag is set. Additionally, if a field with the flag name prefixed with "no" is present, mapped to a boolean of any value, the specified flag is unset. e.g. A flag field of value {place_center_x = true, place_center_y=false, place_center_z=true} is equivalent to {place_center_x = true, noplace_center_y=true, place_center_z=true} which is equivalent to "place_center_x, noplace_center_y, place_center_z" or even "place_center_x, place_center_z" since, by default, no schematic attributes are set. Items ------ Node (register_node): A node from the world Tool (register_tool): A tool/weapon that can dig and damage things according to tool_capabilities Craftitem (register_craftitem): A miscellaneous item Items and item stacks can exist in three formats: Serialized; This is called stackstring or itemstring: e.g. 'default:dirt 5' e.g. 'default:pick_wood 21323' e.g. 'default:apple' Table format: e.g. {name="default:dirt", count=5, wear=0, metadata=""} ^ 5 dirt nodes e.g. {name="default:pick_wood", count=1, wear=21323, metadata=""} ^ a wooden pick about 1/3 worn out e.g. {name="default:apple", count=1, wear=0, metadata=""} ^ an apple. ItemStack: C++ native format with many helper methods. Useful for converting between formats. See the Class reference section for details. When an item must be passed to a function, it can usually be in any of these formats. Groups ------- In a number of places, there is a group table. Groups define the properties of a thing (item, node, armor of entity, capabilities of tool) in such a way that the engine and other mods can can interact with the thing without actually knowing what the thing is. Usage: - Groups are stored in a table, having the group names with keys and the group ratings as values. For example: groups = {crumbly=3, soil=1} ^ Default dirt groups = {crumbly=2, soil=1, level=2, outerspace=1} ^ A more special dirt-kind of thing - Groups always have a rating associated with them. If there is no useful meaning for a rating for an enabled group, it shall be 1. - When not defined, the rating of a group defaults to 0. Thus when you read groups, you must interpret nil and 0 as the same value, 0. You can read the rating of a group for an item or a node by using minetest.get_item_group(itemname, groupname) Groups of items ---------------- Groups of items can define what kind of an item it is (e.g. wool). Groups of nodes ---------------- In addition to the general item things, groups are used to define whether a node is destroyable and how long it takes to destroy by a tool. Groups of entities ------------------- For entities, groups are, as of now, used only for calculating damage. The rating is the percentage of damage caused by tools with this damage group. See "Entity damage mechanism". object.get_armor_groups() -> a group-rating table (e.g. {fleshy=100}) object.set_armor_groups({fleshy=30, cracky=80}) Groups of tools ---------------- Groups in tools define which groups of nodes and entities they are effective towards. Groups in crafting recipes --------------------------- An example: Make meat soup from any meat, any water and any bowl { output = 'food:meat_soup_raw', recipe = { {'group:meat'}, {'group:water'}, {'group:bowl'}, }, -- preserve = {'group:bowl'}, -- Not implemented yet (TODO) } An another example: Make red wool from white wool and red dye { type = 'shapeless', output = 'wool:red', recipe = {'wool:white', 'group:dye,basecolor_red'}, } Special groups --------------- - immortal: Disables the group damage system for an entity - level: Can be used to give an additional sense of progression in the game. - A larger level will cause e.g. a weapon of a lower level make much less damage, and get worn out much faster, or not be able to get drops from destroyed nodes. - 0 is something that is directly accessible at the start of gameplay - There is no upper limit - dig_immediate: (player can always pick up node without tool wear) - 2: node is removed without tool wear after 0.5 seconds or so (rail, sign) - 3: node is removed without tool wear immediately (torch) - disable_jump: Player (and possibly other things) cannot jump from node - fall_damage_add_percent: damage speed = speed * (1 + value/100) - bouncy: value is bounce speed in percent - falling_node: if there is no walkable block under the node it will fall - attached_node: if the node under it is not a walkable block the node will be dropped as an item. If the node is wallmounted the wallmounted direction is checked. - soil: saplings will grow on nodes in this group - connect_to_raillike: makes nodes of raillike drawtype connect to other group members with same drawtype Known damage and digging time defining groups ---------------------------------------------- - crumbly: dirt, sand - cracky: tough but crackable stuff like stone. - snappy: something that can be cut using fine tools; e.g. leaves, small plants, wire, sheets of metal - choppy: something that can be cut using force; e.g. trees, wooden planks - fleshy: Living things like animals and the player. This could imply some blood effects when hitting. - explody: Especially prone to explosions - oddly_breakable_by_hand: Can be added to nodes that shouldn't logically be breakable by the hand but are. Somewhat similar to dig_immediate, but times are more like {[1]=3.50,[2]=2.00,[3]=0.70} and this does not override the speed of a tool if the tool can dig at a faster speed than this suggests for the hand. Examples of custom groups -------------------------- Item groups are often used for defining, well, //groups of items//. - meat: any meat-kind of a thing (rating might define the size or healing ability or be irrelevant - it is not defined as of yet) - eatable: anything that can be eaten. Rating might define HP gain in half hearts. - flammable: can be set on fire. Rating might define the intensity of the fire, affecting e.g. the speed of the spreading of an open fire. - wool: any wool (any origin, any color) - metal: any metal - weapon: any weapon - heavy: anything considerably heavy Digging time calculation specifics ----------------------------------- Groups such as **crumbly**, **cracky** and **snappy** are used for this purpose. Rating is 1, 2 or 3. A higher rating for such a group implies faster digging time. The **level** group is used to limit the toughness of nodes a tool can dig and to scale the digging times / damage to a greater extent. ^ PLEASE DO UNDERSTAND THIS, otherwise you cannot use the system to it's full potential. Tools define their properties by a list of parameters for groups. They cannot dig other groups; thus it is important to use a standard bunch of groups to enable interaction with tools. **Tools define:** * Full punch interval * Maximum drop level * For an arbitrary list of groups: * Uses (until the tool breaks) * Maximum level (usually 0, 1, 2 or 3) * Digging times * Damage groups **Full punch interval**: When used as a weapon, the tool will do full damage if this time is spent between punches. If e.g. half the time is spent, the tool will do half damage. **Maximum drop level** Suggests the maximum level of node, when dug with the tool, that will drop it's useful item. (e.g. iron ore to drop a lump of iron). - This is not automated; it is the responsibility of the node definition to implement this **Uses** Determines how many uses the tool has when it is used for digging a node, of this group, of the maximum level. For lower leveled nodes, the use count is multiplied by 3^leveldiff. - uses=10, leveldiff=0 -> actual uses: 10 - uses=10, leveldiff=1 -> actual uses: 30 - uses=10, leveldiff=2 -> actual uses: 90 **Maximum level** Tells what is the maximum level of a node of this group that the tool will be able to dig. **Digging times** List of digging times for different ratings of the group, for nodes of the maximum level. * For example, as a Lua table, ''times={2=2.00, 3=0.70}''. This would result in the tool to be able to dig nodes that have a rating of 2 or 3 for this group, and unable to dig the rating 1, which is the toughest. Unless there is a matching group that enables digging otherwise. **Damage groups** List of damage for groups of entities. See "Entity damage mechanism". Example definition of the capabilities of a tool ------------------------------------------------- tool_capabilities = { full_punch_interval=1.5, max_drop_level=1, groupcaps={ crumbly={maxlevel=2, uses=20, times={[1]=1.60, [2]=1.20, [3]=0.80}} } damage_groups = {fleshy=2}, } This makes the tool be able to dig nodes that fulfil both of these: - Have the **crumbly** group - Have a **level** group less or equal to 2 Table of resulting digging times: crumbly 0 1 2 3 4 <- level -> 0 - - - - - 1 0.80 1.60 1.60 - - 2 0.60 1.20 1.20 - - 3 0.40 0.80 0.80 - - level diff: 2 1 0 -1 -2 Table of resulting tool uses: -> 0 - - - - - 1 180 60 20 - - 2 180 60 20 - - 3 180 60 20 - - Notes: - At crumbly=0, the node is not diggable. - At crumbly=3, the level difference digging time divider kicks in and makes easy nodes to be quickly breakable. - At level > 2, the node is not diggable, because it's level > maxlevel Entity damage mechanism ------------------------ Damage calculation: damage = 0 foreach group in cap.damage_groups: damage += cap.damage_groups[group] * limit(actual_interval / cap.full_punch_interval, 0.0, 1.0) * (object.armor_groups[group] / 100.0) -- Where object.armor_groups[group] is 0 for inexistent values return damage Client predicts damage based on damage groups. Because of this, it is able to give an immediate response when an entity is damaged or dies; the response is pre-defined somehow (e.g. by defining a sprite animation) (not implemented; TODO). - Currently a smoke puff will appear when an entity dies. The group **immortal** completely disables normal damage. Entities can define a special armor group, which is **punch_operable**. This group disables the regular damage mechanism for players punching it by hand or a non-tool item, so that it can do something else than take damage. On the Lua side, every punch calls ''entity:on_punch(puncher, time_from_last_punch, tool_capabilities, direction)''. This should never be called directly, because damage is usually not handled by the entity itself. * ''puncher'' is the object performing the punch. Can be nil. Should never be accessed unless absolutely required, to encourage interoperability. * ''time_from_last_punch'' is time from last punch (by puncher) or nil. * ''tool_capabilities'' can be nil. * ''direction'' is a unit vector, pointing from the source of the punch to the punched object. To punch an entity/object in Lua, call ''object:punch(puncher, time_from_last_punch, tool_capabilities, direction)''. * Return value is tool wear. * Parameters are equal to the above callback. * If ''direction'' is nil and ''puncher'' is not nil, ''direction'' will be automatically filled in based on the location of ''puncher''. Node Metadata ------------- The instance of a node in the world normally only contains the three values mentioned in "Nodes". However, it is possible to insert extra data into a node. It is called "node metadata"; See "NodeMetaRef". Metadata contains two things: - A key-value store - An inventory Some of the values in the key-value store are handled specially: - formspec: Defines a right-click inventory menu. See "Formspec". - infotext: Text shown on the screen when the node is pointed at Example stuff: local meta = minetest.get_meta(pos) meta:set_string("formspec", "size[8,9]".. "list[context;main;0,0;8,4;]".. "list[current_player;main;0,5;8,4;]") meta:set_string("infotext", "Chest"); local inv = meta:get_inventory() inv:set_size("main", 8*4) print(dump(meta:to_table())) meta:from_table({ inventory = { main = {[1] = "default:dirt", [2] = "", [3] = "", [4] = "", [5] = "", [6] = "", [7] = "", [8] = "", [9] = "", [10] = "", [11] = "", [12] = "", [13] = "", [14] = "default:cobble", [15] = "", [16] = "", [17] = "", [18] = "", [19] = "", [20] = "default:cobble", [21] = "", [22] = "", [23] = "", [24] = "", [25] = "", [26] = "", [27] = "", [28] = "", [29] = "", [30] = "", [31] = "", [32] = ""} }, fields = { formspec = "size[8,9]list[context;main;0,0;8,4;]list[current_player;main;0,5;8,4;]", infotext = "Chest" } }) Formspec -------- Formspec defines a menu. Currently not much else than inventories are supported. It is a string, with a somewhat strange format. Spaces and newlines can be inserted between the blocks, as is used in the examples. Examples: - Chest: size[8,9] list[context;main;0,0;8,4;] list[current_player;main;0,5;8,4;] - Furnace: size[8,9] list[context;fuel;2,3;1,1;] list[context;src;2,1;1,1;] list[context;dst;5,1;2,2;] list[current_player;main;0,5;8,4;] - Minecraft-like player inventory size[8,7.5] image[1,0.6;1,2;player.png] list[current_player;main;0,3.5;8,4;] list[current_player;craft;3,0;3,3;] list[current_player;craftpreview;7,1;1,1;] Elements: size[,,] ^ Define the size of the menu in inventory slots ^ fixed_size true/false (optional) ^ deprecated: invsize[,;] list[;;,;,;] list[;;,;,;] ^ Show an inventory list listcolors[;] ^ Sets background color of slots in HEX-Color format ^ Sets background color of slots on mouse hovering listcolors[;;] ^ Sets background color of slots in HEX-Color format ^ Sets background color of slots on mouse hovering ^ Sets color of slots border listcolors[;;;;] ^ Sets background color of slots in HEX-Color format ^ Sets background color of slots on mouse hovering ^ Sets color of slots border ^ Sets default background color of tooltips ^ Sets default font color of tooltips tooltip[;;,] ^ Adds tooltip for an element ^ tooltip background color in HEX-Color format (optional) ^ tooltip font color in HEX-Color format (optional) image[,;,;] ^ Show an image ^ Position and size units are inventory slots item_image[,;,;] ^ Show an inventory image of registered item/node ^ Position and size units are inventory slots bgcolor[;] ^ Sets background color of formspec in HEX-Color format ^ If true the background color is drawn fullscreen (does not effect the size of the formspec) background[,;,;] ^ Use a background. Inventory rectangles are not drawn then. ^ Position and size units are inventory slots ^ Example for formspec 8x4 in 16x resolution: image shall be sized 8*16px x 4*16px background[,;,;;] ^ Use a background. Inventory rectangles are not drawn then. ^ Position and size units are inventory slots ^ Example for formspec 8x4 in 16x resolution: image shall be sized 8*16px x 4*16px ^ If true the background is clipped to formspec size (x and y are used as offset values, w and h are ignored) pwdfield[,;,;;