scarlett-msdf-bmfont-xml


Converts a .ttf font file into multichannel signed distance fields, then outputs packed spritesheets and a xml(.fnt} or json representation of an AngelCode BMfont.

Signed distance fields are a method of reproducing vector shapes from a texture representation, popularized in this paper by Valve.
This tool uses Chlumsky/msdfgen to generate multichannel signed distance fields to preserve corners. The distance fields are created from vector fonts, then rendered into texture pages. A BMFont object is provided for character layout.

!Preview image

Install as CLI

``bash
$ npm install scarlett-msdf-bmfont-xml -g
`
Then you just need to call msdf-bmfont from console to generate font file.
Type in msdf-bmfont --help for more detail usage.

!Console-Demo

$3

`
Usage: msdf-bmfont [options]

Creates a BMFont compatible bitmap font of signed distance fields from a font file

Options:

-V, --version output the version number
-f, --output-type font file format: xml(default) | json
-o, --filename filename of font textures (defaut: font-face)
font filename always set to font-face name
-s, --font-size font size for generated textures (default: 42)
-i, --charset-file user-specified charactors from text-file
-m, --texture-size Width/Height of generated textures (default: 512,512)
-p, --texture-padding padding between glyphs (default: 1)
-r, --distance-range distance range for SDF (default: 4)
-t, --field-type msdf(default) | sdf | psdf | svg
-d, --round-decimal rounded digits of the output font file. (Defaut: 0)
-v, --vector generate svg vector file for debuging
-u, --reuse [file.cfg] use old config to append font, ommit file to save new cfg
--tolerance use point tolerance to filter problematic vector shape (Defaut: 0)
--smart-size shrink atlas to the smallest possible square (Default: false)
--pot atlas size shall be power of 2 (Default: false)
--square atlas size shall be square (Default: false)
--rtl use RTL(Arabic/Persian) charators fix (Default: false)
-h, --help output usage information
`

$3

Generate a multi-channel signed distance field font atlas with ASCII charset, font size 42, spread 3, maximum texture size 512x256, padding 1, and save out config file:

`bash
msdf-bmfont --reuse -o path/to/atlas.png -m 512,256 -s 42 -r 3 -p 1 -t msdf path/to/font.ttf
`

We will get three file: atlas.0.png atlas.0.cfg & font.fnt and this is the generated atlas in the minimum pot size (256x256):

!Atlas0

Then we want to use the old setting except a different font and use monochrome signed distance field atlas, and output an extra .svg version of atlas:

`bash
msdf-bmfont -v -u path/to/atlas.0.cfg -t sdf -p 0 -r 8 path/to/anotherfont.ttf
`

This time we get a modified atlas.0.png with new bitmap font appended:

!Atlas1

Not satisfied with the style? Remember we got a svg atlas!

!svg

How about fire up some graphic editor and add some neat effect and lay on the output atlas?

!final

Install as Module

`bash
$ npm install msdf-bmfont-xml
`

Examples

Writing the distance fields and font data to disk:
`js
const generateBMFont = require('scarlett-msdf-bmfont-xml');
const fs = require('fs');

generateBMFont('Some-Font.ttf', (error, textures, font) => {
if (error) throw error;
textures.forEach((texture, index) => {
fs.writeFile(texture.filename, texture.texture, (err) => {
if (err) throw err;
});
});
fs.writeFile(font.filename, font.data, (err) => {
if (err) throw err;
});
});
`

Generating a single channel signed distance field with a custom character set:
`js
const generateBMFont = require('scarlett-msdf-bmfont');

const opt = {
charset: 'ABC.ez_as-123!',
fieldType: 'sdf'
};
generateBMFont('Some-Font.ttf', opt, (error, textures, font) => {
...
});
`

Usage

#### generateBMFont(fontPath, [opt], callback)

Renders a bitmap font from the font at fontPath with optional opt settings, triggering callback on complete.

Options:
- outputType (String)
- type of output font file. Defaults to xml
- xml a BMFont standard .fnt file which is wildly supported.
- json a JSON file compatible with Hiero
- filename (String)
- filename of both font file and font atlas. If omited, font face name is used.
- charset (String|Array)
- the characters to include in the bitmap font. Defaults to all ASCII printable characters.
- fontSize (Number)
- the font size at which to generate the distance field. Defaults to 42
- textureWidth, textureHeight (Number)
- the dimensions of an output texture sheet, normally power-of-2 for GPU usage. Both dimensions default to 512
- texturePadding (Number)
- pixels between each glyph in the texture. Defaults to 2
- fieldType (String)
- what kind of distance field to generate. Defaults to msdf. Must be one of:
- msdf Multi-channel signed distance field
- sdf Monochrome signed distance field
- psdf monochrome signed pseudo-distance field
- distanceRange (Number)
- the width of the range around the shape between the minimum and maximum representable signed distance in pixels, defaults to 3
- roundDecimal (Number)
- rounded digits of the output font metics. For xml output, roundDecimal: 0 recommended.
- vector (Boolean)
- output a SVG Vector file for debugging. Defauts to false
- smart-size (Boolean)
- shrink atlas to the smallest possible square. Default: false
- pot (Boolean)
- output atlas size shall be power of 2. Default: false
- square (Boolean)
- output atlas size shall be square. Default: false
- rtl (Boolean)
- use RTL(Arabic/Persian) charators fix. Default: false

The callback is called with the arguments (error, textures, font)

- error on success will be null/undefined
- textures an array of js objects of texture spritesheet.
- textures[index].filename Spritesheet filename
- textures[index].texture Image Buffers, containing the PNG data of one texture sheet
- font an object containing the BMFont data, to be used to render the font
- font.filename font filename
- font.data stringified xml\json data to be written to disk

Since opt is optional, you can specify callback` as the second argument.

License

MIT, see LICENSE.md for details.