/****************************************************************************** * * 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 7e07230bbff24eb333608de4dbd460b7312839d0 2017-12-11 19:08:47Z Even Rouault $") /************************************************************************/ /* 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 FALSE; // 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 ) { /* -------------------------------------------------------------------- */ /* Open the file. */ /* -------------------------------------------------------------------- */ VSILFILE *fp = VSIFOpenL( pszFilename, bUpdate ? "rb+" : "rb"); if( fp == nullptr ) { CPLError( CE_Failure, CPLE_OpenFailed, "Unable to open `%s' for read access.\n", pszFilename ); return nullptr; } /* -------------------------------------------------------------------- */ /* Verify the format ... add later. */ /* -------------------------------------------------------------------- */ GByte abyHeader[512]; const int nHeaderBytes = static_cast(VSIFReadL( abyHeader, 1, sizeof(abyHeader), fp )); if( !DGNTestOpen( abyHeader, nHeaderBytes ) ) { CPLError( CE_Failure, CPLE_AppDefined, "File `%s' does not have expected DGN header.\n", pszFilename ); VSIFCloseL( fp ); return nullptr; } VSIRewindL( fp ); /* -------------------------------------------------------------------- */ /* Create the info structure. */ /* -------------------------------------------------------------------- */ DGNInfo *psDGN = static_cast(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 = nullptr; 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 interpret 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 ) { if( psDGN->sf_converted_to_uor || !psDGN->has_spatial_filter || !psDGN->got_tcb ) return; DGNPoint sMin = { psDGN->sf_min_x_geo, psDGN->sf_min_y_geo, 0 }; DGNPoint sMax = { psDGN->sf_max_x_geo, psDGN->sf_max_y_geo, 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; VSIFCloseL( 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; }