Activate X-flip on image: negative width in drawImage

vendor/clouds3d.js

@@ -350,9 +350,12 @@ function drawTileAt(lng, perp, dx, dz, centerTileX, centerTileY) {
         // the corridor orientation (east tiles have their image east
         // on the left of the drawn area, west tiles on the right).
         // Labels are drawn separately in normal orientation, so the
-        // No X-flip on the image. Map content reads normally.
-        groundCtx.drawImage(img, canvasX, canvasY,
-            GROUND_TILE_SIZE, GROUND_TILE_SIZE);
+        // X-flip activated: draw with negative width to mirror
+        // horizontally. The image is anchored at the right edge
+        // (canvasX + TILE_SIZE) and extends leftward, producing a
+        // horizontally mirrored image.
+        groundCtx.drawImage(img, canvasX + GROUND_TILE_SIZE, canvasY,
+            -GROUND_TILE_SIZE, GROUND_TILE_SIZE);
         groundLoadedTiles[tileX + '_' + tileY] = true;
 
         // Thin border so the user can see where one tile ends and the