ashatora/openlayers
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Premptively load low resolution tiles

Browse Source
This commit is contained in:
Tom Payne
2013-03-12 18:04:28 +01:00
parent e3abe376f1
commit 80df629319
6 changed files with 86 additions and 46 deletions
Download Patch File Download Diff File Expand all files Collapse all files

11
src/ol/map.js
View File

@@ -484,9 +484,13 @@ 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} Tile priority.
*/
ol.Map.prototype.getTilePriority = function(tile, tileSourceKey, tileCenter) {
ol.Map.prototype.getTilePriority =
function(tile, tileSourceKey, tileCenter, tileResolution) {
// Filter out tiles at higher zoom levels than the current zoom level, or that
// are outside the visible extent.
var frameState = this.frameState_;
if (goog.isNull(frameState) || !(tileSourceKey in frameState.wantedTiles)) {
return ol.TileQueue.DROP;
@@ -495,11 +499,14 @@ ol.Map.prototype.getTilePriority = function(tile, tileSourceKey, tileCenter) {
if (!frameState.wantedTiles[tileSourceKey][coordKey]) {
return ol.TileQueue.DROP;
}
// Prioritize tiles closest to the focus or center. The + 1 helps to
// prioritize tiles at higher zoom levels over tiles at lower zoom levels,
// even if the tile's center is close to the focus.
var focus = goog.isNull(this.focus_) ?
frameState.view2DState.center : this.focus_;
var deltaX = tileCenter.x - focus.x;
var deltaY = tileCenter.y - focus.y;
return deltaX * deltaX + deltaY * deltaY;
return tileResolution * (deltaX * deltaX + deltaY * deltaY + 1);
};

12
src/ol/renderer/canvas/canvastilelayerrenderer.js
View File

@@ -96,7 +96,6 @@ ol.renderer.canvas.TileLayer.prototype.renderFrame =
var tileLayer = this.getTileLayer();
var tileSource = tileLayer.getTileSource();
var tileSourceKey = goog.getUid(tileSource).toString();
var tileGrid = tileSource.getTileGrid();
if (goog.isNull(tileGrid)) {
tileGrid = ol.tilegrid.getForProjection(projection);
@@ -156,19 +155,14 @@ ol.renderer.canvas.TileLayer.prototype.renderFrame =
tilesToDrawByZ, getTileIfLoaded);
var allTilesLoaded = true;
var tile, tileCenter, tileCoord, tileState, x, y;
var tile, tileCoord, tileState, x, y;
for (x = tileRange.minX; x <= tileRange.maxX; ++x) {
for (y = tileRange.minY; y <= tileRange.maxY; ++y) {
tileCoord = new ol.TileCoord(z, x, y);
tile = tileSource.getTile(tileCoord, tileGrid, projection);
tileState = tile.getState();
if (tileState == ol.TileState.IDLE) {
this.updateWantedTiles(frameState.wantedTiles, tileSource, tileCoord);
tileCenter = tileGrid.getTileCoordCenter(tileCoord);
frameState.tileQueue.enqueue(tile, tileSourceKey, tileCenter);
} else if (tileState == ol.TileState.LOADED ||
tileState == ol.TileState.EMPTY) {
if (tileState == ol.TileState.LOADED || tileState == ol.TileState.EMPTY) {
tilesToDrawByZ[z][tileCoord.toString()] = tile;
continue;
} else if (tileState == ol.TileState.ERROR) {
@@ -246,6 +240,8 @@ ol.renderer.canvas.TileLayer.prototype.renderFrame =
}
this.updateUsedTiles(frameState.usedTiles, tileSource, z, tileRange);
this.manageTilePyramid(
frameState, tileSource, tileGrid, projection, extent, z);
this.scheduleExpireCache(frameState, tileSource);
var transform = this.transform_;

11
src/ol/renderer/dom/domtilelayerrenderer.js
View File

@@ -83,7 +83,6 @@ ol.renderer.dom.TileLayer.prototype.renderFrame =
var tileLayer = this.getTileLayer();
var tileSource = tileLayer.getTileSource();
var tileSourceKey = goog.getUid(tileSource).toString();
var tileGrid = tileSource.getTileGrid();
if (goog.isNull(tileGrid)) {
tileGrid = ol.tilegrid.getForProjection(projection);
@@ -113,18 +112,14 @@ ol.renderer.dom.TileLayer.prototype.renderFrame =
tilesToDrawByZ, getTileIfLoaded);
var allTilesLoaded = true;
var tile, tileCenter, tileCoord, tileState, x, y;
var tile, tileCoord, tileState, x, y;
for (x = tileRange.minX; x <= tileRange.maxX; ++x) {
for (y = tileRange.minY; y <= tileRange.maxY; ++y) {
tileCoord = new ol.TileCoord(z, x, y);
tile = tileSource.getTile(tileCoord, tileGrid, projection);
tileState = tile.getState();
if (tileState == ol.TileState.IDLE) {
this.updateWantedTiles(frameState.wantedTiles, tileSource, tileCoord);
tileCenter = tileGrid.getTileCoordCenter(tileCoord);
frameState.tileQueue.enqueue(tile, tileSourceKey, tileCenter);
} else if (tileState == ol.TileState.LOADED) {
if (tileState == ol.TileState.LOADED) {
tilesToDrawByZ[z][tileCoord.toString()] = tile;
continue;
} else if (tileState == ol.TileState.ERROR ||
@@ -224,6 +219,8 @@ ol.renderer.dom.TileLayer.prototype.renderFrame =
}
this.updateUsedTiles(frameState.usedTiles, tileSource, z, tileRange);
this.manageTilePyramid(
frameState, tileSource, tileGrid, projection, extent, z);
this.scheduleExpireCache(frameState, tileSource);
};

70
src/ol/renderer/layerrenderer.js
View File

@@ -18,6 +18,12 @@ goog.require('ol.layer.LayerState');
goog.require('ol.source.TileSource');
/**
* @define {boolean} Preemptively load low resolution tiles.
*/
ol.PREEMPTIVELY_LOAD_LOW_RESOLUTION_TILES = true;
/**
* @constructor
@@ -246,23 +252,6 @@ ol.renderer.Layer.prototype.updateUsedTiles =
};
/**
* @protected
* @param {Object.<string, Object.<string, boolean>>} wantedTiles Wanted tiles.
* @param {ol.source.TileSource} tileSource Tile source.
* @param {ol.TileCoord} tileCoord Tile coordinate.
*/
ol.renderer.Layer.prototype.updateWantedTiles =
function(wantedTiles, tileSource, tileCoord) {
var tileSourceKey = goog.getUid(tileSource).toString();
var coordKey = tileCoord.toString();
if (!(tileSourceKey in wantedTiles)) {
wantedTiles[tileSourceKey] = {};
}
wantedTiles[tileSourceKey][coordKey] = true;
};
/**
* @param {function(ol.Tile): boolean} isLoadedFunction Function to
* determine if the tile is loaded.
@@ -293,3 +282,50 @@ ol.renderer.Layer.prototype.snapCenterToPixel =
resolution * (Math.round(center.x / resolution) + (size.width % 2) / 2),
resolution * (Math.round(center.y / resolution) + (size.height % 2) / 2));
};
/**
* Manage tile pyramid.
* This function performs a number of functions related to the tiles at the
* current zoom and lower zoom levels:
* - registers idle tiles in frameState.wantedTiles so that they are not
* discarded by the tile queue
* - enqueues missing tiles
* @param {ol.FrameState} frameState Frame state.
* @param {ol.source.TileSource} tileSource Tile source.
* @param {ol.tilegrid.TileGrid} tileGrid Tile grid.
* @param {ol.Projection} projection Projection.
* @param {ol.Extent} extent Extent.
* @param {number} currentZ Current Z.
* @protected
*/
ol.renderer.Layer.prototype.manageTilePyramid =
function(frameState, tileSource, tileGrid, projection, extent, currentZ) {
var tileSourceKey = goog.getUid(tileSource).toString();
if (!(tileSourceKey in frameState.wantedTiles)) {
frameState.wantedTiles[tileSourceKey] = {};
}
var wantedTiles = frameState.wantedTiles[tileSourceKey];
var tileQueue = frameState.tileQueue;
var tile, tileCenter, tileCoord, tileRange, tileResolution, x, y, z;
// FIXME this should loop up to tileGrid's minZ when implemented
for (z = currentZ; z >= 0; --z) {
tileRange = tileGrid.getTileRangeForExtentAndZ(extent, z);
tileResolution = tileGrid.getResolution(z);
for (x = tileRange.minX; x <= tileRange.maxX; ++x) {
for (y = tileRange.minY; y <= tileRange.maxY; ++y) {
if (ol.PREEMPTIVELY_LOAD_LOW_RESOLUTION_TILES || z == currentZ) {
tileCoord = new ol.TileCoord(z, x, y);
tile = tileSource.getTile(tileCoord, tileGrid, projection);
if (tile.getState() == ol.TileState.IDLE) {
tileCenter = tileGrid.getTileCoordCenter(tileCoord);
wantedTiles[tileCoord.toString()] = true;
tileQueue.enqueue(tile, tileSourceKey, tileCenter, tileResolution);
}
} else {
tileSource.useTile(z + '/' + x + '/' + y);
}
}
}
}
};

9
src/ol/renderer/webgl/webgltilelayerrenderer.js
View File

@@ -285,7 +285,6 @@ ol.renderer.webgl.TileLayer.prototype.renderFrame =
var tileLayer = this.getTileLayer();
var tileSource = tileLayer.getTileSource();
var tileSourceKey = goog.getUid(tileSource).toString();
var tileGrid = tileSource.getTileGrid();
if (goog.isNull(tileGrid)) {
tileGrid = ol.tilegrid.getForProjection(projection);
@@ -394,11 +393,7 @@ ol.renderer.webgl.TileLayer.prototype.renderFrame =
tileCoord = new ol.TileCoord(z, x, y);
tile = tileSource.getTile(tileCoord, tileGrid, projection);
tileState = tile.getState();
if (tileState == ol.TileState.IDLE) {
this.updateWantedTiles(frameState.wantedTiles, tileSource, tileCoord);
tileCenter = tileGrid.getTileCoordCenter(tileCoord);
frameState.tileQueue.enqueue(tile, tileSourceKey, tileCenter);
} else if (tileState == ol.TileState.LOADED) {
if (tileState == ol.TileState.LOADED) {
if (mapRenderer.isTileTextureLoaded(tile)) {
tilesToDrawByZ[z][tileCoord.toString()] = tile;
continue;
@@ -466,6 +461,8 @@ ol.renderer.webgl.TileLayer.prototype.renderFrame =
}
this.updateUsedTiles(frameState.usedTiles, tileSource, z, tileRange);
this.manageTilePyramid(
frameState, tileSource, tileGrid, projection, extent, z);
this.scheduleExpireCache(frameState, tileSource);
goog.vec.Mat4.makeIdentity(this.texCoordMatrix_);

19
src/ol/tilequeue.js
View File

@@ -20,7 +20,7 @@ goog.require('ol.TileState');
/**
* @typedef {function(ol.Tile, string, ol.Coordinate): number}
* @typedef {function(ol.Tile, string, ol.Coordinate, number): number}
*/
ol.TilePriorityFunction;
@@ -106,16 +106,20 @@ ol.TileQueue.prototype.dequeue_ = function() {
* @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, tileSourceKey, tileCenter) {
ol.TileQueue.prototype.enqueue = function(
tile, tileSourceKey, tileCenter, tileResolution) {
if (tile.getState() != ol.TileState.IDLE) {
return;
}
var tileKey = tile.getKey();
if (!(tileKey in this.queuedTileKeys_)) {
var priority = this.tilePriorityFunction_(tile, tileSourceKey, tileCenter);
var priority = this.tilePriorityFunction_(
tile, tileSourceKey, tileCenter, tileResolution);
if (priority != ol.TileQueue.DROP) {
this.heap_.push([priority, tile, tileSourceKey, tileCenter]);
this.heap_.push(
[priority, tile, tileSourceKey, tileCenter, tileResolution]);
this.queuedTileKeys_[tileKey] = true;
this.siftDown_(0, this.heap_.length - 1);
}
@@ -245,13 +249,16 @@ ol.TileQueue.prototype.siftDown_ = function(startIndex, index) {
*/
ol.TileQueue.prototype.reprioritize = function() {
var heap = this.heap_;
var i, n = 0, node, priority, tile, tileCenter, tileKey, tileSourceKey;
var i, n = 0, node, priority;
var tile, tileCenter, tileKey, tileResolution, tileSourceKey;
for (i = 0; i < heap.length; ++i) {
node = heap[i];
tile = /** @type {ol.Tile} */ (node[1]);
tileSourceKey = /** @type {string} */ (node[2]);
tileCenter = /** @type {ol.Coordinate} */ (node[3]);
priority = this.tilePriorityFunction_(tile, tileSourceKey, tileCenter);
tileResolution = /** @type {number} */ (node[4]);
priority = this.tilePriorityFunction_(
tile, tileSourceKey, tileCenter, tileResolution);
if (priority == ol.TileQueue.DROP) {
tileKey = tile.getKey();
delete this.queuedTileKeys_[tileKey];