https://github.com/akhenakh/tgo

Go bindings for TG Fast point-in-polygon Geometry
https://github.com/akhenakh/tgo

geometry point-in-polygon polygon

Last synced: 24 days ago
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Go bindings for TG Fast point-in-polygon Geometry

• Host: GitHub
• URL: https://github.com/akhenakh/tgo
• Owner: akhenakh
• License: other
• Created: 2023-09-25T22:00:04.000Z (about 1 year ago)
• Default Branch: main
• Last Pushed: 2024-03-07T13:20:27.000Z (8 months ago)
• Last Synced: 2024-03-07T14:39:45.987Z (8 months ago)
• Topics: geometry, point-in-polygon, polygon
• Language: C
• Homepage:
• Size: 298 KB
• Stars: 6
• Watchers: 2
• Forks: 0
• Open Issues: 1
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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---

![Tests](https://github.com/akhenakh/tgo/actions/workflows/build.yml/badge.svg)

[![GoDoc](https://pkg.go.dev/badge/github.com/akhenakh/tgo)](https://pkg.go.dev/github.com/akhenakh/tgo)

[](https://github.com/akhenakh/tgo/)

Go bindings for [tidwall/tg](https://github.com/tidwall/tg) Geometry library for C - Fast point-in-polygon 

This is partial but functional, tg is a very small self contained C library, tgo compiles tg, no external dependencies needed.

## Usage

Simply go get this library with CGO enabled (you'll need a C compiler).

#### Read from WKT

```go

// Unmarshal from WKT

input := "POLYGON((0 0,0 1,1 1,1 0,0 0))"

g, _ := tgo.UnmarshalWKT(input)

// Marshal to WKT

output := g.AsText()

fmt.Println(output) // Prints: POLYGON((0 0,0 1,1 1,1 0,0 0))

```

#### Read from GeoJSON

```go

input := `{"type":"Feature","properties":{},"geometry":{"coordinates":[-79.20159897229003,43.636785010689835],"type":"Point"}}`

g, _ := tgo.UnmarshalGeoJSON(input)

```

#### Read from WKB

```go

input := []byte{1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 248, 63, 0, 0, 0, 0, 0, 0, 4, 64}

g, _ := tgo.UnmarshalWKB(input)

```

#### Intersects

```go

if Intersects(g1, g2) {

	fmt.Println("Intersects")

}

```

#### Point in Polygon on large FeatureCollections

```go

// load your collection using UnmarshalGeoJSON

found := g.StabOne(2, 48)

if found != nil {

	fmt.Println(found.Properties())

}

// Output: {"properties":{ "ADMIN": "France", "ISO_A2": "FR", "ISO_A3": "FRA" }}

```

#### Types

```go

input := "POLYGON((0 0,0 1,1 1,1 0,0 0))"

g, _ := tgo.UnmarshalWKT(input)

if g.Types() == tgo.Polygon() {

	p, _ := g.AsPoly()

	p.HolesCount()

}

```

## Tests

Some tests are borrowed from [simplefeatures](https://github.com/peterstace/simplefeatures).