dgnread.cpp

GIS系统支持库Geospatial Data Abstraction Library代码.GDAL is a translator library for raster geospatial dat

          
          if( psDGN->dimension == 2 )
          {
              psEllipse->rotation = DGN_INT32( psDGN->abyElem + 60 );
              psEllipse->rotation = psEllipse->rotation / 360000.0;
          
              memcpy( &(psEllipse->origin.x), psDGN->abyElem + 64, 8 );
              DGN2IEEEDouble( &(psEllipse->origin.x) );
              
              memcpy( &(psEllipse->origin.y), psDGN->abyElem + 72, 8 );
              DGN2IEEEDouble( &(psEllipse->origin.y) );
          }
          else 
          {
              /* for now we don't try to handle quaternion */
              psEllipse->rotation = 0;
          
              memcpy( &(psEllipse->origin.x), psDGN->abyElem + 76, 8 );
              DGN2IEEEDouble( &(psEllipse->origin.x) );
              
              memcpy( &(psEllipse->origin.y), psDGN->abyElem + 84, 8 );
              DGN2IEEEDouble( &(psEllipse->origin.y) );

              memcpy( &(psEllipse->origin.z), psDGN->abyElem + 92, 8 );
              DGN2IEEEDouble( &(psEllipse->origin.z) );

              psEllipse->quat[0] = DGN_INT32( psDGN->abyElem + 60 );
              psEllipse->quat[1] = DGN_INT32( psDGN->abyElem + 64 );
              psEllipse->quat[2] = DGN_INT32( psDGN->abyElem + 68 );
              psEllipse->quat[3] = DGN_INT32( psDGN->abyElem + 72 );
          }

          DGNTransformPoint( psDGN, &(psEllipse->origin) );

      }
      break;

      case DGNT_TEXT:
      {
          DGNElemText *psText;
          int         num_chars, text_off;

          if( psDGN->dimension == 2 )
              num_chars = psDGN->abyElem[58];
          else
              num_chars = psDGN->abyElem[74];

          psText = (DGNElemText *) CPLCalloc(sizeof(DGNElemText)+num_chars,1);
          psElement = (DGNElemCore *) psText;
          psElement->stype = DGNST_TEXT;
          DGNParseCore( psDGN, psElement );

          psText->font_id = psDGN->abyElem[36];
          psText->justification = psDGN->abyElem[37];
          psText->length_mult = (DGN_INT32( psDGN->abyElem + 38 ))
              * psDGN->scale * 6.0 / 1000.0;
          psText->height_mult = (DGN_INT32( psDGN->abyElem + 42 ))
              * psDGN->scale * 6.0 / 1000.0;

          if( psDGN->dimension == 2 )
          {
              psText->rotation = DGN_INT32( psDGN->abyElem + 46 );
              psText->rotation = psText->rotation / 360000.0;

              psText->origin.x = DGN_INT32( psDGN->abyElem + 50 );
              psText->origin.y = DGN_INT32( psDGN->abyElem + 54 );
              text_off = 60;
          }
          else
          {
              /* leave quaternion for later */

              psText->origin.x = DGN_INT32( psDGN->abyElem + 62 );
              psText->origin.y = DGN_INT32( psDGN->abyElem + 66 );
              psText->origin.z = DGN_INT32( psDGN->abyElem + 70 );
              text_off = 76;
          }

          DGNTransformPoint( psDGN, &(psText->origin) );

          /* experimental multibyte support from Ason Kang ([e-mail])*/
          if (*(psDGN->abyElem + text_off) == 0xFF 
              && *(psDGN->abyElem + text_off + 1) == 0xFD) 
          {
              int n=0;
              for (int i=0;i<num_chars/2-1;i++) {
                  unsigned short w;
                  memcpy(&w,psDGN->abyElem + text_off + 2 + i*2 ,2);
                  w = CPL_LSBWORD16(w);
                  if (w<256) { // if alpa-numeric code area : Normal character 
                      *(psText->string + n) = (char) (w & 0xFF); 
                      n++; // skip 1 byte;
                  }
                  else { // if extend code area : 2 byte Korean character 
                      *(psText->string + n)     = (char) (w >> 8);   // hi
                      *(psText->string + n + 1) = (char) (w & 0xFF); // lo
                      n+=2; // 2 byte
                  }
              }
              psText->string[n] = '\0'; // terminate C string
          }
          else
          {
              memcpy( psText->string, psDGN->abyElem + text_off, num_chars );
              psText->string[num_chars] = '\0';
          }
      }
      break;

      case DGNT_TCB:
        psElement = DGNParseTCB( psDGN );
        break;

      case DGNT_COMPLEX_CHAIN_HEADER:
      case DGNT_COMPLEX_SHAPE_HEADER:
      {
          DGNElemComplexHeader *psHdr;

          psHdr = (DGNElemComplexHeader *) 
              CPLCalloc(sizeof(DGNElemComplexHeader),1);
          psElement = (DGNElemCore *) psHdr;
          psElement->stype = DGNST_COMPLEX_HEADER;
          DGNParseCore( psDGN, psElement );

          psHdr->totlength = psDGN->abyElem[36] + psDGN->abyElem[37] * 256;
          psHdr->numelems = psDGN->abyElem[38] + psDGN->abyElem[39] * 256;
      }
      break;

      case DGNT_TAG_VALUE:
      {
          DGNElemTagValue *psTag;

          psTag = (DGNElemTagValue *) 
              CPLCalloc(sizeof(DGNElemTagValue),1);
          psElement = (DGNElemCore *) psTag;
          psElement->stype = DGNST_TAG_VALUE;
          DGNParseCore( psDGN, psElement );

          psTag->tagType = psDGN->abyElem[74] + psDGN->abyElem[75] * 256;
          memcpy( &(psTag->tagSet), psDGN->abyElem + 68, 4 );
          psTag->tagSet = CPL_LSBWORD32(psTag->tagSet);
          psTag->tagIndex = psDGN->abyElem[72] + psDGN->abyElem[73] * 256;
          psTag->tagLength = psDGN->abyElem[150] + psDGN->abyElem[151] * 256;

          if( psTag->tagType == 1 )
          {
              psTag->tagValue.string = 
                  CPLStrdup( (char *) psDGN->abyElem + 154 );
          }
          else if( psTag->tagType == 3 )
          {
              memcpy( &(psTag->tagValue.integer), 
                      psDGN->abyElem + 154, 4 );
              psTag->tagValue.integer = 
                  CPL_LSBWORD32( psTag->tagValue.integer );
          }
          else if( psTag->tagType == 4 )
          {
              memcpy( &(psTag->tagValue.real), 
                      psDGN->abyElem + 154, 8 );
              DGN2IEEEDouble( &(psTag->tagValue.real) );
          }
      }
      break;

      case DGNT_APPLICATION_ELEM:
        if( nLevel == 24 )
        {
            psElement = DGNParseTagSet( psDGN );
        }
        else
        {
            psElement = (DGNElemCore *) CPLCalloc(sizeof(DGNElemCore),1);
            psElement->stype = DGNST_CORE;
            DGNParseCore( psDGN, psElement );
        }
        break;

      case DGNT_CONE:
        {
          DGNElemCone *psCone;

          psCone = (DGNElemCone *) CPLCalloc(sizeof(DGNElemCone),1);
          psElement = (DGNElemCore *) psCone;
          psElement->stype = DGNST_CONE;
          DGNParseCore( psDGN, psElement );

          CPLAssert( psDGN->dimension == 3 );
          psCone->unknown = psDGN->abyElem[36] + psDGN->abyElem[37] * 256;
          psCone->quat[0] = DGN_INT32( psDGN->abyElem + 38 );
          psCone->quat[1] = DGN_INT32( psDGN->abyElem + 42 );
          psCone->quat[2] = DGN_INT32( psDGN->abyElem + 46 );
          psCone->quat[3] = DGN_INT32( psDGN->abyElem + 50 );
 
          memcpy( &(psCone->center_1.x), psDGN->abyElem + 54, 8 );
          DGN2IEEEDouble( &(psCone->center_1.x) );
          memcpy( &(psCone->center_1.y), psDGN->abyElem + 62, 8 );
          DGN2IEEEDouble( &(psCone->center_1.y) );
          memcpy( &(psCone->center_1.z), psDGN->abyElem + 70, 8 );
          DGN2IEEEDouble( &(psCone->center_1.z) );
          memcpy( &(psCone->radius_1), psDGN->abyElem + 78, 8 );
          DGN2IEEEDouble( &(psCone->radius_1) );

          memcpy( &(psCone->center_2.x), psDGN->abyElem + 86, 8 );
          DGN2IEEEDouble( &(psCone->center_2.x) );
          memcpy( &(psCone->center_2.y), psDGN->abyElem + 94, 8 );
          DGN2IEEEDouble( &(psCone->center_2.y) );
          memcpy( &(psCone->center_2.z), psDGN->abyElem + 102, 8 );
          DGN2IEEEDouble( &(psCone->center_2.z) );
          memcpy( &(psCone->radius_2), psDGN->abyElem + 110, 8 );
          DGN2IEEEDouble( &(psCone->radius_2) );

          psCone->radius_1 *= psDGN->scale;
          psCone->radius_2 *= psDGN->scale;
          DGNTransformPoint( psDGN, &psCone->center_1 );
          DGNTransformPoint( psDGN, &psCone->center_2 );
        }
        break;

      case DGNT_3DSURFACE_HEADER:
      case DGNT_3DSOLID_HEADER:
        {
          DGNElemComplexHeader *psShape;

          psShape = 
            (DGNElemComplexHeader *) CPLCalloc(sizeof(DGNElemComplexHeader),1);
          psElement = (DGNElemCore *) psShape;
          psElement->stype = DGNST_COMPLEX_HEADER;
          DGNParseCore( psDGN, psElement );

          // Read complex header
          psShape->totlength = psDGN->abyElem[36] + psDGN->abyElem[37] * 256;
          psShape->numelems = psDGN->abyElem[38] + psDGN->abyElem[39] * 256;
          psShape->surftype = psDGN->abyElem[40] + psDGN->abyElem[41] * 256;
        }
        break;

      default:
      {
          psElement = (DGNElemCore *) CPLCalloc(sizeof(DGNElemCore),1);
          psElement->stype = DGNST_CORE;
          DGNParseCore( psDGN, psElement );
      }
      break;
    }

/* -------------------------------------------------------------------- */
/*      If the element structure type is "core" or if we are running    */
/*      in "capture all" mode, record the complete binary image of      */
/*      the element.                                                    */
/* -------------------------------------------------------------------- */
    if( psElement->stype == DGNST_CORE 
        || (psDGN->options & DGNO_CAPTURE_RAW_DATA) )
    {
        psElement->raw_bytes = psDGN->nElemBytes;
        psElement->raw_data = (unsigned char *)CPLMalloc(psElement->raw_bytes);

        memcpy( psElement->raw_data, psDGN->abyElem, psElement->raw_bytes );
    }

/* -------------------------------------------------------------------- */
/*      Collect some additional generic information.                    */
/* -------------------------------------------------------------------- */
    psElement->element_id = psDGN->next_element_id - 1;

    psElement->offset = VSIFTell( psDGN->fp ) - psDGN->nElemBytes;
    psElement->size = psDGN->nElemBytes;

    return psElement;
}

/************************************************************************/
/*                           DGNReadElement()                           */
/************************************************************************/

/**
 * Read a DGN element.
 *
 * This function will return the next element in the file, starting with the
 * first.  It is affected by DGNGotoElement() calls. 
 *
 * The element is read into a structure which includes the DGNElemCore 
 * structure.  It is expected that applications will inspect the stype
 * field of the returned DGNElemCore and use it to cast the pointer to the
 * appropriate element structure type such as DGNElemMultiPoint. 
 *
 * @param hDGN the handle of the file to read from.
 *
 * @return pointer to element structure, or NULL on EOF or processing error.
 * The structure should be freed with DGNFreeElement() when no longer needed.
 */

DGNElemCore *DGNReadElement( DGNHandle hDGN )

{
    DGNInfo     *psDGN = (DGNInfo *) hDGN;
    DGNElemCore *psElement = NULL;
    int         nType, nLevel;
    int         bInsideFilter;

/* -------------------------------------------------------------------- */
/*      Load the element data into the current buffer.  If a spatial    */
/*      filter is in effect, loop until we get something within our     */
/*      spatial constraints.                                            */
/* -------------------------------------------------------------------- */
    do { 
        bInsideFilter = TRUE;

        if( !DGNLoadRawElement( psDGN, &nType, &nLevel ) )
            return NULL;
        
        if( psDGN->has_spatial_filter )
        {
            GUInt32     nXMin, nXMax, nYMin, nYMax;
            
            if( !psDGN->sf_converted_to_uor )
                DGNSpatialFilterToUOR( psDGN );

            if( !DGNGetRawExtents( psDGN, nType, NULL,
                                   &nXMin, &nYMin, NULL,
                                   &nXMax, &nYMax, NULL ) )
            {
                /* If we don't have spatial characterists for the element
                   we will pass it through. */
                bInsideFilter = TRUE;
            }
            else if( nXMin > psDGN->sf_max_x
                     || nYMin > psDGN->sf_max_y
                     || nXMax < psDGN->sf_min_x
                     || nYMax < psDGN->sf_min_y )
                bInsideFilter = FALSE;

            /*
            ** We want to select complex elements based on the extents of
            ** the header, not the individual elements.
            */
            if( nType == DGNT_COMPLEX_CHAIN_HEADER
                || nType == DGNT_COMPLEX_SHAPE_HEADER )
            {
                psDGN->in_complex_group = TRUE;
                psDGN->select_complex_group = bInsideFilter;
            }
            else if( psDGN->abyElem[0] & 0x80 /* complex flag set */ )
            {
                if( psDGN->in_complex_group )
                    bInsideFilter = psDGN->select_complex_group;
            }
            else
                psDGN->in_complex_group = FALSE;
        }
    } while( !bInsideFilter );

/* -------------------------------------------------------------------- */
/*      Convert into an element structure.                              */
/* -------------------------------------------------------------------- */
    psElement = DGNProcessElement( psDGN, nType, nLevel );

    return psElement;
}

/************************************************************************/
/*                       DGNElemTypeHasDispHdr()                        */
/************************************************************************/

/**
 * Does element type have display header.