Discard unwanted tiles from tile queue

src/ol/framestate.js

@@ -1,4 +1,6 @@
 // FIXME add view3DState
+// FIXME rename tileUsage to usedTiles
+// FIXME factor out common code between tileUsage and wantedTiles
 
 goog.provide('ol.FrameState');
 goog.provide('ol.PostRenderFunction');
@@ -29,7 +31,8 @@ goog.require('ol.layer.LayerState');
  *            tileUsage: Object.<string, Object.<string, ol.TileRange>>,
  *            time: number,
  *            view2DState: ol.View2DState,
- *            viewHints: Array.<number>}}
+ *            viewHints: Array.<number>,
+ *            wantedTiles: Object.<string, Object.<string, ol.TileRange>>}}
  */
 ol.FrameState;
 

src/ol/map.js

@@ -453,19 +453,24 @@ ol.Map.prototype.getOverlayContainer = function() {
 
 /**
  * @param {ol.Tile} tile Tile.
+ * @param {string} tileSourceKey Tile source key.
  * @param {ol.Coordinate} tileCenter Tile center.
- * @param {number} tileResolution Tile resolution.
  * @return {number|undefined} Tile priority.
  */
-ol.Map.prototype.getTilePriority = function(tile, tileCenter, tileResolution) {
+ol.Map.prototype.getTilePriority = function(tile, tileSourceKey, tileCenter) {
-  if (goog.isNull(this.frameState_)) {
+  var frameState = this.frameState_;
+  if (goog.isNull(frameState) || !(tileSourceKey in frameState.wantedTiles)) {
     return undefined;
-  } else {
-    var center = this.frameState_.view2DState.center;
-    var deltaX = tileCenter.x - center.x;
-    var deltaY = tileCenter.y - center.y;
-    return Math.sqrt(deltaX * deltaX + deltaY * deltaY) / tileResolution;
   }
+  var zKey = tile.tileCoord.z.toString();
+  if (!(zKey in frameState.wantedTiles[tileSourceKey]) ||
+      !frameState.wantedTiles[tileSourceKey][zKey].contains(tile.tileCoord)) {
+    return undefined;
+  }
+  var center = frameState.view2DState.center;
+  var deltaX = tileCenter.x - center.x;
+  var deltaY = tileCenter.y - center.y;
+  return deltaX * deltaX + deltaY * deltaY;
 };
 
 
@@ -630,7 +635,8 @@ ol.Map.prototype.renderFrame_ = function(time) {
       tileUsage: {},
       time: time,
       view2DState: view2DState,
-      viewHints: viewHints
+      viewHints: viewHints,
+      wantedTiles: {}
     };
   }
 

src/ol/renderer/canvas/canvastilelayerrenderer.js

@@ -87,6 +87,7 @@ ol.renderer.canvas.TileLayer.prototype.renderFrame =
 
   var tileLayer = this.getTileLayer();
   var tileSource = tileLayer.getTileSource();
+  var tileSourceKey = goog.getUid(tileSource).toString();
   var tileGrid = tileSource.getTileGrid();
   var tileSize = tileGrid.getTileSize();
   var z = tileGrid.getZForResolution(view2DState.resolution);
@@ -165,7 +166,7 @@ ol.renderer.canvas.TileLayer.prototype.renderFrame =
       tileState = tile.getState();
       if (tileState == ol.TileState.IDLE) {
         tileCenter = tileGrid.getTileCoordCenter(tileCoord);
-        frameState.tileQueue.enqueue(tile, tileCenter, tileResolution);
+        frameState.tileQueue.enqueue(tile, tileSourceKey, tileCenter);
       } else if (tileState == ol.TileState.LOADED) {
         tilesToDrawByZ[z][tileCoord.toString()] = tile;
         continue;
@@ -216,6 +217,7 @@ ol.renderer.canvas.TileLayer.prototype.renderFrame =
   }
 
   this.updateTileUsage(frameState.tileUsage, tileSource, z, tileRange);
+  this.updateWantedTiles(frameState.wantedTiles, tileSource, z, tileRange);
 
   var transform = this.transform_;
   goog.vec.Mat4.makeIdentity(transform);

src/ol/renderer/dom/domtilelayerrenderer.js

@@ -83,6 +83,7 @@ ol.renderer.dom.TileLayer.prototype.renderFrame =
 
   var tileLayer = this.getTileLayer();
   var tileSource = tileLayer.getTileSource();
+  var tileSourceKey = goog.getUid(tileSource).toString();
   var tileGrid = tileSource.getTileGrid();
   var z = tileGrid.getZForResolution(view2DState.resolution);
   var tileResolution = tileGrid.getResolution(z);
@@ -132,7 +133,7 @@ ol.renderer.dom.TileLayer.prototype.renderFrame =
       tileState = tile.getState();
       if (tileState == ol.TileState.IDLE) {
         tileCenter = tileGrid.getTileCoordCenter(tileCoord);
-        frameState.tileQueue.enqueue(tile, tileCenter, tileResolution);
+        frameState.tileQueue.enqueue(tile, tileSourceKey, tileCenter);
       } else if (tileState == ol.TileState.LOADED) {
         tilesToDrawByZ[z][tileCoord.toString()] = tile;
         continue;
@@ -237,6 +238,7 @@ ol.renderer.dom.TileLayer.prototype.renderFrame =
   }
 
   this.updateTileUsage(frameState.tileUsage, tileSource, z, tileRange);
+  this.updateWantedTiles(frameState.wantedTiles, tileSource, z, tileRange);
 
 };
 

src/ol/renderer/layerrenderer.js

@@ -151,3 +151,28 @@ ol.renderer.Layer.prototype.updateTileUsage =
     tileUsage[sourceKey][zKey] = tileRange;
   }
 };
+
+
+/**
+ * @protected
+ * @param {Object.<string, Object.<string, ol.TileRange>>} wantedTiles Wanted
+ *     tile ranges.
+ * @param {ol.source.Source} source Source.
+ * @param {number} z Z.
+ * @param {ol.TileRange} tileRange Tile range.
+ */
+ol.renderer.Layer.prototype.updateWantedTiles =
+    function(wantedTiles, source, z, tileRange) {
+  var sourceKey = goog.getUid(source).toString();
+  var zKey = z.toString();
+  if (sourceKey in wantedTiles) {
+    if (zKey in wantedTiles[sourceKey]) {
+      wantedTiles[sourceKey][zKey].extend(tileRange);
+    } else {
+      wantedTiles[sourceKey][zKey] = tileRange;
+    }
+  } else {
+    wantedTiles[sourceKey] = {};
+    wantedTiles[sourceKey][zKey] = tileRange;
+  }
+};

src/ol/renderer/webgl/webgltilelayerrenderer.js

@@ -270,6 +270,7 @@ ol.renderer.webgl.TileLayer.prototype.renderFrame =
 
   var tileLayer = this.getTileLayer();
   var tileSource = tileLayer.getTileSource();
+  var tileSourceKey = goog.getUid(tileSource).toString();
   var tileGrid = tileSource.getTileGrid();
   var z = tileGrid.getZForResolution(view2DState.resolution);
   var tileResolution = tileGrid.getResolution(z);
@@ -392,7 +393,7 @@ ol.renderer.webgl.TileLayer.prototype.renderFrame =
         tileState = tile.getState();
         if (tileState == ol.TileState.IDLE) {
           tileCenter = tileGrid.getTileCoordCenter(tileCoord);
-          frameState.tileQueue.enqueue(tile, tileCenter, tileResolution);
+          frameState.tileQueue.enqueue(tile, tileSourceKey, tileCenter);
         } else if (tileState == ol.TileState.LOADED) {
           if (mapRenderer.isTileTextureLoaded(tile)) {
             tilesToDrawByZ[z][tileCoord.toString()] = tile;
@@ -460,6 +461,7 @@ ol.renderer.webgl.TileLayer.prototype.renderFrame =
   }
 
   this.updateTileUsage(frameState.tileUsage, tileSource, z, tileRange);
+  this.updateWantedTiles(frameState.wantedTiles, tileSource, z, tileRange);
 
   goog.vec.Mat4.makeIdentity(this.matrix_);
   goog.vec.Mat4.translate(this.matrix_,

src/ol/tilequeue.js

@@ -21,7 +21,7 @@ goog.require('ol.TileState');
 
 
 /**
- * @typedef {function(ol.Tile, ol.Coordinate, number): (number|undefined)}
+ * @typedef {function(ol.Tile, string, ol.Coordinate): (number|undefined)}
  */
 ol.TilePriorityFunction;
 
@@ -102,18 +102,18 @@ ol.TileQueue.prototype.dequeue_ = function() {
 /**
  * Enqueue a tile. O(logn).
  * @param {ol.Tile} tile Tile.
+ * @param {string} tileSourceKey Tile source key.
  * @param {ol.Coordinate} tileCenter Tile center.
- * @param {number} tileResolution Tile resolution.
  */
-ol.TileQueue.prototype.enqueue = function(tile, tileCenter, tileResolution) {
+ol.TileQueue.prototype.enqueue = function(tile, tileSourceKey, tileCenter) {
   if (tile.getState() != ol.TileState.IDLE) {
     return;
   }
   var tileKey = tile.getKey();
   if (!(tileKey in this.queuedTileKeys_)) {
-    var priority = this.tilePriorityFunction_(tile, tileCenter, tileResolution);
+    var priority = this.tilePriorityFunction_(tile, tileSourceKey, tileCenter);
     if (goog.isDef(priority)) {
-      this.heap_.push([priority, tile, tileCenter, tileResolution]);
+      this.heap_.push([priority, tile, tileSourceKey, tileCenter]);
       this.queuedTileKeys_[tileKey] = true;
       this.siftDown_(0, this.heap_.length - 1);
     } else {
@@ -245,13 +245,13 @@ ol.TileQueue.prototype.siftDown_ = function(startIndex, index) {
 ol.TileQueue.prototype.reprioritize = function() {
   var heap = this.heap_;
   var count = heap.length;
-  var i, priority, node, tile, tileCenter, tileResolution;
+  var i, priority, node, tile, tileCenter, tileSourceKey;
   for (i = count - 1; i >= 0; i--) {
     node = heap[i];
     tile = /** @type {ol.Tile} */ (node[1]);
-    tileCenter = /** @type {ol.Coordinate} */ (node[2]);
+    tileSourceKey = /** @type {string} */ (node[2]);
-    tileResolution = /** @type {number} */ (node[3]);
+    tileCenter = /** @type {ol.Coordinate} */ (node[3]);
-    priority = this.tilePriorityFunction_(tile, tileCenter, tileResolution);
+    priority = this.tilePriorityFunction_(tile, tileSourceKey, tileCenter);
     if (goog.isDef(priority)) {
       node[0] = priority;
     } else {

test/spec/ol/tilequeue.test.js

@@ -23,7 +23,7 @@ describe('ol.TileQueue', function() {
     for (i = 0; i < num; i++) {
       tile = new ol.Tile();
       priority = Math.floor(Math.random() * 100);
-      tq.heap_.push([priority, tile, new ol.Coordinate(0, 0), 1]);
+      tq.heap_.push([priority, tile, '', new ol.Coordinate(0, 0)]);
       tq.queuedTileKeys_[tile.getKey()] = true;
     }
   }