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Simpler and more thorough tile pruning

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The render method always generates a map of all tiles that should be drawn
(called tilesToDrawByZ).  This includes tiles at alternate resolutions, tiles
still loading, and tiles previously rendered.  At the end of the render
sequence we can simply remove all previously rendered tiles that aren't in
tilesToDrawByZ.  This provides an alternate solution to the problem described
in #53 and more.
This commit is contained in:
Tim Schaub
2012-10-08 00:41:21 -06:00
parent 2c2d40a53c
commit a14a15159f
1 changed files with 9 additions and 47 deletions
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56
src/ol/renderer/dom/tilelayer.js
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@@ -33,12 +33,6 @@ ol.renderer.dom.TileLayer = function(mapRenderer, tileLayer, target) {
*/
this.renderedMapResolution_ = undefined;
/**
* @type {ol.Extent}
* @private
*/
this.renderedExtent_ = null;
/**
* @type {number|undefined}
* @private
@@ -85,35 +79,18 @@ ol.renderer.dom.TileLayer.prototype.getTileOffset_ = function(z, resolution) {
/**
* Get rid of tiles that are not at the currently rendered z.
* Get rid of all tiles that weren't drawn in the most recent rendering.
* @param {Object.<number, Object.<string, ol.Tile>>} tilesDrawnByZ Tiles just
* rendered.
* @private
*/
ol.renderer.dom.TileLayer.prototype.removeAltZTiles_ = function() {
var z = this.renderedZ_;
var key, tileCoord, tile;
ol.renderer.dom.TileLayer.prototype.removeExtraTiles_ =
function(tilesDrawnByZ) {
var key, tileCoord, tilesDrawn, tile;
for (key in this.renderedTiles_) {
tileCoord = ol.TileCoord.createFromString(key);
if (tileCoord.z !== z) {
tile = this.renderedTiles_[key];
delete this.renderedTiles_[key];
goog.dom.removeNode(tile.getImage(this));
}
}
};
/**
* Get rid of tiles outside the rendered extent.
* @private
*/
ol.renderer.dom.TileLayer.prototype.removeOutOfRangeTiles_ = function() {
var mapExtent = this.renderedExtent_;
var grid = this.getLayer().getTileSource().getTileGrid();
var key, tileCoord, tileExtent, tile;
for (key in this.renderedTiles_) {
tileCoord = ol.TileCoord.createFromString(key);
tileExtent = grid.getTileCoordExtent(tileCoord);
if (!tileExtent.intersects(mapExtent)) {
tilesDrawn = tilesDrawnByZ[tileCoord.z];
if (!(tilesDrawn && key in tilesDrawn)) {
tile = this.renderedTiles_[key];
delete this.renderedTiles_[key];
goog.dom.removeNode(tile.getImage(this));
@@ -133,15 +110,6 @@ ol.renderer.dom.TileLayer.prototype.handleTileChange_ = function(event) {
if (tileCoord.z === this.renderedZ_) {
var key = tileCoord.toString();
delete this.loadingTiles_[key];
// determine if we've fully loaded this zoom level
var loaded = true;
for (key in this.loadingTiles_) {
loaded = false;
break;
}
if (loaded) {
this.removeAltZTiles_();
}
}
};
@@ -195,7 +163,6 @@ ol.renderer.dom.TileLayer.prototype.render = function() {
// first pass through the tile range to determine all the tiles needed
var allTilesLoaded = true;
tileRange.forEachTileCoord(z, function(tileCoord) {
var tile = tileSource.getTile(tileCoord);
if (goog.isNull(tile)) {
@@ -214,7 +181,6 @@ ol.renderer.dom.TileLayer.prototype.render = function() {
this.loadingTiles_[key] = tile;
tile.load();
}
allTilesLoaded = false;
// TODO: only append after load?
tilesToDrawByZ[z][key] = tile;
}
@@ -302,12 +268,8 @@ ol.renderer.dom.TileLayer.prototype.render = function() {
goog.dom.appendChild(this.target, fragment);
}
this.renderedExtent_ = mapExtent;
this.renderedZ_ = z;
this.renderedMapResolution_ = mapResolution;
if (allTilesLoaded) {
this.removeAltZTiles_();
}
this.removeOutOfRangeTiles_();
this.removeExtraTiles_(tilesToDrawByZ);
};