54 lines
2.0 KiB
JavaScript
54 lines
2.0 KiB
JavaScript
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export default function(input, digits) {
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if (!(0 <= (digits = +digits) && digits <= 20)) throw new Error("invalid digits");
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function quantizePoint(input) {
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var n = input.length, i = 2, output = new Array(n);
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output[0] = +input[0].toFixed(digits);
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output[1] = +input[1].toFixed(digits);
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while (i < n) output[i] = input[i], ++i;
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return output;
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}
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function quantizePoints(input) {
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return input.map(quantizePoint);
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}
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function quantizePolygon(input) {
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return input.map(quantizePoints);
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}
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function quantizeGeometry(input) {
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if (input == null) return input;
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var output;
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switch (input.type) {
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case "GeometryCollection": output = {type: "GeometryCollection", geometries: input.geometries.map(quantizeGeometry)}; break;
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case "Point": output = {type: "Point", coordinates: quantizePoint(input.coordinates)}; break;
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case "MultiPoint": case "LineString": output = {type: input.type, coordinates: quantizePoints(input.coordinates)}; break;
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case "MultiLineString": case "Polygon": output = {type: input.type, coordinates: quantizePolygon(input.coordinates)}; break;
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case "MultiPolygon": output = {type: "MultiPolygon", coordinates: input.coordinates.map(quantizePolygon)}; break;
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default: return input;
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}
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if (input.bbox != null) output.bbox = input.bbox;
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return output;
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}
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function quantizeFeature(input) {
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var output = {type: "Feature", properties: input.properties, geometry: quantizeGeometry(input.geometry)};
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if (input.id != null) output.id = input.id;
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if (input.bbox != null) output.bbox = input.bbox;
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return output;
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}
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if (input != null) switch (input.type) {
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case "Feature": return quantizeFeature(input);
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case "FeatureCollection": {
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var output = {type: "FeatureCollection", features: input.features.map(quantizeFeature)};
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if (input.bbox != null) output.bbox = input.bbox;
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return output;
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}
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default: return quantizeGeometry(input);
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}
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return input;
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}
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