Line data    Source code

       1             : /******************************************************************************
       2             :  *
       3             :  * Project:  GeoTIFF Driver
       4             :  * Purpose:  GDAL GeoTIFF support.
       5             :  * Author:   Frank Warmerdam, warmerdam@pobox.com
       6             :  *
       7             :  ******************************************************************************
       8             :  * Copyright (c) 1998, 2002, Frank Warmerdam <warmerdam@pobox.com>
       9             :  * Copyright (c) 2007-2015, Even Rouault <even dot rouault at spatialys dot com>
      10             :  *
      11             :  * SPDX-License-Identifier: MIT
      12             :  ****************************************************************************/
      13             : 
      14             : #include "gtiffsplitband.h"
      15             : 
      16             : #include "gtiffdataset.h"
      17             : #include "gdal_priv.h"
      18             : 
      19             : /************************************************************************/
      20             : /*                           GTiffSplitBand()                           */
      21             : /************************************************************************/
      22             : 
      23      131118 : GTiffSplitBand::GTiffSplitBand(GTiffDataset *poDSIn, int nBandIn)
      24      131118 :     : GTiffRasterBand(poDSIn, nBandIn)
      25             : {
      26      131118 :     nBlockXSize = poDS->GetRasterXSize();
      27      131118 :     nBlockYSize = 1;
      28      131118 : }
      29             : 
      30             : /************************************************************************/
      31             : /*                       IGetDataCoverageStatus()                       */
      32             : /************************************************************************/
      33             : 
      34           0 : int GTiffSplitBand::IGetDataCoverageStatus(int, int, int, int, int, double *)
      35             : {
      36             :     return GDAL_DATA_COVERAGE_STATUS_UNIMPLEMENTED |
      37           0 :            GDAL_DATA_COVERAGE_STATUS_DATA;
      38             : }
      39             : 
      40             : /************************************************************************/
      41             : /*                             IReadBlock()                             */
      42             : /************************************************************************/
      43             : 
      44       78291 : CPLErr GTiffSplitBand::IReadBlock(int /* nBlockXOff */, int nBlockYOff,
      45             :                                   void *pImage)
      46             : 
      47             : {
      48       78291 :     m_poGDS->Crystalize();
      49             : 
      50             :     // Optimization when reading the same line in a contig multi-band TIFF.
      51       78291 :     if (m_poGDS->m_nPlanarConfig == PLANARCONFIG_CONTIG &&
      52       48291 :         m_poGDS->nBands > 1 && m_poGDS->m_nLoadedBlock == nBlockYOff)
      53             :     {
      54        4011 :         goto extract_band_data;
      55             :     }
      56             : 
      57       74280 :     if (m_poGDS->m_nPlanarConfig == PLANARCONFIG_CONTIG && m_poGDS->nBands > 1)
      58             :     {
      59       40276 :         if (m_poGDS->m_pabyBlockBuf == nullptr)
      60             :         {
      61          14 :             m_poGDS->m_pabyBlockBuf = static_cast<GByte *>(
      62           7 :                 VSI_MALLOC_VERBOSE(TIFFScanlineSize(m_poGDS->m_hTIFF)));
      63           7 :             if (m_poGDS->m_pabyBlockBuf == nullptr)
      64             :             {
      65           1 :                 return CE_Failure;
      66             :             }
      67             :         }
      68             :     }
      69             :     else
      70             :     {
      71       34004 :         CPLAssert(TIFFScanlineSize(m_poGDS->m_hTIFF) == nBlockXSize);
      72             :     }
      73             : 
      74             :     /* -------------------------------------------------------------------- */
      75             :     /*      Read through to target scanline.                                */
      76             :     /* -------------------------------------------------------------------- */
      77       74279 :     if (m_poGDS->m_nLoadedBlock >= nBlockYOff)
      78          33 :         m_poGDS->m_nLoadedBlock = -1;
      79             : 
      80       74279 :     if (m_poGDS->m_nPlanarConfig == PLANARCONFIG_SEPARATE &&
      81       30000 :         m_poGDS->nBands > 1)
      82             :     {
      83             :         // If we change of band, we must start reading the
      84             :         // new strip from its beginning.
      85       30000 :         if (m_poGDS->m_nLastBandRead != nBand)
      86          20 :             m_poGDS->m_nLoadedBlock = -1;
      87       30000 :         m_poGDS->m_nLastBandRead = nBand;
      88             :     }
      89             : 
      90      203674 :     while (m_poGDS->m_nLoadedBlock < nBlockYOff)
      91             :     {
      92      129397 :         ++m_poGDS->m_nLoadedBlock;
      93      194550 :         if (TIFFReadScanline(m_poGDS->m_hTIFF,
      94       61149 :                              m_poGDS->m_pabyBlockBuf ? m_poGDS->m_pabyBlockBuf
      95             :                                                      : pImage,
      96      129397 :                              m_poGDS->m_nLoadedBlock,
      97      129397 :                              (m_poGDS->m_nPlanarConfig == PLANARCONFIG_SEPARATE)
      98       64244 :                                  ? static_cast<uint16_t>(nBand - 1)
      99      129399 :                                  : 0) == -1 &&
     100           2 :             !m_poGDS->m_bIgnoreReadErrors)
     101             :         {
     102           2 :             ReportError(CE_Failure, CPLE_AppDefined,
     103             :                         "TIFFReadScanline() failed.");
     104           2 :             m_poGDS->m_nLoadedBlock = -1;
     105           2 :             return CE_Failure;
     106             :         }
     107             :     }
     108             : 
     109       74277 : extract_band_data:
     110             :     /* -------------------------------------------------------------------- */
     111             :     /*      Extract band data from contig buffer.                           */
     112             :     /* -------------------------------------------------------------------- */
     113       78288 :     if (m_poGDS->m_pabyBlockBuf != nullptr)
     114             :     {
     115       44286 :         for (int iPixel = 0, iSrcOffset = nBand - 1, iDstOffset = 0;
     116      180732 :              iPixel < nBlockXSize;
     117      136446 :              ++iPixel, iSrcOffset += m_poGDS->nBands, ++iDstOffset)
     118             :         {
     119      136446 :             static_cast<GByte *>(pImage)[iDstOffset] =
     120      136446 :                 m_poGDS->m_pabyBlockBuf[iSrcOffset];
     121             :         }
     122             :     }
     123             : 
     124       78288 :     return CE_None;
     125             : }
     126             : 
     127             : /************************************************************************/
     128             : /*                            IWriteBlock()                             */
     129             : /************************************************************************/
     130             : 
     131           0 : CPLErr GTiffSplitBand::IWriteBlock(int /* nBlockXOff */, int /* nBlockYOff */,
     132             :                                    void * /* pImage */)
     133             : 
     134             : {
     135           0 :     ReportError(CE_Failure, CPLE_AppDefined, "Split bands are read-only.");
     136           0 :     return CE_Failure;
     137             : }