This is a KaTeX plugin that adds support for Persian math formulas. It adds the following to the KaTeX:

1. Support for Persian and Arabic numerals [۰-۹] in formulas (math mode)
2. Support for Persian and Arabic characters [unicode 0x0660 to 0x06FF] in text inside formules (text mode) All the Persian and Arabic characters use open source Vazir font.

To use this plugin follow KaTeX usage guidelines in order to add KaTeX to your environment.

Then install the plugin by:

npm

• install package: npm install persian-katex-plugin or yarn add persian-katex-plugin
• import css files using a bundler like webpack and css-loader: import 'perisan-katex-plugin/dist/index.css'
• you also need file-loader in your webpack config in order for the plugin to load font files.

Finally you need to add the plugin to KaTeX before calling katex.render. Your final code should be something like this:

import katex from 'katex';
import 'katex/dist/katex.css';
import addPersianTo from 'persian-katex-plugin';
import 'perisan-katex-plugin/dist/index.css';

addPersianTo(katex);

All the persian and arabic characters will render using the 'Vazir' font. You should change your western numeral characters ([0-9]) to eastern numerals [۰-۹].

changing the font

As KaTeX calculates the character sizes statically (at compile time) using a new font for your formulas is not as easy as changing the font of a css class.
To change the font of Persian and Arabic characters and numerals you need to first calculate the character metrics for your font and then provide the metrics and fontName to the plugin as its second options paramter.

1. using persian-katex-plugin/utils/generateMetrics.js script you can create a json file for you metrics. Following is an example for how we generated default Vazir font metrics.
   You have to provide the path to truetype (ttf) files of your font (metrics are usually the same for other file types).
   You also need to provide each font name in the following format: [fontname]-[Regular/Bold/Italic/BoldItalic].
   You can also provide an aditional unicodeRange array to define which range of unicode characters you want to extract from font file.

const generateMetrics = require("perisan-katex-plugin/utils/generateMetrics");
const path = require("path");

const metricOptions = [
    {
        fontname: 'Vazir-Regular',
        filepath: path.resolve("fonts/Vazir.ttf"),
    //  unicodeRange: defualts to [0x0600, 0x06FF]
    },
    {
        fontname: 'Vazir-Bold',
        filepath: path.resolve("fonts/Vazir-Bold.ttf"),
    },
];
const outputPath = path.resolve(__dirname, "src/fontMetrics.json");

generateMetrics(metricOptions, outputPath);

2. After generating the font metrics file you need to add the metrics and font name options to the plugin.

import katex from 'katex';
import 'katex/dist/katex.css';
import addPersianTo from 'persian-katex-plugin';
import 'perisan-katex-plugin/dist/index.css';
import awesomeFontMetrics from 'path-to-awesomeFontMetrics.js';

addPersianTo(katex, {
  fontName: "MyAwesomeFont",
  fontMetrics: awesomeFontMetrics
});

3. finally add a font-face and following css class for each fontname you provided to generateFontMetrics.

@font-face {
    font-family: 'AwesomeFont-Regular';
    font-weight: normal;
    font-style: normal;
    src: url('../fonts/AwesomeFont.woff2') format('woff2'),
        url('../fonts/AwesomeFont.woff') format('woff'),
        url('../fonts/AwesomeFont.ttf') format('ttf');
}

@font-face {
    font-family: 'AwesomeFont-Bold';
    font-weight: bold;
    font-style: normal;
    src: url('../fonts/AwesomeFont-Bold.woff2') format('woff2'),
        url('../fonts/AwesomeFont-Bold.woff') format('woff'),
        url('../fonts/AwesomeFont-Bold.ttf') format('ttf');
}

// bidi algorithm generates wrong result for 
// inline persian and english \text combinations 
// so we make all \text inline-block
.katex .mord.text .AwesomeFont-Regular, 
.katex .mord.text .AwesomeFont-Bold {
    display: inline-block;
}

.AwesomeFont-Regular {
    font-family: 'AwesomeFont-Regular';
}

.AwesomeFont-Bold {
    font-family: 'AwesomeFont-Bold';
}

run yarn install then yarn run dev to run development server.