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Refactor tile functions

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* Add support for minZoom in XYZ tile grids and tile sources
* Factor out common tile coordinate transforms
This commit is contained in:
Tom Payne
2013-04-29 17:15:33 +02:00
parent 2447f09128
commit 6976fd96e3
8 changed files with 133 additions and 131 deletions
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59
src/ol/source/xyzsource.js
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@@ -1,15 +1,10 @@
// FIXME add minZoom support
goog.provide('ol.source.XYZ');
goog.provide('ol.source.XYZOptions');
goog.require('goog.math');
goog.require('ol.Attribution');
goog.require('ol.Projection');
goog.require('ol.TileCoord');
goog.require('ol.TileUrlFunction');
goog.require('ol.TileUrlFunctionType');
goog.require('ol.extent');
goog.require('ol.projection');
goog.require('ol.source.ImageTileSource');
goog.require('ol.tilegrid.XYZ');
@@ -21,6 +16,7 @@ goog.require('ol.tilegrid.XYZ');
* extent: (ol.Extent|undefined),
* logo: (string|undefined),
* maxZoom: number,
* minZoom: (number|undefined),
* projection: (ol.Projection|undefined),
* tileUrlFunction: (ol.TileUrlFunctionType|undefined),
* url: (string|undefined),
@@ -54,55 +50,16 @@ ol.source.XYZ = function(options) {
}
var tileGrid = new ol.tilegrid.XYZ({
maxZoom: options.maxZoom
maxZoom: options.maxZoom,
minZoom: options.minZoom
});
// FIXME factor out common code
if (goog.isDef(options.extent)) {
var tileCoordTransform = tileGrid.createTileCoordTransform({
extent: options.extent
});
var extent = options.extent;
var tmpExtent = ol.extent.createEmptyExtent();
var tmpTileCoord = new ol.TileCoord(0, 0, 0);
tileUrlFunction = ol.TileUrlFunction.withTileCoordTransform(
function(tileCoord) {
if (options.maxZoom < tileCoord.z) {
return null;
}
var n = 1 << tileCoord.z;
var y = -tileCoord.y - 1;
if (y < 0 || n <= y) {
return null;
}
var x = goog.math.modulo(tileCoord.x, n);
tmpTileCoord.z = tileCoord.z;
tmpTileCoord.x = x;
tmpTileCoord.y = tileCoord.y;
var tileExtent = tileGrid.getTileCoordExtent(tmpTileCoord, tmpExtent);
if (!ol.extent.intersects(tileExtent, extent)) {
return null;
}
return new ol.TileCoord(tileCoord.z, x, y);
},
tileUrlFunction);
} else {
tileUrlFunction = ol.TileUrlFunction.withTileCoordTransform(
function(tileCoord) {
if (options.maxZoom < tileCoord.z) {
return null;
}
var n = 1 << tileCoord.z;
var y = -tileCoord.y - 1;
if (y < 0 || n <= y) {
return null;
} else {
var x = goog.math.modulo(tileCoord.x, n);
return new ol.TileCoord(tileCoord.z, x, y);
}
},
tileUrlFunction);
}
tileUrlFunction = ol.TileUrlFunction.withTileCoordTransform(
tileCoordTransform, tileUrlFunction);
goog.base(this, {
attributions: options.attributions,