bytev-charts/lib/plugin/three.js/examples/js/misc/ConvexObjectBreaker.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.string.sub.js";
console.warn("THREE.ConvexObjectBreaker: 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.");
/**
 * @fileoverview This class can be used to subdivide a convex Geometry object into pieces.
 *
 * Usage:
 *
 * Use the function prepareBreakableObject to prepare a Mesh object to be broken.
 *
 * Then, call the various functions to subdivide the object (subdivideByImpact, cutByPlane)
 *
 * Sub-objects that are product of subdivision don't need prepareBreakableObject to be called on them.
 *
 * Requisites for the object:
 *
 *  - Mesh object must have a BufferGeometry (not Geometry) and a Material
 *
 *  - Vertex normals must be planar (not smoothed)
 *
 *  - The geometry must be convex (this is not checked in the library). You can create convex
 *  geometries with THREE.ConvexBufferGeometry. The BoxBufferGeometry, SphereBufferGeometry and other convex primitives
 *  can also be used.
 *
 * Note: This lib adds member variables to object's userData member (see prepareBreakableObject function)
 * Use with caution and read the code when using with other libs.
 *
 * @param {double} minSizeForBreak Min size a debris can have to break.
 * @param {double} smallDelta Max distance to consider that a point belongs to a plane.
 *
*/

THREE.ConvexObjectBreaker = function (minSizeForBreak, smallDelta) {
  this.minSizeForBreak = minSizeForBreak || 1.4;
  this.smallDelta = smallDelta || 0.0001;
  this.tempLine1 = new THREE.Line3();
  this.tempPlane1 = new THREE.Plane();
  this.tempPlane2 = new THREE.Plane();
  this.tempPlane_Cut = new THREE.Plane();
  this.tempCM1 = new THREE.Vector3();
  this.tempCM2 = new THREE.Vector3();
  this.tempVector3 = new THREE.Vector3();
  this.tempVector3_2 = new THREE.Vector3();
  this.tempVector3_3 = new THREE.Vector3();
  this.tempVector3_P0 = new THREE.Vector3();
  this.tempVector3_P1 = new THREE.Vector3();
  this.tempVector3_P2 = new THREE.Vector3();
  this.tempVector3_N0 = new THREE.Vector3();
  this.tempVector3_N1 = new THREE.Vector3();
  this.tempVector3_AB = new THREE.Vector3();
  this.tempVector3_CB = new THREE.Vector3();
  this.tempResultObjects = {
    object1: null,
    object2: null
  };
  this.segments = [];
  var n = 30 * 30;

  for (var i = 0; i < n; i++) {
    this.segments[i] = false;
  }
};

THREE.ConvexObjectBreaker.prototype = {
  constructor: THREE.ConvexObjectBreaker,
  prepareBreakableObject: function prepareBreakableObject(object, mass, velocity, angularVelocity, breakable) {
    // object is a THREE.Object3d (normally a Mesh), must have a BufferGeometry, and it must be convex.
    // Its material property is propagated to its children (sub-pieces)
    // mass must be > 0
    if (!object.geometry.isBufferGeometry) {
      console.error('THREE.ConvexObjectBreaker.prepareBreakableObject(): Parameter object must have a BufferGeometry.');
    }

    var userData = object.userData;
    userData.mass = mass;
    userData.velocity = velocity.clone();
    userData.angularVelocity = angularVelocity.clone();
    userData.breakable = breakable;
  },

  /*
   * @param {int} maxRadialIterations Iterations for radial cuts.
   * @param {int} maxRandomIterations Max random iterations for not-radial cuts
   *
   * Returns the array of pieces
   */
  subdivideByImpact: function subdivideByImpact(object, pointOfImpact, normal, maxRadialIterations, maxRandomIterations) {
    var debris = [];
    var tempPlane1 = this.tempPlane1;
    var tempPlane2 = this.tempPlane2;
    this.tempVector3.addVectors(pointOfImpact, normal);
    tempPlane1.setFromCoplanarPoints(pointOfImpact, object.position, this.tempVector3);
    var maxTotalIterations = maxRandomIterations + maxRadialIterations;
    var scope = this;

    function subdivideRadial(subObject, startAngle, endAngle, numIterations) {
      if (Math.random() < numIterations * 0.05 || numIterations > maxTotalIterations) {
        debris.push(subObject);
        return;
      }

      var angle = Math.PI;

      if (numIterations === 0) {
        tempPlane2.normal.copy(tempPlane1.normal);
        tempPlane2.constant = tempPlane1.constant;
      } else {
        if (numIterations <= maxRadialIterations) {
          angle = (endAngle - startAngle) * (0.2 + 0.6 * Math.random()) + startAngle; // Rotate tempPlane2 at impact point around normal axis and the angle

          scope.tempVector3_2.copy(object.position).sub(pointOfImpact).applyAxisAngle(normal, angle).add(pointOfImpact);
          tempPlane2.setFromCoplanarPoints(pointOfImpact, scope.tempVector3, scope.tempVector3_2);
        } else {
          angle = (0.5 * (numIterations & 1) + 0.2 * (2 - Math.random())) * Math.PI; // Rotate tempPlane2 at object position around normal axis and the angle

          scope.tempVector3_2.copy(pointOfImpact).sub(subObject.position).applyAxisAngle(normal, angle).add(subObject.position);
          scope.tempVector3_3.copy(normal).add(subObject.position);
          tempPlane2.setFromCoplanarPoints(subObject.position, scope.tempVector3_3, scope.tempVector3_2);
        }
      } // Perform the cut


      scope.cutByPlane(subObject, tempPlane2, scope.tempResultObjects);
      var obj1 = scope.tempResultObjects.object1;
      var obj2 = scope.tempResultObjects.object2;

      if (obj1) {
        subdivideRadial(obj1, startAngle, angle, numIterations + 1);
      }

      if (obj2) {
        subdivideRadial(obj2, angle, endAngle, numIterations + 1);
      }
    }

    subdivideRadial(object, 0, 2 * Math.PI, 0);
    return debris;
  },
  cutByPlane: function cutByPlane(object, plane, output) {
    // Returns breakable objects in output.object1 and output.object2 members, the resulting 2 pieces of the cut.
    // object2 can be null if the plane doesn't cut the object.
    // object1 can be null only in case of internal error
    // Returned value is number of pieces, 0 for error.
    var geometry = object.geometry;
    var coords = geometry.attributes.position.array;
    var normals = geometry.attributes.normal.array;
    var numPoints = coords.length / 3;
    var numFaces = numPoints / 3;
    var indices = geometry.getIndex();

    if (indices) {
      indices = indices.array;
      numFaces = indices.length / 3;
    }

    function getVertexIndex(faceIdx, vert) {
      // vert = 0, 1 or 2.
      var idx = faceIdx * 3 + vert;
      return indices ? indices[idx] : idx;
    }

    var points1 = [];
    var points2 = [];
    var delta = this.smallDelta; // Reset segments mark

    var numPointPairs = numPoints * numPoints;

    for (var i = 0; i < numPointPairs; i++) {
      this.segments[i] = false;
    }

    var p0 = this.tempVector3_P0;
    var p1 = this.tempVector3_P1;
    var n0 = this.tempVector3_N0;
    var n1 = this.tempVector3_N1; // Iterate through the faces to mark edges shared by coplanar faces

    for (var i = 0; i < numFaces - 1; i++) {
      var a1 = getVertexIndex(i, 0);
      var b1 = getVertexIndex(i, 1);
      var c1 = getVertexIndex(i, 2); // Assuming all 3 vertices have the same normal

      n0.set(normals[a1], normals[a1] + 1, normals[a1] + 2);

      for (var j = i + 1; j < numFaces; j++) {
        var a2 = getVertexIndex(j, 0);
        var b2 = getVertexIndex(j, 1);
        var c2 = getVertexIndex(j, 2); // Assuming all 3 vertices have the same normal

        n1.set(normals[a2], normals[a2] + 1, normals[a2] + 2);
        var coplanar = 1 - n0.dot(n1) < delta;

        if (coplanar) {
          if (a1 === a2 || a1 === b2 || a1 === c2) {
            if (b1 === a2 || b1 === b2 || b1 === c2) {
              this.segments[a1 * numPoints + b1] = true;
              this.segments[b1 * numPoints + a1] = true;
            } else {
              this.segments[c1 * numPoints + a1] = true;
              this.segments[a1 * numPoints + c1] = true;
            }
          } else if (b1 === a2 || b1 === b2 || b1 === c2) {
            this.segments[c1 * numPoints + b1] = true;
            this.segments[b1 * numPoints + c1] = true;
          }
        }
      }
    } // Transform the plane to object local space


    var localPlane = this.tempPlane_Cut;
    object.updateMatrix();
    THREE.ConvexObjectBreaker.transformPlaneToLocalSpace(plane, object.matrix, localPlane); // Iterate through the faces adding points to both pieces

    for (var i = 0; i < numFaces; i++) {
      var va = getVertexIndex(i, 0);
      var vb = getVertexIndex(i, 1);
      var vc = getVertexIndex(i, 2);

      for (var segment = 0; segment < 3; segment++) {
        var i0 = segment === 0 ? va : segment === 1 ? vb : vc;
        var i1 = segment === 0 ? vb : segment === 1 ? vc : va;
        var segmentState = this.segments[i0 * numPoints + i1];
        if (segmentState) continue; // The segment already has been processed in another face
        // Mark segment as processed (also inverted segment)

        this.segments[i0 * numPoints + i1] = true;
        this.segments[i1 * numPoints + i0] = true;
        p0.set(coords[3 * i0], coords[3 * i0 + 1], coords[3 * i0 + 2]);
        p1.set(coords[3 * i1], coords[3 * i1 + 1], coords[3 * i1 + 2]); // mark: 1 for negative side, 2 for positive side, 3 for coplanar point

        var mark0 = 0;
        var d = localPlane.distanceToPoint(p0);

        if (d > delta) {
          mark0 = 2;
          points2.push(p0.clone());
        } else if (d < -delta) {
          mark0 = 1;
          points1.push(p0.clone());
        } else {
          mark0 = 3;
          points1.push(p0.clone());
          points2.push(p0.clone());
        } // mark: 1 for negative side, 2 for positive side, 3 for coplanar point


        var mark1 = 0;
        var d = localPlane.distanceToPoint(p1);

        if (d > delta) {
          mark1 = 2;
          points2.push(p1.clone());
        } else if (d < -delta) {
          mark1 = 1;
          points1.push(p1.clone());
        } else {
          mark1 = 3;
          points1.push(p1.clone());
          points2.push(p1.clone());
        }

        if (mark0 === 1 && mark1 === 2 || mark0 === 2 && mark1 === 1) {
          // Intersection of segment with the plane
          this.tempLine1.start.copy(p0);
          this.tempLine1.end.copy(p1);
          var intersection = new THREE.Vector3();
          intersection = localPlane.intersectLine(this.tempLine1, intersection);

          if (intersection === undefined) {
            // Shouldn't happen
            console.error("Internal error: segment does not intersect plane.");
            output.segmentedObject1 = null;
            output.segmentedObject2 = null;
            return 0;
          }

          points1.push(intersection);
          points2.push(intersection.clone());
        }
      }
    } // Calculate debris mass (very fast and imprecise):


    var newMass = object.userData.mass * 0.5; // Calculate debris Center of Mass (again fast and imprecise)

    this.tempCM1.set(0, 0, 0);
    var radius1 = 0;
    var numPoints1 = points1.length;

    if (numPoints1 > 0) {
      for (var i = 0; i < numPoints1; i++) {
        this.tempCM1.add(points1[i]);
      }

      this.tempCM1.divideScalar(numPoints1);

      for (var i = 0; i < numPoints1; i++) {
        var p = points1[i];
        p.sub(this.tempCM1);
        radius1 = Math.max(radius1, p.x, p.y, p.z);
      }

      this.tempCM1.add(object.position);
    }

    this.tempCM2.set(0, 0, 0);
    var radius2 = 0;
    var numPoints2 = points2.length;

    if (numPoints2 > 0) {
      for (var i = 0; i < numPoints2; i++) {
        this.tempCM2.add(points2[i]);
      }

      this.tempCM2.divideScalar(numPoints2);

      for (var i = 0; i < numPoints2; i++) {
        var p = points2[i];
        p.sub(this.tempCM2);
        radius2 = Math.max(radius2, p.x, p.y, p.z);
      }

      this.tempCM2.add(object.position);
    }

    var object1 = null;
    var object2 = null;
    var numObjects = 0;

    if (numPoints1 > 4) {
      object1 = new THREE.Mesh(new THREE.ConvexBufferGeometry(points1), object.material);
      object1.position.copy(this.tempCM1);
      object1.quaternion.copy(object.quaternion);
      this.prepareBreakableObject(object1, newMass, object.userData.velocity, object.userData.angularVelocity, 2 * radius1 > this.minSizeForBreak);
      numObjects++;
    }

    if (numPoints2 > 4) {
      object2 = new THREE.Mesh(new THREE.ConvexBufferGeometry(points2), object.material);
      object2.position.copy(this.tempCM2);
      object2.quaternion.copy(object.quaternion);
      this.prepareBreakableObject(object2, newMass, object.userData.velocity, object.userData.angularVelocity, 2 * radius2 > this.minSizeForBreak);
      numObjects++;
    }

    output.object1 = object1;
    output.object2 = object2;
    return numObjects;
  }
};

THREE.ConvexObjectBreaker.transformFreeVector = function (v, m) {
  // input:
  // vector interpreted as a free vector
  // THREE.Matrix4 orthogonal matrix (matrix without scale)
  var x = v.x,
      y = v.y,
      z = v.z;
  var e = m.elements;
  v.x = e[0] * x + e[4] * y + e[8] * z;
  v.y = e[1] * x + e[5] * y + e[9] * z;
  v.z = e[2] * x + e[6] * y + e[10] * z;
  return v;
};

THREE.ConvexObjectBreaker.transformFreeVectorInverse = function (v, m) {
  // input:
  // vector interpreted as a free vector
  // THREE.Matrix4 orthogonal matrix (matrix without scale)
  var x = v.x,
      y = v.y,
      z = v.z;
  var e = m.elements;
  v.x = e[0] * x + e[1] * y + e[2] * z;
  v.y = e[4] * x + e[5] * y + e[6] * z;
  v.z = e[8] * x + e[9] * y + e[10] * z;
  return v;
};

THREE.ConvexObjectBreaker.transformTiedVectorInverse = function (v, m) {
  // input:
  // vector interpreted as a tied (ordinary) vector
  // THREE.Matrix4 orthogonal matrix (matrix without scale)
  var x = v.x,
      y = v.y,
      z = v.z;
  var e = m.elements;
  v.x = e[0] * x + e[1] * y + e[2] * z - e[12];
  v.y = e[4] * x + e[5] * y + e[6] * z - e[13];
  v.z = e[8] * x + e[9] * y + e[10] * z - e[14];
  return v;
};

THREE.ConvexObjectBreaker.transformPlaneToLocalSpace = function () {
  var v1 = new THREE.Vector3();
  return function transformPlaneToLocalSpace(plane, m, resultPlane) {
    resultPlane.normal.copy(plane.normal);
    resultPlane.constant = plane.constant;
    var referencePoint = THREE.ConvexObjectBreaker.transformTiedVectorInverse(plane.coplanarPoint(v1), m);
    THREE.ConvexObjectBreaker.transformFreeVectorInverse(resultPlane.normal, m); // recalculate constant (like in setFromNormalAndCoplanarPoint)

    resultPlane.constant = -referencePoint.dot(resultPlane.normal);
  };
}();