@urban-toolkit/autk-core

---

@urban-toolkit/autk-core / TriangulatorPolygons

Class: TriangulatorPolygons

Defined in: triangulator-polygons.ts:43

Triangulates polygonal GeoJSON features into fill and border mesh chunks.

TriangulatorPolygons accepts LineString, MultiLineString, Polygon, MultiPolygon, and GeometryCollection features containing those geometry types. Fill meshes are triangulated with earcut after translating vertices into local coordinates relative to the supplied origin. Border meshes are generated as line-index pairs, with open borders for line strings and closed rings for polygon outlines and holes. Unsupported or missing geometries are skipped with a warning.

Constructors

Constructor

new TriangulatorPolygons(): TriangulatorPolygons

Returns

TriangulatorPolygons

Methods

buildBorder()

static buildBorder(geojson, origin): [LayerBorder[], LayerBorderComponent[]]

Defined in: triangulator-polygons.ts:112

Builds border line geometry for a feature collection.

Parameters

geojson

FeatureCollection

Source feature collection.

origin

number[]

World-space origin used to derive local XY coordinates.

Returns

[LayerBorder[], LayerBorderComponent[]]

A tuple of border chunks and per-feature border counts.

Throws

Never throws. Unsupported features are skipped with a console warning.

Example

const [borders, borderComps] = TriangulatorPolygons.buildBorder(polyFC, origin);

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buildMesh()

static buildMesh(geojson, origin): [LayerGeometry[], LayerComponent[]]

Defined in: triangulator-polygons.ts:54

Builds triangulated fill geometry for a feature collection.

Parameters

geojson

FeatureCollection

Source feature collection.

origin

number[]

World-space origin used to derive local XY coordinates.

Returns

[LayerGeometry[], LayerComponent[]]

A tuple of mesh chunks and per-feature component counts.

Throws

Never throws. Unsupported features are skipped with a console warning.

Example

const [meshes, comps] = TriangulatorPolygons.buildMesh(polyFC, origin);

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geometryCollectionToBorderMesh()

static geometryCollectionToBorderMesh(feature, origin, featureIndex): object[]

Defined in: triangulator-polygons.ts:366

Flattens supported children of a GeometryCollection into border meshes.

Parameters

feature

Feature

Source feature with GeometryCollection geometry.

origin

number[]

World-space origin used to derive local XY coordinates.

featureIndex

number

Index of the parent feature in the source collection.

Returns

object[]

Border line meshes for all supported child geometries.

Throws

Never throws. Unsupported children are skipped with a console warning.

Example

const borders = TriangulatorPolygons.geometryCollectionToBorderMesh(gcFeature, origin, 0);

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geometryCollectionToMesh()

static geometryCollectionToMesh(feature, origin, featureIndex): object[]

Defined in: triangulator-polygons.ts:341

Flattens supported children of a GeometryCollection into fill meshes.

Parameters

feature

Feature

Source feature with GeometryCollection geometry.

origin

number[]

World-space origin used to derive local XY coordinates.

featureIndex

number

Index of the parent feature in the source collection.

Returns

object[]

Triangulated fill meshes for all supported child geometries.

Throws

Never throws. Unsupported children are skipped with a console warning.

Example

const meshes = TriangulatorPolygons.geometryCollectionToMesh(gcFeature, origin, 0);

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lineStringToBorderMesh()

static lineStringToBorderMesh(feature, origin): object[]

Defined in: triangulator-polygons.ts:187

Converts a LineString feature into open border line geometry.

Parameters

feature

Feature

Source feature with LineString geometry.

origin

number[]

World-space origin used to derive local XY coordinates.

Returns

object[]

Border line meshes for the feature.

Throws

Never throws.

Example

const [border] = TriangulatorPolygons.lineStringToBorderMesh(lineFeature, origin);

---

lineStringToMesh()

static lineStringToMesh(feature, origin): object[]

Defined in: triangulator-polygons.ts:170

Converts a LineString feature into triangulated fill geometry.

Parameters

feature

Feature

Source feature with LineString geometry.

origin

number[]

World-space origin used to derive local XY coordinates.

Returns

object[]

Triangulated fill meshes for the feature.

Throws

Never throws.

Example

const [mesh] = TriangulatorPolygons.lineStringToMesh(lineFeature, origin);

---

multiLineStringToBorderMesh()

static multiLineStringToBorderMesh(feature, origin): object[]

Defined in: triangulator-polygons.ts:225

Converts a MultiLineString feature into border line geometry.

Parameters

feature

Feature

Source feature with MultiLineString geometry.

origin

number[]

World-space origin used to derive local XY coordinates.

Returns

object[]

Border line meshes for each constituent line string.

Throws

Never throws.

Example

const borders = TriangulatorPolygons.multiLineStringToBorderMesh(mlsFeature, origin);

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multiLineStringToMesh()

static multiLineStringToMesh(feature, origin): object[]

Defined in: triangulator-polygons.ts:204

Converts a MultiLineString feature into triangulated fill geometry.

Parameters

feature

Feature

Source feature with MultiLineString geometry.

origin

number[]

World-space origin used to derive local XY coordinates.

Returns

object[]

Triangulated fill meshes for each constituent line string.

Throws

Never throws.

Example

const meshes = TriangulatorPolygons.multiLineStringToMesh(mlsFeature, origin);

---

multiPolygonToBorderMesh()

static multiPolygonToBorderMesh(feature, origin): object[]

Defined in: triangulator-polygons.ts:317

Converts a MultiPolygon feature into border line geometry.

Parameters

feature

Feature

Source feature with MultiPolygon geometry.

origin

number[]

World-space origin used to derive local XY coordinates.

Returns

object[]

Border line meshes for all rings in all polygons.

Throws

Never throws.

Example

const borders = TriangulatorPolygons.multiPolygonToBorderMesh(mpFeature, origin);

---

multiPolygonToMesh()

static multiPolygonToMesh(feature, origin): object[]

Defined in: triangulator-polygons.ts:289

Converts a MultiPolygon feature into triangulated fill geometry.

Parameters

feature

Feature

Source feature with MultiPolygon geometry.

origin

number[]

World-space origin used to derive local XY coordinates.

Returns

object[]

Triangulated fill meshes for each polygon in the collection.

Throws

Never throws.

Example

const meshes = TriangulatorPolygons.multiPolygonToMesh(mpFeature, origin);

---

polygonToBorderMesh()

static polygonToBorderMesh(feature, origin): object[]

Defined in: triangulator-polygons.ts:270

Converts a Polygon feature into closed border line geometry.

Parameters

feature

Feature

Source feature with Polygon geometry.

origin

number[]

World-space origin used to derive local XY coordinates.

Returns

object[]

Border line meshes for all polygon rings.

Throws

Never throws.

Example

const borders = TriangulatorPolygons.polygonToBorderMesh(polyFeature, origin);

---

polygonToMesh()

static polygonToMesh(feature, origin): object[]

Defined in: triangulator-polygons.ts:246

Converts a Polygon feature into triangulated fill geometry with hole support.

Parameters

feature

Feature

Source feature with Polygon geometry.

origin

number[]

World-space origin used to derive local XY coordinates.

Returns

object[]

Triangulated fill meshes for the polygon, including holes.

Throws

Never throws.

Example

const [mesh] = TriangulatorPolygons.polygonToMesh(polyFeature, origin);