1- import seedrandom from 'seedrandom' ;
2-
3-
41/**
52 * Generates a random point coordinate within a given polygon.
63 *
74 * @param {Array } polygon - An array of coordinate arrays representing the polygon.
85 * @param {number } index - An index to differentiate points for polygons with similar coordinates.
96 * @returns {Array } The random point coordinate [longitude, latitude].
107 */
11- export const getRandomPointInPolygon = ( polygon , index ) => {
8+ export const getRandomPointInPolygon = ( polygon ) => {
129 // Calculate the bounding box of the polygon
1310 const bounds = polygon . reduce (
1411 ( prev , curr ) => {
@@ -23,45 +20,39 @@ export const getRandomPointInPolygon = (polygon, index) => {
2320 { minLon : Infinity , maxLon : - Infinity , minLat : Infinity , maxLat : - Infinity }
2421 ) ;
2522
26- // Create a seed based on the polygon's coordinates and the index
27- const seed = JSON . stringify ( polygon ) + index ;
28- const rng = seedrandom ( seed ) ;
29-
30- // Generate a random point within the bounding box
31- let randomPoint ;
32- let isInPolygon = false ;
33- while ( ! isInPolygon ) {
34- const lon = bounds . minLon + rng ( ) * ( bounds . maxLon - bounds . minLon ) ;
35- const lat = bounds . minLat + rng ( ) * ( bounds . maxLat - bounds . minLat ) ;
36- randomPoint = [ lon , lat ] ;
37-
38- // Check if the random point is within the polygon
39- isInPolygon = isPointInPolygon ( randomPoint , polygon ) ;
23+ // Helper function to check if a point is inside the polygon
24+ const isPointInPolygon = ( point , polygon ) => {
25+ let inside = false ;
26+ for ( let i = 0 , j = polygon . length - 1 ; i < polygon . length ; j = i ++ ) {
27+ const xi = polygon [ i ] [ 0 ] , yi = polygon [ i ] [ 1 ] ;
28+ const xj = polygon [ j ] [ 0 ] , yj = polygon [ j ] [ 1 ] ;
29+
30+ const intersect = ( ( yi > point [ 1 ] ) !== ( yj > point [ 1 ] ) )
31+ && ( point [ 0 ] < ( xj - xi ) * ( point [ 1 ] - yi ) / ( yj - yi ) + xi ) ;
32+ if ( intersect ) inside = ! inside ;
33+ }
34+ return inside ;
35+ } ;
36+
37+ // Generate random points until we find one inside the polygon
38+ let attempts = 0 ;
39+ const maxAttempts = 1000 ; // Prevent infinite loop
40+
41+ while ( attempts < maxAttempts ) {
42+ const randomLon = bounds . minLon + Math . random ( ) * ( bounds . maxLon - bounds . minLon ) ;
43+ const randomLat = bounds . minLat + Math . random ( ) * ( bounds . maxLat - bounds . minLat ) ;
44+
45+ if ( isPointInPolygon ( [ randomLon , randomLat ] , polygon ) ) {
46+ return [ randomLon , randomLat , 0 ] ; // Adding 0 for elevation to match input format
47+ }
48+
49+ attempts ++ ;
4050 }
41-
42- return randomPoint ;
51+
52+ // If we couldn't find a point after max attempts, return center of bounding box
53+ return [
54+ ( bounds . minLon + bounds . maxLon ) / 2 ,
55+ ( bounds . minLat + bounds . maxLat ) / 2 ,
56+ 0
57+ ] ;
4358} ;
44-
45- /**
46- * Checks if a point is within a given polygon.
47- *
48- * @param {Array } point - The point coordinate [longitude, latitude].
49- * @param {Array } polygon - An array of coordinate arrays representing the polygon.
50- * @returns {boolean } True if the point is within the polygon, false otherwise.
51- */
52- function isPointInPolygon ( point , polygon ) {
53- const [ x , y ] = point ;
54- let isInside = false ;
55-
56- for ( let i = 0 , j = polygon . length - 1 ; i < polygon . length ; j = i ++ ) {
57- const [ x1 , y1 ] = polygon [ i ] ;
58- const [ x2 , y2 ] = polygon [ j ] ;
59-
60- const intersect =
61- y1 > y !== y2 > y && x < ( ( x2 - x1 ) * ( y - y1 ) ) / ( y2 - y1 ) + x1 ;
62-
63- if ( intersect ) isInside = ! isInside ;
64- }
65-
66- return isInside ;
67- }
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