/****************************************************************************** * $Id: dgnopen.cpp 10646 2007-01-18 02:38:10Z warmerdam $ * * Project:  Microstation DGN Access Library * Purpose:  DGN Access Library file open code. * Author:   Frank Warmerdam, warmerdam@pobox.com * ****************************************************************************** * Copyright (c) 2000, Avenza Systems Inc, http://www.avenza.com/ * * 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. ****************************************************************************/#include "dgnlibp.h"CPL_CVSID("$Id: dgnopen.cpp 10646 2007-01-18 02:38:10Z warmerdam $");/************************************************************************//*                            DGNTestOpen()                             *//************************************************************************//**  * Test if header is DGN. * * @param pabyHeader block of header data from beginning of file. * @param nByteCount number of bytes in pabyHeader.  * * @return TRUE if the header appears to be from a DGN file, otherwise FALSE. */int DGNTestOpen( GByte *pabyHeader, int nByteCount ){    if( nByteCount < 4 )        return TRUE;    // Is it a cell library?    if( pabyHeader[0] == 0x08        && pabyHeader[1] == 0x05        && pabyHeader[2] == 0x17        && pabyHeader[3] == 0x00 )        return TRUE;    // Is it not a regular 2D or 3D file?    if( (pabyHeader[0] != 0x08 && pabyHeader[0] != 0xC8)         || pabyHeader[1] != 0x09        || pabyHeader[2] != 0xFE || pabyHeader[3] != 0x02 )        return FALSE;    return TRUE;}/************************************************************************//*                              DGNOpen()                               *//************************************************************************//** * Open a DGN file.  * * The file is opened, and minimally verified to ensure it is a DGN (ISFF) * file.  If the file cannot be opened for read access an error with code * CPLE_OpenFailed with be reported via CPLError() and NULL returned.   * If the file header does * not appear to be a DGN file, an error with code CPLE_AppDefined will be * reported via CPLError(), and NULL returned. * * If successful a handle for further access is returned.  This should be * closed with DGNClose() when no longer needed.   * * DGNOpen() does not scan the file on open, and should be very fast even for * large files.   * * @param pszFilename name of file to try opening. * @param bUpdate should the file be opened with read+update (r+) mode? * * @return handle to use for further access to file using DGN API, or NULL * if open fails. */DGNHandle DGNOpen( const char * pszFilename, int bUpdate ){    DGNInfo     *psDGN;    FILE        *fp;/* -------------------------------------------------------------------- *//*      Open the file.                                                  *//* -------------------------------------------------------------------- */    if( bUpdate )        fp = VSIFOpen( pszFilename, "rb+" );    else        fp = VSIFOpen( pszFilename, "rb" );    if( fp == NULL )    {        CPLError( CE_Failure, CPLE_OpenFailed,                   "Unable to open `%s' for read access.\n",                   pszFilename );        return NULL;    }/* -------------------------------------------------------------------- *//*      Verify the format ... add later.                                *//* -------------------------------------------------------------------- */    GByte       abyHeader[512];    VSIFRead( abyHeader, 1, sizeof(abyHeader), fp );    if( !DGNTestOpen( abyHeader, sizeof(abyHeader) ) )    {        CPLError( CE_Failure, CPLE_AppDefined,                  "File `%s' does not have expected DGN header.\n",                   pszFilename );        VSIFClose( fp );        return NULL;    }    VSIRewind( fp );/* -------------------------------------------------------------------- *//*      Create the info structure.                                      *//* -------------------------------------------------------------------- */    psDGN = (DGNInfo *) CPLCalloc(sizeof(DGNInfo),1);    psDGN->fp = fp;    psDGN->next_element_id = 0;    psDGN->got_tcb = FALSE;    psDGN->scale = 1.0;    psDGN->origin_x = 0.0;    psDGN->origin_y = 0.0;    psDGN->origin_z = 0.0;                                                 psDGN->index_built = FALSE;    psDGN->element_count = 0;    psDGN->element_index = NULL;    psDGN->got_bounds = FALSE;    if( abyHeader[0] == 0xC8 )        psDGN->dimension = 3;    else        psDGN->dimension = 2;    psDGN->has_spatial_filter = FALSE;    psDGN->sf_converted_to_uor = FALSE;    psDGN->select_complex_group = FALSE;    psDGN->in_complex_group = FALSE;    return (DGNHandle) psDGN;}/************************************************************************//*                           DGNSetOptions()                            *//************************************************************************//** * Set file access options. * * Sets a flag affecting how the file is accessed.  Currently * there is only one support flag: * * DGNO_CAPTURE_RAW_DATA: If this is enabled (it is off by default), * then the raw binary data associated with elements will be kept in * the raw_data field within the DGNElemCore when they are read.  This * is required if the application needs to interprete the raw data itself. * It is also necessary if the element is to be written back to this file, * or another file using DGNWriteElement().  Off by default (to conserve * memory).  * * @param hDGN handle to file returned by DGNOpen().  * @param nOptions ORed option flags. */void DGNSetOptions( DGNHandle hDGN, int nOptions ){    DGNInfo     *psDGN = (DGNInfo *) hDGN;    psDGN->options = nOptions;}/************************************************************************//*                        DGNSetSpatialFilter()                         *//************************************************************************//** * Set rectangle for which features are desired. * * If a spatial filter is set with this function, DGNReadElement() will * only return spatial elements (elements with a known bounding box) and * only those elements for which this bounding box overlaps the requested * region.  * * If all four values (dfXMin, dfXMax, dfYMin and dfYMax) are zero, the * spatial filter is disabled.   Note that installing a spatial filter * won't reduce the amount of data read from disk.  All elements are still * scanned, but the amount of processing work for elements outside the  * spatial filter is minimized.   * * @param hDGN Handle from DGNOpen() for file to update. * @param dfXMin minimum x coordinate for extents (georeferenced coordinates). * @param dfYMin minimum y coordinate for extents (georeferenced coordinates). * @param dfXMax maximum x coordinate for extents (georeferenced coordinates). * @param dfYMax maximum y coordinate for extents (georeferenced coordinates). */ void DGNSetSpatialFilter( DGNHandle hDGN,                           double dfXMin, double dfYMin,                           double dfXMax, double dfYMax ){    DGNInfo     *psDGN = (DGNInfo *) hDGN;    if( dfXMin == 0.0 && dfXMax == 0.0        && dfYMin == 0.0 && dfYMax == 0.0 )    {        psDGN->has_spatial_filter = FALSE;        return;    }    psDGN->has_spatial_filter = TRUE;    psDGN->sf_converted_to_uor = FALSE;    psDGN->sf_min_x_geo = dfXMin;    psDGN->sf_min_y_geo = dfYMin;    psDGN->sf_max_x_geo = dfXMax;    psDGN->sf_max_y_geo = dfYMax;    DGNSpatialFilterToUOR( psDGN );}/************************************************************************//*                       DGNSpatialFilterToUOR()                        *//************************************************************************/void DGNSpatialFilterToUOR( DGNInfo *psDGN ){    DGNPoint    sMin, sMax;    if( psDGN->sf_converted_to_uor         || !psDGN->has_spatial_filter         || !psDGN->got_tcb )        return;    sMin.x = psDGN->sf_min_x_geo;    sMin.y = psDGN->sf_min_y_geo;    sMin.z = 0;        sMax.x = psDGN->sf_max_x_geo;    sMax.y = psDGN->sf_max_y_geo;    sMax.z = 0;    DGNInverseTransformPoint( psDGN, &sMin );    DGNInverseTransformPoint( psDGN, &sMax );    psDGN->sf_min_x = (GUInt32) (sMin.x + 2147483648.0);    psDGN->sf_min_y = (GUInt32) (sMin.y + 2147483648.0);    psDGN->sf_max_x = (GUInt32) (sMax.x + 2147483648.0);    psDGN->sf_max_y = (GUInt32) (sMax.y + 2147483648.0);    psDGN->sf_converted_to_uor = TRUE;}/************************************************************************//*                              DGNClose()                              *//************************************************************************//** * Close DGN file.  * * @param hDGN Handle from DGNOpen() for file to close. */void DGNClose( DGNHandle hDGN ){    DGNInfo     *psDGN = (DGNInfo *) hDGN;    VSIFClose( psDGN->fp );    CPLFree( psDGN->element_index );    CPLFree( psDGN );}/************************************************************************//*                          DGNGetDimension()                           *//************************************************************************//** * Return 2D/3D dimension of file. * * Return 2 or 3 depending on the dimension value of the provided file. */int DGNGetDimension( DGNHandle hDGN ){    DGNInfo     *psDGN = (DGNInfo *) hDGN;    return psDGN->dimension;}