gen_parallels_xldgen_parallels_xldGenParallelsXldGenParallelsXld (Operator)


gen_parallels_xldgen_parallels_xldGenParallelsXldGenParallelsXld — Extract parallel XLD polygons.


gen_parallels_xld(Polygons : Parallels : Len, Dist, Alpha, Merge : )

Herror gen_parallels_xld(const Hobject Polygons, Hobject* Parallels, double Len, double Dist, double Alpha, const char* Merge)

Herror T_gen_parallels_xld(const Hobject Polygons, Hobject* Parallels, const Htuple Len, const Htuple Dist, const Htuple Alpha, const Htuple Merge)

void GenParallelsXld(const HObject& Polygons, HObject* Parallels, const HTuple& Len, const HTuple& Dist, const HTuple& Alpha, const HTuple& Merge)

HXLDPara HXLDPoly::GenParallelsXld(const HTuple& Len, const HTuple& Dist, const HTuple& Alpha, const HString& Merge) const

HXLDPara HXLDPoly::GenParallelsXld(double Len, double Dist, double Alpha, const HString& Merge) const

HXLDPara HXLDPoly::GenParallelsXld(double Len, double Dist, double Alpha, const char* Merge) const

HXLDPara HXLDPoly::GenParallelsXld(double Len, double Dist, double Alpha, const wchar_t* Merge) const   (Windows only)

static void HOperatorSet.GenParallelsXld(HObject polygons, out HObject parallels, HTuple len, HTuple dist, HTuple alpha, HTuple merge)

HXLDPara HXLDPoly.GenParallelsXld(HTuple len, HTuple dist, HTuple alpha, string merge)

HXLDPara HXLDPoly.GenParallelsXld(double len, double dist, double alpha, string merge)


gen_parallels_xldgen_parallels_xldGenParallelsXldGenParallelsXldGenParallelsXld examines the XLD polygons passed in PolygonsPolygonsPolygonsPolygonspolygons for parallelism. The resulting parallel polygons are returned in ParallelsParallelsParallelsParallelsparallels. If the parameter MergeMergeMergeMergemerge is set to 'true'"true""true""true""true", adjacent parallel polygons are returned in a single parallel relation. Otherwise, one parallel relation is returned for each pair of parallel line segments.

Only polygon segments longer than LenLenLenLenlen are taken into account. Whether two polygon segments are parallel depends on a maximum allowed angle difference AlphaAlphaAlphaAlphaalpha (in radians). Furthermore, the projections of the two segments onto their angle bisector have to overlap. Finally, the overlap on the angle bisector is reprojected onto the two segments. If the maximal distance of the reprojections is smaller than DistDistDistDistdist, the segments are stored in ParallelsParallelsParallelsParallelsparallels.

As a side effect, a quality factor is calculated for each pair of parallels, compare mod_parallels_xldmod_parallels_xldModParallelsXldModParallelsXldModParallelsXld. It is based on the normalized angular difference and the normalized length of the overlap: Here, is the angle difference of the polygon segments, is the length of the overlap, and the lengths of the polygon segments, and the resulting quality factor. The quality factor is a measure of parallelism (the larger its value, the “more parallel” the polygons). Finally, the quality factors of all parallel polygon segments contained in a single polygon are added, weighted with their length of the overlapping area. Note that you can query the range for the quality factor with info_parallels_xldinfo_parallels_xldInfoParallelsXldInfoParallelsXldInfoParallelsXld.

Execution Information


PolygonsPolygonsPolygonsPolygonspolygons (input_object)  xld_poly-array objectHXLDPolyHXLDPolyHobject

Input polygons.

ParallelsParallelsParallelsParallelsparallels (output_object)  xld_para-array objectHXLDParaHXLDParaHobject *

Parallel polygons.

LenLenLenLenlen (input_control)  number HTupleHTupleHtuple (real / integer) (double / int / long) (double / Hlong) (double / Hlong)

Minimum length of the individual polygon segments.

Default value: 10.0

Suggested values: 5.0, 10.0, 15.0, 20.0

Restriction: Len > 0.0

DistDistDistDistdist (input_control)  number HTupleHTupleHtuple (real / integer) (double / int / long) (double / Hlong) (double / Hlong)

Maximum distance between the polygon segments.

Default value: 30.0

Suggested values: 20.0, 25.0, 30.0, 40.0, 50.0, 75.0

Restriction: Dist > 0.0

AlphaAlphaAlphaAlphaalpha (input_control)  number HTupleHTupleHtuple (real / integer) (double / int / long) (double / Hlong) (double / Hlong)

Maximum angle difference of the polygon segments.

Default value: 0.15

Suggested values: 0.05, 0.10, 0.15, 0.20, 0.30

Restriction: 0 <= Alpha && Alpha <= pi / 2

MergeMergeMergeMergemerge (input_control)  string HTupleHTupleHtuple (string) (string) (HString) (char*)

Should adjacent parallel relations be merged?

Default value: 'true' "true" "true" "true" "true"

List of values: 'false'"false""false""false""false", 'true'"true""true""true""true"

Possible Predecessors


Possible Successors

mod_parallels_xldmod_parallels_xldModParallelsXldModParallelsXldModParallelsXld, get_parallels_xldget_parallels_xldGetParallelsXldGetParallelsXldGetParallelsXld, info_parallels_xldinfo_parallels_xldInfoParallelsXldInfoParallelsXldInfoParallelsXld