/********************************************************************

 *                                                                  *

 * THIS FILE IS PART OF THE OggVorbis 'TREMOR' CODEC SOURCE CODE.   *

 *                                                                  *

 * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS     *

 * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *

 * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING.       *

 *                                                                  *

 * THE OggVorbis 'TREMOR' SOURCE CODE IS (C) COPYRIGHT 1994-2002    *

 * BY THE Xiph.Org FOUNDATION http://www.xiph.org/                  *

 *                                                                  *

 ********************************************************************

 function: window functions

 ********************************************************************/

#include <stdlib.h>

#include <math.h>

#include "misc.h"

#include "window.h"

#include "window_lookup.h"

const void *_vorbis_window(int type, int left){

  switch(type){

  case 0:

    switch(left){

    case 32:

      return vwin64;

    case 64:

      return vwin128;

    case 128:

      return vwin256;

    case 256:

      return vwin512;

    case 512:

      return vwin1024;

    case 1024:

      return vwin2048;

    case 2048:

      return vwin4096;

    case 4096:

      return vwin8192;

    default:

      return(0);

    }

    break;

  default:

    return(0);

  }

}

void _vorbis_apply_window(ogg_int32_t *d,const void *window_p[2],

			  long *blocksizes,

			  int lW,int W,int nW){

  LOOKUP_T *window[2]={window_p[0],window_p[1]};

  long n=blocksizes[W];

  long ln=blocksizes[lW];

  long rn=blocksizes[nW];

  long leftbegin=n/4-ln/4;

  long leftend=leftbegin+ln/2;

  long rightbegin=n/2+n/4-rn/4;

  long rightend=rightbegin+rn/2;

  int i,p;

  for(i=0;i<leftbegin;i++)

    d[i]=0;

  for(p=0;i<leftend;i++,p++)

    d[i]=MULT31(d[i],window[lW][p]);

  for(i=rightbegin,p=rn/2-1;i<rightend;i++,p--)

    d[i]=MULT31(d[i],window[nW][p]);

  for(;i<n;i++)

    d[i]=0;

}