three
Version:
JavaScript 3D library
243 lines (164 loc) • 4.96 kB
JavaScript
import {
FileLoader,
Loader,
ShapePath
} from 'three';
/**
* A loader for loading fonts.
*
* You can convert fonts online using [facetype.js]{@link https://gero3.github.io/facetype.js/}.
*
* ```js
* const loader = new FontLoader();
* const font = await loader.loadAsync( 'fonts/helvetiker_regular.typeface.json' );
* ```
*
* @augments Loader
* @three_import import { FontLoader } from 'three/addons/loaders/FontLoader.js';
*/
class FontLoader extends Loader {
/**
* Constructs a new font loader.
*
* @param {LoadingManager} [manager] - The loading manager.
*/
constructor( manager ) {
super( manager );
}
/**
* Starts loading from the given URL and passes the loaded font
* 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(Font)} 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.setRequestHeader( this.requestHeader );
loader.setWithCredentials( this.withCredentials );
loader.load( url, function ( text ) {
const font = scope.parse( JSON.parse( text ) );
if ( onLoad ) onLoad( font );
}, onProgress, onError );
}
/**
* Parses the given font data and returns the resulting font.
*
* @param {Object} json - The raw font data as a JSON object.
* @return {Font} The font.
*/
parse( json ) {
return new Font( json );
}
}
/**
* Class representing a font.
*/
class Font {
/**
* Constructs a new font.
*
* @param {Object} data - The font data as JSON.
*/
constructor( data ) {
/**
* This flag can be used for type testing.
*
* @type {boolean}
* @readonly
* @default true
*/
this.isFont = true;
this.type = 'Font';
/**
* The font data as JSON.
*
* @type {Object}
*/
this.data = data;
}
/**
* Generates geometry shapes from the given text and size. The result of this method
* should be used with {@link ShapeGeometry} to generate the actual geometry data.
*
* @param {string} text - The text.
* @param {number} [size=100] - The text size.
* @return {Array<Shape>} An array of shapes representing the text.
*/
generateShapes( text, size = 100 ) {
const shapes = [];
const paths = createPaths( text, size, this.data );
for ( let p = 0, pl = paths.length; p < pl; p ++ ) {
shapes.push( ...paths[ p ].toShapes() );
}
return shapes;
}
}
function createPaths( text, size, data ) {
const chars = Array.from( text );
const scale = size / data.resolution;
const line_height = ( data.boundingBox.yMax - data.boundingBox.yMin + data.underlineThickness ) * scale;
const paths = [];
let offsetX = 0, offsetY = 0;
for ( let i = 0; i < chars.length; i ++ ) {
const char = chars[ i ];
if ( char === '\n' ) {
offsetX = 0;
offsetY -= line_height;
} else {
const ret = createPath( char, scale, offsetX, offsetY, data );
offsetX += ret.offsetX;
paths.push( ret.path );
}
}
return paths;
}
function createPath( char, scale, offsetX, offsetY, data ) {
const glyph = data.glyphs[ char ] || data.glyphs[ '?' ];
if ( ! glyph ) {
console.error( 'THREE.Font: character "' + char + '" does not exists in font family ' + data.familyName + '.' );
return;
}
const path = new ShapePath();
let x, y, cpx, cpy, cpx1, cpy1, cpx2, cpy2;
if ( glyph.o ) {
const outline = glyph._cachedOutline || ( glyph._cachedOutline = glyph.o.split( ' ' ) );
for ( let i = 0, l = outline.length; i < l; ) {
const action = outline[ i ++ ];
switch ( action ) {
case 'm': // moveTo
x = outline[ i ++ ] * scale + offsetX;
y = outline[ i ++ ] * scale + offsetY;
path.moveTo( x, y );
break;
case 'l': // lineTo
x = outline[ i ++ ] * scale + offsetX;
y = outline[ i ++ ] * scale + offsetY;
path.lineTo( x, y );
break;
case 'q': // quadraticCurveTo
cpx = outline[ i ++ ] * scale + offsetX;
cpy = outline[ i ++ ] * scale + offsetY;
cpx1 = outline[ i ++ ] * scale + offsetX;
cpy1 = outline[ i ++ ] * scale + offsetY;
path.quadraticCurveTo( cpx1, cpy1, cpx, cpy );
break;
case 'b': // bezierCurveTo
cpx = outline[ i ++ ] * scale + offsetX;
cpy = outline[ i ++ ] * scale + offsetY;
cpx1 = outline[ i ++ ] * scale + offsetX;
cpy1 = outline[ i ++ ] * scale + offsetY;
cpx2 = outline[ i ++ ] * scale + offsetX;
cpy2 = outline[ i ++ ] * scale + offsetY;
path.bezierCurveTo( cpx1, cpy1, cpx2, cpy2, cpx, cpy );
break;
}
}
}
return { offsetX: glyph.ha * scale, path: path };
}
export { FontLoader, Font };