nakarte

commit 0a3410bee4c3e0a7f7a6d13cdccf92465aebf344
parent a3f091ec6dafa32b0c0d5d00020a03e03686ba38
Author: Sergey Orlov <wladimirych@gmail.com>
Date:   Mon,  2 Nov 2020 21:07:31 +0100

coordinates: fix rounding errors for DM and DMS formats

Number.prototype.toFixed rounds the value which can cause result like
60.00 minutes when the value is slightly less than integer value.

Diffstat:
M
src/lib/leaflet.control.coordinates/formats.js
 | 
23
+++++++++++++++++++----

1 file changed, 19 insertions(+), 4 deletions(-)
diff --git a/src/lib/leaflet.control.coordinates/formats.js b/src/lib/leaflet.control.coordinates/formats.js
@@ -1,13 +1,28 @@
+function truncToFixed(x, precision) {
+    let s = x.toString();
+    let point = s.indexOf('.');
+    if (point === -1) {
+        point = s.length;
+        s += '.';
+    }
+    let sliceEnd = point + precision;
+    if (precision > 0) {
+        s = s.padEnd(point + precision + 1, '0');
+        sliceEnd += 1;
+    }
+    s = s.slice(0, sliceEnd);
+    return s;
+}
+
 function formatNumber(value, size, precision = 0) {
     if (value < 0) {
-      return value.toFixed(precision);
+      throw new Error('Negative values not supported');
     }
 
     if (precision > 0) {
         size += 1;
     }
-
-    return value.toFixed(precision).padStart(size + precision, '0');
+    return truncToFixed(value, precision).padStart(size + precision, '0');
 }
 
 function coordinatePresentations(coordinate, isLat) {
@@ -25,7 +40,7 @@ function coordinatePresentations(coordinate, isLat) {
     }
 
     return {
-        signedDegrees: formatNumber(coordinate, 0, 5),
+        signedDegrees: coordinate.toFixed(5),
         degrees: formatNumber(degrees, 0, 5),
         intDegrees: formatNumber(intDegrees, 0),
         minutes: formatNumber(minutes, 2, 3),