45 lines
1.1 KiB
JavaScript
Executable File
45 lines
1.1 KiB
JavaScript
Executable File
import distance from '@turf/distance';
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/**
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* Takes a bounding box and calculates the minimum square bounding box that
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* would contain the input.
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*
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* @name square
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* @param {BBox} bbox extent in [west, south, east, north] order
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* @returns {BBox} a square surrounding `bbox`
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* @example
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* var bbox = [-20, -20, -15, 0];
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* var squared = turf.square(bbox);
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*
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* //addToMap
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* var addToMap = [turf.bboxPolygon(bbox), turf.bboxPolygon(squared)]
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*/
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function square(bbox) {
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var west = bbox[0];
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var south = bbox[1];
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var east = bbox[2];
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var north = bbox[3];
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var horizontalDistance = distance(bbox.slice(0, 2), [east, south]);
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var verticalDistance = distance(bbox.slice(0, 2), [west, north]);
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if (horizontalDistance >= verticalDistance) {
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var verticalMidpoint = (south + north) / 2;
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return [
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west,
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verticalMidpoint - (east - west) / 2,
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east,
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verticalMidpoint + (east - west) / 2,
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];
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} else {
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var horizontalMidpoint = (west + east) / 2;
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return [
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horizontalMidpoint - (north - south) / 2,
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south,
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horizontalMidpoint + (north - south) / 2,
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north,
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];
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}
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}
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export default square;
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