w1cdn/spothole
1
0
Fork 0
mirror of https://git.ianrenton.com/ian/spothole.git synced 2025-10-27 08:49:27 +00:00
Code Issues 11 Packages Projects Releases Wiki Activity

Implement bearing to spot column. Closes #19

Browse Source
This commit is contained in:
Ian Renton
2025-10-12 17:39:26 +01:00
parent bb2813c2a5
commit 35a82a41bd
3 changed files with 41 additions and 3 deletions
Download Patch File Download Diff File Expand all files Collapse all files

15
webassets/js/common.js
View File

@@ -109,6 +109,21 @@ function columnsUpdated() {
saveSettings();
}
// Calculate great circle bearing between two lat/lon points.
function calcBearing(lat1, lon1, lat2, lon2) {
lat1 *= Math.PI / 180;
lon1 *= Math.PI / 180;
lat2 *= Math.PI / 180;
lon2 *= Math.PI / 180;
var lonDelta = lon2 - lon1;
var y = Math.sin(lonDelta) * Math.cos(lat2);
var x = Math.cos(lat1) * Math.sin(lat2) - Math.sin(lat1) * Math.cos(lat2) * Math.cos(lonDelta);
var bearing = Math.atan2(y, x);
bearing = bearing * (180 / Math.PI);
if ( bearing < 0 ) { bearing += 360; }
return bearing;
}
// Convert a Maidenhead grid reference of arbitrary precision to the lat/long of the centre point of the square.
// Returns null if the grid format is invalid.
function latLonForGridCentre(grid) {