(function (global, factory) {
  if (typeof define === "function" && define.amd) {
    define(["exports", "three"], factory);
  } else if (typeof exports !== "undefined") {
    factory(exports, require("three"));
  } else {
    var mod = {
      exports: {}
    };
    factory(mod.exports, global.three);
    global.BufferGeometryUtils = mod.exports;
  }
})(typeof globalThis !== "undefined" ? globalThis : typeof self !== "undefined" ? self : this, function (_exports, _three) {
  "use strict";

  Object.defineProperty(_exports, "__esModule", {
    value: true
  });
  _exports.computeMorphedAttributes = computeMorphedAttributes;
  _exports.computeTangents = computeTangents;
  _exports.estimateBytesUsed = estimateBytesUsed;
  _exports.interleaveAttributes = interleaveAttributes;
  _exports.mergeBufferAttributes = mergeBufferAttributes;
  _exports.mergeBufferGeometries = mergeBufferGeometries;
  _exports.mergeVertices = mergeVertices;
  _exports.toTrianglesDrawMode = toTrianglesDrawMode;

  function computeTangents(geometry) {
    geometry.computeTangents();
    console.warn('THREE.BufferGeometryUtils: .computeTangents() has been removed. Use BufferGeometry.computeTangents() instead.');
  }
  /**
  	 * @param  {Array<BufferGeometry>} geometries
  	 * @param  {Boolean} useGroups
  	 * @return {BufferGeometry}
  	 */


  function mergeBufferGeometries(geometries) {
    var useGroups = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : false;
    var isIndexed = geometries[0].index !== null;
    var attributesUsed = new Set(Object.keys(geometries[0].attributes));
    var morphAttributesUsed = new Set(Object.keys(geometries[0].morphAttributes));
    var attributes = {};
    var morphAttributes = {};
    var morphTargetsRelative = geometries[0].morphTargetsRelative;
    var mergedGeometry = new _three.BufferGeometry();
    var offset = 0;

    for (var i = 0; i < geometries.length; ++i) {
      var geometry = geometries[i];
      var attributesCount = 0; // ensure that all geometries are indexed, or none

      if (isIndexed !== (geometry.index !== null)) {
        console.error('THREE.BufferGeometryUtils: .mergeBufferGeometries() failed with geometry at index ' + i + '. All geometries must have compatible attributes; make sure index attribute exists among all geometries, or in none of them.');
        return null;
      } // gather attributes, exit early if they're different


      for (var name in geometry.attributes) {
        if (!attributesUsed.has(name)) {
          console.error('THREE.BufferGeometryUtils: .mergeBufferGeometries() failed with geometry at index ' + i + '. All geometries must have compatible attributes; make sure "' + name + '" attribute exists among all geometries, or in none of them.');
          return null;
        }

        if (attributes[name] === undefined) attributes[name] = [];
        attributes[name].push(geometry.attributes[name]);
        attributesCount++;
      } // ensure geometries have the same number of attributes


      if (attributesCount !== attributesUsed.size) {
        console.error('THREE.BufferGeometryUtils: .mergeBufferGeometries() failed with geometry at index ' + i + '. Make sure all geometries have the same number of attributes.');
        return null;
      } // gather morph attributes, exit early if they're different


      if (morphTargetsRelative !== geometry.morphTargetsRelative) {
        console.error('THREE.BufferGeometryUtils: .mergeBufferGeometries() failed with geometry at index ' + i + '. .morphTargetsRelative must be consistent throughout all geometries.');
        return null;
      }

      for (var _name in geometry.morphAttributes) {
        if (!morphAttributesUsed.has(_name)) {
          console.error('THREE.BufferGeometryUtils: .mergeBufferGeometries() failed with geometry at index ' + i + '.  .morphAttributes must be consistent throughout all geometries.');
          return null;
        }

        if (morphAttributes[_name] === undefined) morphAttributes[_name] = [];

        morphAttributes[_name].push(geometry.morphAttributes[_name]);
      } // gather .userData


      mergedGeometry.userData.mergedUserData = mergedGeometry.userData.mergedUserData || [];
      mergedGeometry.userData.mergedUserData.push(geometry.userData);

      if (useGroups) {
        var count = void 0;

        if (isIndexed) {
          count = geometry.index.count;
        } else if (geometry.attributes.position !== undefined) {
          count = geometry.attributes.position.count;
        } else {
          console.error('THREE.BufferGeometryUtils: .mergeBufferGeometries() failed with geometry at index ' + i + '. The geometry must have either an index or a position attribute');
          return null;
        }

        mergedGeometry.addGroup(offset, count, i);
        offset += count;
      }
    } // merge indices


    if (isIndexed) {
      var indexOffset = 0;
      var mergedIndex = [];

      for (var _i = 0; _i < geometries.length; ++_i) {
        var index = geometries[_i].index;

        for (var j = 0; j < index.count; ++j) {
          mergedIndex.push(index.getX(j) + indexOffset);
        }

        indexOffset += geometries[_i].attributes.position.count;
      }

      mergedGeometry.setIndex(mergedIndex);
    } // merge attributes


    for (var _name2 in attributes) {
      var mergedAttribute = mergeBufferAttributes(attributes[_name2]);

      if (!mergedAttribute) {
        console.error('THREE.BufferGeometryUtils: .mergeBufferGeometries() failed while trying to merge the ' + _name2 + ' attribute.');
        return null;
      }

      mergedGeometry.setAttribute(_name2, mergedAttribute);
    } // merge morph attributes


    for (var _name3 in morphAttributes) {
      var numMorphTargets = morphAttributes[_name3][0].length;
      if (numMorphTargets === 0) break;
      mergedGeometry.morphAttributes = mergedGeometry.morphAttributes || {};
      mergedGeometry.morphAttributes[_name3] = [];

      for (var _i2 = 0; _i2 < numMorphTargets; ++_i2) {
        var morphAttributesToMerge = [];

        for (var _j = 0; _j < morphAttributes[_name3].length; ++_j) {
          morphAttributesToMerge.push(morphAttributes[_name3][_j][_i2]);
        }

        var mergedMorphAttribute = mergeBufferAttributes(morphAttributesToMerge);

        if (!mergedMorphAttribute) {
          console.error('THREE.BufferGeometryUtils: .mergeBufferGeometries() failed while trying to merge the ' + _name3 + ' morphAttribute.');
          return null;
        }

        mergedGeometry.morphAttributes[_name3].push(mergedMorphAttribute);
      }
    }

    return mergedGeometry;
  }
  /**
   * @param {Array<BufferAttribute>} attributes
   * @return {BufferAttribute}
   */


  function mergeBufferAttributes(attributes) {
    var TypedArray;
    var itemSize;
    var normalized;
    var arrayLength = 0;

    for (var i = 0; i < attributes.length; ++i) {
      var attribute = attributes[i];

      if (attribute.isInterleavedBufferAttribute) {
        console.error('THREE.BufferGeometryUtils: .mergeBufferAttributes() failed. InterleavedBufferAttributes are not supported.');
        return null;
      }

      if (TypedArray === undefined) TypedArray = attribute.array.constructor;

      if (TypedArray !== attribute.array.constructor) {
        console.error('THREE.BufferGeometryUtils: .mergeBufferAttributes() failed. BufferAttribute.array must be of consistent array types across matching attributes.');
        return null;
      }

      if (itemSize === undefined) itemSize = attribute.itemSize;

      if (itemSize !== attribute.itemSize) {
        console.error('THREE.BufferGeometryUtils: .mergeBufferAttributes() failed. BufferAttribute.itemSize must be consistent across matching attributes.');
        return null;
      }

      if (normalized === undefined) normalized = attribute.normalized;

      if (normalized !== attribute.normalized) {
        console.error('THREE.BufferGeometryUtils: .mergeBufferAttributes() failed. BufferAttribute.normalized must be consistent across matching attributes.');
        return null;
      }

      arrayLength += attribute.array.length;
    }

    var array = new TypedArray(arrayLength);
    var offset = 0;

    for (var _i3 = 0; _i3 < attributes.length; ++_i3) {
      array.set(attributes[_i3].array, offset);
      offset += attributes[_i3].array.length;
    }

    return new _three.BufferAttribute(array, itemSize, normalized);
  }
  /**
   * @param {Array<BufferAttribute>} attributes
   * @return {Array<InterleavedBufferAttribute>}
   */


  function interleaveAttributes(attributes) {
    // Interleaves the provided attributes into an InterleavedBuffer and returns
    // a set of InterleavedBufferAttributes for each attribute
    var TypedArray;
    var arrayLength = 0;
    var stride = 0; // calculate the the length and type of the interleavedBuffer

    for (var i = 0, l = attributes.length; i < l; ++i) {
      var attribute = attributes[i];
      if (TypedArray === undefined) TypedArray = attribute.array.constructor;

      if (TypedArray !== attribute.array.constructor) {
        console.error('AttributeBuffers of different types cannot be interleaved');
        return null;
      }

      arrayLength += attribute.array.length;
      stride += attribute.itemSize;
    } // Create the set of buffer attributes


    var interleavedBuffer = new _three.InterleavedBuffer(new TypedArray(arrayLength), stride);
    var offset = 0;
    var res = [];
    var getters = ['getX', 'getY', 'getZ', 'getW'];
    var setters = ['setX', 'setY', 'setZ', 'setW'];

    for (var j = 0, _l = attributes.length; j < _l; j++) {
      var _attribute = attributes[j];
      var itemSize = _attribute.itemSize;
      var count = _attribute.count;
      var iba = new _three.InterleavedBufferAttribute(interleavedBuffer, itemSize, offset, _attribute.normalized);
      res.push(iba);
      offset += itemSize; // Move the data for each attribute into the new interleavedBuffer
      // at the appropriate offset

      for (var c = 0; c < count; c++) {
        for (var k = 0; k < itemSize; k++) {
          iba[setters[k]](c, _attribute[getters[k]](c));
        }
      }
    }

    return res;
  }
  /**
   * @param {Array<BufferGeometry>} geometry
   * @return {number}
   */


  function estimateBytesUsed(geometry) {
    // Return the estimated memory used by this geometry in bytes
    // Calculate using itemSize, count, and BYTES_PER_ELEMENT to account
    // for InterleavedBufferAttributes.
    var mem = 0;

    for (var name in geometry.attributes) {
      var attr = geometry.getAttribute(name);
      mem += attr.count * attr.itemSize * attr.array.BYTES_PER_ELEMENT;
    }

    var indices = geometry.getIndex();
    mem += indices ? indices.count * indices.itemSize * indices.array.BYTES_PER_ELEMENT : 0;
    return mem;
  }
  /**
   * @param {BufferGeometry} geometry
   * @param {number} tolerance
   * @return {BufferGeometry>}
   */


  function mergeVertices(geometry) {
    var tolerance = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : 1e-4;
    tolerance = Math.max(tolerance, Number.EPSILON); // Generate an index buffer if the geometry doesn't have one, or optimize it
    // if it's already available.

    var hashToIndex = {};
    var indices = geometry.getIndex();
    var positions = geometry.getAttribute('position');
    var vertexCount = indices ? indices.count : positions.count; // next value for triangle indices

    var nextIndex = 0; // attributes and new attribute arrays

    var attributeNames = Object.keys(geometry.attributes);
    var attrArrays = {};
    var morphAttrsArrays = {};
    var newIndices = [];
    var getters = ['getX', 'getY', 'getZ', 'getW']; // initialize the arrays

    for (var i = 0, l = attributeNames.length; i < l; i++) {
      var name = attributeNames[i];
      attrArrays[name] = [];
      var morphAttr = geometry.morphAttributes[name];

      if (morphAttr) {
        morphAttrsArrays[name] = new Array(morphAttr.length).fill().map(function () {
          return [];
        });
      }
    } // convert the error tolerance to an amount of decimal places to truncate to


    var decimalShift = Math.log10(1 / tolerance);
    var shiftMultiplier = Math.pow(10, decimalShift);

    for (var _i4 = 0; _i4 < vertexCount; _i4++) {
      var index = indices ? indices.getX(_i4) : _i4; // Generate a hash for the vertex attributes at the current index 'i'

      var hash = '';

      for (var j = 0, _l2 = attributeNames.length; j < _l2; j++) {
        var _name4 = attributeNames[j];
        var attribute = geometry.getAttribute(_name4);
        var itemSize = attribute.itemSize;

        for (var k = 0; k < itemSize; k++) {
          // double tilde truncates the decimal value
          hash += "".concat(~~(attribute[getters[k]](index) * shiftMultiplier), ",");
        }
      } // Add another reference to the vertex if it's already
      // used by another index


      if (hash in hashToIndex) {
        newIndices.push(hashToIndex[hash]);
      } else {
        // copy data to the new index in the attribute arrays
        for (var _j2 = 0, _l3 = attributeNames.length; _j2 < _l3; _j2++) {
          var _name5 = attributeNames[_j2];

          var _attribute2 = geometry.getAttribute(_name5);

          var _morphAttr = geometry.morphAttributes[_name5];
          var _itemSize = _attribute2.itemSize;
          var newarray = attrArrays[_name5];
          var newMorphArrays = morphAttrsArrays[_name5];

          for (var _k = 0; _k < _itemSize; _k++) {
            var getterFunc = getters[_k];
            newarray.push(_attribute2[getterFunc](index));

            if (_morphAttr) {
              for (var m = 0, ml = _morphAttr.length; m < ml; m++) {
                newMorphArrays[m].push(_morphAttr[m][getterFunc](index));
              }
            }
          }
        }

        hashToIndex[hash] = nextIndex;
        newIndices.push(nextIndex);
        nextIndex++;
      }
    } // Generate typed arrays from new attribute arrays and update
    // the attributeBuffers


    var result = geometry.clone();

    for (var _i5 = 0, _l4 = attributeNames.length; _i5 < _l4; _i5++) {
      var _name6 = attributeNames[_i5];
      var oldAttribute = geometry.getAttribute(_name6);
      var buffer = new oldAttribute.array.constructor(attrArrays[_name6]);

      var _attribute3 = new _three.BufferAttribute(buffer, oldAttribute.itemSize, oldAttribute.normalized);

      result.setAttribute(_name6, _attribute3); // Update the attribute arrays

      if (_name6 in morphAttrsArrays) {
        for (var _j3 = 0; _j3 < morphAttrsArrays[_name6].length; _j3++) {
          var oldMorphAttribute = geometry.morphAttributes[_name6][_j3];

          var _buffer = new oldMorphAttribute.array.constructor(morphAttrsArrays[_name6][_j3]);

          var morphAttribute = new _three.BufferAttribute(_buffer, oldMorphAttribute.itemSize, oldMorphAttribute.normalized);
          result.morphAttributes[_name6][_j3] = morphAttribute;
        }
      }
    } // indices


    result.setIndex(newIndices);
    return result;
  }
  /**
   * @param {BufferGeometry} geometry
   * @param {number} drawMode
   * @return {BufferGeometry>}
   */


  function toTrianglesDrawMode(geometry, drawMode) {
    if (drawMode === _three.TrianglesDrawMode) {
      console.warn('THREE.BufferGeometryUtils.toTrianglesDrawMode(): Geometry already defined as triangles.');
      return geometry;
    }

    if (drawMode === _three.TriangleFanDrawMode || drawMode === _three.TriangleStripDrawMode) {
      var index = geometry.getIndex(); // generate index if not present

      if (index === null) {
        var indices = [];
        var position = geometry.getAttribute('position');

        if (position !== undefined) {
          for (var i = 0; i < position.count; i++) {
            indices.push(i);
          }

          geometry.setIndex(indices);
          index = geometry.getIndex();
        } else {
          console.error('THREE.BufferGeometryUtils.toTrianglesDrawMode(): Undefined position attribute. Processing not possible.');
          return geometry;
        }
      } //


      var numberOfTriangles = index.count - 2;
      var newIndices = [];

      if (drawMode === _three.TriangleFanDrawMode) {
        // gl.TRIANGLE_FAN
        for (var _i6 = 1; _i6 <= numberOfTriangles; _i6++) {
          newIndices.push(index.getX(0));
          newIndices.push(index.getX(_i6));
          newIndices.push(index.getX(_i6 + 1));
        }
      } else {
        // gl.TRIANGLE_STRIP
        for (var _i7 = 0; _i7 < numberOfTriangles; _i7++) {
          if (_i7 % 2 === 0) {
            newIndices.push(index.getX(_i7));
            newIndices.push(index.getX(_i7 + 1));
            newIndices.push(index.getX(_i7 + 2));
          } else {
            newIndices.push(index.getX(_i7 + 2));
            newIndices.push(index.getX(_i7 + 1));
            newIndices.push(index.getX(_i7));
          }
        }
      }

      if (newIndices.length / 3 !== numberOfTriangles) {
        console.error('THREE.BufferGeometryUtils.toTrianglesDrawMode(): Unable to generate correct amount of triangles.');
      } // build final geometry


      var newGeometry = geometry.clone();
      newGeometry.setIndex(newIndices);
      newGeometry.clearGroups();
      return newGeometry;
    } else {
      console.error('THREE.BufferGeometryUtils.toTrianglesDrawMode(): Unknown draw mode:', drawMode);
      return geometry;
    }
  }
  /**
   * Calculates the morphed attributes of a morphed/skinned BufferGeometry.
   * Helpful for Raytracing or Decals.
   * @param {Mesh | Line | Points} object An instance of Mesh, Line or Points.
   * @return {Object} An Object with original position/normal attributes and morphed ones.
   */


  function computeMorphedAttributes(object) {
    if (object.geometry.isBufferGeometry !== true) {
      console.error('THREE.BufferGeometryUtils: Geometry is not of type BufferGeometry.');
      return null;
    }

    var _vA = new _three.Vector3();

    var _vB = new _three.Vector3();

    var _vC = new _three.Vector3();

    var _tempA = new _three.Vector3();

    var _tempB = new _three.Vector3();

    var _tempC = new _three.Vector3();

    var _morphA = new _three.Vector3();

    var _morphB = new _three.Vector3();

    var _morphC = new _three.Vector3();

    function _calculateMorphedAttributeData(object, material, attribute, morphAttribute, morphTargetsRelative, a, b, c, modifiedAttributeArray) {
      _vA.fromBufferAttribute(attribute, a);

      _vB.fromBufferAttribute(attribute, b);

      _vC.fromBufferAttribute(attribute, c);

      var morphInfluences = object.morphTargetInfluences;

      if (material.morphTargets && morphAttribute && morphInfluences) {
        _morphA.set(0, 0, 0);

        _morphB.set(0, 0, 0);

        _morphC.set(0, 0, 0);

        for (var _i8 = 0, _il = morphAttribute.length; _i8 < _il; _i8++) {
          var influence = morphInfluences[_i8];
          var morph = morphAttribute[_i8];
          if (influence === 0) continue;

          _tempA.fromBufferAttribute(morph, a);

          _tempB.fromBufferAttribute(morph, b);

          _tempC.fromBufferAttribute(morph, c);

          if (morphTargetsRelative) {
            _morphA.addScaledVector(_tempA, influence);

            _morphB.addScaledVector(_tempB, influence);

            _morphC.addScaledVector(_tempC, influence);
          } else {
            _morphA.addScaledVector(_tempA.sub(_vA), influence);

            _morphB.addScaledVector(_tempB.sub(_vB), influence);

            _morphC.addScaledVector(_tempC.sub(_vC), influence);
          }
        }

        _vA.add(_morphA);

        _vB.add(_morphB);

        _vC.add(_morphC);
      }

      if (object.isSkinnedMesh) {
        object.boneTransform(a, _vA);
        object.boneTransform(b, _vB);
        object.boneTransform(c, _vC);
      }

      modifiedAttributeArray[a * 3 + 0] = _vA.x;
      modifiedAttributeArray[a * 3 + 1] = _vA.y;
      modifiedAttributeArray[a * 3 + 2] = _vA.z;
      modifiedAttributeArray[b * 3 + 0] = _vB.x;
      modifiedAttributeArray[b * 3 + 1] = _vB.y;
      modifiedAttributeArray[b * 3 + 2] = _vB.z;
      modifiedAttributeArray[c * 3 + 0] = _vC.x;
      modifiedAttributeArray[c * 3 + 1] = _vC.y;
      modifiedAttributeArray[c * 3 + 2] = _vC.z;
    }

    var geometry = object.geometry;
    var material = object.material;
    var a, b, c;
    var index = geometry.index;
    var positionAttribute = geometry.attributes.position;
    var morphPosition = geometry.morphAttributes.position;
    var morphTargetsRelative = geometry.morphTargetsRelative;
    var normalAttribute = geometry.attributes.normal;
    var morphNormal = geometry.morphAttributes.position;
    var groups = geometry.groups;
    var drawRange = geometry.drawRange;
    var i, j, il, jl;
    var group, groupMaterial;
    var start, end;
    var modifiedPosition = new Float32Array(positionAttribute.count * positionAttribute.itemSize);
    var modifiedNormal = new Float32Array(normalAttribute.count * normalAttribute.itemSize);

    if (index !== null) {
      // indexed buffer geometry
      if (Array.isArray(material)) {
        for (i = 0, il = groups.length; i < il; i++) {
          group = groups[i];
          groupMaterial = material[group.materialIndex];
          start = Math.max(group.start, drawRange.start);
          end = Math.min(group.start + group.count, drawRange.start + drawRange.count);

          for (j = start, jl = end; j < jl; j += 3) {
            a = index.getX(j);
            b = index.getX(j + 1);
            c = index.getX(j + 2);

            _calculateMorphedAttributeData(object, groupMaterial, positionAttribute, morphPosition, morphTargetsRelative, a, b, c, modifiedPosition);

            _calculateMorphedAttributeData(object, groupMaterial, normalAttribute, morphNormal, morphTargetsRelative, a, b, c, modifiedNormal);
          }
        }
      } else {
        start = Math.max(0, drawRange.start);
        end = Math.min(index.count, drawRange.start + drawRange.count);

        for (i = start, il = end; i < il; i += 3) {
          a = index.getX(i);
          b = index.getX(i + 1);
          c = index.getX(i + 2);

          _calculateMorphedAttributeData(object, material, positionAttribute, morphPosition, morphTargetsRelative, a, b, c, modifiedPosition);

          _calculateMorphedAttributeData(object, material, normalAttribute, morphNormal, morphTargetsRelative, a, b, c, modifiedNormal);
        }
      }
    } else if (positionAttribute !== undefined) {
      // non-indexed buffer geometry
      if (Array.isArray(material)) {
        for (i = 0, il = groups.length; i < il; i++) {
          group = groups[i];
          groupMaterial = material[group.materialIndex];
          start = Math.max(group.start, drawRange.start);
          end = Math.min(group.start + group.count, drawRange.start + drawRange.count);

          for (j = start, jl = end; j < jl; j += 3) {
            a = j;
            b = j + 1;
            c = j + 2;

            _calculateMorphedAttributeData(object, groupMaterial, positionAttribute, morphPosition, morphTargetsRelative, a, b, c, modifiedPosition);

            _calculateMorphedAttributeData(object, groupMaterial, normalAttribute, morphNormal, morphTargetsRelative, a, b, c, modifiedNormal);
          }
        }
      } else {
        start = Math.max(0, drawRange.start);
        end = Math.min(positionAttribute.count, drawRange.start + drawRange.count);

        for (i = start, il = end; i < il; i += 3) {
          a = i;
          b = i + 1;
          c = i + 2;

          _calculateMorphedAttributeData(object, material, positionAttribute, morphPosition, morphTargetsRelative, a, b, c, modifiedPosition);

          _calculateMorphedAttributeData(object, material, normalAttribute, morphNormal, morphTargetsRelative, a, b, c, modifiedNormal);
        }
      }
    }

    var morphedPositionAttribute = new _three.Float32BufferAttribute(modifiedPosition, 3);
    var morphedNormalAttribute = new _three.Float32BufferAttribute(modifiedNormal, 3);
    return {
      positionAttribute: positionAttribute,
      normalAttribute: normalAttribute,
      morphedPositionAttribute: morphedPositionAttribute,
      morphedNormalAttribute: morphedNormalAttribute
    };
  }
});