gittr

Gittr (from Gitter /ˈɡɪtɐ/, the german word for grid) cuts an input polygon into equal sized grid cells. Grid cells are only created if they either touch or are within the input polygon. It also accounts for polygon holes.

Installation

go get -u github.com/iwpnd/gittr

Usage

package main

import (
	"encoding/json"
	"fmt"

	"github.com/iwpnd/gittr"
)

func main() {
	raw := []byte(`{
              "type": "Feature",
              "properties": {"id": 3},
              "geometry": {
                  "type": "Polygon",
                  "coordinates": [
                      [
                          [13.398424, 52.481369],
                          [13.395336, 52.480271],
                          [13.391905, 52.478598],
                          [13.390017, 52.478076],
                          [13.3871, 52.477971],
                          [13.386929, 52.471384],
                          [13.389503, 52.470338],
                          [13.392076, 52.46924],
                          [13.397395, 52.466626],
                          [13.402971, 52.465527],
                          [13.40992, 52.465789],
                          [13.417384, 52.469867],
                          [13.420558, 52.470338],
                          [13.419185, 52.473946],
                          [13.418499, 52.477501],
                          [13.418756, 52.479592],
                          [13.413781, 52.48048],
                          [13.406489, 52.482153],
                          [13.401856, 52.482728],
                          [13.398424, 52.481369]
                      ],
                      [
                          [13.391561, 52.475096],
                          [13.414552, 52.476194],
                          [13.415324, 52.47107],
                          [13.391647, 52.470756],
                          [13.391561, 52.475096]
                      ]
                  ]
              }
          }`)

	var f gittr.Feature
	err := json.Unmarshal(raw, &f)
	if err != nil {
		panic("something went wrong")
	}

	// create grid with a cell size of 100m
	grid, err := f.ToGrid(100)
	if err != nil {
		panic(err)
	}

	fmt.Printf("cell count: %v\n", len(grid.Features))
}

License

MIT

Maintainer

Benjamin Ramser - @iwpnd

Project Link: https://github.com/iwpnd/gittr

Acknowledgement

Paul Mach - go.geojson