james-willis commented on code in PR #60:
URL:
https://github.com/apache/sedona-spatialbench/pull/60#discussion_r2511600039
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spatialbench/src/spatial/utils/antimeridian.rs:
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@@ -0,0 +1,258 @@
+use geo::{Centroid, LineString, Polygon};
+
+/// Wraps a longitude value to ensure it stays within the valid range of
[-180, 180] degrees.
+///
+/// Longitude is a circular coordinate:
+/// - If longitude exceeds 180°, it wraps around from the eastern hemisphere
back to the western hemisphere.
+/// - If longitude is below -180°, it wraps around from the western hemisphere
back to the eastern hemisphere.
+pub fn wrap_around_longitude(mut lon: f64) -> f64 {
+ while lon > 180.0 {
+ lon -= 360.0;
+ }
+ while lon < -180.0 {
+ lon += 360.0;
+ }
+ lon
+}
+
+/// Checks if a polygon crosses the dateline (antimeridian at ±180°)
+pub fn crosses_dateline(polygon: &Polygon) -> bool {
+ let coords = polygon.exterior().coords();
+ let mut has_east = false;
+ let mut has_west = false;
+
+ for coord in coords {
+ if (coord.x > 90.0 && coord.x <= 180.0) || coord.x < -180.0 {
+ has_east = true;
+ }
+ if coord.x > 180.0 || (coord.x >= -180.0 && coord.x < -90.0) {
+ has_west = true;
+ }
+ if has_east && has_west {
+ return true;
+ }
+ }
+ false
+}
+
+/// Clamps a polygon's longitude coordinates to one side of the antimeridian
(±180°).
+///
+/// When a polygon crosses the dateline, this function constrains its
coordinates to remain
+/// on either the eastern (0° to 180°) or western (-180° to 0°) hemisphere
based on where
+/// the polygon's centroid is located.
+///
+/// # Behavior
+/// - If the centroid is in the eastern hemisphere (≥ 0°), coordinates are
clamped to [0°, 180°]
+/// or kept at their original values if already within [-180°, 0°]
+/// - If the centroid is in the western hemisphere (< 0°), coordinates are
clamped to [-180°, 0°]
+/// or kept at their original values if already within [0°, 180°]
+/// - Latitude values (y-coordinates) remain unchanged
+///
+pub fn clamp_polygon_to_dateline(polygon: &Polygon) -> Polygon {
+ let centroid = polygon.centroid().expect("Polygon should have centroid");
+ let east_bound = centroid.x() >= 0.0;
+ let keep_east = (centroid.x() >= 0.0 && centroid.x() <= 180.0) ||
(centroid.x() < -180.0);
+
+ let exterior_coords: Vec<_> = polygon
+ .exterior()
+ .coords()
+ .map(|coord| {
Review Comment:
Is there some risk this creates an invalid polygon?
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