ultimatepp/bazaar/plugin/gdal/frmts/pgchip/pgchiprasterband.cpp

/******************************************************************************
 *
 * File :    pgchiprasterband.cpp
 * Project:  PGCHIP Driver
 * Purpose:  GDALRasterBand code for POSTGIS CHIP/GDAL Driver 
 * Author:   Benjamin Simon, noumayoss@gmail.com
 *
 ******************************************************************************
 * Copyright (c) 2005, Benjamin Simon, noumayoss@gmail.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.
 ******************************************************************************
 * 
 * Revision 1.1  2005/08/29 bsimon
 * New
 *
 */

/************************************************************************/
/* ==================================================================== */
/*                            PGCHIPRasterBand                          */
/* ==================================================================== */
/************************************************************************/

#include "pgchip.h"


/************************************************************************/
/*                           PGCHIPRasterBand()                         */
/************************************************************************/

PGCHIPRasterBand::PGCHIPRasterBand( PGCHIPDataset *poDS, int nBand ){

    this->poDS = poDS;
    this->nBand = nBand;
    
    if( poDS->nBitDepth == 16 )
        eDataType = GDT_UInt16;
    else
        eDataType = GDT_Byte;

    nBlockXSize = poDS->GetRasterXSize();
    nBlockYSize = 1;
    
}

/************************************************************************/
/*                             IReadBlock()                             */
/************************************************************************/

CPLErr PGCHIPRasterBand::IReadBlock( int nBlockXOff, int nBlockYOff,
                                  void * pImage ){

    PGCHIPDataset *poGDS = (PGCHIPDataset *) poDS;
        
    int        chipDataSize;
    int        bandSize;
    int        nPixelSize;
    int        nPixelOffset;
    int        nXSize;
    int        i;
    
    // Must start on the very left
    CPLAssert( nBlockXOff == 0 );
           
    
    if( poGDS->nBitDepth == 16 )
        nPixelSize = 2;
    else
        nPixelSize = 1;
    
    nXSize = GetXSize();
    bandSize = nPixelSize * nXSize;
    int sizePalette = 0;        
    
    if(poGDS->nColorType == PGCHIP_COLOR_TYPE_PALETTE){
        sizePalette = (int)poGDS->PGCHIP->compression * sizeof(pgchip_color);
    }
    
    // Determine size of whole Image Data
    chipDataSize = poGDS->PGCHIP->size - (sizeof(CHIP)-sizeof(void*)) - sizePalette;
    
//printf("sizePalette: %d\n", sizePalette);
     
/* -------------------------------------------------------------------- */
/*      Extracting band from pointer                                    */
/* -------------------------------------------------------------------- */
     
               
//printf("About to IReadBlock nBlockXOff: %d  nBlockYOff: %d, pixelSize: %d, pixelOffset:%d nXSize: %d, bandSize:%d\n", nBlockXOff, nBlockYOff, nPixelSize, nPixelOffset, nXSize, bandSize);

    char* dataptr = (char*)&(poGDS->PGCHIP->data);
    size_t bandoffset = nBlockYOff * bandSize + nBlockXOff * nPixelSize;

    // This is for supporting nBands > 1
    nPixelOffset = poGDS->nBands * nPixelSize;

    if( nPixelSize == 1 ){
    
        char *bufferData = (char*)(dataptr + bandoffset);
            
        for(i = 0; i < nXSize; i++ ){
            ((char *) pImage)[i] = bufferData[i*nPixelOffset];
        }
    }
    else {

        CPLAssert (nPixelSize==2);
    
        //GUInt16 *bufferData = (GUInt16 *)((char*)(dataptr + bandoffset));
         
        for(i = 0; i < nXSize; i++ )
        {
            // I'm not sure what we need this for
            size_t offset = i*nPixelOffset;

#if 0
            printf("Reading from ptr %p at offset %d (%d total offset - %d)\n",
                bufferData, offset,
                (char*)&(bufferData[offset])-dataptr,
                bandoffset+offset);
#endif
            
            ((GUInt16 *) pImage)[i] = *(GUInt16*)&dataptr[bandoffset+offset];
            
        }
    }
     
         
    return CE_None;
}



/************************************************************************/
/*                       GetColorInterpretation()                       */
/************************************************************************/
GDALColorInterp PGCHIPRasterBand::GetColorInterpretation(){

    PGCHIPDataset	*poGDS = (PGCHIPDataset *) poDS;

    if( poGDS->nColorType == PGCHIP_COLOR_TYPE_GRAY ){
        return GCI_GrayIndex;
    }
    else  if( poGDS->nColorType == PGCHIP_COLOR_TYPE_PALETTE ){
        return GCI_PaletteIndex;    
    }
    else if(poGDS->nColorType == PGCHIP_COLOR_TYPE_RGB_ALPHA){
        if( nBand == 1 )
            return GCI_RedBand;
        else if( nBand == 2 )
            return GCI_GreenBand;
        else if( nBand == 3 )
            return GCI_BlueBand;
        else 
            return GCI_AlphaBand;
    }
    
    return GCI_GrayIndex;
}


/************************************************************************/
/*                           GetColorTable()                            */
/************************************************************************/

GDALColorTable *PGCHIPRasterBand::GetColorTable(){

    PGCHIPDataset	*poGDS = (PGCHIPDataset *) poDS;

    if( nBand == 1 )
        return poGDS->poColorTable;
    else
        return NULL;
}