Interface for transforming between coordinate systems. More...

#include <ogr_spatialref.h>

Inherited by AxisMappingCoordinateTransformation, CompositeCT, CutlineTransformer, GCPCoordTransformation, and GeoTransformCoordinateTransformation.

Public Member Functions
virtual const OGRSpatialReference *	GetSourceCS () const =0
	Fetch internal source coordinate system.

virtual const OGRSpatialReference *	GetTargetCS () const =0
	Fetch internal target coordinate system.

virtual bool	GetEmitErrors () const
	Whether the transformer will emit CPLError.

virtual void	SetEmitErrors (bool)
	Set if the transformer must emit CPLError.

int	Transform (size_t nCount, double x, double y, double z=nullptr, int pabSuccess=nullptr)
	Transform points from source to destination space.

virtual int	Transform (size_t nCount, double x, double y, double z, double t, int *pabSuccess)=0
	Transform points from source to destination space.

virtual int	TransformWithErrorCodes (size_t nCount, double x, double y, double z, double t, int *panErrorCodes)
	Transform points from source to destination space.

virtual int	TransformBounds (const double xmin, const double ymin, const double xmax, const double ymax, double out_xmin, double out_ymin, double out_xmax, double out_ymax, const int densify_pts)
	Transform boundary.

virtual OGRCoordinateTransformation *	Clone () const =0
	Clone.

virtual OGRCoordinateTransformation *	GetInverse () const =0
	Return a coordinate transformation that performs the inverse transformation of the current one.

Static Public Member Functions
static void	DestroyCT (OGRCoordinateTransformation *poCT)
	OGRCoordinateTransformation destructor.

static OGRCoordinateTransformationH	ToHandle (OGRCoordinateTransformation *poCT)
	Convert a OGRCoordinateTransformation* to a OGRCoordinateTransformationH.

static OGRCoordinateTransformation *	FromHandle (OGRCoordinateTransformationH hCT)
	Convert a OGRCoordinateTransformationH to a OGRCoordinateTransformation*.

Detailed Description

Interface for transforming between coordinate systems.

Currently, the only implementation within OGR is OGRProjCT, which requires the PROJ library.

Also, see OGRCreateCoordinateTransformation() for creating transformations.

Member Function Documentation

◆ Clone()

virtual OGRCoordinateTransformation * OGRCoordinateTransformation::Clone ( ) const

pure virtual

Clone.

Since: GDAL 3.1

◆ DestroyCT()

void OGRCoordinateTransformation::DestroyCT ( OGRCoordinateTransformation * poCT )

static

OGRCoordinateTransformation destructor.

This function is the same as OGRCoordinateTransformation::~OGRCoordinateTransformation() and OCTDestroyCoordinateTransformation()

This static method will destroy a OGRCoordinateTransformation. It is equivalent to calling delete on the object, but it ensures that the deallocation is properly executed within the OGR libraries heap on platforms where this can matter (win32).

Parameters

poCT	the object to delete

Since: GDAL 1.7.0

◆ FromHandle()

static OGRCoordinateTransformation * OGRCoordinateTransformation::FromHandle ( OGRCoordinateTransformationH hCT )

inlinestatic

Convert a OGRCoordinateTransformationH to a OGRCoordinateTransformation*.

Since: GDAL 2.3

◆ GetInverse()

virtual OGRCoordinateTransformation * OGRCoordinateTransformation::GetInverse ( ) const

pure virtual

Return a coordinate transformation that performs the inverse transformation of the current one.

In some cases, this is not possible, and this method might return nullptr, or fail to perform the transformations.

Returns: the new coordinate transformation, or nullptr in case of error.

Since: GDAL 3.3

◆ ToHandle()

static OGRCoordinateTransformationH OGRCoordinateTransformation::ToHandle ( OGRCoordinateTransformation * poCT )

inlinestatic

Convert a OGRCoordinateTransformation* to a OGRCoordinateTransformationH.

Since: GDAL 2.3

◆ Transform() [1/2]

virtual int OGRCoordinateTransformation::Transform	(	size_t	nCount,
		double *	x,
		double *	y,
		double *	z,
		double *	t,
		int *	pabSuccess
	)

pure virtual

Transform points from source to destination space.

This method is the same as the C function OCTTransform4D().

Parameters

nCount	number of points to transform (`size_t` type since 3.9, `int` in previous versions).
x	array of nCount X vertices, modified in place. Should not be NULL.
y	array of nCount Y vertices, modified in place. Should not be NULL.
z	array of nCount Z vertices, modified in place. Might be NULL.
t	array of nCount time values, modified in place. Might be NULL.
pabSuccess	array of per-point flags set to TRUE if that point transforms, or FALSE if it does not. Might be NULL.

Returns: TRUE if a transformation could be found (but not all points may have necessarily succeed to transform), otherwise FALSE.

◆ Transform() [2/2]

int OGRCoordinateTransformation::Transform	(	size_t	nCount,
		double *	x,
		double *	y,
		double *	z = `nullptr`,
		int *	pabSuccess = `nullptr`
	)

Transform points from source to destination space.

This method is the same as the C function OCTTransformEx().

Parameters

nCount	number of points to transform (`size_t` type since 3.9, `int` in previous versions).
x	array of nCount X vertices, modified in place. Should not be NULL.
y	array of nCount Y vertices, modified in place. Should not be NULL.
z	array of nCount Z vertices, modified in place. Might be NULL.
pabSuccess	array of per-point flags set to TRUE if that point transforms, or FALSE if it does not. Might be NULL.

Returns: TRUE if a transformation could be found (but not all points may have necessarily succeed to transform), otherwise FALSE.

◆ TransformBounds()

virtual int OGRCoordinateTransformation::TransformBounds	(	const double	xmin,
		const double	ymin,
		const double	xmax,
		const double	ymax,
		double *	out_xmin,
		double *	out_ymin,
		double *	out_xmax,
		double *	out_ymax,
		const int	densify_pts
	)

inlinevirtual

Transform boundary.

This method is the same as the C function OCTTransformBounds().

Transform boundary densifying the edges to account for nonlinear transformations along these edges and extracting the outermost bounds.

If the destination CRS is geographic, the first axis is longitude, and xmax < xmin then the bounds crossed the antimeridian. In this scenario there are two polygons, one on each side of the antimeridian. The first polygon should be constructed with (xmin, ymin, 180, ymax) and the second with (-180, ymin, xmax, ymax).

If the destination CRS is geographic, the first axis is latitude, and ymax < ymin then the bounds crossed the antimeridian. In this scenario there are two polygons, one on each side of the antimeridian. The first polygon should be constructed with (ymin, xmin, ymax, 180) and the second with (ymin, -180, ymax, xmax).

Parameters

xmin	Minimum bounding coordinate of the first axis in source CRS.
ymin	Minimum bounding coordinate of the second axis in source CRS.
xmax	Maximum bounding coordinate of the first axis in source CRS.
ymax	Maximum bounding coordinate of the second axis in source CRS.
out_xmin	Minimum bounding coordinate of the first axis in target CRS
out_ymin	Minimum bounding coordinate of the second axis in target CRS.
out_xmax	Maximum bounding coordinate of the first axis in target CRS.
out_ymax	Maximum bounding coordinate of the second axis in target CRS.
densify_pts	Recommended to use 21. This is the number of points to use to densify the bounding polygon in the transformation.

Returns: TRUE if successful. FALSE if failures encountered.

Since: 3.4

◆ TransformWithErrorCodes()

virtual int OGRCoordinateTransformation::TransformWithErrorCodes	(	size_t	nCount,
		double *	x,
		double *	y,
		double *	z,
		double *	t,
		int *	panErrorCodes
	)

virtual

Transform points from source to destination space.

This method is the same as the C function OCTTransform4DWithErrorCodes().

Parameters

nCount	number of points to transform (`size_t` type since 3.9, `int` in previous versions).
x	array of nCount X vertices, modified in place. Should not be NULL.
y	array of nCount Y vertices, modified in place. Should not be NULL.
z	array of nCount Z vertices, modified in place. Might be NULL.
t	array of nCount time values, modified in place. Might be NULL.
panErrorCodes	Output array of nCount value that will be set to 0 for success, or a non-zero value for failure. Refer to PROJ 8 public error codes. Might be NULL

Returns: TRUE if a transformation could be found (but not all points may have necessarily succeed to transform), otherwise FALSE.

Since: GDAL 3.3, and PROJ 8 to be able to use PROJ public error codes

The documentation for this class was generated from the following files:

ogr_spatialref.h
ogrct.cpp

Public Member Functions

Static Public Member Functions

Detailed Description

Member Function Documentation

◆ Clone()

◆ DestroyCT()

◆ FromHandle()

◆ GetInverse()

◆ ToHandle()

◆ Transform() [1/2]

◆ Transform() [2/2]

◆ TransformBounds()

◆ TransformWithErrorCodes()