s=this.getPoint(i),a=this.getPoint(r),o=e||(s.isVector2?new vt:new Lt);return o.copy(a).sub(s).normalize(),o}getTangentAt(t,e){const n=this.getUtoTmapping(t);return this.getTangent(n,e)}computeFrenetFrames(t,e){const n=new Lt,i=[],r=[],s=[],a=new Lt,o=new se;for(let e=0;e<=t;e++){const n=e/t;i[e]=this.getTangentAt(n,new Lt),i[e].normalize()}r[0]=new Lt,s[0]=new Lt;let l=Number.MAX_VALUE;const c=Math.abs(i[0].x),h=Math.abs(i[0].y),u=Math.abs(i[0].z);c<=l&&(l=c,n.set(1,0,0)),h<=l&&(l=h,n.set(0,1,0)),u<=l&&n.set(0,0,1),a.crossVectors(i[0],n).normalize(),r[0].crossVectors(i[0],a),s[0].crossVectors(i[0],r[0]);for(let e=1;e<=t;e++){if(r[e]=r[e-1].clone(),s[e]=s[e-1].clone(),a.crossVectors(i[e-1],i[e]),a.length()>Number.EPSILON){a.normalize();const t=Math.acos(ht(i[e-1].dot(i[e]),-1,1));r[e].applyMatrix4(o.makeRotationAxis(a,t))}s[e].crossVectors(i[e],r[e])}if(!0===e){let e=Math.acos(ht(r[0].dot(r[t]),-1,1));e/=t,i[0].dot(a.crossVectors(r[0],r[t]))>0&&(e=-e);for(let n=1;n<=t;n++)r[n].applyMatrix4(o.makeRotationAxis(i[n],e*n)),s[n].crossVectors(i[n],r[n])}return{tangents:i,normals:r,binormals:s}}clone(){return(new this.constructor).copy(this)}copy(t){return this.arcLengthDivisions=t.arcLengthDivisions,this}toJSON(){const t={metadata:{version:4.5,type:"Curve",generator:"Curve.toJSON"}};return t.arcLengthDivisions=this.arcLengthDivisions,t.type=this.type,t}fromJSON(t){return this.arcLengthDivisions=t.arcLengthDivisions,this}}class fl extends ml{constructor(t=0,e=0,n=1,i=1,r=0,s=2*Math.PI,a=!1,o=0){super(),this.type="EllipseCurve",this.aX=t,this.aY=e,this.xRadius=n,this.yRadius=i,this.aStartAngle=r,this.aEndAngle=s,this.aClockwise=a,this.aRotation=o}getPoint(t,e){const n=e||new vt,i=2*Math.PI;let r=this.aEndAngle-this.aStartAngle;const s=Math.abs(r)i;)r-=i;r0?0:(Math.floor(Math.abs(l)/r)+1)*r:0===c&&l===r-1&&(l=r-2,c=1),this.closed||l>0?a=i[(l-1)%r]:(yl.subVectors(i[0],i[1]).add(i[0]),a=yl);const h=i[l%r],u=i[(l+1)%r];if(this.closed||l+2