wip

mapbox · Apr 2, 2018 · 7bc39da · 7bc39da
1 parent 25097b2
commit 7bc39da
Showing 1 changed file with 17 additions and 11 deletions.
diff --git a/src/source/source_cache.js b/src/source/source_cache.js
@@ -321,11 +321,18 @@ class SourceCache extends Evented {
     _findLoadedChildren(tileID: OverscaledTileID, maxCoveringZoom: number, retain: {[any]: OverscaledTileID}): boolean {
         let found = false;
 
-        for (const id in this._tiles) {
-            let tile = this._tiles[id];
+        for (const id in this._prevTiles) {
+            let tile;
+            for (const prevTile of this._prevTiles[id]) {
+                if (prevTile.hasData()) {
+                    tile = prevTile;
+                    break;
+                }
+            }
+            if (!tile) continue;
 
             // only consider renderable tiles on higher zoom levels (up to maxCoveringZoom)
-            if (retain[id] || !tile.hasData() || tile.tileID.overscaledZ <= tileID.overscaledZ || tile.tileID.overscaledZ > maxCoveringZoom) continue;
+            if (tile.tileID.overscaledZ <= tileID.overscaledZ || tile.tileID.overscaledZ > maxCoveringZoom) continue;
 
             // disregard tiles that are not descendants of the given tile coordinate
             const z2 = Math.pow(2, tile.tileID.canonical.z - tileID.canonical.z);
@@ -334,7 +341,7 @@ class SourceCache extends Evented {
                 continue;
 
             // found loaded child
-            retain[id] = tile.tileID;
+            this._addTile(tileID);
             found = true;
 
             // loop through parents; retain the topmost loaded one if found
@@ -356,18 +363,17 @@ class SourceCache extends Evented {
      * Find a loaded parent of the given tile (up to minCoveringZoom);
      * adds the found tile to retain object and returns the tile if found
      */
-    findLoadedParent(tileID: OverscaledTileID, minCoveringZoom: number, retain: {[any]: OverscaledTileID}): ?Tile {
+    findLoadedParent(tileID: OverscaledTileID, minCoveringZoom: number): ?Tile {
         for (let z = tileID.overscaledZ - 1; z >= minCoveringZoom; z--) {
             const parent = tileID.scaledTo(z);
             if (!parent) return;
-            const id = String(parent.key);
             const tile = this._getPrevTile(parent);
+            const id = String(parent.key);
             if (tile && tile.hasData()) {
-                retain[id] = parent;
+                this._tiles[tileID.key] = tile;
                 return tile;
             }
             if (this._cache.has(id)) {
-                retain[id] = parent;
                 return this._cache.get(id);
             }
         }
@@ -608,12 +614,12 @@ class SourceCache extends Evented {
      * Add a tile, given its coordinate, to the pyramid.
      * @private
      */
-    _addTile(tileID: OverscaledTileID): Tile {
+    _addTile(tileID: OverscaledTileID, onlyLoaded: boolean): Tile {
         let tile = this._tiles[tileID.key];
         if (tile)
             return tile;
 
-        tile = this._getPrevTile(tileID);
+        tile = this._getPrevTile(tileID, onlyLoaded);
         if (tile) {
             this._tiles[tileID.key] = tile;
             return tile;
@@ -631,7 +637,7 @@ class SourceCache extends Evented {
         }
 
         const cached = Boolean(tile);
-        if (!cached) {
+        if (!cached && !onlyLoaded) {
             tile = new Tile(tileID, this._source.tileSize * tileID.overscaleFactor());
             this._loadTile(tile, this._tileLoaded.bind(this, tile, tileID.key, tile.state));
         }