bytev-charts-beta/lib/plugin/three.js/examples/js/modifiers/TessellateModifier.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;

console.warn("THREE.TessellateModifier: 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.");
/**
 * Break faces with edges longer than maxEdgeLength
 * - not recursive
 */

THREE.TessellateModifier = function (maxEdgeLength) {
  this.maxEdgeLength = maxEdgeLength;
};

THREE.TessellateModifier.prototype.modify = function (geometry) {
  var edge;
  var faces = [];
  var faceVertexUvs = [];
  var maxEdgeLengthSquared = this.maxEdgeLength * this.maxEdgeLength;

  for (var i = 0, il = geometry.faceVertexUvs.length; i < il; i++) {
    faceVertexUvs[i] = [];
  }

  for (var i = 0, il = geometry.faces.length; i < il; i++) {
    var face = geometry.faces[i];

    if (face instanceof THREE.Face3) {
      var a = face.a;
      var b = face.b;
      var c = face.c;
      var va = geometry.vertices[a];
      var vb = geometry.vertices[b];
      var vc = geometry.vertices[c];
      var dab = va.distanceToSquared(vb);
      var dbc = vb.distanceToSquared(vc);
      var dac = va.distanceToSquared(vc);

      if (dab > maxEdgeLengthSquared || dbc > maxEdgeLengthSquared || dac > maxEdgeLengthSquared) {
        var m = geometry.vertices.length;
        var triA = face.clone();
        var triB = face.clone();

        if (dab >= dbc && dab >= dac) {
          var vm = va.clone();
          vm.lerp(vb, 0.5);
          triA.a = a;
          triA.b = m;
          triA.c = c;
          triB.a = m;
          triB.b = b;
          triB.c = c;

          if (face.vertexNormals.length === 3) {
            var vnm = face.vertexNormals[0].clone();
            vnm.lerp(face.vertexNormals[1], 0.5);
            triA.vertexNormals[1].copy(vnm);
            triB.vertexNormals[0].copy(vnm);
          }

          if (face.vertexColors.length === 3) {
            var vcm = face.vertexColors[0].clone();
            vcm.lerp(face.vertexColors[1], 0.5);
            triA.vertexColors[1].copy(vcm);
            triB.vertexColors[0].copy(vcm);
          }

          edge = 0;
        } else if (dbc >= dab && dbc >= dac) {
          var vm = vb.clone();
          vm.lerp(vc, 0.5);
          triA.a = a;
          triA.b = b;
          triA.c = m;
          triB.a = m;
          triB.b = c;
          triB.c = a;

          if (face.vertexNormals.length === 3) {
            var vnm = face.vertexNormals[1].clone();
            vnm.lerp(face.vertexNormals[2], 0.5);
            triA.vertexNormals[2].copy(vnm);
            triB.vertexNormals[0].copy(vnm);
            triB.vertexNormals[1].copy(face.vertexNormals[2]);
            triB.vertexNormals[2].copy(face.vertexNormals[0]);
          }

          if (face.vertexColors.length === 3) {
            var vcm = face.vertexColors[1].clone();
            vcm.lerp(face.vertexColors[2], 0.5);
            triA.vertexColors[2].copy(vcm);
            triB.vertexColors[0].copy(vcm);
            triB.vertexColors[1].copy(face.vertexColors[2]);
            triB.vertexColors[2].copy(face.vertexColors[0]);
          }

          edge = 1;
        } else {
          var vm = va.clone();
          vm.lerp(vc, 0.5);
          triA.a = a;
          triA.b = b;
          triA.c = m;
          triB.a = m;
          triB.b = b;
          triB.c = c;

          if (face.vertexNormals.length === 3) {
            var vnm = face.vertexNormals[0].clone();
            vnm.lerp(face.vertexNormals[2], 0.5);
            triA.vertexNormals[2].copy(vnm);
            triB.vertexNormals[0].copy(vnm);
          }

          if (face.vertexColors.length === 3) {
            var vcm = face.vertexColors[0].clone();
            vcm.lerp(face.vertexColors[2], 0.5);
            triA.vertexColors[2].copy(vcm);
            triB.vertexColors[0].copy(vcm);
          }

          edge = 2;
        }

        faces.push(triA, triB);
        geometry.vertices.push(vm);

        for (var j = 0, jl = geometry.faceVertexUvs.length; j < jl; j++) {
          if (geometry.faceVertexUvs[j].length) {
            var uvs = geometry.faceVertexUvs[j][i];
            var uvA = uvs[0];
            var uvB = uvs[1];
            var uvC = uvs[2]; // AB

            if (edge === 0) {
              var uvM = uvA.clone();
              uvM.lerp(uvB, 0.5);
              var uvsTriA = [uvA.clone(), uvM.clone(), uvC.clone()];
              var uvsTriB = [uvM.clone(), uvB.clone(), uvC.clone()]; // BC
            } else if (edge === 1) {
              var uvM = uvB.clone();
              uvM.lerp(uvC, 0.5);
              var uvsTriA = [uvA.clone(), uvB.clone(), uvM.clone()];
              var uvsTriB = [uvM.clone(), uvC.clone(), uvA.clone()]; // AC
            } else {
              var uvM = uvA.clone();
              uvM.lerp(uvC, 0.5);
              var uvsTriA = [uvA.clone(), uvB.clone(), uvM.clone()];
              var uvsTriB = [uvM.clone(), uvB.clone(), uvC.clone()];
            }

            faceVertexUvs[j].push(uvsTriA, uvsTriB);
          }
        }
      } else {
        faces.push(face);

        for (var j = 0, jl = geometry.faceVertexUvs.length; j < jl; j++) {
          faceVertexUvs[j].push(geometry.faceVertexUvs[j][i]);
        }
      }
    }
  }

  geometry.faces = faces;
  geometry.faceVertexUvs = faceVertexUvs;
};