bytev-charts/lib/plugin/three.js/examples/js/renderers/CSS2DRenderer.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.sort.js";
import _Object$assign from "@babel/runtime-corejs2/core-js/object/assign";
import _Object$create from "@babel/runtime-corejs2/core-js/object/create";
import _WeakMap from "@babel/runtime-corejs2/core-js/weak-map";
console.warn("THREE.CSS2DRenderer: 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.");

THREE.CSS2DObject = function (element) {
  THREE.Object3D.call(this);
  this.element = element || document.createElement('div');
  this.element.style.position = 'absolute';
  this.addEventListener('removed', function () {
    this.traverse(function (object) {
      if (object.element instanceof Element && object.element.parentNode !== null) {
        object.element.parentNode.removeChild(object.element);
      }
    });
  });
};

THREE.CSS2DObject.prototype = _Object$assign(_Object$create(THREE.Object3D.prototype), {
  constructor: THREE.CSS2DObject,
  copy: function copy(source, recursive) {
    THREE.Object3D.prototype.copy.call(this, source, recursive);
    this.element = source.element.cloneNode(true);
    return this;
  }
}); //

THREE.CSS2DRenderer = function () {
  var _this = this;

  var _width, _height;

  var _widthHalf, _heightHalf;

  var vector = new THREE.Vector3();
  var viewMatrix = new THREE.Matrix4();
  var viewProjectionMatrix = new THREE.Matrix4();
  var cache = {
    objects: new _WeakMap()
  };
  var domElement = document.createElement('div');
  domElement.style.overflow = 'hidden';
  this.domElement = domElement;

  this.getSize = function () {
    return {
      width: _width,
      height: _height
    };
  };

  this.setSize = function (width, height) {
    _width = width;
    _height = height;
    _widthHalf = _width / 2;
    _heightHalf = _height / 2;
    domElement.style.width = width + 'px';
    domElement.style.height = height + 'px';
  };

  var renderObject = function renderObject(object, scene, camera) {
    if (object instanceof THREE.CSS2DObject) {
      object.onBeforeRender(_this, scene, camera);
      vector.setFromMatrixPosition(object.matrixWorld);
      vector.applyMatrix4(viewProjectionMatrix);
      var element = object.element;
      var style = 'translate(-50%,-50%) translate(' + (vector.x * _widthHalf + _widthHalf) + 'px,' + (-vector.y * _heightHalf + _heightHalf) + 'px)';
      element.style.WebkitTransform = style;
      element.style.MozTransform = style;
      element.style.oTransform = style;
      element.style.transform = style;
      element.style.display = object.visible && vector.z >= -1 && vector.z <= 1 ? '' : 'none';
      var objectData = {
        distanceToCameraSquared: getDistanceToSquared(camera, object)
      };
      cache.objects.set(object, objectData);

      if (element.parentNode !== domElement) {
        domElement.appendChild(element);
      }

      object.onAfterRender(_this, scene, camera);
    }

    for (var i = 0, l = object.children.length; i < l; i++) {
      renderObject(object.children[i], scene, camera);
    }
  };

  var getDistanceToSquared = function () {
    var a = new THREE.Vector3();
    var b = new THREE.Vector3();
    return function (object1, object2) {
      a.setFromMatrixPosition(object1.matrixWorld);
      b.setFromMatrixPosition(object2.matrixWorld);
      return a.distanceToSquared(b);
    };
  }();

  var filterAndFlatten = function filterAndFlatten(scene) {
    var result = [];
    scene.traverse(function (object) {
      if (object instanceof THREE.CSS2DObject) result.push(object);
    });
    return result;
  };

  var zOrder = function zOrder(scene) {
    var sorted = filterAndFlatten(scene).sort(function (a, b) {
      var distanceA = cache.objects.get(a).distanceToCameraSquared;
      var distanceB = cache.objects.get(b).distanceToCameraSquared;
      return distanceA - distanceB;
    });
    var zMax = sorted.length;

    for (var i = 0, l = sorted.length; i < l; i++) {
      sorted[i].element.style.zIndex = zMax - i;
    }
  };

  this.render = function (scene, camera) {
    if (scene.autoUpdate === true) scene.updateMatrixWorld();
    if (camera.parent === null) camera.updateMatrixWorld();
    viewMatrix.copy(camera.matrixWorldInverse);
    viewProjectionMatrix.multiplyMatrices(camera.projectionMatrix, viewMatrix);
    renderObject(scene, scene, camera);
    zOrder(scene);
  };
};