/*
 * $RCSfile: InvWTFull.java,v $
 * $Revision: 1.1 $
 * $Date: 2005/02/11 05:02:32 $
 * $State: Exp $
 *
 * Class:                   InvWTFull
 *
 * Description:             This class implements a full page inverse DWT for
 *                          int and float data.
 *
 *                          the InvWTFullInt and InvWTFullFloat
 *                          classes by Bertrand Berthelot, Apr-19-1999
 *
 *
 * COPYRIGHT:
 *
 * This software module was originally developed by Raphaël Grosbois and
 * Diego Santa Cruz (Swiss Federal Institute of Technology-EPFL); Joel
 * Askelöf (Ericsson Radio Systems AB); and Bertrand Berthelot, David
 * Bouchard, Félix Henry, Gerard Mozelle and Patrice Onno (Canon Research
 * Centre France S.A) in the course of development of the JPEG2000
 * standard as specified by ISO/IEC 15444 (JPEG 2000 Standard). This
 * software module is an implementation of a part of the JPEG 2000
 * Standard. Swiss Federal Institute of Technology-EPFL, Ericsson Radio
 * Systems AB and Canon Research Centre France S.A (collectively JJ2000
 * Partners) agree not to assert against ISO/IEC and users of the JPEG
 * 2000 Standard (Users) any of their rights under the copyright, not
 * including other intellectual property rights, for this software module
 * with respect to the usage by ISO/IEC and Users of this software module
 * or modifications thereof for use in hardware or software products
 * claiming conformance to the JPEG 2000 Standard. Those intending to use
 * this software module in hardware or software products are advised that
 * their use may infringe existing patents. The original developers of
 * this software module, JJ2000 Partners and ISO/IEC assume no liability
 * for use of this software module or modifications thereof. No license
 * or right to this software module is granted for non JPEG 2000 Standard
 * conforming products. JJ2000 Partners have full right to use this
 * software module for his/her own purpose, assign or donate this
 * software module to any third party and to inhibit third parties from
 * using this software module for non JPEG 2000 Standard conforming
 * products. This copyright notice must be included in all copies or
 * derivative works of this software module.
 *
 * Copyright (c) 1999/2000 JJ2000 Partners.
 * */
package jj2000.j2k.wavelet.synthesis;
import java.awt.Point;

import jj2000.j2k.wavelet.*;
import jj2000.j2k.decoder.*;
import jj2000.j2k.image.*;
import jj2000.j2k.util.*;

/**
 * This class implements the InverseWT with the full-page approach for int and
 * float data.
 *
 * <P>The image can be reconstructed at different (image) resolution levels
 * indexed from the lowest resolution available for each tile-component. This
 * is controlled by the setImgResLevel() method.
 *
 * <P>Note: Image resolution level indexes may differ from tile-component
 * resolution index. They are indeed indexed starting from the lowest number
 * of decomposition levels of each component of each tile.
 *
 * <P>Example: For an image (1 tile) with 2 components (component 0 having 2
 * decomposition levels and component 1 having 3 decomposition levels), the
 * first (tile-) component has 3 resolution levels and the second one has 4
 * resolution levels, whereas the image has only 3 resolution levels
 * available.
 *
 * <P>This implementation does not support progressive data, all data is
 * considered to be non-progressive (i.e. "final" data) and the 'progressive'
 * attribute of the 'DataBlk' class is always set to false, see the 'DataBlk'
 * class.
 *
 * @see DataBlk
 * */
public class InvWTFull extends InverseWT {

    /** Reference to the ProgressWatch instance if any */
    private ProgressWatch pw = null;

    /** The total number of code-blocks to decode */
    private int cblkToDecode = 0;

    /** The number of already decoded code-blocks */
    private int nDecCblk = 0;

    /** the code-block buffer's source i.e. the quantizer */
    private CBlkWTDataSrcDec src;

    /** Current data type */
    private int dtype;

    /**
     * block storing the reconstructed image for each component
     */
    private DataBlk reconstructedComps[];

    /** Number of decomposition levels in each component */
    private int[] ndl;

    /**
     * The reversible flag for each component in each tile. The first index is
     * the tile index, the second one is the component index. The
     * reversibility of the components for each tile are calculated on a as
     * needed basis.
     * */
    private boolean reversible[][];

    /**
     * Initializes this object with the given source of wavelet
     * coefficients. It initializes the resolution level for full resolutioin
     * reconstruction.
     *
     * @param src from where the wavelet coefficinets should be
     * obtained.
     *
     * @param decSpec The decoder specifications
     * */
    public InvWTFull(CBlkWTDataSrcDec src, DecoderSpecs decSpec){
        super(src,decSpec);
        this.src = src;

        int nc = src.getNumComps();
        reconstructedComps = new DataBlk[nc];
        ndl = new int[nc];
        pw = FacilityManager.getProgressWatch();
    }

   /**
     * Returns the reversibility of the current subband. It computes
     * iteratively the reversibility of the child subbands. For each subband
     * it tests the reversibility of the horizontal and vertical synthesis
     * filters used to reconstruct this subband.
     *
     * @param subband The current subband.
     *
     * @return true if all the  filters used to reconstruct the current 
     * subband are reversible
     * */
    private boolean isSubbandReversible(Subband subband) {
        if(subband.isNode) {
            // It's reversible if the filters to obtain the 4 subbands are
            // reversible and the ones for this one are reversible too.
            return
                isSubbandReversible(subband.getLL()) &&
                isSubbandReversible(subband.getHL()) &&
                isSubbandReversible(subband.getLH()) &&
                isSubbandReversible(subband.getHH()) &&
                ((SubbandSyn)subband).hFilter.isReversible() &&
                ((SubbandSyn)subband).vFilter.isReversible();
        } else {
            // Leaf subband. Reversibility of data depends on source, so say
            // it's true
            return true;
        }
    }


    /**
     * Returns the reversibility of the wavelet transform for the specified
     * component, in the current tile. A wavelet transform is reversible when
     * it is suitable for lossless and lossy-to-lossless compression.
     *
     * @param t The index of the tile.
     *
     * @param c The index of the component.
     *
     * @return true is the wavelet transform is reversible, false if not.
     * */
    public boolean isReversible(int t,int c) {
        if (reversible[t] == null) {
            // Reversibility not yet calculated for this tile
            reversible[t] = new boolean[getNumComps()];
            for (int i=reversible.length-1; i>=0 ; i--) {
                reversible[t][i] =
                    isSubbandReversible(src.getSynSubbandTree(t,i));
            }
        }
        return reversible[t][c];
    }


    /**
     * Returns the number of bits, referred to as the "range bits",
     * corresponding to the nominal range of the data in the specified
     * component.
     *
     * <P>The returned value corresponds to the nominal dynamic range of the
     * reconstructed image data, as long as the getNomRangeBits() method of
     * the source returns a value corresponding to the nominal dynamic range
     * of the image data and not not of the wavelet coefficients.
     *
     * <P>If this number is <i>b</b> then for unsigned data the nominal range
     * is between 0 and 2^b-1, and for signed data it is between -2^(b-1) and
     * 2^(b-1)-1.
     *
     * @param c The index of the component.
     *
     * @return The number of bits corresponding to the nominal range of the
     * data.
     * */
    public int getNomRangeBits(int c) {
        return src.getNomRangeBits(c);
    }

    /**
     * Returns the position of the fixed point in the specified
     * component. This is the position of the least significant integral
     * (i.e. non-fractional) bit, which is equivalent to the number of
     * fractional bits. For instance, for fixed-point values with 2 fractional
     * bits, 2 is returned. For floating-point data this value does not apply
     * and 0 should be returned. Position 0 is the position of the least
     * significant bit in the data.
     *
     * <P>This default implementation assumes that the wavelet transform does
     * not modify the fixed point. If that were the case this method should be
     * overriden.
     *
     * @param c The index of the component.
     *
     * @return The position of the fixed-point, which is the same as the
     * number of fractional bits. For floating-point data 0 is returned.
     * */
    public int getFixedPoint(int c) {
        return src.getFixedPoint(c);
    }

    /**
     * Returns a block of image data containing the specifed rectangular area,
     * in the specified component, as a reference to the internal buffer (see
     * below). The rectangular area is specified by the coordinates and
     * dimensions of the 'blk' object.
     *
     * <p>The area to return is specified by the 'ulx', 'uly', 'w' and 'h'
     * members of the 'blk' argument. These members are not modified by this
     * method.</p>
     *
     * <p>The data returned by this method can be the data in the internal
     * buffer of this object, if any, and thus can not be modified by the
     * caller. The 'offset' and 'scanw' of the returned data can be
     * arbitrary. See the 'DataBlk' class.</p>
     *
     * <p>The returned data has its 'progressive' attribute unset
     * (i.e. false).</p>
     *
     * @param blk Its coordinates and dimensions specify the area to return.
     *
     * @param c The index of the component from which to get the data.
     *
     * @return The requested DataBlk
     *
     * @see #getInternCompData
     * */
    public final DataBlk getInternCompData(DataBlk blk, int c) {
        int tIdx = getTileIdx();
        if(src.getSynSubbandTree(tIdx,c).getHorWFilter()==null) {
            dtype = DataBlk.TYPE_INT;
        } else {
            dtype =
                src.getSynSubbandTree(tIdx,c).getHorWFilter().getDataType();
        }

        //If the source image has not been decomposed 
        if(reconstructedComps[c]==null) {
            //Allocate component data buffer
            switch (dtype) {
            case DataBlk.TYPE_FLOAT:
                reconstructedComps[c] =
                    new DataBlkFloat(0,0,getTileCompWidth(tIdx,c),
                                     getTileCompHeight(tIdx,c));
                break;
            case DataBlk.TYPE_INT:
                reconstructedComps[c] =
                    new DataBlkInt(0,0,getTileCompWidth(tIdx,c),
                                   getTileCompHeight(tIdx,c));
                break;
            }
            //Reconstruct source image
            waveletTreeReconstruction(reconstructedComps[c],
                                      src.getSynSubbandTree(tIdx,c),c);
            if(pw!=null && c==src.getNumComps()-1) {
                pw.terminateProgressWatch();
            }
        }

        if(blk.getDataType()!=dtype) {
            if(dtype==DataBlk.TYPE_INT) {
                blk = new DataBlkInt(blk.ulx,blk.uly,blk.w,blk.h);
            } else {
                blk = new DataBlkFloat(blk.ulx,blk.uly,blk.w,blk.h);
            }
        }
        // Set the reference to the internal buffer
        blk.setData(reconstructedComps[c].getData());
        blk.offset = reconstructedComps[c].w*blk.uly+blk.ulx;
        blk.scanw = reconstructedComps[c].w;
        blk.progressive = false;
        return blk;
    }

    /**
     * Returns a block of image data containing the specifed rectangular area,
     * in the specified component, as a copy (see below). The rectangular area
     * is specified by the coordinates and dimensions of the 'blk' object.
     *
     * <P>The area to return is specified by the 'ulx', 'uly', 'w' and 'h'
     * members of the 'blk' argument. These members are not modified by this
     * method.
     *
     * <P>The data returned by this method is always a copy of the internal
     * data of this object, if any, and it can be modified "in place" without
     * any problems after being returned. The 'offset' of the returned data is
     * 0, and the 'scanw' is the same as the block's width. See the 'DataBlk'
     * class.
     *
     * <P>If the data array in 'blk' is <tt>null</tt>, then a new one is
     * created. If the data array is not <tt>null</tt> then it must be big
     * enough to contain the requested area.
     *
     * <P>The returned data always has its 'progressive' attribute unset (i.e
     * false)
     *
     * @param blk Its coordinates and dimensions specify the area to
     * return. If it contains a non-null data array, then it must be large
     * enough. If it contains a null data array a new one is created. The
     * fields in this object are modified to return the data.
     *
     * @param c The index of the component from which to get the data.
     *
     * @return The requested DataBlk
     *
     * @see #getCompData
     * */
    public DataBlk getCompData(DataBlk blk, int c) {
        int j;
        Object src_data,dst_data;
        int src_data_int[],dst_data_int[];
        float src_data_float[],dst_data_float[];

        // To keep compiler happy
        dst_data = null;

        // Ensure output buffer
        switch (blk.getDataType()) {
        case DataBlk.TYPE_INT:
            dst_data_int = (int[]) blk.getData();
            if (dst_data_int == null || dst_data_int.length < blk.w*blk.h) {
                dst_data_int = new int[blk.w*blk.h];
            }
            dst_data = dst_data_int;
            break;
        case DataBlk.TYPE_FLOAT:
            dst_data_float = (float[]) blk.getData();
            if (dst_data_float == null || dst_data_float.length < blk.w*blk.h) {
                dst_data_float = new float[blk.w*blk.h];
            }
            dst_data = dst_data_float;
            break;
        }

        // Use getInternCompData() to get the data, since getInternCompData()
        // returns reference to internal buffer, we must copy it.
        blk = getInternCompData(blk,c);

        // Copy the data
        blk.setData(dst_data);
        blk.offset = 0;
        blk.scanw = blk.w;
        return blk;
    }

    /**
     * Performs the 2D inverse wavelet transform on a subband of the image, on
     * the specified component. This method will successively perform 1D
     * filtering steps on all columns and then all lines of the subband.
     *
     * @param db the buffer for the image/wavelet data.
     *
     * @param sb The subband to reconstruct.
     *
     * @param c The index of the component to reconstruct 
     * */
    private void wavelet2DReconstruction(DataBlk db,SubbandSyn sb,int c) {
        Object data;
        Object buf;
        int ulx, uly, w, h;
        int i,j,k;
        int offset;

        // If subband is empty (i.e. zero size) nothing to do
        if (sb.w==0 || sb.h==0) {
            return;
        }

        data = db.getData();

        ulx = sb.ulx;
        uly = sb.uly;
        w = sb.w;
        h = sb.h;

        buf = null;  // To keep compiler happy

        switch (sb.getHorWFilter().getDataType()) {
        case DataBlk.TYPE_INT:
            buf = new int[(w>=h) ? w : h];
            break;
        case DataBlk.TYPE_FLOAT:
            buf = new float[(w>=h) ? w : h];
            break;
        }

        //Perform the horizontal reconstruction
        offset = (uly-db.uly)*db.w + ulx-db.ulx;
        if (sb.ulcx%2==0) { // start index is even => use LPF
            for(i=0; i<h; i++, offset += db.w) {
                System.arraycopy(data,offset,buf,0,w);
                sb.hFilter.synthetize_lpf(buf,0,(w+1)/2,1,buf,(w+1)/2,w/2,1,
                                          data,offset,1);
            }
        } else { // start index is odd => use HPF
            for(i=0; i<h; i++, offset += db.w) {
                System.arraycopy(data,offset,buf,0,w);
                sb.hFilter.synthetize_hpf(buf,0,w/2,1,buf,w/2,(w+1)/2,1,
                                          data,offset,1);
            }
        }

        //Perform the vertical reconstruction 
        offset = (uly-db.uly)*db.w+ulx-db.ulx;
        switch (sb.getVerWFilter().getDataType()) {
        case DataBlk.TYPE_INT:
            int data_int[], buf_int[];
            data_int = (int[]) data;
            buf_int = (int[]) buf;
            if (sb.ulcy%2==0) { // start index is even => use LPF
                for(j=0; j<w; j++, offset++) {
                    for(i=h-1, k=offset+i*db.w; i>=0; i--, k-=db.w)
                        buf_int[i] = data_int[k];
                    sb.vFilter.synthetize_lpf(buf,0,(h+1)/2,1,buf,(h+1)/2,
                                              h/2,1,data,offset,db.w);
                }
            } else { // start index is odd => use HPF
                for(j=0; j<w; j++, offset++) {
                    for(i=h-1, k=offset+i*db.w; i>=0; i--, k-= db.w)
                        buf_int[i] = data_int[k];
                    sb.vFilter.synthetize_hpf(buf,0,h/2,1,buf,h/2,(h+1)/2,1,
                                              data,offset,db.w);
                }
            }
            break;
        case DataBlk.TYPE_FLOAT:
            float data_float[], buf_float[];
            data_float = (float[]) data;
            buf_float = (float[]) buf;
            if (sb.ulcy%2==0) { // start index is even => use LPF
                for(j=0; j<w; j++, offset++) {
                    for(i=h-1, k=offset+i*db.w; i>=0; i--, k-= db.w)
                        buf_float[i] = data_float[k];
                    sb.vFilter.synthetize_lpf(buf,0,(h+1)/2,1,buf,(h+1)/2,
                                              h/2,1,data,offset,db.w);
                }
            } else { // start index is odd => use HPF
                for(j=0; j<w; j++, offset++) {
                    for(i=h-1, k=offset+i*db.w; i>=0; i--, k-= db.w)
                        buf_float[i] = data_float[k];
                    sb.vFilter.synthetize_hpf(buf,0,h/2,1,buf,h/2,(h+1)/2,1,
                                              data,offset,db.w);
                }
            }
            break;
        }
    }

    /**
     * Performs the inverse wavelet transform on the whole component. It
     * iteratively reconstructs the subbands from leaves up to the root
     * node. This method is recursive, the first call to it the 'sb' must be
     * the root of the subband tree. The method will then process the entire
     * subband tree by calling itslef recursively.
     *
     * @param img The buffer for the image/wavelet data.
     *
     * @param sb The subband to reconstruct.
     *
     * @param c The index of the component to reconstruct 
     * */
    private void waveletTreeReconstruction(DataBlk img,SubbandSyn sb,int c) {

        DataBlk subbData;

        // If the current subband is a leaf then get the data from the source
        if(!sb.isNode) {
            int i,m,n;
            Object src_data,dst_data;
            Point ncblks;

            if (sb.w==0 || sb.h==0) {
                return; // If empty subband do nothing
            }

            // Get all code-blocks in subband
            if(dtype==DataBlk.TYPE_INT) {
                subbData = new DataBlkInt();
            } else {
                subbData = new DataBlkFloat();
            }
            ncblks = sb.numCb;
            dst_data = img.getData();
            for (m=0; m<ncblks.y; m++) {
                for (n=0; n<ncblks.x; n++) {
                    subbData = src.getInternCodeBlock(c,m,n,sb,subbData);
                    src_data = subbData.getData();
                    if(pw!=null) {
                        nDecCblk++;
                        pw.updateProgressWatch(nDecCblk,null);
                    }
                    // Copy the data line by line
                    for (i=subbData.h-1; i>=0; i--) {
                        System.arraycopy(src_data,
                                         subbData.offset+i*subbData.scanw,
                                         dst_data,
                                         (subbData.uly+i)*img.w+subbData.ulx,
                                         subbData.w);
                    }
                }
            }
        } else if(sb.isNode) {
            // Reconstruct the lower resolution levels if the current subbands
            // is a node

            //Perform the reconstruction of the LL subband
            waveletTreeReconstruction(img,(SubbandSyn)sb.getLL(),c);

            if(sb.resLvl<=reslvl-maxImgRes+ndl[c]){
                //Reconstruct the other subbands
                waveletTreeReconstruction(img,(SubbandSyn)sb.getHL(),c);
                waveletTreeReconstruction(img,(SubbandSyn)sb.getLH(),c);
                waveletTreeReconstruction(img,(SubbandSyn)sb.getHH(),c);

                //Perform the 2D wavelet decomposition of the current subband
                wavelet2DReconstruction(img,(SubbandSyn)sb,c);
            }
        }
    }

    /**
     * Returns the implementation type of this wavelet transform, WT_IMPL_FULL
     * (full-page based transform). All components return the same.
     *
     * @param c The index of the component.
     *
     * @return WT_IMPL_FULL
     *
     * @see WaveletTransform#WT_IMPL_FULL
     * */
    public int getImplementationType(int c) {
        return WaveletTransform.WT_IMPL_FULL;
    }

    /**
     * Changes the current tile, given the new indexes. An
     * IllegalArgumentException is thrown if the indexes do not correspond to
     * a valid tile.
     *
     * @param x The horizontal index of the tile.
     *
     * @param y The vertical index of the new tile.
     * */
    public void setTile(int x,int y) {
        int i;

        // Change tile
        super.setTile(x,y);

        int nc = src.getNumComps();
        int tIdx = src.getTileIdx();
        for(int c=0; c<nc; c++) {
            ndl[c] = src.getSynSubbandTree(tIdx,c).resLvl;
        }

        // Reset the decomposed component buffers.
        if (reconstructedComps != null) {
            for (i=reconstructedComps.length-1; i>=0; i--) {
                reconstructedComps[i] = null;
            }
        }

        cblkToDecode = 0;
        SubbandSyn root,sb;
        for(int c=0; c<nc; c++) {
            root = src.getSynSubbandTree(tIdx,c);
            for(int r=0; r<=reslvl-maxImgRes+root.resLvl; r++) {
                if(r==0) {
                    sb = (SubbandSyn)root.getSubbandByIdx(0,0);
                    if(sb!=null) cblkToDecode += sb.numCb.x*sb.numCb.y;
                } else {
                    sb = (SubbandSyn)root.getSubbandByIdx(r,1);
                    if(sb!=null) cblkToDecode += sb.numCb.x*sb.numCb.y;
                    sb = (SubbandSyn)root.getSubbandByIdx(r,2);
                    if(sb!=null) cblkToDecode += sb.numCb.x*sb.numCb.y;
                    sb = (SubbandSyn)root.getSubbandByIdx(r,3);
                    if(sb!=null) cblkToDecode += sb.numCb.x*sb.numCb.y;
                }
            } // Loop on resolution levels
        } // Loop on components
        nDecCblk = 0;

        if(pw!=null) {
            pw.initProgressWatch(0,cblkToDecode,"Decoding tile "+tIdx+"...");
        }
    }

    /**
     * Advances to the next tile, in standard scan-line order (by rows then
     * columns). An 'NoNextElementException' is thrown if the current tile is
     * the last one (i.e. there is no next tile).
     * */
    public void nextTile() {
        int i;

        // Change tile
        super.nextTile();

        int nc = src.getNumComps();
        int tIdx = src.getTileIdx();
        for(int c=0; c<nc; c++) {
            ndl[c] = src.getSynSubbandTree(tIdx,c).resLvl;
        }

        // Reset the decomposed component buffers.
        if (reconstructedComps != null) {
            for (i=reconstructedComps.length-1; i>=0; i--) {
                reconstructedComps[i] = null;
            }
        }
    }

}