templ_wavlttransimpl.h

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/*+
________________________________________________________________________

 (C) dGB Beheer B.V.; (LICENSE) http://opendtect.org/OpendTect_license.txt
 Author:        K. Tingdahl
 Date:          2001
 RCS:           $Id$
________________________________________________________________________

 This is part of another include file. Do not protect against multiple
 inclusion.

-*/

template <class T> inline
void transform1Dt( const T* in, T* out, int space ) const
{
    if ( in != out )
    {
        int end = sz_ * space;

        for ( int idx=0; idx<end; idx+=space )
            out[idx] = in[idx];
    }

    if ( forward_ )
    {
        for ( int nn=sz_; nn>=2; nn>>=1 )
        {
            mAllocLargeVarLenArr( T, wksp, nn );
            OD::sysMemZero( wksp, sizeof(T)*nn );
            int nmod = nn*filtersz_;
            int n1 = nn-1;
            int nh = nn >> 1;

            int i = 1;
            for ( int ii=0; i<=nn; i+=2, ii++ )
            {
                int ni=i+nmod+ioff_;
                int nj=i+nmod+joff_;

                for ( int k=1; k<=filtersz_; k++ )
                {
                    int jf = n1 & (ni+k);
                    int jr = n1 & (nj+k);

                    wksp[ii] += cc_[k]*out[jf*space];
                    wksp[ii+nh] += cr_[k]*out[jr*space];
                }
            }

            for ( int j=0; j<nn; j++ )
                out[j*space] = wksp[j];
        }
    }
    else
    {
        for ( int nn=2; nn<=sz_; nn<<=1 )
        {
            mAllocLargeVarLenArr( T, wksp, nn );
            OD::sysMemZero( wksp, sizeof(T)*nn );
            int nmod = nn*filtersz_;
            int n1 = nn-1;
            int nh = nn >> 1;

            int i = 1;
            for ( int ii=0; i<nn; i+=2, ii++ )
            {
                T ai=out[ii*space];
                T ai1=out[(ii+nh)*space];
                int ni =i+nmod+ioff_;
                int nj =i+nmod+joff_;

                for (int k=1; k<=filtersz_; k++ )
                {
                    int jf = (n1 & (ni+k));
                    int jr = (n1 & (nj+k));

                    wksp[jf] += cc_[k]*ai;
                    wksp[jr] += cr_[k]*ai1;
                }
            }

            for ( int j=0; j<nn; j++ )
                out[j*space] = wksp[j];
        }
    }
}