mitab_mapcoordblock.cpp

用于读取TAB、MIF、SHP文件的类

/**********************************************************************
 * $Id: mitab_mapcoordblock.cpp,v 1.14 2005/10/06 19:15:31 dmorissette Exp $
 *
 * Name:     mitab_mapcoordblock.cpp
 * Project:  MapInfo TAB Read/Write library
 * Language: C++
 * Purpose:  Implementation of the TABMAPCoordBlock class used to handle
 *           reading/writing of the .MAP files' coordinate blocks
 * Author:   Daniel Morissette, [e-mail]
 *
 **********************************************************************
 * Copyright (c) 1999-2001, Daniel Morissette
 *
 * 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.
 **********************************************************************
 *
 * $Log: mitab_mapcoordblock.cpp,v $
 * Revision 1.14  2005/10/06 19:15:31  dmorissette
 * Collections: added support for reading/writing pen/brush/symbol ids and
 * for writing collection objects to .TAB/.MAP (bug 1126)
 *
 * Revision 1.13  2004/06/30 20:29:04  dmorissette
 * Fixed refs to old address [e-mail]
 *
 * Revision 1.12  2002/08/27 17:18:23  warmerda
 * improved CPL error testing
 *
 * Revision 1.11  2001/11/17 21:54:06  daniel
 * Made several changes in order to support writing objects in 16 bits coordinate format.
 * New TABMAPObjHdr-derived classes are used to hold object info in mem until block is full.
 *
 * Revision 1.10  2001/05/09 17:45:12  daniel
 * Support reading and writing data blocks > 512 bytes (for text objects).
 *
 * Revision 1.9  2000/10/10 19:05:12  daniel
 * Fixed ReadBytes() to allow strings overlapping on 2 blocks
 *
 * Revision 1.8  2000/02/28 16:58:55  daniel
 * Added V450 object types with num_points > 32767 and pen width in points
 *
 * Revision 1.7  2000/01/15 22:30:44  daniel
 * Switch to MIT/X-Consortium OpenSource license
 *
 * Revision 1.6  1999/11/08 04:29:31  daniel
 * Fixed problem with compressed coord. offset for regions and multiplines
 *
 * Revision 1.5  1999/10/06 15:19:11  daniel
 * Do not automatically init. curr. feature MBR when block is initialized
 *
 * Revision 1.4  1999/10/06 13:18:55  daniel
 * Fixed uninitialized class members
 *
 * Revision 1.3  1999/09/29 04:25:42  daniel
 * Fixed typo in GetFeatureMBR()
 *
 * Revision 1.2  1999/09/26 14:59:36  daniel
 * Implemented write support
 *
 * Revision 1.1  1999/07/12 04:18:24  daniel
 * Initial checkin
 *
 **********************************************************************/

#include "mitab.h"

/*=====================================================================
 *                      class TABMAPCoordBlock
 *====================================================================*/

#define MAP_COORD_HEADER_SIZE   8

/**********************************************************************
 *                   TABMAPCoordBlock::TABMAPCoordBlock()
 *
 * Constructor.
 **********************************************************************/
TABMAPCoordBlock::TABMAPCoordBlock(TABAccess eAccessMode /*= TABRead*/):
    TABRawBinBlock(eAccessMode, TRUE)
{
    m_nComprOrgX = m_nComprOrgY = m_nNextCoordBlock = m_numDataBytes = 0;

    m_numBlocksInChain = 1;  // Current block counts as 1
 
    m_poBlockManagerRef = NULL;

    m_nTotalDataSize = 0;
    m_nFeatureDataSize = 0;

    m_nFeatureXMin = m_nMinX = 1000000000;
    m_nFeatureYMin = m_nMinY = 1000000000;
    m_nFeatureXMax = m_nMaxX = -1000000000;
    m_nFeatureYMax = m_nMaxY = -1000000000;

}

/**********************************************************************
 *                   TABMAPCoordBlock::~TABMAPCoordBlock()
 *
 * Destructor.
 **********************************************************************/
TABMAPCoordBlock::~TABMAPCoordBlock()
{

}


/**********************************************************************
 *                   TABMAPCoordBlock::InitBlockFromData()
 *
 * Perform some initialization on the block after its binary data has
 * been set or changed (or loaded from a file).
 *
 * Returns 0 if succesful or -1 if an error happened, in which case 
 * CPLError() will have been called.
 **********************************************************************/
int     TABMAPCoordBlock::InitBlockFromData(GByte *pabyBuf, int nSize, 
                                         GBool bMakeCopy /* = TRUE */,
                                         FILE *fpSrc /* = NULL */, 
                                         int nOffset /* = 0 */)
{
    int nStatus;

    /*-----------------------------------------------------------------
     * First of all, we must call the base class' InitBlockFromData()
     *----------------------------------------------------------------*/
    nStatus = TABRawBinBlock::InitBlockFromData(pabyBuf, nSize, bMakeCopy,
                                            fpSrc, nOffset);
    if (nStatus != 0)   
        return nStatus;

    /*-----------------------------------------------------------------
     * Validate block type
     *----------------------------------------------------------------*/
    if (m_nBlockType != TABMAP_COORD_BLOCK)
    {
        CPLError(CE_Failure, CPLE_FileIO,
                 "InitBlockFromData(): Invalid Block Type: got %d expected %d",
                 m_nBlockType, TABMAP_COORD_BLOCK);
        CPLFree(m_pabyBuf);
        m_pabyBuf = NULL;
        return -1;
    }

    /*-----------------------------------------------------------------
     * Init member variables
     *----------------------------------------------------------------*/
    GotoByteInBlock(0x002);
    m_numDataBytes = ReadInt16();       /* Excluding 8 bytes header */

    m_nNextCoordBlock = ReadInt32();

    // Set the real SizeUsed based on numDataBytes
    m_nSizeUsed = m_numDataBytes + MAP_COORD_HEADER_SIZE;

    /*-----------------------------------------------------------------
     * The read ptr is now located at the beginning of the data part.
     *----------------------------------------------------------------*/
    GotoByteInBlock(MAP_COORD_HEADER_SIZE);

    return 0;
}

/**********************************************************************
 *                   TABMAPCoordBlock::CommitToFile()
 *
 * Commit the current state of the binary block to the file to which 
 * it has been previously attached.
 *
 * This method makes sure all values are properly set in the map object
 * block header and then calls TABRawBinBlock::CommitToFile() to do
 * the actual writing to disk.
 *
 * Returns 0 if succesful or -1 if an error happened, in which case 
 * CPLError() will have been called.
 **********************************************************************/
int     TABMAPCoordBlock::CommitToFile()
{
    int nStatus = 0;

    CPLErrorReset();

    if ( m_pabyBuf == NULL )
    {
        CPLError(CE_Failure, CPLE_AssertionFailed, 
                 "CommitToFile(): Block has not been initialized yet!");
        return -1;
    }

    /*-----------------------------------------------------------------
     * Make sure 8 bytes block header is up to date.
     *----------------------------------------------------------------*/
    GotoByteInBlock(0x000);

    WriteInt16(TABMAP_COORD_BLOCK);    // Block type code
    WriteInt16(m_nSizeUsed - MAP_COORD_HEADER_SIZE); // num. bytes used
    WriteInt32(m_nNextCoordBlock);

    if( CPLGetLastErrorType() == CE_Failure )
        nStatus = CPLGetLastErrorNo();

    /*-----------------------------------------------------------------
     * OK, call the base class to write the block to disk.
     *----------------------------------------------------------------*/
    if (nStatus == 0)
        nStatus = TABRawBinBlock::CommitToFile();

    return nStatus;
}

/**********************************************************************
 *                   TABMAPCoordBlock::InitNewBlock()
 *
 * Initialize a newly created block so that it knows to which file it
 * is attached, its block size, etc . and then perform any specific 
 * initialization for this block type, including writing a default 
 * block header, etc. and leave the block ready to receive data.
 *
 * This is an alternative to calling ReadFromFile() or InitBlockFromData()
 * that puts the block in a stable state without loading any initial
 * data in it.
 *
 * Returns 0 if succesful or -1 if an error happened, in which case 
 * CPLError() will have been called.
 **********************************************************************/
int     TABMAPCoordBlock::InitNewBlock(FILE *fpSrc, int nBlockSize, 
                                        int nFileOffset /* = 0*/)
{
    CPLErrorReset();

    /*-----------------------------------------------------------------
     * Start with the default initialisation
     *----------------------------------------------------------------*/
    if ( TABRawBinBlock::InitNewBlock(fpSrc, nBlockSize, nFileOffset) != 0)
        return -1;

    /*-----------------------------------------------------------------
     * And then set default values for the block header.
     *
     * IMPORTANT: Do not reset m_nComprOrg here because its value needs to be
     * maintained between blocks in the same chain.
     *----------------------------------------------------------------*/
    m_nNextCoordBlock = 0;
 
    m_numDataBytes = 0;

    // m_nMin/Max are used to keep track of current block MBR
    // FeatureMin/Max should not be reset here since feature coords can
    // be split on several blocks
    m_nMinX = 1000000000;
    m_nMinY = 1000000000;
    m_nMaxX = -1000000000;
    m_nMaxY = -1000000000;

    if (m_eAccess != TABRead)
    {
        GotoByteInBlock(0x000);

        WriteInt16(TABMAP_COORD_BLOCK); // Block type code
        WriteInt16(0);                  // num. bytes used, excluding header
        WriteInt32(0);                  // Pointer to next coord block
    }

    if (CPLGetLastErrorType() == CE_Failure )
        return -1;

    return 0;