Geometry handling functions: advanced. More...

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Functions
GAIAGEO_DECLARE double	gaiaRadsToDegs (double rads)
	Converts and angle from Radians into Degrees.
GAIAGEO_DECLARE double	gaiaDegsToRads (double degs)
	Converts and angle from Degrees into Radians.
GAIAGEO_DECLARE gaiaGeomCollPtr	gaiaTransform (gaiaGeomCollPtr org, char proj_from, char proj_to)
	Tansforms a Geometry object into a different Reference System [aka Reprojection].
GAIAGEO_DECLARE void	gaiaResetGeosMsg (void)
	Resets the GEOS error and warning messages to an empty state.
GAIAGEO_DECLARE const char *	gaiaGetGeosErrorMsg (void)
	Return the latest GEOS error message (if any)
GAIAGEO_DECLARE const char *	gaiaGetGeosWarningMsg (void)
	Return the latest GEOS warning message (if any)
GAIAGEO_DECLARE void	gaiaSetGeosErrorMsg (const char *msg)
	Set the current GEOS error message.
GAIAGEO_DECLARE void	gaiaSetGeosWarningMsg (const char *msg)
	Set the current GEOS warning message.
GAIAGEO_DECLARE void *	gaiaToGeos (const gaiaGeomCollPtr gaia)
	Converts a Geometry object into a GEOS Geometry.
GAIAGEO_DECLARE gaiaGeomCollPtr	gaiaFromGeos_XY (const void *geos)
	Converts a GEOS Geometry into a Geometry object [XY dims].
GAIAGEO_DECLARE gaiaGeomCollPtr	gaiaFromGeos_XYZ (const void *geos)
	Converts a GEOS Geometry into a Geometry object [XYZ dims].
GAIAGEO_DECLARE gaiaGeomCollPtr	gaiaFromGeos_XYM (const void *geos)
	Converts a GEOS Geometry into a Geometry object [XYM dims].
GAIAGEO_DECLARE gaiaGeomCollPtr	gaiaFromGeos_XYZM (const void *geos)
	Converts a GEOS Geometry into a Geometry object [XYZM dims].
GAIAGEO_DECLARE int	gaiaIsSimple (gaiaGeomCollPtr geom)
	Checks if a Geometry object represents an OGC Simple Geometry.
GAIAGEO_DECLARE int	gaiaIsClosed (gaiaLinestringPtr line)
	Checks if a Linestring object represents an OGC Closed Geometry.
GAIAGEO_DECLARE int	gaiaIsRing (gaiaLinestringPtr line)
	Checks if a Linestring object represents an OGC Ring Geometry.
GAIAGEO_DECLARE int	gaiaIsValid (gaiaGeomCollPtr geom)
	Checks if a Geometry object represents an OGC Valid Geometry.
GAIAGEO_DECLARE int	gaiaGeomCollLength (gaiaGeomCollPtr geom, double *length)
	Measures the total Length for a Geometry object.
GAIAGEO_DECLARE int	gaiaGeomCollArea (gaiaGeomCollPtr geom, double *area)
	Measures the total Area for a Geometry object.
GAIAGEO_DECLARE gaiaGeomCollPtr	gaiaPolygonize (gaiaGeomCollPtr geom, int force_multi)
	Attempts to rearrange a generic Geometry object into a Polygon or MultiPolygon.
GAIAGEO_DECLARE int	gaiaGeomCollEquals (gaiaGeomCollPtr geom1, gaiaGeomCollPtr geom2)
	Spatial relationship evalution: Equals.
GAIAGEO_DECLARE int	gaiaGeomCollDisjoint (gaiaGeomCollPtr geom1, gaiaGeomCollPtr geom2)
	Spatial relationship evalution: Disjoint.
GAIAGEO_DECLARE int	gaiaGeomCollIntersects (gaiaGeomCollPtr geom1, gaiaGeomCollPtr geom2)
	Spatial relationship evalution: Intesects.
GAIAGEO_DECLARE int	gaiaGeomCollOverlaps (gaiaGeomCollPtr geom1, gaiaGeomCollPtr geom2)
	Spatial relationship evalution: Overlaps.
GAIAGEO_DECLARE int	gaiaGeomCollCrosses (gaiaGeomCollPtr geom1, gaiaGeomCollPtr geom2)
	Spatial relationship evalution: Crosses.
GAIAGEO_DECLARE int	gaiaGeomCollContains (gaiaGeomCollPtr geom1, gaiaGeomCollPtr geom2)
	Spatial relationship evalution: Contains.
GAIAGEO_DECLARE int	gaiaGeomCollWithin (gaiaGeomCollPtr geom1, gaiaGeomCollPtr geom2)
	Spatial relationship evalution: Within.
GAIAGEO_DECLARE int	gaiaGeomCollTouches (gaiaGeomCollPtr geom1, gaiaGeomCollPtr geom2)
	Spatial relationship evalution: Touches.
GAIAGEO_DECLARE int	gaiaGeomCollRelate (gaiaGeomCollPtr geom1, gaiaGeomCollPtr geom2, const char *pattern)
	Spatial relationship evalution: Relate.
GAIAGEO_DECLARE int	gaiaGeomCollDistance (gaiaGeomCollPtr geom1, gaiaGeomCollPtr geom2, double *dist)
	Calculates the minimum distance intercurring between two Geometry objects.
GAIAGEO_DECLARE gaiaGeomCollPtr	gaiaGeometryIntersection (gaiaGeomCollPtr geom1, gaiaGeomCollPtr geom2)
	Spatial operator: Intersection.
GAIAGEO_DECLARE gaiaGeomCollPtr	gaiaGeometryUnion (gaiaGeomCollPtr geom1, gaiaGeomCollPtr geom2)
	Spatial operator: Union.
GAIAGEO_DECLARE gaiaGeomCollPtr	gaiaGeometryDifference (gaiaGeomCollPtr geom1, gaiaGeomCollPtr geom2)
	Spatial operator: Difference.
GAIAGEO_DECLARE gaiaGeomCollPtr	gaiaGeometrySymDifference (gaiaGeomCollPtr geom1, gaiaGeomCollPtr geom2)
	Spatial operator: SymDifference.
GAIAGEO_DECLARE gaiaGeomCollPtr	gaiaBoundary (gaiaGeomCollPtr geom)
	Spatial operator: Boundary.
GAIAGEO_DECLARE int	gaiaGeomCollCentroid (gaiaGeomCollPtr geom, double x, double y)
	Spatial operator: Centroid.
GAIAGEO_DECLARE int	gaiaGetPointOnSurface (gaiaGeomCollPtr geom, double x, double y)
	Spatial operator: PointOnSurface.
GAIAGEO_DECLARE gaiaGeomCollPtr	gaiaGeomCollSimplify (gaiaGeomCollPtr geom, double tolerance)
	Spatial operator: Simplify.
GAIAGEO_DECLARE gaiaGeomCollPtr	gaiaGeomCollSimplifyPreserveTopology (gaiaGeomCollPtr geom, double tolerance)
	Spatial operator: Simplify [preserving topology].
GAIAGEO_DECLARE gaiaGeomCollPtr	gaiaConvexHull (gaiaGeomCollPtr geom)
	Spatial operator: ConvexHull.
GAIAGEO_DECLARE gaiaGeomCollPtr	gaiaGeomCollBuffer (gaiaGeomCollPtr geom, double radius, int points)
	Spatial operator: Buffer.
GAIAGEO_DECLARE int	gaiaHausdorffDistance (gaiaGeomCollPtr geom1, gaiaGeomCollPtr geom2, double *dist)
	Calculates the Hausdorff distance intercurring between two Geometry objects.
GAIAGEO_DECLARE gaiaGeomCollPtr	gaiaOffsetCurve (gaiaGeomCollPtr geom, double radius, int points, int left_right)
	Spatial operator: Offset Curve.
GAIAGEO_DECLARE gaiaGeomCollPtr	gaiaSingleSidedBuffer (gaiaGeomCollPtr geom, double radius, int points, int left_right)
	Spatial operator: Single Sided Buffer.
GAIAGEO_DECLARE gaiaGeomCollPtr	gaiaSharedPaths (gaiaGeomCollPtr geom1, gaiaGeomCollPtr geom2)
	Spatial operator: Shared Paths.
GAIAGEO_DECLARE gaiaGeomCollPtr	gaiaLineInterpolatePoint (gaiaGeomCollPtr ln_geom, double fraction)
	Spatial operator: Line Interpolate Point.
GAIAGEO_DECLARE gaiaGeomCollPtr	gaiaLineSubstring (gaiaGeomCollPtr ln_geom, double start_fraction, double end_fraction)
	Spatial operator: Line Substring.
GAIAGEO_DECLARE gaiaGeomCollPtr	gaiaShortestLine (gaiaGeomCollPtr geom1, gaiaGeomCollPtr geom2)
	Spatial operator: Shortest Line.
GAIAGEO_DECLARE gaiaGeomCollPtr	gaiaSnap (gaiaGeomCollPtr geom1, gaiaGeomCollPtr geom2, double tolerance)
	Spatial operator: Shortest Line.
GAIAGEO_DECLARE gaiaGeomCollPtr	gaiaLineMerge (gaiaGeomCollPtr geom)
	Spatial operator: Line Merge.
GAIAGEO_DECLARE gaiaGeomCollPtr	gaiaUnaryUnion (gaiaGeomCollPtr geom)
	Spatial operator: Unary Union.
GAIAGEO_DECLARE double	gaiaLineLocatePoint (gaiaGeomCollPtr ln_geom, gaiaGeomCollPtr pt_geom)
	Determines the location of the closest Point on Linestring to the given Point.
GAIAGEO_DECLARE int	gaiaGeomCollCovers (gaiaGeomCollPtr geom1, gaiaGeomCollPtr geom2)
	Topology check: test if a Geometry covers another one.
GAIAGEO_DECLARE int	gaiaGeomCollCoveredBy (gaiaGeomCollPtr geom1, gaiaGeomCollPtr geom2)
	Topology check: test if a Geometry is covered by another one.

Detailed Description

Geometry handling functions: advanced.

Function Documentation

GAIAGEO_DECLARE gaiaGeomCollPtr gaiaBoundary ( gaiaGeomCollPtr geom )

Spatial operator: Boundary.

Parameters:

geom	the Geometry object to be evaluated

Returns:: the pointer to newly created Geometry object representing the geometry Boundary of the input Geometry: NULL on failure.

See also:: gaiaFreeGeomColl

Note:: you are responsible to destroy (before or after) any allocated Geometry, this including any Geometry returned by gaiaBoundary()

Remarks:: GEOS support required.

GAIAGEO_DECLARE gaiaGeomCollPtr gaiaConvexHull ( gaiaGeomCollPtr geom )

Spatial operator: ConvexHull.

Parameters:

geom	the input Geometry object

Returns:: the pointer to newly created Geometry object representing the ConvexHull of input Geometry: NULL on failure.

See also:: gaiaFreeGeomColl

Note:: you are responsible to destroy (before or after) any allocated Geometry, this including any Geometry returned by gaiaConvexHull()

Remarks:: GEOS support required.

GAIAGEO_DECLARE double gaiaDegsToRads ( double degs )

Converts and angle from Degrees into Radians.

Parameters:

degs	the angle measured in Degrees.

Returns:: the angle measured in Radians.

See also:: gaiaRadsToDegs

Remarks:: PROJ.4 support required

GAIAGEO_DECLARE gaiaGeomCollPtr gaiaFromGeos_XY ( const void * geos )

Converts a GEOS Geometry into a Geometry object [XY dims].

Parameters:

geos	handle to GEOS Geometry

Returns:: the pointer to the newly created Geometry object

See also:: gaiaToGeos, gaiaFromGeos_XYZ, gaiaFromGeos_XYM, gaiaFromGeos_XYZM

Note:: you are responsible to destroy (before or after) any allocated Geometry, this including any Geometry returned by gaiaFromGeos_XY()

Remarks:: GEOS support required.

GAIAGEO_DECLARE gaiaGeomCollPtr gaiaFromGeos_XYM ( const void * geos )

Converts a GEOS Geometry into a Geometry object [XYM dims].

Parameters:

geos	handle to GEOS Geometry

Returns:: the pointer to the newly created Geometry object

See also:: gaiaToGeos, gaiaFromGeos_XY, gaiaFromGeos_XYZ, gaiaFromGeos_XYZM

Note:: you are responsible to destroy (before or after) any allocated Geometry, this including any Geometry returned by gaiaFromGeos_XYM()

Remarks:: GEOS support required.

GAIAGEO_DECLARE gaiaGeomCollPtr gaiaFromGeos_XYZ ( const void * geos )

Converts a GEOS Geometry into a Geometry object [XYZ dims].

Parameters:

geos	handle to GEOS Geometry

Returns:: the pointer to the newly created Geometry object

See also:: gaiaToGeos, gaiaFromGeos_XY, gaiaFromGeos_XYM, gaiaFromGeos_XYZM

Note:: you are responsible to destroy (before or after) any allocated Geometry, this including any Geometry returned by gaiaFromGeos_XYZ()

Remarks:: GEOS support required.

GAIAGEO_DECLARE gaiaGeomCollPtr gaiaFromGeos_XYZM ( const void * geos )

Converts a GEOS Geometry into a Geometry object [XYZM dims].

Parameters:

geos	handle to GEOS Geometry

Returns:: the pointer to the newly created Geometry object

See also:: gaiaToGeos, gaiaFromGeos_XY, gaiaFromGeos_XYZ, gaiaFromGeos_XYM

Note:: you are responsible to destroy (before or after) any allocated Geometry, this including any Geometry returned by gaiaFromGeos_XYZM()

Remarks:: GEOS support required.

GAIAGEO_DECLARE int gaiaGeomCollArea	(	gaiaGeomCollPtr	geom,
		double *	area
	)

Measures the total Area for a Geometry object.

Parameters:

geom	pointer to Geometry object
area	on completion this variable will contain the measured area

Returns:: 0 on failure: any other value on success

See also:: gaiaGeomCollLength, gaiaMeasureArea

Remarks:: GEOS support required.

Examples:: demo1.c.

GAIAGEO_DECLARE gaiaGeomCollPtr gaiaGeomCollBuffer	(	gaiaGeomCollPtr	geom,
		double	radius,
		int	points
	)

Spatial operator: Buffer.

Parameters:

geom	the input Geometry object
radius	the buffer's radius
points	number of points (aka vertices) to be used in order to approximate a circular arc.

Returns:: the pointer to newly created Geometry object representing the Buffer of input Geometry: NULL on failure.

See also:: gaiaFreeGeomColl

Note:: you are responsible to destroy (before or after) any allocated Geometry, this including any Geometry returned by gaiaGeomCollBuffer()

Remarks:: GEOS support required.

GAIAGEO_DECLARE int gaiaGeomCollCentroid	(	gaiaGeomCollPtr	geom,
		double *	x,
		double *	y
	)

Spatial operator: Centroid.

Parameters:

geom	pointer to Geometry object.
x	on completion this variable will contain the centroid X coordinate
y	on completion this variable will contain the centroid Y coordinate

Returns:: 0 on failure: any other value on success

See also:: gaiaRingCentroid

Remarks:: GEOS support required.

GAIAGEO_DECLARE int gaiaGeomCollContains	(	gaiaGeomCollPtr	geom1,
		gaiaGeomCollPtr	geom2
	)

Spatial relationship evalution: Contains.

Parameters:

geom1	the first Geometry object to be evaluated
geom2	the second Geometry object to be evaluated

Returns:: 0 if false: any other value if true

See also:: gaiaGeomCollEquals, gaiaGeomCollDisjoint, gaiaGeomCollIntersects, gaiaGeomCollOverlaps, gaiaGeomCollCrosses, gaiaGeomCollWithin, gaiaGeomCollTouches, gaiaGeomCollRelate

Remarks:: GEOS support required.

GAIAGEO_DECLARE int gaiaGeomCollCoveredBy	(	gaiaGeomCollPtr	geom1,
		gaiaGeomCollPtr	geom2
	)

Topology check: test if a Geometry is covered by another one.

Parameters:

geom1	pointer to first input Geometry object.
geom2	pointer to second input Geometry object.

Returns:: 0 if false; any other value if geom2 is spatially covered by geom1.

See also:: gaiaGeomCollCovers

Remarks:: GEOS-ADVANCED support required.

GAIAGEO_DECLARE int gaiaGeomCollCovers	(	gaiaGeomCollPtr	geom1,
		gaiaGeomCollPtr	geom2
	)

Topology check: test if a Geometry covers another one.

Parameters:

geom1	pointer to first input Geometry object.
geom2	pointer to second input Geometry object.

Returns:: 0 if false; any other value if geom1 spatially covers geom2.

See also:: gaiaGeomCollCoveredBy

Remarks:: GEOS-ADVANCED support required.

GAIAGEO_DECLARE int gaiaGeomCollCrosses	(	gaiaGeomCollPtr	geom1,
		gaiaGeomCollPtr	geom2
	)

Spatial relationship evalution: Crosses.

Parameters:

geom1	the first Geometry object to be evaluated
geom2	the second Geometry object to be evaluated

Returns:: 0 if false: any other value if true

See also:: gaiaGeomCollEquals, gaiaGeomCollDisjoint, gaiaGeomCollIntersects, gaiaGeomCollOverlaps, gaiaGeomCollContains, gaiaGeomCollWithin, gaiaGeomCollTouches, gaiaGeomCollRelate

Remarks:: GEOS support required.

GAIAGEO_DECLARE int gaiaGeomCollDisjoint	(	gaiaGeomCollPtr	geom1,
		gaiaGeomCollPtr	geom2
	)

Spatial relationship evalution: Disjoint.

Parameters:

geom1	the first Geometry object to be evaluated
geom2	the second Geometry object to be evaluated

Returns:: 0 if false: any other value if true

See also:: gaiaGeomCollEquals, gaiaGeomCollIntersects, gaiaGeomCollOverlaps, gaiaGeomCollCrosses, gaiaGeomCollContains, gaiaGeomCollWithin, gaiaGeomCollTouches, gaiaGeomCollRelate

Remarks:: GEOS support required.

GAIAGEO_DECLARE int gaiaGeomCollDistance	(	gaiaGeomCollPtr	geom1,
		gaiaGeomCollPtr	geom2,
		double *	dist
	)

Calculates the minimum distance intercurring between two Geometry objects.

Parameters:

geom1	the first Geometry object
geom2	the second Geometry object
dist	on completion this variable will contain the calculated distance

Returns:: 0 on failuer: any other value on success.

Remarks:: GEOS support required.

GAIAGEO_DECLARE int gaiaGeomCollEquals	(	gaiaGeomCollPtr	geom1,
		gaiaGeomCollPtr	geom2
	)

Spatial relationship evalution: Equals.

Parameters:

geom1	the first Geometry object to be evaluated
geom2	the second Geometry object to be evaluated

Returns:: 0 if false: any other value if true

See also:: gaiaGeomCollDisjoint, gaiaGeomCollIntersects, gaiaGeomCollOverlaps, gaiaGeomCollCrosses, gaiaGeomCollContains, gaiaGeomCollWithin, gaiaGeomCollTouches, gaiaGeomCollRelate

Remarks:: GEOS support required.

GAIAGEO_DECLARE int gaiaGeomCollIntersects	(	gaiaGeomCollPtr	geom1,
		gaiaGeomCollPtr	geom2
	)

Spatial relationship evalution: Intesects.

Parameters:

geom1	the first Geometry object to be evaluated
geom2	the second Geometry object to be evaluated

Returns:: 0 if false: any other value if true

See also:: gaiaGeomCollEquals, gaiaGeomCollDisjoint, gaiaGeomCollOverlaps, gaiaGeomCollCrosses, gaiaGeomCollContains, gaiaGeomCollWithin, gaiaGeomCollTouches, gaiaGeomCollRelate

Remarks:: GEOS support required.

GAIAGEO_DECLARE int gaiaGeomCollLength	(	gaiaGeomCollPtr	geom,
		double *	length
	)

Measures the total Length for a Geometry object.

Parameters:

geom	pointer to Geometry object
length	on completion this variable will contain the measured length

Returns:: 0 on failure: any other value on success

See also:: gaiaGeomCollArea, gaiaMeasureLength

Remarks:: GEOS support required.

Examples:: demo1.c.

GAIAGEO_DECLARE int gaiaGeomCollOverlaps	(	gaiaGeomCollPtr	geom1,
		gaiaGeomCollPtr	geom2
	)

Spatial relationship evalution: Overlaps.

Parameters:

geom1	the first Geometry object to be evaluated
geom2	the second Geometry object to be evaluated

Returns:: 0 if false: any other value if true

See also:: gaiaGeomCollEquals, gaiaGeomCollDisjoint, gaiaGeomCollIntersects, gaiaGeomCollCrosses, gaiaGeomCollContains, gaiaGeomCollWithin, gaiaGeomCollTouches, gaiaGeomCollRelate

Remarks:: GEOS support required.

GAIAGEO_DECLARE int gaiaGeomCollRelate	(	gaiaGeomCollPtr	geom1,
		gaiaGeomCollPtr	geom2,
		const char *	pattern
	)

Spatial relationship evalution: Relate.

Parameters:

geom1	the first Geometry object to be evaluated
geom2	the second Geometry object to be evaluated
pattern	intersection matrix pattern [DE-9IM]

Returns:: 0 if false: any other value if true

See also:: gaiaGeomCollEquals, gaiaGeomCollDisjoint, gaiaGeomCollIntersects, gaiaGeomCollOverlaps, gaiaGeomCollCrosses, gaiaGeomCollContains, gaiaGeomCollWithin, gaiaGeomCollTouches

Remarks:: GEOS support required.

GAIAGEO_DECLARE gaiaGeomCollPtr gaiaGeomCollSimplify	(	gaiaGeomCollPtr	geom,
		double	tolerance
	)

Spatial operator: Simplify.

Parameters:

geom	the input Geometry object
tolerance	approximation threshold

Returns:: the pointer to newly created Geometry object representing the simplified Geometry [applying the Douglas-Peucker algorithm]: NULL on failure.

See also:: gaiaFreeGeomColl, gaiaGeomCollSimplifyPreserveTopology

Note:: you are responsible to destroy (before or after) any allocated Geometry, this including any Geometry returned by gaiaGeomCollSimplify()

Remarks:: GEOS support required.

GAIAGEO_DECLARE gaiaGeomCollPtr gaiaGeomCollSimplifyPreserveTopology	(	gaiaGeomCollPtr	geom,
		double	tolerance
	)

Spatial operator: Simplify [preserving topology].

Parameters:

geom	the input Geometry object
tolerance	approximation threshold

Returns:: the pointer to newly created Geometry object representing the simplified Geometry [applying the Douglas-Peucker algorithm]: NULL on failure.

See also:: gaiaFreeGeomColl, gaiaGeomCollSimplify

Note:: you are responsible to destroy (before or after) any allocated Geometry, this including any Geometry returned by gaiaGeomCollSimplify()

Remarks:: GEOS support required.

GAIAGEO_DECLARE int gaiaGeomCollTouches	(	gaiaGeomCollPtr	geom1,
		gaiaGeomCollPtr	geom2
	)

Spatial relationship evalution: Touches.

Parameters:

geom1	the first Geometry object to be evaluated
geom2	the second Geometry object to be evaluated

Returns:: 0 if false: any other value if true

See also:: gaiaGeomCollEquals, gaiaGeomCollDisjoint, gaiaGeomCollIntersects, gaiaGeomCollOverlaps, gaiaGeomCollCrosses, gaiaGeomCollContains, gaiaGeomCollWithin, gaiaGeomCollRelate

Remarks:: GEOS support required.

GAIAGEO_DECLARE int gaiaGeomCollWithin	(	gaiaGeomCollPtr	geom1,
		gaiaGeomCollPtr	geom2
	)

Spatial relationship evalution: Within.

Parameters:

geom1	the first Geometry object to be evaluated
geom2	the second Geometry object to be evaluated

Returns:: 0 if false: any other value if true

See also:: gaiaGeomCollEquals, gaiaGeomCollDisjoint, gaiaGeomCollIntersects, gaiaGeomCollOverlaps, gaiaGeomCollCrosses, gaiaGeomCollContains, gaiaGeomCollTouches, gaiaGeomCollRelate

Remarks:: GEOS support required.

GAIAGEO_DECLARE gaiaGeomCollPtr gaiaGeometryDifference	(	gaiaGeomCollPtr	geom1,
		gaiaGeomCollPtr	geom2
	)

Spatial operator: Difference.

Parameters:

geom1	the first Geometry object
geom2	the second Geometry object

Returns:: the pointer to newly created Geometry object representing the geometry Difference of both input Geometries: NULL on failure.

See also:: gaiaFreeGeomColl

Note:: you are responsible to destroy (before or after) any allocated Geometry, this including any Geometry returned by gaiaGeometryDifference()

Remarks:: GEOS support required.

GAIAGEO_DECLARE gaiaGeomCollPtr gaiaGeometryIntersection	(	gaiaGeomCollPtr	geom1,
		gaiaGeomCollPtr	geom2
	)

Spatial operator: Intersection.

Parameters:

geom1	the first Geometry object
geom2	the second Geometry object

Returns:: the pointer to newly created Geometry object representing the geometry Intersection of both input Geometries: NULL on failure.

See also:: gaiaFreeGeomColl, gaiaGeometryUnion, gaiaGeometryDifference, gaiaGeometrySymDifference, gaiaBoundary

Note:: you are responsible to destroy (before or after) any allocated Geometry, this including any Geometry returned by gaiaGeometryIntersection()

Remarks:: GEOS support required.

GAIAGEO_DECLARE gaiaGeomCollPtr gaiaGeometrySymDifference	(	gaiaGeomCollPtr	geom1,
		gaiaGeomCollPtr	geom2
	)

Spatial operator: SymDifference.

Parameters:

geom1	the first Geometry object
geom2	the second Geometry object

Returns:: the pointer to newly created Geometry object representing the geometry SymDifference of both input Geometries: NULL on failure.

See also:: gaiaFreeGeomColl

Note:: you are responsible to destroy (before or after) any allocated Geometry, this including any Geometry returned by gaiaGeometrySymDifference()

Remarks:: GEOS support required.

GAIAGEO_DECLARE gaiaGeomCollPtr gaiaGeometryUnion	(	gaiaGeomCollPtr	geom1,
		gaiaGeomCollPtr	geom2
	)

Spatial operator: Union.

Parameters:

geom1	the first Geometry object
geom2	the second Geometry object

Returns:: the pointer to newly created Geometry object representing the geometry Union of both input Geometries: NULL on failure.

See also:: gaiaFreeGeomColl, gaiaUnaryUnion

Note:: you are responsible to destroy (before or after) any allocated Geometry, this including any Geometry returned by gaiaGeometryUnion()

Remarks:: GEOS support required.

GAIAGEO_DECLARE const char* gaiaGetGeosErrorMsg ( void )

Return the latest GEOS error message (if any)

Returns:: the latest GEOS error message: an empty string if no error was previoysly found.

See also:: gaiaResetGeosMsg, gaiaGetGeosWarningMsg, gaiaSetGeosErrorMsg, gaiaSetGeosWarningMsg

Remarks:: GEOS support required.

GAIAGEO_DECLARE const char* gaiaGetGeosWarningMsg ( void )

Return the latest GEOS warning message (if any)

Returns:: the latest GEOS warning message: an empty string if no warning was previoysly found.

See also:: gaiaResetGeosMsg, gaiaGetGeosErrorMsg, gaiaSetGeosErrorMsg, gaiaSetGeosWarningMsg

Remarks:: GEOS support required.

GAIAGEO_DECLARE int gaiaGetPointOnSurface	(	gaiaGeomCollPtr	geom,
		double *	x,
		double *	y
	)

Spatial operator: PointOnSurface.

Parameters:

geom	pointer to Geometry object.
x	on completion this variable will contain the Point X coordinate
y	on completion this variable will contain the Point Y coordinate

Returns:: 0 on failure: any other value on success

Remarks:: GEOS support required.

GAIAGEO_DECLARE int gaiaHausdorffDistance	(	gaiaGeomCollPtr	geom1,
		gaiaGeomCollPtr	geom2,
		double *	dist
	)

Calculates the Hausdorff distance intercurring between two Geometry objects.

Parameters:

geom1	pointer to first Geometry object
geom2	pointer to second Geometry object
dist	on completion this variable will contain the calculated Hausdorff distance

Returns:: 0 on failure: any other value on success.

Remarks:: GEOS-ADVANCED support required.

GAIAGEO_DECLARE int gaiaIsClosed ( gaiaLinestringPtr line )

Checks if a Linestring object represents an OGC Closed Geometry.

Parameters:

line	pointer to Geometry object.

Returns:: 0 if false; any other value if true

See also:: gaiaIsSimple, gaiaIsRing, gaiaIsValid

Remarks:: GEOS support required.

GAIAGEO_DECLARE int gaiaIsRing ( gaiaLinestringPtr line )

Checks if a Linestring object represents an OGC Ring Geometry.

Parameters:

line	pointer to Geometry object.

Returns:: 0 if false; any other value if true

See also:: gaiaIsSimple, gaiaIsClosed, gaiaIsValid

Remarks:: GEOS support required.

GAIAGEO_DECLARE int gaiaIsSimple ( gaiaGeomCollPtr geom )

Checks if a Geometry object represents an OGC Simple Geometry.

Parameters:

geom	pointer to Geometry object.

Returns:: 0 if false; any other value if true

See also:: gaiaIsClosed, gaiaIsRing, gaiaIsValid

Remarks:: GEOS support required.

GAIAGEO_DECLARE int gaiaIsValid ( gaiaGeomCollPtr geom )

Checks if a Geometry object represents an OGC Valid Geometry.

Parameters:

geom	pointer to Geometry object.

Returns:: 0 if false; any other value if true

See also:: gaiaIsSimple, gaiaIsClosed, gaiaIsRing

Remarks:: GEOS support required.

Examples:: demo2.c.

GAIAGEO_DECLARE gaiaGeomCollPtr gaiaLineInterpolatePoint	(	gaiaGeomCollPtr	ln_geom,
		double	fraction
	)

Spatial operator: Line Interpolate Point.

Parameters:

ln_geom	the input Geometry object [expected to be of lineal type]
fraction	total length fraction [in the range 0.0 / 1.0]

Returns:: the pointer to newly created Geometry object representing a Point laying on the input Geometry and positioned at the given length fraction: NULL on failure.

See also:: gaiaFreeGeomColl

Note:: you are responsible to destroy (before or after) any allocated Geometry, this including any Geometry returned by gaiaLineInterpolatePoint()

Remarks:: GEOS-ADVANCED support required.

GAIAGEO_DECLARE double gaiaLineLocatePoint	(	gaiaGeomCollPtr	ln_geom,
		gaiaGeomCollPtr	pt_geom
	)

Determines the location of the closest Point on Linestring to the given Point.

Parameters:

ln_geom	pointer to first input Geometry object [expected to be of the lineal type].
pt_geom	pointer to second input Geometry object [expected to be a Point].

Returns:: the fraction [in the range 0.0 / 1.0] of ln_geom total length where the closest Point to pt_geom lays.

Remarks:: GEOS-ADVANCED support required.

GAIAGEO_DECLARE gaiaGeomCollPtr gaiaLineMerge ( gaiaGeomCollPtr geom )

Spatial operator: Line Merge.

Parameters:

geom	pointer to input Geometry object.

Returns:: the pointer to newly created Geometry object; NULL on failure.
if possible, this representing a reassembled Linestring or MultiLinestring.

See also:: gaiaFreeGeomColl

Note:: you are responsible to destroy (before or after) any allocated Geometry, this including any Geometry returned by gaiaLineMerge()

Remarks:: GEOS-ADVANCED support required.

GAIAGEO_DECLARE gaiaGeomCollPtr gaiaLineSubstring	(	gaiaGeomCollPtr	ln_geom,
		double	start_fraction,
		double	end_fraction
	)

Spatial operator: Line Substring.

Parameters:

ln_geom	the input Geometry object [expected to be of lineal type]
start_fraction	substring start, expressed as total length fraction [in the range 0.0 / 1.0]
end_fraction	substring end, expressed as total length fraction

Returns:: the pointer to newly created Geometry object representing a Linestring laying on the input Geometry.
this Linestring will begin (and stop) at given total length fractions. NULL on failure.

See also:: gaiaFreeGeomColl

Note:: you are responsible to destroy (before or after) any allocated Geometry, this including any Geometry returned by gaiaLineSubstring()

Remarks:: GEOS-ADVANCED support required.

GAIAGEO_DECLARE gaiaGeomCollPtr gaiaOffsetCurve	(	gaiaGeomCollPtr	geom,
		double	radius,
		int	points,
		int	left_right
	)

Spatial operator: Offset Curve.

Parameters:

geom	the input Geometry object
radius	the buffer's radius
points	number of points (aka vertices) to be used in order to approximate a circular arc.
left_right	if set to 1 the left-sided OffsetCurve will be returned; otherwise the right-sided one.

Returns:: the pointer to newly created Geometry object representing the OffsetCurve of input Geometry: NULL on failure.

See also:: gaiaFreeGeomColl

Note:: you are responsible to destroy (before or after) any allocated Geometry, this including any Geometry returned by gaiaOffsetCurve()

Remarks:: GEOS-ADVANCED support required.

GAIAGEO_DECLARE gaiaGeomCollPtr gaiaPolygonize	(	gaiaGeomCollPtr	geom,
		int	force_multi
	)

Attempts to rearrange a generic Geometry object into a Polygon or MultiPolygon.

Parameters:

geom	the input Geometry object
force_multi	if not set to 0, then an eventual Polygon will be returned casted to MultiPolygon

Returns:: the pointer to newly created Geometry object representing a Polygon or MultiPolygon Geometry: NULL on failure.

See also:: gaiaFreeGeomColl

Note:: you are responsible to destroy (before or after) any allocated Geometry, this including any Geometry returned by gaiaPolygonize()

Remarks:: GEOS support required.

GAIAGEO_DECLARE double gaiaRadsToDegs ( double rads )

Converts and angle from Radians into Degrees.

Parameters:

rads	the angle measured in Radians.

Returns:: the angle measured in Degrees.

See also:: gaiaDegsToRads

Remarks:: PROJ.4 support required

GAIAGEO_DECLARE void gaiaResetGeosMsg ( void )

Resets the GEOS error and warning messages to an empty state.

See also:: gaiaGetGeosErrorMsg, gaiaGetGeosWarningMsg, gaiaSetGeosErrorMsg, gaiaSetGeosWarningMsg

Remarks:: GEOS support required.

GAIAGEO_DECLARE void gaiaSetGeosErrorMsg ( const char * msg )

Set the current GEOS error message.

Parameters:

msg	the error message to be set.

See also:: gaiaResetGeosMsg, gaiaGetGeosErrorMsg, gaiaGetGeosWarningMsg, gaiaSetGeosWarningMsg

Remarks:: GEOS support required.

GAIAGEO_DECLARE void gaiaSetGeosWarningMsg ( const char * msg )

Set the current GEOS warning message.

Parameters:

msg	the warning message to be set.

See also:: gaiaResetGeosMsg, gaiaGetGeosErrorMsg, gaiaGetGeosWarningMsg, gaiaSetGeosErrorMsg

Remarks:: GEOS support required.

GAIAGEO_DECLARE gaiaGeomCollPtr gaiaSharedPaths	(	gaiaGeomCollPtr	geom1,
		gaiaGeomCollPtr	geom2
	)

Spatial operator: Shared Paths.

Parameters:

geom1	pointer to first Geometry object
geom2	pointer to second Geometry object

Returns:: the pointer to newly created Geometry object representing any Share Path common to both input geometries: NULL on failure.

See also:: gaiaFreeGeomColl

Note:: you are responsible to destroy (before or after) any allocated Geometry, this including any Geometry returned by gaiaSharedPaths()

Remarks:: GEOS-ADVANCED support required.

GAIAGEO_DECLARE gaiaGeomCollPtr gaiaShortestLine	(	gaiaGeomCollPtr	geom1,
		gaiaGeomCollPtr	geom2
	)

Spatial operator: Shortest Line.

Parameters:

geom1	pointer to the first Geometry object.
geom2	pointer to the second Geometry object.

Returns:: the pointer to newly created Geometry object representing a Linestring; NULL on failure.
the returned Linestring graphically represents the minimum distance intercurrinng between both input geometries.

See also:: gaiaFreeGeomColl

Note:: you are responsible to destroy (before or after) any allocated Geometry, this including any Geometry returned by gaiaShortestLine()

Remarks:: GEOS-ADVANCED support required.

GAIAGEO_DECLARE gaiaGeomCollPtr gaiaSingleSidedBuffer	(	gaiaGeomCollPtr	geom,
		double	radius,
		int	points,
		int	left_right
	)

Spatial operator: Single Sided Buffer.

Parameters:

geom	the input Geometry object
radius	the buffer's radius
points	number of points (aka vertices) to be used in order to approximate a circular arc.
left_right	if set to 1 the left-sided Buffer will be returned; otherwise the right-sided one.

Returns:: the pointer to newly created Geometry object representing the single-sided Buffer of input Geometry: NULL on failure.

See also:: gaiaFreeGeomColl

Note:: you are responsible to destroy (before or after) any allocated Geometry, this including any Geometry returned by gaiaSingleSidedBuffer()

Remarks:: GEOS-ADVANCED support required.

GAIAGEO_DECLARE gaiaGeomCollPtr gaiaSnap	(	gaiaGeomCollPtr	geom1,
		gaiaGeomCollPtr	geom2,
		double	tolerance
	)

Spatial operator: Shortest Line.

Parameters:

geom1	pointer to the first Geometry object.
geom2	pointer to the second Geometry object.
tolerance	approximation factor

Returns:: the pointer to newly created Geometry object; NULL on failure.
the returned Geometry represents the first input Geometry (nicely snapped to the second input Geometry, whenever is possible).

See also:: gaiaFreeGeomColl

Note:: you are responsible to destroy (before or after) any allocated Geometry, this including any Geometry returned by gaiaShortestLine()

Remarks:: GEOS-ADVANCED support required.

GAIAGEO_DECLARE void* gaiaToGeos ( const gaiaGeomCollPtr gaia )

Converts a Geometry object into a GEOS Geometry.

Parameters:

gaia	pointer to Geometry object

Returns:: handle to GEOS Geometry

See also:: gaiaFromGeos_XY, gaiaFromGeos_XYZ, gaiaFromGeos_XYM, gaiaFromGeos_XYZM

Remarks:: GEOS support required.

GAIAGEO_DECLARE gaiaGeomCollPtr gaiaTransform	(	gaiaGeomCollPtr	org,
		char *	proj_from,
		char *	proj_to
	)

Tansforms a Geometry object into a different Reference System [aka Reprojection].

Parameters:

org	pointer to input Geometry object.
proj_from	geodetic parameters string [EPSG format] qualifying the input Reference System
proj_to	geodetic parameters string [EPSG format] qualifying the output Reference System

Returns:: the pointer to newly created Geometry object: NULL on failure.

See also:: gaiaFreeGeomColl

Note:: you are responsible to destroy (before or after) any allocated Geometry, this including any Geometry returned by gaiaGeometryTransform()

Remarks:: PROJ.4 support required

GAIAGEO_DECLARE gaiaGeomCollPtr gaiaUnaryUnion ( gaiaGeomCollPtr geom )

Spatial operator: Unary Union.

Parameters:

geom	the input Geometry object.

Returns:: the pointer to newly created Geometry object: NULL on failure.
this function is the same as gaiaGeometryUnion, except in that this works internally to the input Geometry itself. NULL on failure.

See also:: gaiaFreeGeomColl, gaiaGeometryUnion

Note:: you are responsible to destroy (before or after) any allocated Geometry, this including any Geometry returned by gaiaUnaryUnion()

Remarks:: GEOS-ADVANCED support required.

Functions

Detailed Description

Function Documentation