three
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JavaScript 3D library
249 lines (167 loc) • 5.25 kB
JavaScript
import {
FileLoader,
Loader
} from 'three';
import opentype from '../libs/opentype.module.js';
/**
* A loader for the TTF format.
*
* Loads TTF files and converts them into typeface JSON that can be used directly
* to create THREE.Font objects.
*
* ```js
* const loader = new TTFLoader();
* const json = await loader.loadAsync( 'fonts/ttf/kenpixel.ttf' );
* const font = new Font( json );
* ```
*
* @augments Loader
*/
class TTFLoader extends Loader {
/**
* Constructs a new TTF loader.
*
* @param {LoadingManager} [manager] - The loading manager.
*/
constructor( manager ) {
super( manager );
/**
* Whether the TTF commands should be reversed or not.
*
* @type {boolean}
* @default false
*/
this.reversed = false;
}
/**
* Starts loading from the given URL and passes the loaded TTF asset
* to the `onLoad()` callback.
*
* @param {string} url - The path/URL of the file to be loaded. This can also be a data URI.
* @param {function(Object)} onLoad - Executed when the loading process has been finished.
* @param {onProgressCallback} onProgress - Executed while the loading is in progress.
* @param {onErrorCallback} onError - Executed when errors occur.
*/
load( url, onLoad, onProgress, onError ) {
const scope = this;
const loader = new FileLoader( this.manager );
loader.setPath( this.path );
loader.setResponseType( 'arraybuffer' );
loader.setRequestHeader( this.requestHeader );
loader.setWithCredentials( this.withCredentials );
loader.load( url, function ( buffer ) {
try {
onLoad( scope.parse( buffer ) );
} catch ( e ) {
if ( onError ) {
onError( e );
} else {
console.error( e );
}
scope.manager.itemError( url );
}
}, onProgress, onError );
}
/**
* Parses the given TTF data and returns a JSON for creating a font.
*
* @param {ArrayBuffer} arraybuffer - The raw TTF data as an array buffer.
* @return {Object} The result JSON.
*/
parse( arraybuffer ) {
function convert( font, reversed ) {
const round = Math.round;
const glyphs = {};
const scale = ( 100000 ) / ( ( font.unitsPerEm || 2048 ) * 72 );
const glyphIndexMap = font.encoding.cmap.glyphIndexMap;
const unicodes = Object.keys( glyphIndexMap );
for ( let i = 0; i < unicodes.length; i ++ ) {
const unicode = unicodes[ i ];
const glyph = font.glyphs.glyphs[ glyphIndexMap[ unicode ] ];
if ( unicode !== undefined ) {
const token = {
ha: round( glyph.advanceWidth * scale ),
x_min: round( glyph.xMin * scale ),
x_max: round( glyph.xMax * scale ),
o: ''
};
if ( reversed ) {
glyph.path.commands = reverseCommands( glyph.path.commands );
}
glyph.path.commands.forEach( function ( command ) {
if ( command.type.toLowerCase() === 'c' ) {
command.type = 'b';
}
token.o += command.type.toLowerCase() + ' ';
if ( command.x !== undefined && command.y !== undefined ) {
token.o += round( command.x * scale ) + ' ' + round( command.y * scale ) + ' ';
}
if ( command.x1 !== undefined && command.y1 !== undefined ) {
token.o += round( command.x1 * scale ) + ' ' + round( command.y1 * scale ) + ' ';
}
if ( command.x2 !== undefined && command.y2 !== undefined ) {
token.o += round( command.x2 * scale ) + ' ' + round( command.y2 * scale ) + ' ';
}
} );
glyphs[ String.fromCodePoint( glyph.unicode ) ] = token;
}
}
return {
glyphs: glyphs,
familyName: font.getEnglishName( 'fullName' ),
ascender: round( font.ascender * scale ),
descender: round( font.descender * scale ),
underlinePosition: font.tables.post.underlinePosition,
underlineThickness: font.tables.post.underlineThickness,
boundingBox: {
xMin: font.tables.head.xMin,
xMax: font.tables.head.xMax,
yMin: font.tables.head.yMin,
yMax: font.tables.head.yMax
},
resolution: 1000,
original_font_information: font.tables.name
};
}
function reverseCommands( commands ) {
const paths = [];
let path;
commands.forEach( function ( c ) {
if ( c.type.toLowerCase() === 'm' ) {
path = [ c ];
paths.push( path );
} else if ( c.type.toLowerCase() !== 'z' ) {
path.push( c );
}
} );
const reversed = [];
paths.forEach( function ( p ) {
const result = {
type: 'm',
x: p[ p.length - 1 ].x,
y: p[ p.length - 1 ].y
};
reversed.push( result );
for ( let i = p.length - 1; i > 0; i -- ) {
const command = p[ i ];
const result = { type: command.type };
if ( command.x2 !== undefined && command.y2 !== undefined ) {
result.x1 = command.x2;
result.y1 = command.y2;
result.x2 = command.x1;
result.y2 = command.y1;
} else if ( command.x1 !== undefined && command.y1 !== undefined ) {
result.x1 = command.x1;
result.y1 = command.y1;
}
result.x = p[ i - 1 ].x;
result.y = p[ i - 1 ].y;
reversed.push( result );
}
} );
return reversed;
}
return convert( opentype.parse( arraybuffer ), this.reversed );
}
}
export { TTFLoader };