/* JOrbis
 * Copyright (C) 2000 ymnk, JCraft,Inc.
 *  
 * Written by: 2000 ymnk<ymnk@jcraft.com>
 *   
 * Many thanks to 
 *   Monty <monty@xiph.org> and 
 *   The XIPHOPHORUS Company http://www.xiph.org/ .
 * JOrbis has been based on their awesome works, Vorbis codec.
 *   
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public License
 * as published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
   
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Library General Public License for more details.
 * 
 * You should have received a copy of the GNU Library General Public
 * License along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

package com.jcraft.jorbis;

class Drft{
  int n;
  float[] trigcache;    
  int[] splitcache;

  void backward(float[] data){
    //System.err.println("Drft.backward");
    if(n==1)return;
    drftb1(n,data,trigcache,trigcache,n,splitcache);
  }

  void init(int n){
    //System.err.println("Drft.init");
    this.n=n;
    trigcache=new float[3*n];
    splitcache=new int[32];
    fdrffti(n, trigcache, splitcache);
  }

  void clear(){
    //System.err.println("Drft.clear");
    if(trigcache!=null)trigcache=null;
    if(splitcache!=null)splitcache=null;
//    memset(l,0,sizeof(drft_lookup));
  }

  static int[] ntryh = { 4,2,3,5 };
  static float tpi = 6.28318530717958647692528676655900577f;
  static float hsqt2 = .70710678118654752440084436210485f;
  static float taui = .86602540378443864676372317075293618f;
  static float taur = -.5f;
  static float sqrt2 = 1.4142135623730950488016887242097f;

  static void drfti1(int n, float[] wa, int index, int[] ifac){
    float arg,argh,argld,fi;
    int ntry=0,i,j=-1;
    int k1, l1, l2, ib;
    int ld, ii, ip, is, nq, nr;
    int ido, ipm, nfm1;
    int nl=n;
    int nf=0;

    int state=101;

    loop: while(true){
      switch(state){
      case 101:
	j++;
	if (j < 4)
	  ntry=ntryh[j];
	else
	  ntry+=2;
      case 104:
	nq=nl/ntry;
	nr=nl-ntry*nq;
	if(nr!=0){
	  state=101;
	  break;
	}
	nf++;
	ifac[nf+1]=ntry;
	nl=nq;
	if(ntry!=2){
	  state=107;
	  break;
	}
	if(nf==1){
	  state=107;
	  break;
	}

	for(i=1;i<nf;i++){
	  ib=nf-i+1;
	  ifac[ib+1]=ifac[ib];
	}
	ifac[2] = 2;
      case 107:
	if(nl!=1){
	  state=104;
	  break;
	}
	ifac[0]=n;
	ifac[1]=nf;
	argh=tpi/n;
	is=0;
	nfm1=nf-1;
	l1=1;

	if(nfm1==0)return;

	for (k1=0;k1<nfm1;k1++){
	  ip=ifac[k1+2];
	  ld=0;
	  l2=l1*ip;
	  ido=n/l2;
	  ipm=ip-1;

	  for (j=0;j<ipm;j++){
	    ld+=l1;
	    i=is;
	    argld=(float)ld*argh;
	    fi=0.f;
	    for (ii=2;ii<ido;ii+=2){
	      fi+=1.f;
	      arg=fi*argld;
	      wa[index+i++]=(float)Math.cos(arg);
	      wa[index+i++]=(float)Math.sin(arg);
	    }
	    is+=ido;
	  }
	  l1=l2;
	}
	break loop;
      }
    }
  }

  static void fdrffti(int n, float[] wsave, int[] ifac){
//System.err.println("fdrffti: n="+n);
    if(n == 1) return;
    drfti1(n, wsave, n, ifac);
  }

  static void dradf2(int ido,int l1,float[] cc, float[] ch, float[] wa1, int index){
    int i,k;
    float ti2,tr2;
    int t0,t1,t2,t3,t4,t5,t6;

    t1=0;
    t0=(t2=l1*ido);
    t3=ido<<1;
    for(k=0;k<l1;k++){
      ch[t1<<1]=cc[t1]+cc[t2];
      ch[(t1<<1)+t3-1]=cc[t1]-cc[t2];
      t1+=ido;
      t2+=ido;
    }
    
    if(ido<2)return;

    if(ido!=2){
      t1=0;
      t2=t0;
      for(k=0;k<l1;k++){
	t3=t2;
	t4=(t1<<1)+(ido<<1);
	t5=t1;
	t6=t1+t1;
	for(i=2;i<ido;i+=2){
	  t3+=2;
	  t4-=2;
	  t5+=2;
	  t6+=2;
	  tr2=wa1[index+i-2]*cc[t3-1]+wa1[index+i-1]*cc[t3];
	  ti2=wa1[index+i-2]*cc[t3]-wa1[index+i-1]*cc[t3-1];
	  ch[t6]=cc[t5]+ti2;
	  ch[t4]=ti2-cc[t5];
	  ch[t6-1]=cc[t5-1]+tr2;
	  ch[t4-1]=cc[t5-1]-tr2;
	}
	t1+=ido;
	t2+=ido;
      }
      if(ido%2==1)return;
    }
    
    t3=(t2=(t1=ido)-1);
    t2+=t0;
    for(k=0;k<l1;k++){
      ch[t1]=-cc[t2];
      ch[t1-1]=cc[t3];
      t1+=ido<<1;
      t2+=ido;
      t3+=ido;
    }
  }

  static void dradf4(int ido,int l1,float[] cc, float[] ch, 
		     float[] wa1, int index1,
		     float[] wa2, int index2,
		     float[] wa3, int index3){
    int i,k,t0,t1,t2,t3,t4,t5,t6;
    float ci2,ci3,ci4,cr2,cr3,cr4,ti1,ti2,ti3,ti4,tr1,tr2,tr3,tr4;
    t0=l1*ido;
  
    t1=t0;
    t4=t1<<1;
    t2=t1+(t1<<1);
    t3=0;

    for(k=0;k<l1;k++){
      tr1=cc[t1]+cc[t2];
      tr2=cc[t3]+cc[t4];

      ch[t5=t3<<2]=tr1+tr2;
      ch[(ido<<2)+t5-1]=tr2-tr1;
      ch[(t5+=(ido<<1))-1]=cc[t3]-cc[t4];
      ch[t5]=cc[t2]-cc[t1];
      
      t1+=ido;
      t2+=ido;
      t3+=ido;
      t4+=ido;
    }
    if(ido<2)return;

    if(ido!=2){
      t1=0;
      for(k=0;k<l1;k++){
	t2=t1;
	t4=t1<<2;
	t5=(t6=ido<<1)+t4;
	for(i=2;i<ido;i+=2){
	  t3=(t2+=2);
	  t4+=2;
	  t5-=2;

	  t3+=t0;
	  cr2=wa1[index1+i-2]*cc[t3-1]+wa1[index1+i-1]*cc[t3];
	  ci2=wa1[index1+i-2]*cc[t3]-wa1[index1+i-1]*cc[t3-1];
	  t3+=t0;
	  cr3=wa2[index2+i-2]*cc[t3-1]+wa2[index2+i-1]*cc[t3];
	  ci3=wa2[index2+i-2]*cc[t3]-wa2[index2+i-1]*cc[t3-1];
	  t3+=t0;
	  cr4=wa3[index3+i-2]*cc[t3-1]+wa3[index3+i-1]*cc[t3];
	  ci4=wa3[index3+i-2]*cc[t3]-wa3[index3+i-1]*cc[t3-1];

	  tr1=cr2+cr4;
	  tr4=cr4-cr2;
	  ti1=ci2+ci4;
	  ti4=ci2-ci4;

	  ti2=cc[t2]+ci3;
	  ti3=cc[t2]-ci3;
	  tr2=cc[t2-1]+cr3;
	  tr3=cc[t2-1]-cr3;
	  
	  ch[t4-1]=tr1+tr2;
	  ch[t4]=ti1+ti2;

	  ch[t5-1]=tr3-ti4;
	  ch[t5]=tr4-ti3;

	  ch[t4+t6-1]=ti4+tr3;
	  ch[t4+t6]=tr4+ti3;

	  ch[t5+t6-1]=tr2-tr1;
	  ch[t5+t6]=ti1-ti2;
	}
	t1+=ido;
      }
      if((ido&1)!=0)return;
    }

    t2=(t1=t0+ido-1)+(t0<<1);
    t3=ido<<2;
    t4=ido;
    t5=ido<<1;
    t6=ido;

    for(k=0;k<l1;k++){
      ti1=-hsqt2*(cc[t1]+cc[t2]);
      tr1=hsqt2*(cc[t1]-cc[t2]);

      ch[t4-1]=tr1+cc[t6-1];
      ch[t4+t5-1]=cc[t6-1]-tr1;

      ch[t4]=ti1-cc[t1+t0];
      ch[t4+t5]=ti1+cc[t1+t0];
      
      t1+=ido;
      t2+=ido;
      t4+=t3;
      t6+=ido;
    }
  }

  static void dradfg(int ido,int ip,int l1,int idl1,float[] cc,float[] c1,
		     float[] c2, float[] ch, float[] ch2, float[] wa, int index){
    int idij,ipph,i,j,k,l,ic,ik,is;
    int t0,t1,t2=0,t3,t4,t5,t6,t7,t8,t9,t10;
    float dc2,ai1,ai2,ar1,ar2,ds2;
    int nbd;
    float dcp=0,arg,dsp=0,ar1h,ar2h;
    int idp2,ipp2;
  
    arg=tpi/(float)ip;
    dcp=(float)Math.cos(arg);
    dsp=(float)Math.sin(arg);
    ipph=(ip+1)>>1;
    ipp2=ip;
    idp2=ido;
    nbd=(ido-1)>>1;
    t0=l1*ido;
    t10=ip*ido;

    int state=100;
    loop: while(true){
      switch(state){
      case 101:
	if(ido==1){
	  state=119;
	  break;
	}
	for(ik=0;ik<idl1;ik++)ch2[ik]=c2[ik];

	t1=0;
	for(j=1;j<ip;j++){
	  t1+=t0;
	  t2=t1;
	  for(k=0;k<l1;k++){
	    ch[t2]=c1[t2];
	    t2+=ido;
	  }
	}

	is=-ido;
	t1=0;
	if(nbd>l1){
	  for(j=1;j<ip;j++){
	    t1+=t0;
	    is+=ido;
	    t2= -ido+t1;
	    for(k=0;k<l1;k++){
	      idij=is-1;
	      t2+=ido;
	      t3=t2;
	      for(i=2;i<ido;i+=2){
		idij+=2;
		t3+=2;
		ch[t3-1]=wa[index+idij-1]*c1[t3-1]+wa[index+idij]*c1[t3];
		ch[t3]=wa[index+idij-1]*c1[t3]-wa[index+idij]*c1[t3-1];
	      }
	    }
	  }
	}
	else{

	  for(j=1;j<ip;j++){
	    is+=ido;
	    idij=is-1;
	    t1+=t0;
	    t2=t1;
	    for(i=2;i<ido;i+=2){
	      idij+=2;
	      t2+=2;
	      t3=t2;
	      for(k=0;k<l1;k++){
		ch[t3-1]=wa[index+idij-1]*c1[t3-1]+wa[index+idij]*c1[t3];
		ch[t3]=wa[index+idij-1]*c1[t3]-wa[index+idij]*c1[t3-1];
		t3+=ido;
	      }
	    }
	  }
	}

	t1=0;
	t2=ipp2*t0;
	if(nbd<l1){
	  for(j=1;j<ipph;j++){
	    t1+=t0;
	    t2-=t0;
	    t3=t1;
	    t4=t2;
	    for(i=2;i<ido;i+=2){
	      t3+=2;
	      t4+=2;
	      t5=t3-ido;
	      t6=t4-ido;
	      for(k=0;k<l1;k++){
		t5+=ido;
		t6+=ido;
		c1[t5-1]=ch[t5-1]+ch[t6-1];
		c1[t6-1]=ch[t5]-ch[t6];
		c1[t5]=ch[t5]+ch[t6];
		c1[t6]=ch[t6-1]-ch[t5-1];
	      }
	    }
	  }
	}
	else{
	  for(j=1;j<ipph;j++){
	    t1+=t0;
	    t2-=t0;
	    t3=t1;
	    t4=t2;
	    for(k=0;k<l1;k++){
	      t5=t3;
	      t6=t4;
	      for(i=2;i<ido;i+=2){
		t5+=2;
		t6+=2;
		c1[t5-1]=ch[t5-1]+ch[t6-1];
		c1[t6-1]=ch[t5]-ch[t6];
		c1[t5]=ch[t5]+ch[t6];
		c1[t6]=ch[t6-1]-ch[t5-1];
	      }
	      t3+=ido;
	      t4+=ido;
	    }
	  }
	}
      case 119:
	for(ik=0;ik<idl1;ik++)c2[ik]=ch2[ik];

	t1=0;
	t2=ipp2*idl1;
	for(j=1;j<ipph;j++){
	  t1+=t0;
	  t2-=t0;
	  t3=t1-ido;
	  t4=t2-ido;
	  for(k=0;k<l1;k++){
	    t3+=ido;
	    t4+=ido;
	    c1[t3]=ch[t3]+ch[t4];
	    c1[t4]=ch[t4]-ch[t3];
	  }
	}

	ar1=1.f;
	ai1=0.f;
	t1=0;
	t2=ipp2*idl1;
	t3=(ip-1)*idl1;
	for(l=1;l<ipph;l++){
	  t1+=idl1;
	  t2-=idl1;
	  ar1h=dcp*ar1-dsp*ai1;
	  ai1=dcp*ai1+dsp*ar1;
	  ar1=ar1h;
	  t4=t1;
	  t5=t2;
	  t6=t3;
	  t7=idl1;

	  for(ik=0;ik<idl1;ik++){
	    ch2[t4++]=c2[ik]+ar1*c2[t7++];
	    ch2[t5++]=ai1*c2[t6++];
	  }

	  dc2=ar1;
	  ds2=ai1;
	  ar2=ar1;
	  ai2=ai1;

	  t4=idl1;
	  t5=(ipp2-1)*idl1;
	  for(j=2;j<ipph;j++){
	    t4+=idl1;
	    t5-=idl1;

	    ar2h=dc2*ar2-ds2*ai2;
	    ai2=dc2*ai2+ds2*ar2;
	    ar2=ar2h;

	    t6=t1;
	    t7=t2;
	    t8=t4;
	    t9=t5;
	    for(ik=0;ik<idl1;ik++){
	      ch2[t6++]+=ar2*c2[t8++];
	      ch2[t7++]+=ai2*c2[t9++];
	    }
	  }
	}
	t1=0;
	for(j=1;j<ipph;j++){
	  t1+=idl1;
	  t2=t1;
	  for(ik=0;ik<idl1;ik++)ch2[ik]+=c2[t2++];
	}

	if(ido<l1){
	  state=132;
	  break;
	}

	t1=0;
	t2=0;
	for(k=0;k<l1;k++){
	  t3=t1;
	  t4=t2;
	  for(i=0;i<ido;i++)cc[t4++]=ch[t3++];
	  t1+=ido;
	  t2+=t10;
	}
	state=135;
	break;

      case 132:
	for(i=0;i<ido;i++){
	  t1=i;
	  t2=i;
	  for(k=0;k<l1;k++){
	    cc[t2]=ch[t1];
	    t1+=ido;
	    t2+=t10;
	  }
	}
      case 135:
	t1=0;
	t2=ido<<1;
	t3=0;
	t4=ipp2*t0;
	for(j=1;j<ipph;j++){
	  t1+=t2;
	  t3+=t0;
	  t4-=t0;

	  t5=t1;
	  t6=t3;
	  t7=t4;

	  for(k=0;k<l1;k++){
	    cc[t5-1]=ch[t6];
	    cc[t5]=ch[t7];
	    t5+=t10;
	    t6+=ido;
	    t7+=ido;
	  }
	}

	if(ido==1)return;
	if(nbd<l1){
	  state=141;
	  break;
	}

	t1=-ido;
	t3=0;
	t4=0;
	t5=ipp2*t0;
	for(j=1;j<ipph;j++){
	  t1+=t2;
	  t3+=t2;
	  t4+=t0;
	  t5-=t0;
	  t6=t1;
	  t7=t3;
	  t8=t4;
	  t9=t5;
	  for(k=0;k<l1;k++){
	    for(i=2;i<ido;i+=2){
	      ic=idp2-i;
	      cc[i+t7-1]=ch[i+t8-1]+ch[i+t9-1];
	      cc[ic+t6-1]=ch[i+t8-1]-ch[i+t9-1];
	      cc[i+t7]=ch[i+t8]+ch[i+t9];
	      cc[ic+t6]=ch[i+t9]-ch[i+t8];
	    }
	    t6+=t10;
	    t7+=t10;
	    t8+=ido;
	    t9+=ido;
	  }
	}
	return;
      case 141:
	t1=-ido;
	t3=0;
	t4=0;
	t5=ipp2*t0;
	for(j=1;j<ipph;j++){
	  t1+=t2;
	  t3+=t2;
	  t4+=t0;
	  t5-=t0;
	  for(i=2;i<ido;i+=2){
	    t6=idp2+t1-i;
	    t7=i+t3;
	    t8=i+t4;
	    t9=i+t5;
	    for(k=0;k<l1;k++){
	      cc[t7-1]=ch[t8-1]+ch[t9-1];
	      cc[t6-1]=ch[t8-1]-ch[t9-1];
	      cc[t7]=ch[t8]+ch[t9];
	      cc[t6]=ch[t9]-ch[t8];
	      t6+=t10;
	      t7+=t10;
	      t8+=ido;
	      t9+=ido;
	    }
	  }
	}
	break loop;
      }
    }
  }

  static void drftf1(int n,float[] c, float[] ch, float[] wa, int[] ifac){
    int i,k1,l1,l2;
    int na,kh,nf;
    int ip,iw,ido,idl1,ix2,ix3;

    nf=ifac[1];
    na=1;
    l2=n;
    iw=n;

    for(k1=0;k1<nf;k1++){
      kh=nf-k1;
      ip=ifac[kh+1];
      l1=l2/ip;
      ido=n/l2;
      idl1=ido*l1;
      iw-=(ip-1)*ido;
      na=1-na;

      int state=100;
      loop: while(true){
	switch(state){
	case 100:
	  if(ip!=4){
	    state=102;
	    break;
	  }

	  ix2=iw+ido;
	  ix3=ix2+ido;
	  if(na!=0)
	    dradf4(ido,l1,ch,c,wa,iw-1,wa,ix2-1,wa,ix3-1);
	  else
	    dradf4(ido,l1,c,ch,wa,iw-1,wa,ix2-1,wa,ix3-1);
	  state=110;
	  break;
	case 102:
	  if(ip!=2){
	    state=104;
	    break;
	  }
	  if(na!=0){
	    state=103;
	    break;
	  }
	  dradf2(ido,l1,c,ch,wa, iw-1);
	  state=110;
	  break;
	case 103:
	  dradf2(ido,l1,ch,c,wa, iw-1);
	case 104:
	  if(ido==1)na=1-na;
	  if(na!=0){
	    state=109;
	    break;
	  }
	  dradfg(ido,ip,l1,idl1,c,c,c,ch,ch,wa,iw-1);
	  na=1;
	  state=110;
	  break;
	case 109:
	  dradfg(ido,ip,l1,idl1,ch,ch,ch,c,c,wa,iw-1);
	  na=0;
	case 110:
	  l2=l1;
  	  break loop;
	}
      }
    }
    if(na==1)return;
    for(i=0;i<n;i++)c[i]=ch[i];
  }

  static void dradb2(int ido,int l1,float[] cc,float[] ch,float[] wa1, int index){
    int i,k,t0,t1,t2,t3,t4,t5,t6;
    float ti2,tr2;

    t0=l1*ido;
    
    t1=0;
    t2=0;
    t3=(ido<<1)-1;
    for(k=0;k<l1;k++){
      ch[t1]=cc[t2]+cc[t3+t2];
      ch[t1+t0]=cc[t2]-cc[t3+t2];
      t2=(t1+=ido)<<1;
    }

    if(ido<2)return;
    if(ido!=2){
      t1=0;
      t2=0;
      for(k=0;k<l1;k++){
	t3=t1;
	t5=(t4=t2)+(ido<<1);
	t6=t0+t1;
	for(i=2;i<ido;i+=2){
	  t3+=2;
	  t4+=2;
	  t5-=2;
	  t6+=2;
	  ch[t3-1]=cc[t4-1]+cc[t5-1];
	  tr2=cc[t4-1]-cc[t5-1];
	  ch[t3]=cc[t4]-cc[t5];
	  ti2=cc[t4]+cc[t5];
	  ch[t6-1]=wa1[index+i-2]*tr2-wa1[index+i-1]*ti2;
	  ch[t6]=wa1[index+i-2]*ti2+wa1[index+i-1]*tr2;
	}
	t2=(t1+=ido)<<1;
      }
      if((ido%2)==1)return;
    }

    t1=ido-1;
    t2=ido-1;
    for(k=0;k<l1;k++){
      ch[t1]=cc[t2]+cc[t2];
      ch[t1+t0]=-(cc[t2+1]+cc[t2+1]);
      t1+=ido;
      t2+=ido<<1;
    }
  }

  static void dradb3(int ido,int l1,float[] cc,float[] ch,
		     float[] wa1, int index1,
		     float[] wa2, int index2){
    int i,k,t0,t1,t2,t3,t4,t5,t6,t7,t8,t9,t10;
    float ci2,ci3,di2,di3,cr2,cr3,dr2,dr3,ti2,tr2;
    t0=l1*ido;

    t1=0;
    t2=t0<<1;
    t3=ido<<1;
    t4=ido+(ido<<1);
    t5=0;
    for(k=0;k<l1;k++){
      tr2=cc[t3-1]+cc[t3-1];
      cr2=cc[t5]+(taur*tr2);
      ch[t1]=cc[t5]+tr2;
      ci3=taui*(cc[t3]+cc[t3]);
      ch[t1+t0]=cr2-ci3;
      ch[t1+t2]=cr2+ci3;
      t1+=ido;
      t3+=t4;
      t5+=t4;
    }

    if(ido==1)return;

    t1=0;
    t3=ido<<1;
    for(k=0;k<l1;k++){
      t7=t1+(t1<<1);
      t6=(t5=t7+t3);
      t8=t1;
      t10=(t9=t1+t0)+t0;

      for(i=2;i<ido;i+=2){
	t5+=2;
	t6-=2;
	t7+=2;
	t8+=2;
	t9+=2;
	t10+=2;
	tr2=cc[t5-1]+cc[t6-1];
	cr2=cc[t7-1]+(taur*tr2);
	ch[t8-1]=cc[t7-1]+tr2;
	ti2=cc[t5]-cc[t6];
	ci2=cc[t7]+(taur*ti2);
	ch[t8]=cc[t7]+ti2;
	cr3=taui*(cc[t5-1]-cc[t6-1]);
	ci3=taui*(cc[t5]+cc[t6]);
	dr2=cr2-ci3;
	dr3=cr2+ci3;
	di2=ci2+cr3;
	di3=ci2-cr3;
	ch[t9-1]=wa1[index1+i-2]*dr2-wa1[index1+i-1]*di2;
	ch[t9]=wa1[index1+i-2]*di2+wa1[index1+i-1]*dr2;
	ch[t10-1]=wa2[index2+i-2]*dr3-wa2[index2+i-1]*di3;
	ch[t10]=wa2[index2+i-2]*di3+wa2[index2+i-1]*dr3;
      }
      t1+=ido;
    }
  }

  static void dradb4(int ido,int l1,float[] cc,float[] ch,
		     float[] wa1, int index1,
		     float[] wa2, int index2,
		     float[] wa3, int index3){
    int i,k,t0,t1,t2,t3,t4,t5,t6,t7,t8;
    float ci2,ci3,ci4,cr2,cr3,cr4,ti1,ti2,ti3,ti4,tr1,tr2,tr3,tr4;
    t0=l1*ido;
  
    t1=0;
    t2=ido<<2;
    t3=0;
    t6=ido<<1;
    for(k=0;k<l1;k++){
      t4=t3+t6;
      t5=t1;
      tr3=cc[t4-1]+cc[t4-1];
      tr4=cc[t4]+cc[t4]; 
      tr1=cc[t3]-cc[(t4+=t6)-1];
      tr2=cc[t3]+cc[t4-1];
      ch[t5]=tr2+tr3;
      ch[t5+=t0]=tr1-tr4;
      ch[t5+=t0]=tr2-tr3;
      ch[t5+=t0]=tr1+tr4;
      t1+=ido;
      t3+=t2;
    }

    if(ido<2)return;
    if(ido!=2){
      t1=0;
      for(k=0;k<l1;k++){
	t5=(t4=(t3=(t2=t1<<2)+t6))+t6;
	t7=t1;
	for(i=2;i<ido;i+=2){
	  t2+=2;
	  t3+=2;
	  t4-=2;
	  t5-=2;
	  t7+=2;
	  ti1=cc[t2]+cc[t5];
	  ti2=cc[t2]-cc[t5];
	  ti3=cc[t3]-cc[t4];
	  tr4=cc[t3]+cc[t4];
	  tr1=cc[t2-1]-cc[t5-1];
	  tr2=cc[t2-1]+cc[t5-1];
	  ti4=cc[t3-1]-cc[t4-1];
	  tr3=cc[t3-1]+cc[t4-1];
	  ch[t7-1]=tr2+tr3;
	  cr3=tr2-tr3;
	  ch[t7]=ti2+ti3;
	  ci3=ti2-ti3;
	  cr2=tr1-tr4;
	  cr4=tr1+tr4;
	  ci2=ti1+ti4;
	  ci4=ti1-ti4;

	  ch[(t8=t7+t0)-1]=wa1[index1+i-2]*cr2-wa1[index1+i-1]*ci2;
	  ch[t8]=wa1[index1+i-2]*ci2+wa1[index1+i-1]*cr2;
	  ch[(t8+=t0)-1]=wa2[index2+i-2]*cr3-wa2[index2+i-1]*ci3;
	  ch[t8]=wa2[index2+i-2]*ci3+wa2[index2+i-1]*cr3;
	  ch[(t8+=t0)-1]=wa3[index3+i-2]*cr4-wa3[index3+i-1]*ci4;
	  ch[t8]=wa3[index3+i-2]*ci4+wa3[index3+i-1]*cr4;
	}
	t1+=ido;
      }
      if(ido%2 == 1)return;
    }

    t1=ido;
    t2=ido<<2;
    t3=ido-1;
    t4=ido+(ido<<1);
    for(k=0;k<l1;k++){
      t5=t3;
      ti1=cc[t1]+cc[t4];
      ti2=cc[t4]-cc[t1];
      tr1=cc[t1-1]-cc[t4-1];
      tr2=cc[t1-1]+cc[t4-1];
      ch[t5]=tr2+tr2;
      ch[t5+=t0]=sqrt2*(tr1-ti1);
      ch[t5+=t0]=ti2+ti2;
      ch[t5+=t0]=-sqrt2*(tr1+ti1);
      
      t3+=ido;
      t1+=t2;
      t4+=t2;
    }
  }

  static void dradbg(int ido,int ip,int l1,int idl1,float[] cc,float[] c1,
		     float[] c2,float[] ch,float[] ch2,float[] wa, int index ){

    int idij,ipph=0,i,j,k,l,ik,is,t0=0,t1,t2,t3,t4,t5,t6,t7,t8,t9,t10=0,
      t11,t12;
    float dc2,ai1,ai2,ar1,ar2,ds2;
    int nbd=0;
    float dcp=0,arg,dsp=0,ar1h,ar2h;
    int ipp2=0;

    int state=100;

    loop: while(true){
      switch(state){
      case 100:
	t10=ip*ido;
	t0=l1*ido;
	arg=tpi/(float)ip;
	dcp=(float)Math.cos(arg);
	dsp=(float)Math.sin(arg);
	nbd=(ido-1)>>>1;
	ipp2=ip;
	ipph=(ip+1)>>>1;
	if(ido<l1){
	  state=103;
	  break;
	}
	t1=0;
	t2=0;
	for(k=0;k<l1;k++){
	  t3=t1;
	  t4=t2;
	  for(i=0;i<ido;i++){
	    ch[t3]=cc[t4];
	    t3++;
	    t4++;
	  }
	  t1+=ido;
	  t2+=t10;
	}
	state=106;
	break;
      case 103:
	t1=0;
	for(i=0;i<ido;i++){
	  t2=t1;
	  t3=t1;
	  for(k=0;k<l1;k++){
	    ch[t2]=cc[t3];
	    t2+=ido;
	    t3+=t10;
	  }
	  t1++;
	}
      case 106:
	t1=0;
	t2=ipp2*t0;
	t7=(t5=ido<<1);
	for(j=1;j<ipph;j++){
	  t1+=t0;
	  t2-=t0;
	  t3=t1;
	  t4=t2;
	  t6=t5;
	  for(k=0;k<l1;k++){
	    ch[t3]=cc[t6-1]+cc[t6-1];
	    ch[t4]=cc[t6]+cc[t6];
	    t3+=ido;
	    t4+=ido;
	    t6+=t10;
	  }
	  t5+=t7;
	}
	if (ido == 1){
	  state=116;
	  break;
	}
	if(nbd<l1){
	  state=112;
	  break;
	}

	t1=0;
	t2=ipp2*t0;
	t7=0;
	for(j=1;j<ipph;j++){
	  t1+=t0;
	  t2-=t0;
	  t3=t1;
	  t4=t2;

	  t7+=(ido<<1);
	  t8=t7;
	  for(k=0;k<l1;k++){
	    t5=t3;
	    t6=t4;
	    t9=t8;
	    t11=t8;
	    for(i=2;i<ido;i+=2){
	      t5+=2;
	      t6+=2;
	      t9+=2;
	      t11-=2;
	      ch[t5-1]=cc[t9-1]+cc[t11-1];
	      ch[t6-1]=cc[t9-1]-cc[t11-1];
	      ch[t5]=cc[t9]-cc[t11];
	      ch[t6]=cc[t9]+cc[t11];
	    }
	    t3+=ido;
	    t4+=ido;
	    t8+=t10;
	  }
	}
	state=116;
	break;
      case 112:
	t1=0;
	t2=ipp2*t0;
	t7=0;
	for(j=1;j<ipph;j++){
	  t1+=t0;
	  t2-=t0;
	  t3=t1;
	  t4=t2;
	  t7+=(ido<<1);
	  t8=t7;
	  t9=t7;
	  for(i=2;i<ido;i+=2){
	    t3+=2;
	    t4+=2;
	    t8+=2;
	    t9-=2;
	    t5=t3;
	    t6=t4;
	    t11=t8;
	    t12=t9;
	    for(k=0;k<l1;k++){
	      ch[t5-1]=cc[t11-1]+cc[t12-1];
	      ch[t6-1]=cc[t11-1]-cc[t12-1];
	      ch[t5]=cc[t11]-cc[t12];
	      ch[t6]=cc[t11]+cc[t12];
	      t5+=ido;
	      t6+=ido;
	      t11+=t10;
	      t12+=t10;
	    }
	  }
	}
      case 116:
	ar1=1.f;
	ai1=0.f;
	t1=0;
	t9=(t2=ipp2*idl1);
	t3=(ip-1)*idl1;
	for(l=1;l<ipph;l++){
	  t1+=idl1;
	  t2-=idl1;
	  
	  ar1h=dcp*ar1-dsp*ai1;
	  ai1=dcp*ai1+dsp*ar1;
	  ar1=ar1h;
	  t4=t1;
	  t5=t2;
	  t6=0;
	  t7=idl1;
	  t8=t3;
	  for(ik=0;ik<idl1;ik++){
	    c2[t4++]=ch2[t6++]+ar1*ch2[t7++];
	    c2[t5++]=ai1*ch2[t8++];
	  }
	  dc2=ar1;
	  ds2=ai1;
	  ar2=ar1;
	  ai2=ai1;

	  t6=idl1;
	  t7=t9-idl1;
	  for(j=2;j<ipph;j++){
	    t6+=idl1;
	    t7-=idl1;
	    ar2h=dc2*ar2-ds2*ai2;
	    ai2=dc2*ai2+ds2*ar2;
	    ar2=ar2h;
	    t4=t1;
	    t5=t2;
	    t11=t6;
	    t12=t7;
	    for(ik=0;ik<idl1;ik++){
	      c2[t4++]+=ar2*ch2[t11++];
	      c2[t5++]+=ai2*ch2[t12++];
	    }
	  }
	}

	t1=0;
	for(j=1;j<ipph;j++){
	  t1+=idl1;
	  t2=t1;
	  for(ik=0;ik<idl1;ik++)ch2[ik]+=ch2[t2++];
	}

	t1=0;
	t2=ipp2*t0;
	for(j=1;j<ipph;j++){
	  t1+=t0;
	  t2-=t0;
	  t3=t1;
	  t4=t2;
	  for(k=0;k<l1;k++){
	    ch[t3]=c1[t3]-c1[t4];
	    ch[t4]=c1[t3]+c1[t4];
	    t3+=ido;
	    t4+=ido;
	  }
	}

	if(ido==1){
	  state=132;
	  break;
	}
	if(nbd<l1){
	  state=128;
	  break;
	}

	t1=0;
	t2=ipp2*t0;
	for(j=1;j<ipph;j++){
	  t1+=t0;
	  t2-=t0;
	  t3=t1;
	  t4=t2;
	  for(k=0;k<l1;k++){
	    t5=t3;
	    t6=t4;
	    for(i=2;i<ido;i+=2){
	      t5+=2;
	      t6+=2;
	      ch[t5-1]=c1[t5-1]-c1[t6];
	      ch[t6-1]=c1[t5-1]+c1[t6];
	      ch[t5]=c1[t5]+c1[t6-1];
	      ch[t6]=c1[t5]-c1[t6-1];
	    }
	    t3+=ido;
	    t4+=ido;
	  }
	}
	state=132;
	break;
      case 128:
	t1=0;
	t2=ipp2*t0;
	for(j=1;j<ipph;j++){
	  t1+=t0;
	  t2-=t0;
	  t3=t1;
	  t4=t2;
	  for(i=2;i<ido;i+=2){
	    t3+=2;
	    t4+=2;
	    t5=t3;
	    t6=t4;
	    for(k=0;k<l1;k++){
	      ch[t5-1]=c1[t5-1]-c1[t6];
	      ch[t6-1]=c1[t5-1]+c1[t6];
	      ch[t5]=c1[t5]+c1[t6-1];
	      ch[t6]=c1[t5]-c1[t6-1];
	      t5+=ido;
	      t6+=ido;
	    }
	  }
	}
      case 132:
	if(ido==1)return;

	for(ik=0;ik<idl1;ik++)c2[ik]=ch2[ik];

	t1=0;
	for(j=1;j<ip;j++){
	  t2=(t1+=t0);
	  for(k=0;k<l1;k++){
	    c1[t2]=ch[t2];
	    t2+=ido;
	  }
	}

	if(nbd>l1){
	  state=139;
	  break;
	}

	is= -ido-1;
	t1=0;
	for(j=1;j<ip;j++){
	  is+=ido;
	  t1+=t0;
	  idij=is;
	  t2=t1;
	  for(i=2;i<ido;i+=2){
	    t2+=2;
	    idij+=2;
	    t3=t2;
	    for(k=0;k<l1;k++){
	      c1[t3-1]=wa[index+idij-1]*ch[t3-1]-wa[index+idij]*ch[t3];
	      c1[t3]=wa[index+idij-1]*ch[t3]+wa[index+idij]*ch[t3-1];
	      t3+=ido;
	    }
	  }
	}
	return;

      case 139:
	is= -ido-1;
	t1=0;
	for(j=1;j<ip;j++){
	  is+=ido;
	  t1+=t0;
	  t2=t1;
	  for(k=0;k<l1;k++){
	    idij=is;
	    t3=t2;
	    for(i=2;i<ido;i+=2){
	      idij+=2;
	      t3+=2;
	      c1[t3-1]=wa[index+idij-1]*ch[t3-1]-wa[index+idij]*ch[t3];
	      c1[t3]=wa[index+idij-1]*ch[t3]+wa[index+idij]*ch[t3-1];
	    }
	    t2+=ido;
	  }
	}
	break loop; 
      }
    }
  }

  static void drftb1(int n, float[] c, float[] ch, float[] wa, int index, int[] ifac){
    int i,k1,l1,l2=0;
    int na;
    int nf,ip=0,iw,ix2,ix3,ido=0,idl1=0;

    nf=ifac[1];
    na=0;
    l1=1;
    iw=1;

    for(k1=0;k1<nf;k1++){
      int state=100;
      loop: while(true){
	switch(state){
	case 100:
	  ip=ifac[k1 + 2];
	  l2=ip*l1;
	  ido=n/l2;
	  idl1=ido*l1;
	  if(ip!=4){
	    state=103;
	    break;
	  }
	  ix2=iw+ido;
	  ix3=ix2+ido;

	  if(na!=0)
	    dradb4(ido,l1,ch,c,wa,index+iw-1,wa,index+ix2-1,wa,index+ix3-1);
	  else
	    dradb4(ido,l1,c,ch,wa,index+iw-1,wa,index+ix2-1,wa,index+ix3-1);
	  na=1-na;
	  state=115;
	  break;
	case 103:
	  if(ip!=2){
	    state=106;
	    break;
	  }

	  if(na!=0)
	    dradb2(ido,l1,ch,c,wa,index+iw-1);
	  else
	    dradb2(ido,l1,c,ch,wa,index+iw-1);
	  na=1-na;
	  state=115;
	  break;

	case 106:
	  if(ip!=3){
	    state=109;
	    break;
	  }

	  ix2=iw+ido;
	  if(na!=0)
	    dradb3(ido,l1,ch,c,wa,index+iw-1,wa,index+ix2-1);
	  else
	    dradb3(ido,l1,c,ch,wa,index+iw-1,wa,index+ix2-1);
	  na=1-na;
	  state=115;
	  break;
	case 109:
	  //    The radix five case can be translated later.....
	  //    if(ip!=5)goto L112;
          //
	  //ix2=iw+ido;
	  //ix3=ix2+ido;
	  //ix4=ix3+ido;
	  //if(na!=0)
	  //  dradb5(ido,l1,ch,c,wa+iw-1,wa+ix2-1,wa+ix3-1,wa+ix4-1);
	  //else
	  //  dradb5(ido,l1,c,ch,wa+iw-1,wa+ix2-1,wa+ix3-1,wa+ix4-1);
	  //na=1-na;
	  //state=115; 
          //break;
	  if(na!=0)
	    dradbg(ido,ip,l1,idl1,ch,ch,ch,c,c,wa,index+iw-1);
	  else
	    dradbg(ido,ip,l1,idl1,c,c,c,ch,ch,wa,index+iw-1);
	  if(ido==1)na=1-na;

	case 115:
	  l1=l2;
	  iw+=(ip-1)*ido;
  	  break loop;
	}
      }
    }
    if(na==0)return;
    for(i=0;i<n;i++)c[i]=ch[i];
  }
}
