generate reference dataset

Author: delfrrr

generate-reference-triangles/README.md

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+
+Generating reference datasets using original https://github.com/mapbox/delaunator
+
+## Usage
+
+```
+npm i
+./index.js ../test-files/playgrounds-1356-epsg-3857.geojson ../test-files/playgrounds-1356-triangles.json
+```

generate-reference-triangles/index.js

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+#!/usr/bin/env node
+
+/**
+ * generates triangles indices from delaunator;
+ */
+
+const {readFileSync, writeFileSync} = require('fs');
+const Delaunator = require('delaunator');
+const inputFile = process.argv[2];
+const outputFile = process.argv[3];
+const geoJson = JSON.parse(readFileSync(inputFile));
+
+const n = geoJson.features.length;
+const coords = new Float64Array(n * 2);
+for(let i = 0; i < n; i++) {
+    const f = geoJson.features[i];
+    coords[2 * i] = f.geometry.coordinates[0];
+    coords[2 * i + 1] = f.geometry.coordinates[1];
+}
+
+console.time('Delaunator');
+const delaunator = new Delaunator(coords);
+console.timeEnd('Delaunator');
+
+const trianglesAr = Array.from(delaunator.triangles);
+writeFileSync(outputFile, JSON.stringify(trianglesAr));
+