mitab_mapobjectblock.cpp

mitab,读取MapInfo的地图文件

      case TAB_GEOM_ELLIPSE_C:
      case TAB_GEOM_ELLIPSE:
        poObj = new TABMAPObjRectEllipse;
        break;
      case TAB_GEOM_TEXT_C:
      case TAB_GEOM_TEXT:
        poObj = new TABMAPObjText;
        break;
      case TAB_GEOM_MULTIPOINT_C:
      case TAB_GEOM_MULTIPOINT:
      case TAB_GEOM_V800_MULTIPOINT_C:
      case TAB_GEOM_V800_MULTIPOINT:
        poObj = new TABMAPObjMultiPoint;
        break;
      case TAB_GEOM_COLLECTION_C:
      case TAB_GEOM_COLLECTION:
      case TAB_GEOM_V800_COLLECTION_C:
      case TAB_GEOM_V800_COLLECTION:
        poObj = new TABMAPObjCollection();
    break;
      default:
        CPLError(CE_Failure, CPLE_AssertionFailed, 
                 "TABMAPObjHdr::NewObj(): Unsupported object type %d",
                 nNewObjType);
    }

    if (poObj)
    {
        poObj->m_nType = nNewObjType;
        poObj->m_nId = nId;
        poObj->m_nMinX = poObj->m_nMinY = poObj->m_nMaxX = poObj->m_nMaxY = 0;
    }

    return poObj;
}


/**********************************************************************
 *                    TABMAPObjHdr::ReadNextObj()
 *
 * Read next object in this block and allocate/init a new object for it
 * if succesful.  
 * Returns NULL in case of error or if we reached end of block.
 **********************************************************************/
TABMAPObjHdr *TABMAPObjHdr::ReadNextObj(TABMAPObjectBlock *poObjBlock,
                                        TABMAPHeaderBlock *poHeader)
{
    TABMAPObjHdr *poObjHdr = NULL;

    if (poObjBlock->AdvanceToNextObject(poHeader) != -1)
    {
        poObjHdr=TABMAPObjHdr::NewObj(poObjBlock->GetCurObjectType());
        if (poObjHdr &&
            ((poObjHdr->m_nId = poObjBlock->GetCurObjectId()) == -1 ||
             poObjHdr->ReadObj(poObjBlock) != 0 ) )
        {
            // Failed reading object in block... an error was already produced
            delete poObjHdr;
            return NULL;
        }
    }

    return poObjHdr;
}

/**********************************************************************
 *                    TABMAPObjHdr::IsCompressedType()
 *
 * Returns TRUE if the current object type uses compressed coordinates
 * or FALSE otherwise.
 **********************************************************************/
GBool TABMAPObjHdr::IsCompressedType()
{
    // Compressed types are 1, 4, 7, etc.
    return ((m_nType % 3) == 1 ? TRUE : FALSE);
}

/**********************************************************************
 *                   TABMAPObjHdr::WriteObjTypeAndId()
 *
 * Writetype+object id information... should be called only by the derived
 * classes' WriteObj() methods.
 *
 * Returns 0 on success, -1 on error.
 **********************************************************************/
int TABMAPObjHdr::WriteObjTypeAndId(TABMAPObjectBlock *poObjBlock)
{
    poObjBlock->WriteByte(m_nType);
    return poObjBlock->WriteInt32(m_nId);
}

/**********************************************************************
 *                   TABMAPObjHdr::SetMBR()
 *
 **********************************************************************/
void TABMAPObjHdr::SetMBR(GInt32 nMinX, GInt32 nMinY, 
                          GInt32 nMaxX, GInt32 nMaxY)
{
    m_nMinX = MIN(nMinX, nMaxX);
    m_nMinY = MIN(nMinY, nMaxY);
    m_nMaxX = MAX(nMinX, nMaxX);
    m_nMaxY = MAX(nMinY, nMaxY);
}


/**********************************************************************
 *                   class TABMAPObjLine
 *
 * Applies to 2-points LINEs only
 **********************************************************************/

/**********************************************************************
 *                   TABMAPObjLine::ReadObj()
 *
 * Read Object information starting after the object id which should 
 * have been read by TABMAPObjHdr::ReadNextObj() already.
 * This function should be called only by TABMAPObjHdr::ReadNextObj().
 *
 * Returns 0 on success, -1 on error.
 **********************************************************************/
int TABMAPObjLine::ReadObj(TABMAPObjectBlock *poObjBlock)
{
    poObjBlock->ReadIntCoord(IsCompressedType(), m_nX1, m_nY1);
    poObjBlock->ReadIntCoord(IsCompressedType(), m_nX2, m_nY2);

    m_nPenId = poObjBlock->ReadByte();      // Pen index

    SetMBR(m_nX1, m_nY1, m_nX2, m_nY2);

    if (CPLGetLastErrorNo() != 0)
        return -1;

    return 0;
}

/**********************************************************************
 *                   TABMAPObjLine::WriteObj()
 *
 * Write Object information with the type+object id
 *
 * Returns 0 on success, -1 on error.
 **********************************************************************/
int TABMAPObjLine::WriteObj(TABMAPObjectBlock *poObjBlock)
{
    // Write object type and id
    TABMAPObjHdr::WriteObjTypeAndId(poObjBlock);

    poObjBlock->WriteIntCoord(m_nX1, m_nY1, IsCompressedType());
    poObjBlock->WriteIntCoord(m_nX2, m_nY2, IsCompressedType());

    poObjBlock->WriteByte(m_nPenId);      // Pen index

    if (CPLGetLastErrorNo() != 0)
        return -1;

    return 0;
}

/**********************************************************************
 *                   class TABMAPObjPLine
 *
 * Applies to PLINE, MULTIPLINE and REGION object types
 **********************************************************************/

/**********************************************************************
 *                   TABMAPObjPLine::ReadObj()
 *
 * Read Object information starting after the object id which should 
 * have been read by TABMAPObjHdr::ReadNextObj() already.
 * This function should be called only by TABMAPObjHdr::ReadNextObj().
 *
 * Returns 0 on success, -1 on error.
 **********************************************************************/
int TABMAPObjPLine::ReadObj(TABMAPObjectBlock *poObjBlock)
{
    m_nCoordBlockPtr = poObjBlock->ReadInt32();
    m_nCoordDataSize = poObjBlock->ReadInt32();

    if (m_nCoordDataSize & 0x80000000)
    {
        m_bSmooth = TRUE;
        m_nCoordDataSize &= 0x7FFFFFFF; //Take smooth flag out of the value
    }
    else
    {
        m_bSmooth = FALSE;
    }

#ifdef TABDUMP
    printf("TABMAPObjPLine::ReadObj: m_nCoordDataSize = %d @ %d\n", 
           m_nCoordDataSize, m_nCoordBlockPtr);
#endif

    // Number of line segments applies only to MULTIPLINE/REGION but not PLINE
    if (m_nType == TAB_GEOM_PLINE_C ||
        m_nType == TAB_GEOM_PLINE )
    {
        m_numLineSections = 1;
    }
    else if (m_nType == TAB_GEOM_V800_REGION ||
             m_nType == TAB_GEOM_V800_REGION_C ||
             m_nType == TAB_GEOM_V800_MULTIPLINE ||
             m_nType == TAB_GEOM_V800_MULTIPLINE_C )
    {
        /* V800 REGIONS/MULTIPLINES use an int32 */
        m_numLineSections = poObjBlock->ReadInt32();
        /* ... followed by 33 unknown bytes */
        poObjBlock->ReadInt32();
        poObjBlock->ReadInt32();
        poObjBlock->ReadInt32();
        poObjBlock->ReadInt32();
        poObjBlock->ReadInt32();
        poObjBlock->ReadInt32();
        poObjBlock->ReadInt32();
        poObjBlock->ReadInt32();
        poObjBlock->ReadByte();
    }
    else
    {
        /* V300 and V450 REGIONS/MULTIPLINES use an int16 */
        m_numLineSections = poObjBlock->ReadInt16();
    }

#ifdef TABDUMP
    printf("PLINE/REGION: id=%d, type=%d, "
           "CoordBlockPtr=%d, CoordDataSize=%d, numLineSect=%d, bSmooth=%d\n",
           m_nId, m_nType, m_nCoordBlockPtr, m_nCoordDataSize, 
           m_numLineSections, m_bSmooth);
#endif

    if (IsCompressedType())
    {
        // Region center/label point, relative to compr. coord. origin
        // No it's not relative to the Object block center
        m_nLabelX = poObjBlock->ReadInt16();
        m_nLabelY = poObjBlock->ReadInt16();

        // Compressed coordinate origin (present only in compressed case!)
        m_nComprOrgX = poObjBlock->ReadInt32();
        m_nComprOrgY = poObjBlock->ReadInt32();

        m_nLabelX += m_nComprOrgX;
        m_nLabelY += m_nComprOrgY;

        m_nMinX = m_nComprOrgX + poObjBlock->ReadInt16();  // Read MBR
        m_nMinY = m_nComprOrgY + poObjBlock->ReadInt16();
        m_nMaxX = m_nComprOrgX + poObjBlock->ReadInt16();
        m_nMaxY = m_nComprOrgY + poObjBlock->ReadInt16();
    }
    else
    {
        // Region center/label point, relative to compr. coord. origin
        // No it's not relative to the Object block center
        m_nLabelX = poObjBlock->ReadInt32();
        m_nLabelY = poObjBlock->ReadInt32();

        m_nMinX = poObjBlock->ReadInt32();    // Read MBR
        m_nMinY = poObjBlock->ReadInt32();
        m_nMaxX = poObjBlock->ReadInt32();
        m_nMaxY = poObjBlock->ReadInt32();
    }


    if ( ! IsCompressedType() )
    {
        // Init. Compr. Origin to a default value in case type is ever changed
        m_nComprOrgX = (m_nMinX + m_nMaxX) / 2;
        m_nComprOrgY = (m_nMinY + m_nMaxY) / 2;
    }

    m_nPenId = poObjBlock->ReadByte();      // Pen index

    if (m_nType == TAB_GEOM_REGION ||
        m_nType == TAB_GEOM_REGION_C ||
        m_nType == TAB_GEOM_V450_REGION ||
        m_nType == TAB_GEOM_V450_REGION_C ||
        m_nType == TAB_GEOM_V800_REGION ||
        m_nType == TAB_GEOM_V800_REGION_C )
    {
        m_nBrushId = poObjBlock->ReadByte();    // Brush index... REGION only
    }
    else
    {
        m_nBrushId = 0;
    }

    if (CPLGetLastErrorNo() != 0)
        return -1;

    return 0;
}


/**********************************************************************
 *                   TABMAPObjPLine::WriteObj()
 *
 * Write Object information with the type+object id
 *
 * Returns 0 on success, -1 on error.
 **********************************************************************/
int TABMAPObjPLine::WriteObj(TABMAPObjectBlock *poObjBlock)
{
    // Write object type and id
    TABMAPObjHdr::WriteObjTypeAndId(poObjBlock);

    poObjBlock->WriteInt32(m_nCoordBlockPtr);

    // Combine smooth flag in the coord data size.
    if (m_bSmooth)
        poObjBlock->WriteInt32( m_nCoordDataSize | 0x80000000 );
    else
        poObjBlock->WriteInt32( m_nCoordDataSize );

    // Number of line segments applies only to MULTIPLINE/REGION but not PLINE
    if (m_nType == TAB_GEOM_V800_REGION ||
        m_nType == TAB_GEOM_V800_REGION_C ||
        m_nType == TAB_GEOM_V800_MULTIPLINE ||
        m_nType == TAB_GEOM_V800_MULTIPLINE_C )
    {
        /* V800 REGIONS/MULTIPLINES use an int32 */
        poObjBlock->WriteInt32(m_numLineSections);
        /* ... followed by 33 unknown bytes */
        poObjBlock->WriteZeros(33);
    }
    else if (m_nType != TAB_GEOM_PLINE_C &&
             m_nType != TAB_GEOM_PLINE )
    {
        /* V300 and V450 REGIONS/MULTIPLINES use an int16 */
        poObjBlock->WriteInt16(m_numLineSections);
    }

    if (IsCompressedType())
    {
        // Region center/label point, relative to compr. coord. origin
        // No it's not relative to the Object block center
        poObjBlock->WriteInt16(m_nLabelX - m_nComprOrgX);
        poObjBlock->WriteInt16(m_nLabelY - m_nComprOrgY);

        // Compressed coordinate origin (present only in compressed case!)
        poObjBlock->WriteInt32(m_nComprOrgX);
        poObjBlock->WriteInt32(m_nComprOrgY);
    }
    else
    {
        // Region center/label point
        poObjBlock->WriteInt32(m_nLabelX);
        poObjBlock->WriteInt32(m_nLabelY);
    }

    // MBR
    if (IsCompressedType())
    {
        // MBR relative to PLINE origin (and not object block center)
        poObjBlock->WriteInt16(m_nMinX - m_nComprOrgX);
        poObjBlock->WriteInt16(m_nMinY - m_nComprOrgY);
        poObjBlock->WriteInt16(m_nMaxX - m_nComprOrgX);
        poObjBlock->WriteInt16(m_nMaxY - m_nComprOrgY);
    }
    else
    {
        poObjBlock->WriteInt32(m_nMinX);
        poObjBlock->WriteInt32(m_nMinY);
        poObjBlock->WriteInt32(m_nMaxX);
        poObjBlock->WriteInt32(m_nMaxY);
    }

    poObjBlock->WriteByte(m_nPenId);      // Pen index

    if (m_nType == TAB_GEOM_REGION ||
        m_nType == TAB_GEOM_REGION_C ||
        m_nType == TAB_GEOM_V450_REGION ||
        m_nType == TAB_GEOM_V450_REGION_C ||
        m_nType == TAB_GEOM_V800_REGION ||
        m_nType == TAB_GEOM_V800_REGION_C )
    {
        poObjBlock->WriteByte(m_nBrushId);    // Brush index... REGION only
    }

    if (CPLGetLastErrorNo() != 0)
        return -1;

    return 0;