eliminate alternative size tiles

Eliminate alternative tile size provider logic since the effect is now covered by retaining existing tiles until new tiles have loaded. This eliminates significant tile re-rendering, making the map less janky.
greensopinion · Jan 8, 2022 · eecec08 · eecec08
1 parent 10dd2f4
commit eecec08
Show file tree

Hide file tree

Showing 5 changed files with 15 additions and 95 deletions.
diff --git a/lib/src/grid/tile_widgets.dart b/lib/src/grid/tile_widgets.dart
@@ -38,9 +38,6 @@ class TileWidgets extends ChangeNotifier {
 
   void updateWidgets() => _updateWidgets();
 
-  bool get hasNewModels => _newModels.isNotEmpty;
-  bool get hasObsoleteModels => _obsoleteModels.isNotEmpty;
-
   Map<TileIdentity, GridVectorTile> get all => _idToWidget;
 
   void _updateModels(List<TileIdentity> tiles) {

diff --git a/lib/src/stream/caches_tile_provider.dart b/lib/src/stream/caches_tile_provider.dart
@@ -19,28 +19,11 @@ class CachesTileProvider extends TileProvider {
   @override
   Future<Tile> provide(TileIdentity tileIdentity, TileFormat format,
       {double? zoom}) async {
-    final tile =
-        await _provide(tileIdentity, format, zoom: zoom, onlyIfPresent: false);
-    if (tile == null) {
-      throw 'illegal state';
-    }
-    return tile;
-  }
-
-  @override
-  Future<Tile?> provideIfReady(TileIdentity tileIdentity, TileFormat format,
-          {double? zoom}) =>
-      _provide(tileIdentity, format, zoom: zoom, onlyIfPresent: true);
-
-  @override
-  Future<Tile?> _provide(TileIdentity tileIdentity, TileFormat format,
-      {double? zoom, required bool onlyIfPresent}) async {
     if (format == TileFormat.vector) {
-      Map<String, Future<VectorTile?>> futureBySource = {};
+      Map<String, Future<VectorTile>> futureBySource = {};
       for (final source in _caches.providerSources) {
-        futureBySource[source] = onlyIfPresent
-            ? _caches.vectorTileCache.retrieveIfPresent(source, tileIdentity)
-            : _caches.vectorTileCache.retrieve(source, tileIdentity);
+        futureBySource[source] =
+            _caches.vectorTileCache.retrieve(source, tileIdentity);
       }
       Map<String, VectorTile> tileBySource = {};
       for (final entry in futureBySource.entries) {
@@ -55,9 +38,6 @@ class CachesTileProvider extends TileProvider {
             rethrow;
           }
         }
-        if (tile == null) {
-          return null;
-        }
         tileBySource[entry.key] = tile;
       }
       return Tile(
@@ -75,9 +55,6 @@ class CachesTileProvider extends TileProvider {
             tileset: null,
             image: image);
       }
-      if (onlyIfPresent) {
-        return null;
-      }
       final tile = await provide(tileIdentity, TileFormat.vector);
       final loaded = await _caches.imageTileCache
           .retrieve(tile.identity, tile.tileset!, zoom: effectiveZoom);

diff --git a/lib/src/stream/preprocessing_tile_provider.dart b/lib/src/stream/preprocessing_tile_provider.dart
@@ -18,16 +18,6 @@ class PreprocessingTileProvider extends TileProvider {
     return _preprocess(tile);
   }
 
-  @override
-  Future<Tile?> provideIfReady(TileIdentity tileIdentity, TileFormat format,
-      {double? zoom}) async {
-    final tile =
-        await _delegate.provideIfReady(tileIdentity, format, zoom: zoom);
-    if (tile != null) {
-      return _preprocess(tile);
-    }
-  }
-
   Future<Tile> _preprocess(Tile tile) async {
     if (tile.tileset != null) {
       return Tile(

diff --git a/lib/src/stream/provider_supplier.dart b/lib/src/stream/provider_supplier.dart
@@ -1,5 +1,4 @@
 import 'dart:async';
-import 'dart:math';
 
 import '../tile_identity.dart';
 
@@ -9,7 +8,6 @@ import 'tile_supplier.dart';
 class ProviderTileSupplier extends TileSupplier {
   final TileProvider _provider;
   final SlippyMapTranslator _translator;
-  final _maxAlternativeLevels = 2;
 
   ProviderTileSupplier(this._provider)
       : _translator = SlippyMapTranslator(_provider.maximumZoom);
@@ -33,65 +31,25 @@ class ProviderTileSupplier extends TileSupplier {
 
     final secondaryFormat = request.secondaryFormat;
     if (secondaryFormat != null) {
-      final readyTile =
-          await _provideTileOrAlternativeIfReady(request, secondaryFormat);
-      if (readyTile != null) {
-        yield readyTile;
+      final secondary = _provider
+          .provide(tileId, secondaryFormat, zoom: request.tileId.z.toDouble())
+          .toCompleter();
+      if (mainTile.isCompleted) {
+        yield await mainTile.future;
+        providedMainTile = true;
       }
-      if (!request.completed &&
-          (readyTile == null || readyTile.identity.z != tileId.z)) {
-        final imageTile = _provider
-            .provide(tileId, secondaryFormat, zoom: request.tileId.z.toDouble())
-            .toCompleter();
-        if (mainTile.isCompleted) {
-          yield await mainTile.future;
-          providedMainTile = true;
-        }
-        yield await imageTile.future;
-        if (mainTile.isCompleted) {
-          yield await mainTile.future;
-          providedMainTile = true;
-        }
+      final secondaryTile = await secondary.future;
+      if (mainTile.isCompleted) {
+        yield await mainTile.future;
+        providedMainTile = true;
       }
+      yield secondaryTile;
     }
     if (!request.completed && !providedMainTile) {
-      final tileOrAlternative = await _provideTileOrAlternativeIfReady(
-          request, request.primaryFormat);
-      if (tileOrAlternative != null) {
-        yield tileOrAlternative;
-        providedMainTile = tileOrAlternative.identity.z == tileId.z;
-      }
-      if (!request.completed && !providedMainTile) {
-        yield await mainTile.future;
-      }
+      yield await mainTile.future;
     }
     request.complete();
   }
-
-  Future<Tile?> _provideTileOrAlternativeIfReady(
-      TileRequest request, TileFormat format) async {
-    var startZoom = min(request.tileId.z, maximumZoom);
-    for (var translationLevel = 0;
-        translationLevel < _maxAlternativeLevels;
-        ++translationLevel) {
-      final newZoom = startZoom - translationLevel;
-      if (newZoom < 1) {
-        break;
-      }
-      final newTranslation =
-          _translator.specificZoomTranslation(request.tileId, zoom: newZoom);
-      var tile = await _provider.provideIfReady(
-          newTranslation.translated, format,
-          zoom: request.tileId.z.toDouble());
-      if (tile == null && format == TileFormat.raster && request.tileId.z > 3) {
-        tile = await _provider.provideIfReady(newTranslation.translated, format,
-            zoom: (request.tileId.z - 1).toDouble());
-      }
-      if (tile != null) {
-        return tile;
-      }
-    }
-  }
 }
 
 extension _FutureExtension<T> on Future<T> {

diff --git a/lib/src/stream/tile_supplier.dart b/lib/src/stream/tile_supplier.dart
@@ -47,6 +47,4 @@ abstract class TileProvider {
   int get maximumZoom;
   Future<Tile> provide(TileIdentity tileIdentity, TileFormat format,
       {double? zoom});
-  Future<Tile?> provideIfReady(TileIdentity tileIdentity, TileFormat format,
-      {double? zoom});
 }