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diff --git a/doc/lua_api.txt b/doc/lua_api.txt index 762446466..e6d856368 100644 --- a/doc/lua_api.txt +++ b/doc/lua_api.txt @@ -426,6 +426,167 @@ Result is more like what you'd expect if you put a color on top of another color. Meaning white surfaces get a lot of your new color while black parts don't change very much. +Hardware coloring +----------------- +The goal of hardware coloring is to simplify the creation of +colorful nodes. If your textures use the same pattern, and they only +differ in their color (like colored wool blocks), you can use hardware +coloring instead of creating and managing many texture files. +All of these methods use color multiplication (so a white-black texture +with red coloring will result in red-black color). + +### Static coloring +This method is useful if you wish to create nodes/items with +the same texture, in different colors, each in a new node/item definition. + +#### Global color +When you register an item or node, set its `color` field (which accepts a +`ColorSpec`) to the desired color. + +An `ItemStack`s static color can be overwritten by the `color` metadata +field. If you set that field to a `ColorString`, that color will be used. + +#### Tile color +Each tile may have an individual static color, which overwrites every +other coloring methods. To disable the coloring of a face, +set its color to white (because multiplying with white does nothing). +You can set the `color` property of the tiles in the node's definition +if the tile is in table format. + +### Palettes +For nodes and items which can have many colors, a palette is more +suitable. A palette is a texture, which can contain up to 256 pixels. +Each pixel is one possible color for the node/item. +You can register one node/item, which can have up to 256 colors. + +#### Palette indexing +When using palettes, you always provide a pixel index for the given +node or `ItemStack`. The palette is read from left to right and from +top to bottom. If the palette has less than 256 pixels, then it is +stretched to contain exactly 256 pixels (after arranging the pixels +to one line). The indexing starts from 0. + +Examples: +* 16x16 palette, index = 0: the top left corner +* 16x16 palette, index = 4: the fifth pixel in the first row +* 16x16 palette, index = 16: the pixel below the top left corner +* 16x16 palette, index = 255: the bottom right corner +* 2 (width)x4 (height) palette, index=31: the top left corner. + The palette has 8 pixels, so each pixel is stretched to 32 pixels, + to ensure the total 256 pixels. +* 2x4 palette, index=32: the top right corner +* 2x4 palette, index=63: the top right corner +* 2x4 palette, index=64: the pixel below the top left corner + +#### Using palettes with items +When registering an item, set the item definition's `palette` field to +a texture. You can also use texture modifiers. + +The `ItemStack`'s color depends on the `palette_index` field of the +stack's metadata. `palette_index` is an integer, which specifies the +index of the pixel to use. + +#### Linking palettes with nodes +When registering a node, set the item definition's `palette` field to +a texture. You can also use texture modifiers. +The node's color depends on its `param2`, so you also must set an +appropriate `drawtype`: +* `drawtype = "color"` for nodes which use their full `param2` for + palette indexing. These nodes can have 256 different colors. + The palette should contain 256 pixels. +* `drawtype = "colorwallmounted"` for nodes which use the first + five bits (most significant) of `param2` for palette indexing. + The remaining three bits are describing rotation, as in `wallmounted` + draw type. Division by 8 yields the palette index (without stretching the + palette). These nodes can have 32 different colors, and the palette + should contain 32 pixels. + Examples: + * `param2 = 17` is 2 * 8 + 1, so the rotation is 1 and the third (= 2 + 1) + pixel will be picked from the palette. + * `param2 = 35` is 4 * 8 + 3, so the rotation is 3 and the fifth (= 4 + 1) + pixel will be picked from the palette. +* `drawtype = "colorfacedir"` for nodes which use the first + three bits of `param2` for palette indexing. The remaining + five bits are describing rotation, as in `facedir` draw type. + Division by 32 yields the palette index (without stretching the + palette). These nodes can have 8 different colors, and the + palette should contain 8 pixels. + Examples: + * `param2 = 17` is 0 * 32 + 17, so the rotation is 17 and the + first (= 0 + 1) pixel will be picked from the palette. + * `param2 = 35` is 1 * 32 + 3, so the rotation is 3 and the + second (= 1 + 1) pixel will be picked from the palette. + +To colorize a node on the map, set its `param2` value (according +to the node's draw type). + +### Conversion between nodes in the inventory and the on the map +Static coloring is the same for both cases, there is no need +for conversion. + +If the `ItemStack`'s metadata contains the `color` field, it will be +lost on placement, because nodes on the map can only use palettes. + +If the `ItemStack`'s metadata contains the `palette_index` field, you +currently must manually convert between it and the node's `param2` with +custom `on_place` and `on_dig` callbacks. + +### Colored items in craft recipes +Craft recipes only support item strings, but fortunately item strings +can also contain metadata. Example craft recipe registration: + + local stack = ItemStack("wool:block") + dyed:get_meta():set_int("palette_index", 3) -- add index + minetest.register_craft({ + output = dyed:to_string(), -- convert to string + type = "shapeless", + recipe = { + "wool:block", + "dye:red", + }, + }) + +Metadata field filtering in the `recipe` field are not supported yet, +so the craft output is independent of the color of the ingredients. + +Soft texture overlay +-------------------- +Sometimes hardware coloring is not enough, because it affects the +whole tile. Soft texture overlays were added to Minetest to allow +the dynamic coloring of only specific parts of the node's texture. +For example a grass block may have colored grass, while keeping the +dirt brown. + +These overlays are 'soft', because unlike texture modifiers, the layers +are not merged in the memory, but they are simply drawn on top of each +other. This allows different hardware coloring, but also means that +tiles with overlays are drawn slower. Using too much overlays might +cause FPS loss. + +To define an overlay, simply set the `overlay_tiles` field of the node +definition. These tiles are defined in the same way as plain tiles: +they can have a texture name, color etc. +To skip one face, set that overlay tile to an empty string. + +Example (colored grass block): + + minetest.register_node("default:dirt_with_grass", { + description = "Dirt with Grass", + -- Regular tiles, as usual + -- The dirt tile disables palette coloring + tiles = {{name = "default_grass.png"}, + {name = "default_dirt.png", color = "white"}}, + -- Overlay tiles: define them in the same style + -- The top and bottom tile does not have overlay + overlay_tiles = {"", "", + {name = "default_grass_side.png", tileable_vertical = false}}, + -- Global color, used in inventory + color = "green", + -- Palette in the world + paramtype2 = "color", + palette = "default_foilage.png", + }) + Sounds ------ Only Ogg Vorbis files are supported. |