DYT/Tool/OpenSceneGraph-3.6.5/include/ogr_geomcoordinateprecision.h
2024-12-25 07:49:36 +08:00

80 lines
2.9 KiB
C++

/******************************************************************************
*
* Project: OpenGIS Simple Features Reference Implementation
* Purpose: Definition of OGRGeomCoordinatePrecision.
* Author: Even Rouault <even dot rouault at spatialys.com>
*
******************************************************************************
* Copyright (c) 2024, Even Rouault <even dot rouault at spatialys.com>
*
* SPDX-License-Identifier: MIT
****************************************************************************/
#ifndef OGR_GEOMCOORDINATEPRECISION_H
#define OGR_GEOMCOORDINATEPRECISION_H
#if !defined(DOXYGEN_SKIP)
#include <map>
#include "cpl_string.h"
#endif
class OGRSpatialReference;
/** Geometry coordinate precision.
*
* This may affect how many decimal digits (for text-based output) or bits
* (for binary encodings) are used to encode geometries.
*
* It is important to note that the coordinate precision has no direct
* relationship with the "physical" accuracy. It is generally advised that
* the resolution (precision) be at least 10 times smaller than the accuracy.
* @since GDAL 3.9
*/
struct CPL_DLL OGRGeomCoordinatePrecision
{
/** Constant for a UNKNOWN resolution. */
static constexpr double UNKNOWN = 0;
/** Resolution for the coordinate precision of the X and Y coordinates.
* Expressed in the units of the X and Y axis of the SRS.
* For example for a projected SRS with X,Y axis unit in meter, a value
* of 1e-3 corresponds to a 1 mm precision.
* For a geographic SRS (on Earth) with axis unit in degree, a value
* of 8.9e-9 (degree) also corresponds to a 1 mm precision.
* Set to UNKNOWN if unknown.
*/
double dfXYResolution = UNKNOWN;
/** Resolution for the coordinate precision of the Z coordinate.
* Expressed in the units of the Z axis of the SRS.
* Set to UNKNOWN if unknown.
*/
double dfZResolution = UNKNOWN;
/** Resolution for the coordinate precision of the M coordinate.
* Set to UNKNOWN if unknown.
*/
double dfMResolution = UNKNOWN;
/** Map from a format name to a list of format specific options.
*
* This can be for example used to store FileGeodatabase
* xytolerance, xorigin, yorigin, etc. coordinate precision grids
* options, which can be help to maximize preservation of coordinates in
* FileGDB -> FileGDB conversion processes.
*/
std::map<std::string, CPLStringList> oFormatSpecificOptions{};
void SetFromMeter(const OGRSpatialReference *poSRS,
double dfXYMeterResolution, double dfZMeterResolution,
double dfMResolution);
OGRGeomCoordinatePrecision
ConvertToOtherSRS(const OGRSpatialReference *poSRSSrc,
const OGRSpatialReference *poSRSDst) const;
static int ResolutionToPrecision(double dfResolution);
};
#endif /* OGR_GEOMCOORDINATEPRECISION_H */