bytev-charts/lib/plugin/three.js/examples/js/loaders/TTFLoader.js

基于echarts和JavaScript及ES6封装的一个可以直接调用的图表组件库，内置主题设计，简单快捷，且支持用户自定义配置； npm 安装方式: npm install bytev-charts 若启动提示还需额外install插件,则运行 npm install @babel/runtime-corejs2 即可;

import "core-js/modules/es.array.for-each.js";
import "core-js/modules/es.object.to-string.js";
import "core-js/modules/web.dom-collections.for-each.js";
import "core-js/modules/es.function.name.js";
import _Object$assign from "@babel/runtime-corejs2/core-js/object/assign";
import _Object$create from "@babel/runtime-corejs2/core-js/object/create";
import _Object$keys from "@babel/runtime-corejs2/core-js/object/keys";
import _String$fromCodePoint from "@babel/runtime-corejs2/core-js/string/from-code-point";
console.warn("THREE.TTFLoader: As part of the transition to ES6 Modules, the files in 'examples/js' were deprecated in May 2020 (r117) and will be deleted in December 2020 (r124). You can find more information about developing using ES6 Modules in https://threejs.org/docs/#manual/en/introduction/Installation.");
/**
 * Requires opentype.js to be included in the project.
 * Loads TTF files and converts them into typeface JSON that can be used directly
 * to create THREE.Font objects.
 */

THREE.TTFLoader = function (manager) {
  THREE.Loader.call(this, manager);
  this.reversed = false;
};

THREE.TTFLoader.prototype = _Object$assign(_Object$create(THREE.Loader.prototype), {
  constructor: THREE.TTFLoader,
  load: function load(url, onLoad, onProgress, onError) {
    var scope = this;
    var loader = new THREE.FileLoader(this.manager);
    loader.setPath(this.path);
    loader.setResponseType('arraybuffer');
    loader.setRequestHeader(this.requestHeader);
    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);
  },
  parse: function parse(arraybuffer) {
    function convert(font, reversed) {
      var round = Math.round;
      var glyphs = {};
      var scale = 100000 / ((font.unitsPerEm || 2048) * 72);
      var glyphIndexMap = font.encoding.cmap.glyphIndexMap;

      var unicodes = _Object$keys(glyphIndexMap);

      for (var i = 0; i < unicodes.length; i++) {
        var unicode = unicodes[i];
        var glyph = font.glyphs.glyphs[glyphIndexMap[unicode]];

        if (unicode !== undefined) {
          var 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) {
      var paths = [];
      var path;
      commands.forEach(function (c) {
        if (c.type.toLowerCase() === 'm') {
          path = [c];
          paths.push(path);
        } else if (c.type.toLowerCase() !== 'z') {
          path.push(c);
        }
      });
      var reversed = [];
      paths.forEach(function (p) {
        var result = {
          type: 'm',
          x: p[p.length - 1].x,
          y: p[p.length - 1].y
        };
        reversed.push(result);

        for (var i = p.length - 1; i > 0; i--) {
          var command = p[i];
          var 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;
    }

    if (typeof opentype === 'undefined') {
      console.warn('THREE.TTFLoader: The loader requires opentype.js. Make sure it\'s included before using the loader.');
      return null;
    }

    return convert(opentype.parse(arraybuffer), this.reversed);
  }
});