/******************************************************************************
 * $Id: vrtdataset.h 23574 2011-12-14 19:29:48Z rouault $
 *
 * Project:  Virtual GDAL Datasets
 * Purpose:  Declaration of virtual gdal dataset classes.
 * Author:   Frank Warmerdam, warmerdam@pobox.com
 *
 ******************************************************************************
 * Copyright (c) 2001, Frank Warmerdam <warmerdam@pobox.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 ****************************************************************************/

#ifndef VIRTUALDATASET_H_INCLUDED
#define VIRTUALDATASET_H_INCLUDED

#include "gdal_priv.h"
#include "gdal_pam.h"
#include "gdal_vrt.h"
#include "cpl_hash_set.h"

int VRTApplyMetadata( CPLXMLNode *, GDALMajorObject * );
CPLXMLNode *VRTSerializeMetadata( GDALMajorObject * );

int VRTWarpedOverviewTransform( void *pTransformArg, int bDstToSrc,
                                int nPointCount,
                                double *padfX, double *padfY, double *padfZ,
                                int *panSuccess );
void* VRTDeserializeWarpedOverviewTransformer( CPLXMLNode *psTree );

/************************************************************************/
/*                          VRTOverviewInfo()                           */
/************************************************************************/
class VRTOverviewInfo
{
public:
    CPLString       osFilename;
    int             nBand;
    GDALRasterBand *poBand;
    int             bTriedToOpen;
    
    VRTOverviewInfo() : poBand(NULL), bTriedToOpen(FALSE) {}
    ~VRTOverviewInfo() {
        if( poBand == NULL ) 
            /* do nothing */;
        else if( poBand->GetDataset()->GetShared() )
            GDALClose( (GDALDatasetH) poBand->GetDataset() );
        else
            poBand->GetDataset()->Dereference();
    }
};


/************************************************************************/
/*                              VRTSource                               */
/************************************************************************/

class VRTSource 
{
public:
    virtual ~VRTSource();

    virtual CPLErr  RasterIO( int nXOff, int nYOff, int nXSize, int nYSize, 
                              void *pData, int nBufXSize, int nBufYSize, 
                              GDALDataType eBufType, 
                              int nPixelSpace, int nLineSpace ) = 0;

    virtual double GetMinimum( int nXSize, int nYSize, int *pbSuccess ) = 0;
    virtual double GetMaximum( int nXSize, int nYSize, int *pbSuccess ) = 0;

    virtual CPLErr  XMLInit( CPLXMLNode *psTree, const char * ) = 0;
    virtual CPLXMLNode *SerializeToXML( const char *pszVRTPath ) = 0;
    
    virtual void   GetFileList(char*** ppapszFileList, int *pnSize,
                               int *pnMaxSize, CPLHashSet* hSetFiles);

    virtual int    IsSimpleSource() { return FALSE; }
};

typedef VRTSource *(*VRTSourceParser)(CPLXMLNode *, const char *);

VRTSource *VRTParseCoreSources( CPLXMLNode *psTree, const char * );
VRTSource *VRTParseFilterSources( CPLXMLNode *psTree, const char * );

/************************************************************************/
/*                              VRTDataset                              */
/************************************************************************/

class VRTRasterBand;

class CPL_DLL VRTDataset : public GDALDataset
{
    friend class VRTRasterBand;

    char           *pszProjection;

    int            bGeoTransformSet;
    double         adfGeoTransform[6];

    int           nGCPCount;
    GDAL_GCP      *pasGCPList;
    char          *pszGCPProjection;

    int            bNeedsFlush;
    int            bWritable;
    
    char          *pszVRTPath;

    VRTRasterBand *poMaskBand;

    int            bCompatibleForDatasetIO;
    int            CheckCompatibleForDatasetIO();

  protected:
    virtual int         CloseDependentDatasets();

  public:
                 VRTDataset(int nXSize, int nYSize);
                ~VRTDataset();

    void          SetNeedsFlush() { bNeedsFlush = TRUE; }
    virtual void  FlushCache();
    
    void SetWritable(int bWritable) { this->bWritable = bWritable; }

    virtual CPLErr          CreateMaskBand( int nFlags );
    void SetMaskBand(VRTRasterBand* poMaskBand);

    virtual const char *GetProjectionRef(void);
    virtual CPLErr SetProjection( const char * );
    virtual CPLErr GetGeoTransform( double * );
    virtual CPLErr SetGeoTransform( double * );

    virtual CPLErr SetMetadata( char **papszMD, const char *pszDomain = "" );
    virtual CPLErr SetMetadataItem( const char *pszName, const char *pszValue,
                                    const char *pszDomain = "" );

    virtual int    GetGCPCount();
    virtual const char *GetGCPProjection();
    virtual const GDAL_GCP *GetGCPs();
    virtual CPLErr SetGCPs( int nGCPCount, const GDAL_GCP *pasGCPList,
                            const char *pszGCPProjection );

    virtual CPLErr AddBand( GDALDataType eType, 
                            char **papszOptions=NULL );
                            
    virtual char      **GetFileList();

    virtual CPLErr  IRasterIO( GDALRWFlag eRWFlag,
                               int nXOff, int nYOff, int nXSize, int nYSize,
                               void * pData, int nBufXSize, int nBufYSize,
                               GDALDataType eBufType,
                               int nBandCount, int *panBandMap,
                               int nPixelSpace, int nLineSpace, int nBandSpace);

    virtual CPLXMLNode *SerializeToXML( const char *pszVRTPath);
    virtual CPLErr      XMLInit( CPLXMLNode *, const char * );
 
    static int          Identify( GDALOpenInfo * );
    static GDALDataset *Open( GDALOpenInfo * );
    static GDALDataset *OpenXML( const char *, const char * = NULL, GDALAccess eAccess = GA_ReadOnly );
    static GDALDataset *Create( const char * pszName,
                                int nXSize, int nYSize, int nBands,
                                GDALDataType eType, char ** papszOptions );
    static CPLErr       Delete( const char * pszFilename );
};

/************************************************************************/
/*                           VRTWarpedDataset                           */
/************************************************************************/

class GDALWarpOperation;
class VRTWarpedRasterBand;

class CPL_DLL VRTWarpedDataset : public VRTDataset
{
    int               nBlockXSize;
    int               nBlockYSize;
    GDALWarpOperation *poWarper;

    friend class VRTWarpedRasterBand;

  protected:
    virtual int         CloseDependentDatasets();

public:
    int               nOverviewCount;
    VRTWarpedDataset  **papoOverviews;

public:
                      VRTWarpedDataset( int nXSize, int nYSize );
                     ~VRTWarpedDataset();

    CPLErr            Initialize( /* GDALWarpOptions */ void * );

    virtual CPLErr IBuildOverviews( const char *, int, int *,
                                    int, int *, GDALProgressFunc, void * );
    
    virtual CPLXMLNode *SerializeToXML( const char *pszVRTPath );
    virtual CPLErr    XMLInit( CPLXMLNode *, const char * );

    virtual CPLErr AddBand( GDALDataType eType, 
                            char **papszOptions=NULL );
                            
    virtual char      **GetFileList();
    
    CPLErr            ProcessBlock( int iBlockX, int iBlockY );

    void              GetBlockSize( int *, int * );
};

/************************************************************************/
/*                            VRTRasterBand                             */
/*                                                                      */
/*      Provides support for all the various kinds of metadata but      */
/*      no raster access.  That is handled by derived classes.          */
/************************************************************************/

class CPL_DLL VRTRasterBand : public GDALRasterBand
{
  protected:
    int            bIsMaskBand;

    int            bNoDataValueSet;
    int            bHideNoDataValue; // If set to true, will not report the existance of nodata
    double         dfNoDataValue;

    GDALColorTable *poColorTable;

    GDALColorInterp eColorInterp;

    char           *pszUnitType;
    char           **papszCategoryNames;
    
    double         dfOffset;
    double         dfScale;

    CPLXMLNode    *psSavedHistograms;

    void           Initialize( int nXSize, int nYSize );

    std::vector<VRTOverviewInfo> apoOverviews;

    VRTRasterBand *poMaskBand;

  public:

                    VRTRasterBand();
    virtual        ~VRTRasterBand();

    virtual CPLErr         XMLInit( CPLXMLNode *, const char * );
    virtual CPLXMLNode *   SerializeToXML( const char *pszVRTPath );

    virtual CPLErr SetNoDataValue( double );
    virtual double GetNoDataValue( int *pbSuccess = NULL );

    virtual CPLErr SetColorTable( GDALColorTable * ); 
    virtual GDALColorTable *GetColorTable();

    virtual CPLErr SetColorInterpretation( GDALColorInterp );
    virtual GDALColorInterp GetColorInterpretation();

    virtual const char *GetUnitType();
    CPLErr SetUnitType( const char * ); 

    virtual char **GetCategoryNames();
    virtual CPLErr SetCategoryNames( char ** );

    virtual CPLErr SetMetadata( char **papszMD, const char *pszDomain = "" );
    virtual CPLErr SetMetadataItem( const char *pszName, const char *pszValue,
                                    const char *pszDomain = "" );

    virtual double GetOffset( int *pbSuccess = NULL );
    CPLErr SetOffset( double );
    virtual double GetScale( int *pbSuccess = NULL );
    CPLErr SetScale( double );

    virtual int GetOverviewCount();
    virtual GDALRasterBand *GetOverview(int);
    
    virtual CPLErr  GetHistogram( double dfMin, double dfMax,
                          int nBuckets, int * panHistogram,
                          int bIncludeOutOfRange, int bApproxOK,
                          GDALProgressFunc, void *pProgressData );

    virtual CPLErr GetDefaultHistogram( double *pdfMin, double *pdfMax,
                                        int *pnBuckets, int ** ppanHistogram,
                                        int bForce,
                                        GDALProgressFunc, void *pProgressData);

    virtual CPLErr SetDefaultHistogram( double dfMin, double dfMax,
                                        int nBuckets, int *panHistogram );

    CPLErr         CopyCommonInfoFrom( GDALRasterBand * );
    
    virtual void   GetFileList(char*** ppapszFileList, int *pnSize,
                               int *pnMaxSize, CPLHashSet* hSetFiles);
    
    virtual void   SetDescription( const char * );

    virtual GDALRasterBand *GetMaskBand();
    virtual int             GetMaskFlags();

    virtual CPLErr          CreateMaskBand( int nFlags );
    
    void SetMaskBand(VRTRasterBand* poMaskBand);

    void SetIsMaskBand();

    CPLErr UnsetNoDataValue();

    virtual int         CloseDependentDatasets();

    virtual int         IsSourcedRasterBand() { return FALSE; }
};

/************************************************************************/
/*                         VRTSourcedRasterBand                         */
/************************************************************************/

class CPL_DLL VRTSourcedRasterBand : public VRTRasterBand
{
  private:
    int            bAntiRecursionFlag;
    CPLString      osLastLocationInfo;

    void           Initialize( int nXSize, int nYSize );

  public:
    int            nSources;
    VRTSource    **papoSources;
    int            bEqualAreas;

                   VRTSourcedRasterBand( GDALDataset *poDS, int nBand );
                   VRTSourcedRasterBand( GDALDataType eType, 
                                         int nXSize, int nYSize );
                   VRTSourcedRasterBand( GDALDataset *poDS, int nBand, 
                                         GDALDataType eType, 
                                         int nXSize, int nYSize );
    virtual        ~VRTSourcedRasterBand();

    virtual CPLErr IRasterIO( GDALRWFlag, int, int, int, int,
                              void *, int, int, GDALDataType,
                              int, int );

    virtual const char *GetMetadataItem( const char * pszName,
                                         const char * pszDomain = "" );
    virtual char      **GetMetadata( const char * pszDomain = "" );
    virtual CPLErr      SetMetadata( char ** papszMetadata,
                                     const char * pszDomain = "" );
    virtual CPLErr      SetMetadataItem( const char * pszName,
                                         const char * pszValue,
                                         const char * pszDomain = "" );

    virtual CPLErr         XMLInit( CPLXMLNode *, const char * );
    virtual CPLXMLNode *   SerializeToXML( const char *pszVRTPath );

    virtual double GetMinimum( int *pbSuccess = NULL );
    virtual double GetMaximum(int *pbSuccess = NULL );

    CPLErr         AddSource( VRTSource * );
    CPLErr         AddSimpleSource( GDALRasterBand *poSrcBand, 
                                    int nSrcXOff=-1, int nSrcYOff=-1, 
                                    int nSrcXSize=-1, int nSrcYSize=-1, 
                                    int nDstXOff=-1, int nDstYOff=-1, 
                                    int nDstXSize=-1, int nDstYSize=-1,
                                    const char *pszResampling = "near",
                                    double dfNoDataValue = VRT_NODATA_UNSET);
    CPLErr         AddComplexSource( GDALRasterBand *poSrcBand, 
                                     int nSrcXOff=-1, int nSrcYOff=-1, 
                                     int nSrcXSize=-1, int nSrcYSize=-1, 
                                     int nDstXOff=-1, int nDstYOff=-1, 
                                     int nDstXSize=-1, int nDstYSize=-1,
                                     double dfScaleOff=0.0, 
                                     double dfScaleRatio=1.0,
                                     double dfNoDataValue = VRT_NODATA_UNSET,
                                     int nColorTableComponent = 0);

    CPLErr         AddMaskBandSource( GDALRasterBand *poSrcBand,
                                      int nSrcXOff=-1, int nSrcYOff=-1,
                                      int nSrcXSize=-1, int nSrcYSize=-1,
                                      int nDstXOff=-1, int nDstYOff=-1,
                                      int nDstXSize=-1, int nDstYSize=-1 );

    CPLErr         AddFuncSource( VRTImageReadFunc pfnReadFunc, void *hCBData,
                                  double dfNoDataValue = VRT_NODATA_UNSET );


    virtual CPLErr IReadBlock( int, int, void * );
    
    virtual void   GetFileList(char*** ppapszFileList, int *pnSize,
                               int *pnMaxSize, CPLHashSet* hSetFiles);

    virtual int         CloseDependentDatasets();

    virtual int         IsSourcedRasterBand() { return TRUE; }
};

/************************************************************************/
/*                         VRTWarpedRasterBand                          */
/************************************************************************/

class CPL_DLL VRTWarpedRasterBand : public VRTRasterBand
{
  public:
                   VRTWarpedRasterBand( GDALDataset *poDS, int nBand,
                                     GDALDataType eType = GDT_Unknown );
    virtual        ~VRTWarpedRasterBand();

    virtual CPLErr         XMLInit( CPLXMLNode *, const char * );
    virtual CPLXMLNode *   SerializeToXML( const char *pszVRTPath );

    virtual CPLErr IReadBlock( int, int, void * );
    virtual CPLErr IWriteBlock( int, int, void * );

    virtual int GetOverviewCount();
    virtual GDALRasterBand *GetOverview(int);
};

/************************************************************************/
/*                         VRTDerivedRasterBand                         */
/************************************************************************/

class CPL_DLL VRTDerivedRasterBand : public VRTSourcedRasterBand
{

 public:
    char *pszFuncName;
    GDALDataType eSourceTransferType;

    VRTDerivedRasterBand(GDALDataset *poDS, int nBand);
    VRTDerivedRasterBand(GDALDataset *poDS, int nBand, 
                         GDALDataType eType, int nXSize, int nYSize);
    virtual        ~VRTDerivedRasterBand();

    virtual CPLErr IRasterIO( GDALRWFlag, int, int, int, int,
                              void *, int, int, GDALDataType,
                              int, int );

    static CPLErr AddPixelFunction
        (const char *pszFuncName, GDALDerivedPixelFunc pfnPixelFunc);
    static GDALDerivedPixelFunc GetPixelFunction(const char *pszFuncName);

    void SetPixelFunctionName(const char *pszFuncName);
    void SetSourceTransferType(GDALDataType eDataType);

    virtual CPLErr         XMLInit( CPLXMLNode *, const char * );
    virtual CPLXMLNode *   SerializeToXML( const char *pszVRTPath );

};

/************************************************************************/
/*                           VRTRawRasterBand                           */
/************************************************************************/

class RawRasterBand;

class CPL_DLL VRTRawRasterBand : public VRTRasterBand
{
    RawRasterBand  *poRawRaster;

    char           *pszSourceFilename;
    int            bRelativeToVRT;

  public:
                   VRTRawRasterBand( GDALDataset *poDS, int nBand,
                                     GDALDataType eType = GDT_Unknown );
    virtual        ~VRTRawRasterBand();

    virtual CPLErr         XMLInit( CPLXMLNode *, const char * );
    virtual CPLXMLNode *   SerializeToXML( const char *pszVRTPath );

    virtual CPLErr IRasterIO( GDALRWFlag, int, int, int, int,
                              void *, int, int, GDALDataType,
                              int, int );

    virtual CPLErr IReadBlock( int, int, void * );
    virtual CPLErr IWriteBlock( int, int, void * );

    CPLErr         SetRawLink( const char *pszFilename, 
                               const char *pszVRTPath,
                               int bRelativeToVRT, 
                               vsi_l_offset nImageOffset, 
                               int nPixelOffset, int nLineOffset, 
                               const char *pszByteOrder );

    void           ClearRawLink();

    virtual void   GetFileList(char*** ppapszFileList, int *pnSize,
                               int *pnMaxSize, CPLHashSet* hSetFiles);
};

/************************************************************************/
/*                              VRTDriver                               */
/************************************************************************/

class VRTDriver : public GDALDriver
{
    void        *pDeserializerData;

  public:
                 VRTDriver();
                 ~VRTDriver();

    char         **papszSourceParsers;

    virtual char      **GetMetadata( const char * pszDomain = "" );
    virtual CPLErr      SetMetadata( char ** papszMetadata,
                                     const char * pszDomain = "" );

    VRTSource   *ParseSource( CPLXMLNode *psSrc, const char *pszVRTPath );
    void         AddSourceParser( const char *pszElementName, 
                                  VRTSourceParser pfnParser );
};

/************************************************************************/
/*                           VRTSimpleSource                            */
/************************************************************************/

class VRTSimpleSource : public VRTSource
{
protected:
    GDALRasterBand      *poRasterBand;

    /* when poRasterBand is a mask band, poMaskBandMainBand is the band */
    /* from which the mask band is taken */
    GDALRasterBand      *poMaskBandMainBand; 

    int                 nSrcXOff;
    int                 nSrcYOff;
    int                 nSrcXSize;
    int                 nSrcYSize;

    int                 nDstXOff;
    int                 nDstYOff;
    int                 nDstXSize;
    int                 nDstYSize;

    int                 bNoDataSet;
    double              dfNoDataValue;

public:
            VRTSimpleSource();
    virtual ~VRTSimpleSource();

    virtual CPLErr  XMLInit( CPLXMLNode *psTree, const char * );
    virtual CPLXMLNode *SerializeToXML( const char *pszVRTPath );

    void           SetSrcBand( GDALRasterBand * );
    void           SetSrcMaskBand( GDALRasterBand * );
    void           SetSrcWindow( int, int, int, int );
    void           SetDstWindow( int, int, int, int );
    void           SetNoDataValue( double dfNoDataValue );

    int            GetSrcDstWindow( int, int, int, int, int, int, 
                                    int *, int *, int *, int *,
                                    int *, int *, int *, int * );

    virtual CPLErr  RasterIO( int nXOff, int nYOff, int nXSize, int nYSize, 
                              void *pData, int nBufXSize, int nBufYSize, 
                              GDALDataType eBufType, 
                              int nPixelSpace, int nLineSpace );

    virtual double GetMinimum( int nXSize, int nYSize, int *pbSuccess );
    virtual double GetMaximum( int nXSize, int nYSize, int *pbSuccess );

    void            DstToSrc( double dfX, double dfY,
                              double &dfXOut, double &dfYOut );
    void            SrcToDst( double dfX, double dfY,
                              double &dfXOut, double &dfYOut );
    
    virtual void   GetFileList(char*** ppapszFileList, int *pnSize,
                               int *pnMaxSize, CPLHashSet* hSetFiles);

    virtual int    IsSimpleSource() { return TRUE; }
    virtual const char* GetType() { return "SimpleSource"; }

    GDALRasterBand* GetBand();
    int             IsSameExceptBandNumber(VRTSimpleSource* poOtherSource);
    CPLErr          DatasetRasterIO(
                               int nXOff, int nYOff, int nXSize, int nYSize,
                               void * pData, int nBufXSize, int nBufYSize,
                               GDALDataType eBufType,
                               int nBandCount, int *panBandMap,
                               int nPixelSpace, int nLineSpace, int nBandSpace);
};

/************************************************************************/
/*                          VRTAveragedSource                           */
/************************************************************************/

class VRTAveragedSource : public VRTSimpleSource
{
public:
                    VRTAveragedSource();
    virtual CPLErr  RasterIO( int nXOff, int nYOff, int nXSize, int nYSize, 
                              void *pData, int nBufXSize, int nBufYSize, 
                              GDALDataType eBufType, 
                              int nPixelSpace, int nLineSpace );

    virtual double GetMinimum( int nXSize, int nYSize, int *pbSuccess );
    virtual double GetMaximum( int nXSize, int nYSize, int *pbSuccess );

    virtual CPLXMLNode *SerializeToXML( const char *pszVRTPath );
    virtual const char* GetType() { return "AveragedSource"; }
};

/************************************************************************/
/*                           VRTComplexSource                           */
/************************************************************************/

class VRTComplexSource : public VRTSimpleSource
{
public:
                   VRTComplexSource();
    virtual        ~VRTComplexSource();

    virtual CPLErr RasterIO( int nXOff, int nYOff, int nXSize, int nYSize, 
                             void *pData, int nBufXSize, int nBufYSize, 
                             GDALDataType eBufType, 
                             int nPixelSpace, int nLineSpace );

    virtual double GetMinimum( int nXSize, int nYSize, int *pbSuccess );
    virtual double GetMaximum( int nXSize, int nYSize, int *pbSuccess );

    virtual CPLXMLNode *SerializeToXML( const char *pszVRTPath );
    virtual CPLErr XMLInit( CPLXMLNode *, const char * );
    virtual const char* GetType() { return "ComplexSource"; }

    double  LookupValue( double dfInput );

    int            bDoScaling;
    double         dfScaleOff;
    double         dfScaleRatio;
    double         *padfLUTInputs;
    double         *padfLUTOutputs;
    int            nLUTItemCount;
    int            nColorTableComponent;
};

/************************************************************************/
/*                           VRTFilteredSource                          */
/************************************************************************/

class VRTFilteredSource : public VRTComplexSource
{
private:
    int          IsTypeSupported( GDALDataType eType );

protected:
    int          nSupportedTypesCount;
    GDALDataType aeSupportedTypes[20];

    int          nExtraEdgePixels;

public:
            VRTFilteredSource();
    virtual ~VRTFilteredSource();

    void    SetExtraEdgePixels( int );
    void    SetFilteringDataTypesSupported( int, GDALDataType * );

    virtual CPLErr  FilterData( int nXSize, int nYSize, GDALDataType eType, 
                                GByte *pabySrcData, GByte *pabyDstData ) = 0;

    virtual CPLErr  RasterIO( int nXOff, int nYOff, int nXSize, int nYSize, 
                              void *pData, int nBufXSize, int nBufYSize, 
                              GDALDataType eBufType, 
                              int nPixelSpace, int nLineSpace );
};

/************************************************************************/
/*                       VRTKernelFilteredSource                        */
/************************************************************************/

class VRTKernelFilteredSource : public VRTFilteredSource
{
protected:
    int     nKernelSize;

    double  *padfKernelCoefs;

    int     bNormalized;

public:
            VRTKernelFilteredSource();
    virtual ~VRTKernelFilteredSource();

    virtual CPLErr  XMLInit( CPLXMLNode *psTree, const char * );
    virtual CPLXMLNode *SerializeToXML( const char *pszVRTPath );

    virtual CPLErr  FilterData( int nXSize, int nYSize, GDALDataType eType, 
                                GByte *pabySrcData, GByte *pabyDstData );

    CPLErr          SetKernel( int nKernelSize, double *padfCoefs );
    void            SetNormalized( int );
};

/************************************************************************/
/*                       VRTAverageFilteredSource                       */
/************************************************************************/

class VRTAverageFilteredSource : public VRTKernelFilteredSource
{
public:
            VRTAverageFilteredSource( int nKernelSize );
    virtual ~VRTAverageFilteredSource();

    virtual CPLErr  XMLInit( CPLXMLNode *psTree, const char * );
    virtual CPLXMLNode *SerializeToXML( const char *pszVRTPath );
};

/************************************************************************/
/*                            VRTFuncSource                             */
/************************************************************************/
class VRTFuncSource : public VRTSource
{
public:
            VRTFuncSource();
    virtual ~VRTFuncSource();

    virtual CPLErr  XMLInit( CPLXMLNode *, const char *) { return CE_Failure; }
    virtual CPLXMLNode *SerializeToXML( const char *pszVRTPath );

    virtual CPLErr  RasterIO( int nXOff, int nYOff, int nXSize, int nYSize, 
                              void *pData, int nBufXSize, int nBufYSize, 
                              GDALDataType eBufType, 
                              int nPixelSpace, int nLineSpace );

    virtual double GetMinimum( int nXSize, int nYSize, int *pbSuccess );
    virtual double GetMaximum( int nXSize, int nYSize, int *pbSuccess );

    VRTImageReadFunc    pfnReadFunc;
    void               *pCBData;
    GDALDataType        eType;
    
    float               fNoDataValue;
};

#endif /* ndef VIRTUALDATASET_H_INCLUDED */
