nstructor(e=0,t=0,n=0,s=1){this.isQuaternion=!0,this._x=e,this._y=t,this._z=n,this._w=s}static slerpFlat(e,t,n,s,r,a,o){let l=n[s+0],c=n[s+1],h=n[s+2],f=n[s+3],u=r[a+0],d=r[a+1],g=r[a+2],M=r[a+3];if(f!==M||l!==u||c!==d||h!==g){let m=l*u+c*d+h*g+f*M;m<0&&(u=-u,d=-d,g=-g,M=-M,m=-m);let p=1-o;if(m<.9995){let b=Math.acos(m),A=Math.sin(b);p=Math.sin(p*b)/A,o=Math.sin(o*b)/A,l=l*p+u*o,c=c*p+d*o,h=h*p+g*o,f=f*p+M*o}else{l=l*p+u*o,c=c*p+d*o,h=h*p+g*o,f=f*p+M*o;let b=1/Math.sqrt(l*l+c*c+h*h+f*f);l*=b,c*=b,h*=b,f*=b}}e[t]=l,e[t+1]=c,e[t+2]=h,e[t+3]=f}static multiplyQuaternionsFlat(e,t,n,s,r,a){let o=n[s],l=n[s+1],c=n[s+2],h=n[s+3],f=r[a],u=r[a+1],d=r[a+2],g=r[a+3];return e[t]=o*g+h*f+l*d-c*u,e[t+1]=l*g+h*u+c*f-o*d,e[t+2]=c*g+h*d+o*u-l*f,e[t+3]=h*g-o*f-l*u-c*d,e}get x(){return this._x}set x(e){this._x=e,this._onChangeCallback()}get y(){return this._y}set y(e){this._y=e,this._onChangeCallback()}get z(){return this._z}set z(e){this._z=e,this._onChangeCallback()}get w(){return this._w}set w(e){this._w=e,this._onChangeCallback()}set(e,t,n,s){return this._x=e,this._y=t,this._z=n,this._w=s,this._onChangeCallback(),this}clone(){return new this.constructor(this._x,this._y,this._z,this._w)}copy(e){return this._x=e.x,this._y=e.y,this._z=e.z,this._w=e.w,this._onChangeCallback(),this}setFromEuler(e,t=!0){let n=e._x,s=e._y,r=e._z,a=e._order,o=Math.cos,l=Math.sin,c=o(n/2),h=o(s/2),f=o(r/2),u=l(n/2),d=l(s/2),g=l(r/2);switch(a){case"XYZ":this._x=u*h*f+c*d*g,this._y=c*d*f-u*h*g,this._z=c*h*g+u*d*f,this._w=c*h*f-u*d*g;break;case"YXZ":this._x=u*h*f+c*d*g,this._y=c*d*f-u*h*g,this._z=c*h*g-u*d*f,this._w=c*h*f+u*d*g;break;case"ZXY":this._x=u*h*f-c*d*g,this._y=c*d*f+u*h*g,this._z=c*h*g+u*d*f,this._w=c*h*f-u*d*g;break;case"ZYX":this._x=u*h*f-c*d*g,this._y=c*d*f+u*h*g,this._z=c*h*g-u*d*f,this._w=c*h*f+u*d*g;break;case"YZX":this._x=u*h*f+c*d*g,this._y=c*d*f+u*h*g,this._z=c*h*g-u*d*f,this._w=c*h*f-u*d*g;break;case"XZY":this._x=u*h*f-c*d*g,this._y=c*d*f-u*h*g,this._z=c*h*g+u*d*f,this._w=c*h*f+u*d*g;break;default:Be("Quaternion: .setFromEuler() encountered an unknown order: "+a)}return t===!0&&this._onChangeCallback(),this}setFromAxisAngle(e,t){let n=t/2,s=Math.sin(n);return this._x=e.x*s,this._y=e.y*s,this._z=e.z*s,this._w=Math.cos(n),this._onChangeCallback(),this}setFromRotationMatrix(e){let t=e.elements,n=t[0],s=t[4],r=t[8],a=t[1],o=t[5],l=t[9],c=t[2],h=t[6],f=t[10],u=n+o+f;if(u>0){let d=.5/Math.sqrt(u+1);this._w=.25/d,this._x=(h-l)*d,this._y=(r-c)*d,this._z=(a-s)*d}else if(n>o&&n>f){let d=2*Math.sqrt(1+n-o-f);this._w=(h-l)/d,this._x=.25*d,this._y=(s+a)/d,this._z=(r+c)/d}else if(o>f){let d=2*Math.sqrt(1+o-n-f);this._w=(r-c)/d,this._x=(s+a)/d,this._y=.25*d,this._z=(l+h)/d}else{let d=2*Math.sqrt(1+f-n-o);this._w=(a-s)/d,this._x=(r+c)/d,this._y=(l+h)/d,this._z=.25*d}return this._onChangeCallback(),this}setFromUnitVectors(e,t){let n=e.dot(t)+1;return n<1e-8?(n=0,Math.abs(e.x)>Math.abs(e.z)?(this._x=-e.y,this._y=e.x,this._z=0,this._w=n):(this._x=0,this._y=-e.z,this._z=e.y,this._w=n)):(this._x=e.y*t.z-e.z*t.y,this._y=e.z*t.x-e.x*t.z,this._z=e.x*t.y-e.y*t.x,this._w=n),this.normalize()}angleTo(e){return 2*Math.acos(Math.abs(st(this.dot(e),-1,1)))}rotateTowards(e,t){let n=this.angleTo(e);if(n===0)return this;let s=Math.min(1,t/n);return this.slerp(e,s),this}identity(){return this.set(0,0,0,1)}invert(){return this.conjugate()}conjugate(){return this._x*=-1,this._y*=-1,this._z*=-1,this._onChangeCallback(),this}dot(e){return this._x*e._x+this._y*e._y+this._z*e._z+this._w*e._w}lengthSq(){return this._x*this._x+this._y*this._y+this._z*this._z+this._w*this._w}length(){return Math.sqrt(this._x*this._x+this._y*this._y+this._z*this._z+this._w*this._w)}normalize(){let e=this.length();return e===0?(this._x=0,this._y=0,this._z=0,this._w=1):(e=1/e,this._x=this._x*e,this._y=this._y*e,this._z=this._z*e,this._w=this._w*e),this._onChangeCallback(),this}multiply(e){return this.multiplyQuaternions(this,e)}premultiply(e){return this.multiplyQuaternions(e,this)}multiplyQuaternions(e,t){let n=e._x,s=e._y,r=e._z,a=e._w,o=t._x,l=t._y,c=t._z,h=t._w;return this._x=n*h+a*o+s*c-r*l,this._y=s*h+a*l+r*o-n*c,this._z=r*h+a*c+n*l-s*o,this._w=a*h-n*o-s*l-r*c,this._onChangeCallback(),this}slerp(e,t){let n=e._x,s=e._y,r=e._z,a=e._w,o=this.dot(e);o<0&&(n=-n,s=-s,r=-r,a=-a,o=-o);let l=1-t;if(o<.9995){let c=Math.acos(o),h=Math.sin(c);l=Math.sin(l*c)/h,t=Math.sin(t*c)/h,this._x=this._x*l+n*t,this._y=this._y*l+s*t,this._z=this._z*l+r*t,this._w=this._w*l+a*t,this._onChangeCallback()}else this._x=this._x*l+n*t,this._y=this._y*l+s*t,this._z=this._z*l+r*t,this._w=this._w*l+a*t,this.normalize();return this}slerpQuaternions(e,t,n){return this.copy(e).slerp(t,n)}random(){let e=2*Math.PI*Math.random(),t=2*Math.PI*Math.random(),n=Math.random(),s=Math.sqrt(1-n),r=Math.sqrt(n);return this.set(s*Math.sin(e),s*Math.cos(e),r*Math.sin(t),r*Math.cos(t))}equals(e){return e._x===this._x&&e._y===this._y&&e._z===this._z&&e._w===this._w}fromArray(e,t=0){return this._x=e[t],this._y