text: /**
   * @author sunag / http://www.sunag.com.br
   */
  
  import {
  	AnimationClip,
  	AnimationMixer,
  	Euler,
  	Matrix4,
  	Quaternion,
  	QuaternionKeyframeTrack,
  	SkeletonHelper,
  	Vector2,
  	Vector3,
  	VectorKeyframeTrack
  } from "../../../build/three.module.js";
  
  'use strict';
  
  var SkeletonUtils = {
  
  	retarget: function () {
  
  		var pos = new Vector3(),
  			quat = new Quaternion(),
  			scale = new Vector3(),
  			bindBoneMatrix = new Matrix4(),
  			relativeMatrix = new Matrix4(),
  			globalMatrix = new Matrix4();
  
  		return function ( target, source, options ) {
  
  			options = options || {};
  			options.preserveMatrix = options.preserveMatrix !== undefined ? options.preserveMatrix : true;
  			options.preservePosition = options.preservePosition !== undefined ? options.preservePosition : true;
  			options.preserveHipPosition = options.preserveHipPosition !== undefined ? options.preserveHipPosition : false;
  			options.useTargetMatrix = options.useTargetMatrix !== undefined ? options.useTargetMatrix : false;
  			options.hip = options.hip !== undefined ? options.hip : "hip";
  			options.names = options.names || {};
  
  			var sourceBones = source.isObject3D ? source.skeleton.bones : this.getBones( source ),
  				bones = target.isObject3D ? target.skeleton.bones : this.getBones( target ),
  				bindBones,
  				bone, name, boneTo,
  				bonesPosition, i;
  
  			// reset bones
  
  			if ( target.isObject3D ) {
  
  				target.skeleton.pose();
  
  			} else {
  
  				options.useTargetMatrix = true;
  				options.preserveMatrix = false;
  
  			}
  
  			if ( options.preservePosition ) {
  
  				bonesPosition = [];
  
  				for ( i = 0; i < bones.length; i ++ ) {
  
  					bonesPosition.push( bones[ i ].position.clone() );
  
  				}
  
  			}
  
  			if ( options.preserveMatrix ) {
  
  				// reset matrix
  
  				target.updateMatrixWorld();
  
  				target.matrixWorld.identity();
  
  				// reset children matrix
  
  				for ( i = 0; i < target.children.length; ++ i ) {
  
  					target.children[ i ].updateMatrixWorld( true );
  
  				}
  
  			}
  
  			if ( options.offsets ) {
  
  				bindBones = [];
  
  				for ( i = 0; i < bones.length; ++ i ) {
  
  					bone = bones[ i ];
  					name = options.names[ bone.name ] || bone.name;
  
  					if ( options.offsets && options.offsets[ name ] ) {
  
  						bone.matrix.multiply( options.offsets[ name ] );
  
  						bone.matrix.decompose( bone.position, bone.quaternion, bone.scale );
  
  						bone.updateMatrixWorld();
  
  					}
  
  					bindBones.push( bone.matrixWorld.clone() );
  
  				}
  
  			}
  
  			for ( i = 0; i < bones.length; ++ i ) {
  
  				bone = bones[ i ];
  				name = options.names[ bone.name ] || bone.name;
  
  				boneTo = this.getBoneByName( name, sourceBones );
  
  				globalMatrix.copy( bone.matrixWorld );
  
  				if ( boneTo ) {
  
  					boneTo.updateMatrixWorld();
  
  					if ( options.useTargetMatrix ) {
  
  						relativeMatrix.copy( boneTo.matrixWorld );
  
  					} else {
  
  						relativeMatrix.getInverse( target.matrixWorld );
  						relativeMatrix.multiply( boneTo.matrixWorld );
  
  					}
  
  					// ignore scale to extract rotation
  
  					scale.setFromMatrixScale( relativeMatrix );
  					relativeMatrix.scale( scale.set( 1 / scale.x, 1 / scale.y, 1 / scale.z ) );
  
  					// apply to global matrix
  
  					globalMatrix.makeRotationFromQuaternion( quat.setFromRotationMatrix( relativeMatrix ) );
  
  					if ( target.isObject3D ) {
  
  						var boneIndex = bones.indexOf( bone ),
  							wBindMatrix = bindBones ? bindBones[ boneIndex ] : bindBoneMatrix.getInverse( target.skeleton.boneInverses[ boneIndex ] );
  
  						globalMatrix.multiply( wBindMatrix );
  
  					}
  
  					globalMatrix.copyPosition( relativeMatrix );
  
  				}
  
  				if ( bone.parent && bone.parent.isBone ) {
  
  					bone.matrix.getInverse( bone.parent.matrixWorld );
  					bone.matrix.multiply( globalMatrix );
  
  				} else {
  
  					bone.matrix.copy( globalMatrix );
  
  				}
  
  				if ( options.preserveHipPosition && name === options.hip ) {
  
  					bone.matrix.setPosition( pos.set( 0, bone.position.y, 0 ) );
  
  				}
  
  				bone.matrix.decompose( bone.position, bone.quaternion, bone.scale );
  
  				bone.updateMatrixWorld();
  
  			}
  
  			if ( options.preservePosition ) {
  
  				for ( i = 0; i < bones.length; ++ i ) {
  
  					bone = bones[ i ];
  					name = options.names[ bone.name ] || bone.name;
  
  					if ( name !== options.hip ) {
  
  						bone.position.copy( bonesPosition[ i ] );
  
  					}
  
  				}
  
  			}
  
  			if ( options.preserveMatrix ) {
  
  				// restore matrix
  
  				target.updateMatrixWorld( true );
  
  			}
  
  		};
  
  	}(),
  
  	retargetClip: function ( target, source, clip, options ) {
  
  		options = options || {};
  		options.useFirstFramePosition = options.useFirstFramePosition !== undefined ? options.useFirstFramePosition : false;
  		options.fps = options.fps !== undefined ? options.fps : 30;
  		options.names = options.names || [];
  
  		if ( ! source.isObject3D ) {
  
  			source = this.getHelperFromSkeleton( source );
  
  		}
  
  		var numFrames = Math.round( clip.duration * ( options.fps / 1000 ) * 1000 ),
  			delta = 1 / options.fps,
  			convertedTracks = [],
  			mixer = new AnimationMixer( source ),
  			bones = this.getBones( target.skeleton ),
  			boneDatas = [],
  			positionOffset,
  			bone, boneTo, boneData,
  			name, i, j;
  
  		mixer.clipAction( clip ).play();
  		mixer.update( 0 );
  
  		source.updateMatrixWorld();
  
  		for ( i = 0; i < numFrames; ++ i ) {
  
  			var time = i * delta;
  
  			this.retarget( target, source, options );
  
  			for ( j = 0; j < bones.length; ++ j ) {
  
  				name = options.names[ bones[ j ].name ] || bones[ j ].name;
  
  				boneTo = this.getBoneByName( name, source.skeleton );
  
  				if ( boneTo ) {
  
  					bone = bones[ j ];
  					boneData = boneDatas[ j ] = boneDatas[ j ] || { bone: bone };
  
  					if ( options.hip === name ) {
  
  						if ( ! boneData.pos ) {
  
  							boneData.pos = {
  								times: new Float32Array( numFrames ),
  								values: new Float32Array( numFrames * 3 )
  							};
  
  						}
  
  						if ( options.useFirstFramePosition ) {
  
  							if ( i === 0 ) {
  
  								positionOffset = bone.position.clone();
  
  							}
  
  							bone.position.sub( positionOffset );
  
  						}
  
  						boneData.pos.times[ i ] = time;
  
  						bone.position.toArray( boneData.pos.values, i * 3 );
  
  					}
  
  					if ( ! boneData.quat ) {
  
  						boneData.quat = {
  							times: new Float32Array( numFrames ),
  							values: new Float32Array( numFrames * 4 )
  						};
  
  					}
  
  					boneData.quat.times[ i ] = time;
  
  					bone.quaternion.toArray( boneData.quat.values, i * 4 );
  
  				}
  
  			}
  
  			mixer.update( delta );
  
  			source.updateMatrixWorld();
  
  		}
  
  		for ( i = 0; i < boneDatas.length; ++ i ) {
  
  			boneData = boneDatas[ i ];
  
  			if ( boneData ) {
  
  				if ( boneData.pos ) {
  
  					convertedTracks.push( new VectorKeyframeTrack(
  						".bones[" + boneData.bone.name + "].position",
  						boneData.pos.times,
  						boneData.pos.values
  					) );
  
  				}
  
  				convertedTracks.push( new QuaternionKeyframeTrack(
  					".bones[" + boneData.bone.name + "].quaternion",
  					boneData.quat.times,
  					boneData.quat.values
  				) );
  
  			}
  
  		}
  
  		mixer.uncacheAction( clip );
  
  		return new AnimationClip( clip.name, - 1, convertedTracks );
  
  	},
  
  	getHelperFromSkeleton: function ( skeleton ) {
  
  		var source = new SkeletonHelper( skeleton.bones[ 0 ] );
  		source.skeleton = skeleton;
  
  		return source;
  
  	},
  
  	getSkeletonOffsets: function () {
  
  		var targetParentPos = new Vector3(),
  			targetPos = new Vector3(),
  			sourceParentPos = new Vector3(),
  			sourcePos = new Vector3(),
  			targetDir = new Vector2(),
  			sourceDir = new Vector2();
  
  		return function ( target, source, options ) {
  
  			options = options || {};
  			options.hip = options.hip !== undefined ? options.hip : "hip";
  			options.names = options.names || {};
  
  			if ( ! source.isObject3D ) {
  
  				source = this.getHelperFromSkeleton( source );
  
  			}
  
  			var nameKeys = Object.keys( options.names ),
  				nameValues = Object.values( options.names ),
  				sourceBones = source.isObject3D ? source.skeleton.bones : this.getBones( source ),
  				bones = target.isObject3D ? target.skeleton.bones : this.getBones( target ),
  				offsets = [],
  				bone, boneTo,
  				name, i;
  
  			target.skeleton.pose();
  
  			for ( i = 0; i < bones.length; ++ i ) {
  
  				bone = bones[ i ];
  				name = options.names[ bone.name ] || bone.name;
  
  				boneTo = this.getBoneByName( name, sourceBones );
  
  				if ( boneTo && name !== options.hip ) {
  
  					var boneParent = this.getNearestBone( bone.parent, nameKeys ),
  						boneToParent = this.getNearestBone( boneTo.parent, nameValues );
  
  					boneParent.updateMatrixWorld();
  					boneToParent.updateMatrixWorld();
  
  					targetParentPos.setFromMatrixPosition( boneParent.matrixWorld );
  					targetPos.setFromMatrixPosition( bone.matrixWorld );
  
  					sourceParentPos.setFromMatrixPosition( boneToParent.matrixWorld );
  					sourcePos.setFromMatrixPosition( boneTo.matrixWorld );
  
  					targetDir.subVectors(
  						new Vector2( targetPos.x, targetPos.y ),
  						new Vector2( targetParentPos.x, targetParentPos.y )
  					).normalize();
  
  					sourceDir.subVectors(
  						new Vector2( sourcePos.x, sourcePos.y ),
  						new Vector2( sourceParentPos.x, sourceParentPos.y )
  					).normalize();
  
  					var laterialAngle = targetDir.angle() - sourceDir.angle();
  
  					var offset = new Matrix4().makeRotationFromEuler(
  						new Euler(
  							0,
  							0,
  							laterialAngle
  						)
  					);
  
  					bone.matrix.multiply( offset );
  
  					bone.matrix.decompose( bone.position, bone.quaternion, bone.scale );
  
  					bone.updateMatrixWorld();
  
  					offsets[ name ] = offset;
  
  				}
  
  			}
  
  			return offsets;
  
  		};
  
  	}(),
  
  	renameBones: function ( skeleton, names ) {
  
  		var bones = this.getBones( skeleton );
  
  		for ( var i = 0; i < bones.length; ++ i ) {
  
  			var bone = bones[ i ];
  
  			if ( names[ bone.name ] ) {
  
  				bone.name = names[ bone.name ];
  
  			}
  
  		}
  
  		return this;
  
  	},
  
  	getBones: function ( skeleton ) {
  
  		return Array.isArray( skeleton ) ? skeleton : skeleton.bones;
  
  	},
  
  	getBoneByName: function ( name, skeleton ) {
  
  		for ( var i = 0, bones = this.getBones( skeleton ); i < bones.length; i ++ ) {
  
  			if ( name === bones[ i ].name )
  
  				return bones[ i ];
  
  		}
  
  	},
  
  	getNearestBone: function ( bone, names ) {
  
  		while ( bone.isBone ) {
  
  			if ( names.indexOf( bone.name ) !== - 1 ) {
  
  				return bone;
  
  			}
  
  			bone = bone.parent;
  
  		}
  
  	},
  
  	findBoneTrackData: function ( name, tracks ) {
  
  		var regexp = /\[(.*)\]\.(.*)/,
  			result = { name: name };
  
  		for ( var i = 0; i < tracks.length; ++ i ) {
  
  			// 1 is track name
  			// 2 is track type
  			var trackData = regexp.exec( tracks[ i ].name );
  
  			if ( trackData && name === trackData[ 1 ] ) {
  
  				result[ trackData[ 2 ] ] = i;
  
  			}
  
  		}
  
  		return result;
  
  	},
  
  	getEqualsBonesNames: function ( skeleton, targetSkeleton ) {
  
  		var sourceBones = this.getBones( skeleton ),
  			targetBones = this.getBones( targetSkeleton ),
  			bones = [];
  
  		search : for ( var i = 0; i < sourceBones.length; i ++ ) {
  
  			var boneName = sourceBones[ i ].name;
  
  			for ( var j = 0; j < targetBones.length; j ++ ) {
  
  				if ( boneName === targetBones[ j ].name ) {
  
  					bones.push( boneName );
  
  					continue search;
  
  				}
  
  			}
  
  		}
  
  		return bones;
  
  	}
  
  };
  
  export { SkeletonUtils };
  