mirror of
https://github.com/pyrollo/display_modpack.git
synced 2024-11-30 18:13:43 +01:00
202 lines
7.9 KiB
Markdown
202 lines
7.9 KiB
Markdown
# Font API
|
|
This document describes Font API. Font API creates textures for font display on entities.
|
|
|
|
## Settings
|
|
### default_font
|
|
Name of the font to be used when no font is given. The font should be registered.
|
|
|
|
If no default\_font given or if default\_font given but not registered, the first registered font will be used as default.
|
|
|
|
## Use font_api with display_api (to display text on nodes)
|
|
### Base setup
|
|
Font_api offers a direct integration with display_api to display text on nodes.
|
|
|
|
First of all, create a display node with an entity.
|
|
To do this, refer to API.md in display_api mod, in particular "Howto register a display node".
|
|
|
|
The only requirement then is to connect the `on_display_update` callback of the display entity to `font_api.on_display_update`:
|
|
|
|
```
|
|
minetest.register_node("mymod:test_text_node", {
|
|
...
|
|
paramtype2 = "facedir",
|
|
...
|
|
groups = { display_api = 1, ... },
|
|
...
|
|
display_entities = {
|
|
["mymod:text"] = {
|
|
depth = -0.5 - display_api.entity_spacing,
|
|
on_display_update = font_api.on_display_update },
|
|
}
|
|
...
|
|
on_place = display_api.on_place,
|
|
on_construct = display_api.on_construct,
|
|
on_destruct = display_api.on_destruct,
|
|
on_rotate = display_api.on_rotate,
|
|
...
|
|
})
|
|
```
|
|
|
|
At this step, your node already displays text form "display_text" (by default) node meta. If you want to store your text into another meta data field, add a `meta_text` field to display entity definition.
|
|
|
|
But it uses defaults (default font, default size, default color). Likely you need something more.
|
|
|
|
### Style your text
|
|
Font style and size can be chosen by adding some more entries to the display_entities definition table.
|
|
|
|
#### Font size
|
|
Font size can be defined in various ways (maybe more in the future).
|
|
Start with a number of lines, and font_api will make it fit to the entity size.
|
|
* `maxlines` or `lines`: Number of maximum lines of text to be displayed. The font height will be adjusted accordingly.
|
|
|
|
Then specify the char width. Two methods available:
|
|
* `aspect_ratio`: Defines the aspect ratio of chars. Works with all fonts. Should not be used if `columns` is specified.
|
|
* `columns`: Only if using a fixed width font, specifies the number of columns to display.
|
|
|
|
#### Font style
|
|
* `font_name`: name of the font to use. Should correspond to a registered font (from a font mod). If not specified or font not found, default font is used.
|
|
* `color`: color to be used (default black).
|
|
* `halign`: Horizontal alignment: "left", "center" or "right" (default "center").
|
|
* `valign`: Vertical alignement: "top", "middle" or "bottom" (default "middle").
|
|
|
|
### Example
|
|
Using blue //botic// font, three lines height, aligned top left. Text stored in "text" node meta.
|
|
```
|
|
minetest.register_node("mymod:test_text_node", {
|
|
...
|
|
...
|
|
display_entities = {
|
|
["mymod:text"] = {
|
|
depth = -0.5 - display_api.entity_spacing,
|
|
on_display_update = font_api.on_display_update
|
|
meta_text = "text",
|
|
font_name = "botic",
|
|
color = "#0000FF",
|
|
maxlines = 3,
|
|
aspect_ratio = 0.5,
|
|
halign = "left",
|
|
valign = "top",
|
|
},
|
|
}
|
|
...
|
|
})
|
|
```
|
|
## Provided methods
|
|
### font_api.get_default_font_name()
|
|
Returns de default font name.
|
|
|
|
### font_api.register_font(font_name, font_def)
|
|
Register a new font.
|
|
* `font_name`: Name of the font to register. If registering different sizes of the same font, add size in the font name (e.g. times_10, times_12...).
|
|
* `font_def`: Font definition table (see **Font definition table** below).
|
|
|
|
### font_api.on_display_update(pos, objref)
|
|
Standard on_display_update entity callback.
|
|
* `pos`: Node position
|
|
* `objref`: Object reference of entity
|
|
|
|
Node should have a corresponding display_entity with size, resolution and maxlines fields and optionally halign, valign and color fields.
|
|
|
|
## Font definition table
|
|
Font definition table used by **font_api.register_font** and **font\_api.Font:new** may/can contain following elements:
|
|
|
|
* `height` (required): Font height in pixels (all font textures should have the same height) .
|
|
* `widths` (required): Array of character widths in pixels, indexed by UTF codepoints.
|
|
* `margintop` (optional): Margin (in texture pixels) added on top of each char texture.
|
|
* `marginbottom` (optional): Margin (in texture pixels) added at bottom of each char texture.
|
|
* `linespacing` (optional): Spacing (in texture pixels) between each lines.
|
|
|
|
`margintop`, `marginbottom` and `linespacing` can be negative numbers (default 0) and are to be used to adjust various font styles to each other.
|
|
|
|
Font attributes around a single char:\
|
|
|
|
|
|
Font attributes effects on several lines:\
|
|
|
|
|
|
#### Additional requirements
|
|
|
|
Font must have a char 0 which will be used to display any unknown char.
|
|
|
|
All textures corresponding to the indexes in widths array should be present in textures directory with a name matching the pattern :
|
|
|
|
> font\_**{font_name}**_**{utf_code}**.png
|
|
|
|
**{font\_name}**: Name of the font as given in the first argument
|
|
|
|
**{utf\_code}**: UTF code of the char in 4 hexadecimal digits
|
|
|
|
Example : font_courrier_0041.png is for the "A" char in the "courrier" font.
|
|
|
|
To ease that declaration (specially to build the **widths** array), a shell is provided to build a {font\_name}.lua file from the texture files (see provided tools).
|
|
|
|
## Provided tools
|
|
|
|
Still in early stage of development, these tools are helpers to create font mods.
|
|
|
|
### make_font_texture.sh
|
|
|
|
This scripts takes a .ttf file as input and create one .png file per char, that can be used as font texture. Launch it from your future font mod directory.
|
|
|
|
__Advice__
|
|
|
|
This script works much better with pixels font, providing the correct height. There is no antialiasing at all, vector fonts and bad heights gives very ugly results.
|
|
|
|
__Syntax__
|
|
|
|
**make\_font\_texture.sh {fontfile} {fontname} {fontsize}**
|
|
|
|
**{fontfile}**: A TTF font file to use to create textures.
|
|
**{fontname}**: The font name to be used in font_api (should be simple, with no spaces).
|
|
**{fontsize}**: Font height to be rendered.
|
|
|
|
### make_font_lua.sh
|
|
|
|
This script analyses textures in textures directory and creates a font\_{font\_name}.lua files with a call to register_font with images information. Launch it from your future font mod directory.
|
|
|
|
Once the font\_{font\_name}.lua created, it can be included by a init.lua file or directly renamed to init.lua if you are creating a simple font mod.
|
|
|
|
__Syntax__
|
|
|
|
**make\_font_lua.sh {fontname}**
|
|
|
|
**{fontname}**: The font name to be used in font_api (same as given to make\_font\_texture.sh)
|
|
|
|
### An exemple generating a font mod
|
|
|
|
mkdir font_myfont
|
|
cd font_myfont
|
|
/<path_to_font_api>/tools/make_font_texture.sh myfont.ttf myfont 12
|
|
/<path_to_font_api>/tools/make_font_lua.sh myfont
|
|
mv font_myfont.lua init.lua
|
|
|
|
## Font class
|
|
A font usable with font API. This class is supposed to be for internal use but who knows.
|
|
|
|
### font\_api.Font:new(def)
|
|
Create a new font object.
|
|
* `def` is a table containing font definition. See **Font definition table** above.
|
|
|
|
### font:get_char_width(codepoint)
|
|
Returns the width of char `codepoint` in texture pixels.
|
|
* `codepoint`: Unicode codepoint of char.
|
|
|
|
### font:get_height(nb_of_lines)
|
|
Returns line(s) height. Takes care of top and bottom margins and line spacing.
|
|
* `nb_of_lines`: Number of lines in the text.
|
|
|
|
### font:get_width(line)
|
|
Returns the width of a text line. Beware, if line contains any new line char, they are ignored.
|
|
* `line`: Line of text which the width will be computed.
|
|
|
|
### font:renter(text, texturew, textureh, style)
|
|
Builds texture for a multiline colored text.
|
|
* `text`: Text to be rendered.
|
|
* `texturew`: Width of the texture (extra text will be truncated).
|
|
* `textureh`: Height of the texture (extra text will be truncated).
|
|
* `style`: A table with style indications:
|
|
- `lines` or `maxlines`: Maximum number of lines (default none).
|
|
- `halign`: Horizontal text align: "left"/"center"/"right" (default "center")
|
|
- `valign`: Vertical text align: "top"/"middle"/"bottom" (default "middle")
|
|
- `color`: Color of the text (default black)
|