tabmapobjectblock.cpp

linux下一款GIS程序源码

// tabmapobjectblock.cpp: implementation of the TABMAPObjectBlock class.
//
//////////////////////////////////////////////////////////////////////

#include "tabmapobjectblock.h"

#include "ugk_errhandle.h"
#include "ugk_memopr.h"
#include "tabmapobjhdr.h" 

#define MAP_OBJECT_HEADER_SIZE   20


/**********************************************************************
 *                   TABMAPObjectBlock::TABMAPObjectBlock()
 *
 * Constructor.
 **********************************************************************/
TABMAPObjectBlock::TABMAPObjectBlock(TABAccess eAccessMode /*= TABRead*/):
    TABRawBinBlock(eAccessMode, TRUE)
{
    m_papoObjHdr = NULL;
    m_numObjects = 0;
}

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

    m_nMinX = 1000000000;
    m_nMinY = 1000000000;
    m_nMaxX = -1000000000;
    m_nMaxY = -1000000000;

    FreeObjectArray();
}



/**********************************************************************
 *                   TABMAPObjectBlock::FreeObjectArray()
 **********************************************************************/
void TABMAPObjectBlock::FreeObjectArray()
{
    if (m_numObjects > 0 && m_papoObjHdr)
    {
        for(int i=0; i<m_numObjects; i++)
            delete m_papoObjHdr[i];
        UGK_Free(m_papoObjHdr);
    }
    m_numObjects = 0;
}


/**********************************************************************
 *                   TABMAPObjectBlock::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 
 * UGKError() will have been called.
 **********************************************************************/
int     TABMAPObjectBlock::InitBlockFromData(UGKByte *pabyBuf, int nSize, 
                                         UGKBool 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_OBJECT_BLOCK)
    {
        UGKError(ET_Failure, UGKErr_FileIO,
                  "InitBlockFromData(): Invalid Block Type: got %d expected %d",
                  m_nBlockType, TABMAP_OBJECT_BLOCK);
        UGK_Free(m_pabyBuf);       
        return -1;
    }

    /*-----------------------------------------------------------------
     * Init member variables
     *----------------------------------------------------------------*/
    FreeObjectArray();

    GotoByteInBlock(0x002);
    m_numDataBytes = ReadInt16();       /* Excluding 4 bytes header */

    m_nCenterX = ReadInt32();
    m_nCenterY = ReadInt32();

    m_nFirstCoordBlock = ReadInt32();
    m_nLastCoordBlock = ReadInt32();

    m_nCurObjectOffset = -1;
    m_nCurObjectId = -1;

    return 0;
}



/************************************************************************/
/*                        AdvanceToNextObject()                         */
/************************************************************************/

int TABMAPObjectBlock::AdvanceToNextObject( TABMAPHeaderBlock *poHeader )

{
    if( m_nCurObjectId == -1 ) 
    {
        m_nCurObjectOffset = 20;
    }
    else
    {
        m_nCurObjectOffset += poHeader->GetMapObjectSize( m_nCurObjectType );
    }
    
    

    if( m_nCurObjectOffset + 5 < m_numDataBytes + 20 )
    {
        GotoByteInBlock( m_nCurObjectOffset );
        m_nCurObjectType = ReadByte();  //读第一个字节从而知道此对象长度
    }
    else
    {
        m_nCurObjectType = -1;
    }

    if( m_nCurObjectType <= 0 || m_nCurObjectType >= 0x80 )
    {
        m_nCurObjectType = -1;
        m_nCurObjectId = -1;
        m_nCurObjectOffset = -1;
    }
    else
    {
        m_nCurObjectId = ReadInt32(); //读取1-4字节

        // Is this object marked as deleted?  If so, skip it.
        // I check both the top bits but I have only seen this occur
        // with the second highest bit set (ie. in usa/states.tab). NFW.

        if( (((UGKUInt32)m_nCurObjectId) & (UGKUInt32) 0xC0000000) != 0 )
        {
            m_nCurObjectId = AdvanceToNextObject( poHeader ); //表示已经标志删除
        }
    }

    return m_nCurObjectId;
}



/**********************************************************************
 *                   TABMAPObjectBlock::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 
 * UGKError() will have been called.
 **********************************************************************/
int     TABMAPObjectBlock::CommitToFile()
{
    int nStatus = 0;

    if ( m_pabyBuf == NULL )
    {
        UGKError(ET_Failure, UGKErr_AssertionFailed, 
          "TABMAPObjectBlock::CommitToFile(): Block has not been initialized yet!");
        return -1;
    }

    /*-----------------------------------------------------------------
     * Make sure 20 bytes block header is up to date.
     *----------------------------------------------------------------*/
    GotoByteInBlock(0x000);

    WriteInt16(TABMAP_OBJECT_BLOCK);    // Block type code
    WriteInt16(m_nSizeUsed - MAP_OBJECT_HEADER_SIZE); // num. bytes used
    
    WriteInt32(m_nCenterX);
    WriteInt32(m_nCenterY);

    WriteInt32(m_nFirstCoordBlock);
    WriteInt32(m_nLastCoordBlock);

    nStatus = UGKGetLastErrorNo();

    /*-----------------------------------------------------------------
     * Write all the individual objects
     *----------------------------------------------------------------*/
    for(int i=0; i<m_numObjects; i++)
    {
        m_papoObjHdr[i]->WriteObj(this);
    }

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

    return nStatus;
}



/**********************************************************************
 *                   TABMAPObjectBlock::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 
 * UGKError() will have been called.
 **********************************************************************/
int     TABMAPObjectBlock::InitNewBlock(FILE *fpSrc, int nBlockSize, 
                                        int nFileOffset /* = 0*/)
{
    /*-----------------------------------------------------------------
     * Start with the default initialisation
     *----------------------------------------------------------------*/
    if ( TABRawBinBlock::InitNewBlock(fpSrc, nBlockSize, nFileOffset) != 0)
        return -1;

    /*-----------------------------------------------------------------
     * And then set default values for the block header.
     *----------------------------------------------------------------*/
    // Set block MBR to extreme values to force an update on the first
    // UpdateMBR() call.
    m_nMinX = 1000000000;
    m_nMaxX = -1000000000;
    m_nMinY = 1000000000;
    m_nMaxY = -1000000000;

    // Make sure there is no object header left from last time.
    FreeObjectArray();

    m_numDataBytes = 0;       /* Data size excluding header */
    m_nCenterX = m_nCenterY = 0;
    m_nFirstCoordBlock = 0;
    m_nLastCoordBlock = 0;

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

        WriteInt16(TABMAP_OBJECT_BLOCK);// Block type code
        WriteInt16(0);                  // num. bytes used, excluding header
    
        // MBR center here... will be written in CommitToFile()