fix: prevent negative left-shift when using negative zoomOffset (#2133)

monsieurtanuki · web-flow · commit ebc5622a6f48 · 2025-07-23T10:00:24.000Z
diff --git a/lib/src/layer/tile_layer/tile_coordinates.dart b/lib/src/layer/tile_layer/tile_coordinates.dart
@@ -77,10 +77,11 @@ class TileCoordinatesResolver {
     if (!replicatesWorldLongitude) {
       return positionCoordinates;
     }
-    if (positionCoordinates.z < 0) {
+    final z = positionCoordinates.z + zoomOffset;
+    if (z < 0) {
       return positionCoordinates;
     }
-    final modulo = 1 << (positionCoordinates.z + zoomOffset);
+    final modulo = 1 << z;
     int x = positionCoordinates.x;
     while (x < 0) {
       x += modulo;

Original file line number	Diff line number	Diff line change
`@@ -77,10 +77,11 @@ class TileCoordinatesResolver {`
`77`	`77`	`if (!replicatesWorldLongitude) {`
`78`	`78`	`return positionCoordinates;`
`79`	`79`	`}`
`80`		`- if (positionCoordinates.z < 0) {`
	`80`	`+ final z = positionCoordinates.z + zoomOffset;`
	`81`	`+ if (z < 0) {`
`81`	`82`	`return positionCoordinates;`
`82`	`83`	`}`
`83`		`- final modulo = 1 << (positionCoordinates.z + zoomOffset);`
	`84`	`+ final modulo = 1 << z;`
`84`	`85`	`int x = positionCoordinates.x;`
`85`	`86`	`while (x < 0) {`
`86`	`87`	`x += modulo;`