Find intersection of two geometries?

[bertday]

Hello, and thank you for this project!

Is it possible to calculate the spatial intersection of two geometries? Say, the point where two lines intersect? I wasn't able to find it in the docs.

[ewsterrenburg]

Agreed that having only the https://pkg.go.dev/github.com/spatial-go/geoos as documentation makes things a bit of a guessing game to find the right functions (and how to apply them). For an intersection, you could use the following:

package main

import (
	"fmt"

	"github.com/spatial-go/geoos/geoencoding"
	"github.com/spatial-go/geoos/planar"
)

func main() {
	polygon, _ := geoencoding.Decode([]byte(`POLYGON((0 0,0 1,0 2,0 3,1 3,1 2,1 1,2 1,2 2,3 2,3 1,4 1,4 2,5 2,5 1,5 0,4 0,3 0,2 0,1 0,0 0))`), geoencoding.WKT)
	line, _ := geoencoding.Decode([]byte(`LINESTRING(-5 0, 5 5)`), geoencoding.WKT)

	strategy := planar.NormalStrategy()
	i, _ := strategy.Intersection(polygon, line)
	fmt.Println(string(geoencoding.Encode(i, geoencoding.WKT)))
}

(prints "LINESTRING(0 2.5,1 3)")