Files
openlayers/src/ol/tilegrid.js
2012-07-11 17:20:08 +02:00

323 lines
7.7 KiB
JavaScript

goog.provide('ol.TileGrid');
goog.require('goog.array');
goog.require('goog.asserts');
goog.require('goog.math.Size');
goog.require('ol.Extent');
goog.require('ol.Projection');
goog.require('ol.TileBounds');
goog.require('ol.TileCoord');
/**
* @constructor
* @param {!Array.<number>} resolutions Resolutions.
* @param {ol.Extent} extent Extent.
* @param {goog.math.Coordinate|!Array.<goog.math.Coordinate>} origin Origin.
* @param {boolean=} opt_xEast Tile coordinates increase eastwards.
* @param {boolean=} opt_ySouth Tile coordinates increas southwards.
* @param {goog.math.Size=} opt_tileSize Tile size.
*/
ol.TileGrid =
function(resolutions, extent, origin, opt_xEast, opt_ySouth, opt_tileSize) {
/**
* @private
* @type {Array.<number>}
*/
this.resolutions_ = resolutions;
goog.asserts.assert(goog.array.isSorted(resolutions, function(a, b) {
return -goog.array.defaultCompare(a, b);
}, true));
/**
* @private
* @type {number}
*/
this.numResolutions_ = this.resolutions_.length;
/**
* @private
* @type {ol.Extent}
*/
this.extent_ = extent;
/**
* @private
* @type {boolean}
*/
this.xEast_ = goog.isDef(opt_xEast) ? opt_xEast : true;
/**
* @private
* @type {boolean}
*/
this.ySouth_ = goog.isDef(opt_ySouth) ? opt_ySouth : true;
/**
* @private
* @type {goog.math.Coordinate}
*/
this.origin_ = null;
/**
* @private
* @type {Array.<goog.math.Coordinate>}
*/
this.origins_ = null;
if (origin instanceof goog.math.Coordinate) {
this.origin_ = origin;
} else if (goog.isArray(origin)) {
goog.asserts.assert(origin.length == this.numResolutions_);
this.origins_ = origin;
} else {
goog.asserts.assert(false);
}
/**
* @private
* @type {goog.math.Size}
*/
this.tileSize_ = goog.isDef(opt_tileSize) ?
opt_tileSize : new goog.math.Size(256, 256);
};
/**
* @param {number} maxZoom Maximum zoom.
* @return {ol.TileGrid} Tile grid.
*/
ol.TileGrid.createOpenStreetMap = function(maxZoom) {
var resolutions = new Array(maxZoom + 1);
var z;
for (z = 0; z <= maxZoom; ++z) {
resolutions[z] = ol.Projection.EPSG_3857_HALF_SIZE / (128 << z);
}
var extent = ol.Projection.EPSG_3857_EXTENT;
var origin = new goog.math.Coordinate(
-ol.Projection.EPSG_3857_HALF_SIZE, ol.Projection.EPSG_3857_HALF_SIZE);
var tileSize = new goog.math.Size(256, 256);
return new ol.TileGrid(resolutions, extent, origin, true, true, tileSize);
};
/**
* @param {ol.TileCoord} tileCoord Tile coordinate.
* @param {function(number, ol.TileBounds): boolean} callback Callback.
*/
ol.TileGrid.prototype.forEachTileCoordParent = function(tileCoord, callback) {
var tileCoordExtent = this.getTileCoordExtent(tileCoord);
var z = tileCoord.z - 1;
while (z >= 0) {
if (callback(z, this.getExtentTileBounds(z, tileCoordExtent))) {
return;
}
--z;
}
};
/**
* @return {ol.Extent} Extent.
*/
ol.TileGrid.prototype.getExtent = function() {
return this.extent_;
};
/**
* @param {number} z Z.
* @param {ol.Extent} extent Extent.
* @return {ol.TileBounds} Tile bounds.
*/
ol.TileGrid.prototype.getExtentTileBounds = function(z, extent) {
var topRight = new goog.math.Coordinate(extent.right, extent.top);
var bottomLeft = new goog.math.Coordinate(extent.left, extent.bottom);
return ol.TileBounds.boundingTileBounds(
this.getTileCoord(z, topRight),
this.getTileCoord(z, bottomLeft));
};
/**
* @return {number} Maximum resolution.
*/
ol.TileGrid.prototype.getMaxResolution = function() {
return this.getResolutions()[0];
};
/**
* @param {number} z Z.
* @return {goog.math.Coordinate} Origin.
*/
ol.TileGrid.prototype.getOrigin = function(z) {
if (!goog.isNull(this.origin_)) {
return this.origin_;
} else {
goog.asserts.assert(!goog.isNull(this.origins_));
goog.asserts.assert(0 <= z && z < this.origins_.length);
return this.origins_[z];
}
};
/**
* @param {number} z Z.
* @return {number} Resolution.
*/
ol.TileGrid.prototype.getResolution = function(z) {
goog.asserts.assert(0 <= z && z < this.numResolutions_);
return this.resolutions_[z];
};
/**
* @return {Array.<number>} Resolutions.
*/
ol.TileGrid.prototype.getResolutions = function() {
return this.resolutions_;
};
/**
* @param {number} z Z.
* @param {goog.math.Coordinate} coordinate Coordinate.
* @return {ol.TileCoord} Tile coordinate.
*/
ol.TileGrid.prototype.getTileCoord = function(z, coordinate) {
var origin = this.getOrigin(z);
var resolution = this.getResolution(z);
var tileSize = this.getTileSize();
var x;
if (this.xEast_) {
x = Math.floor((coordinate.x - origin.x) / (tileSize.width * resolution));
} else {
x = Math.floor((origin.x - coordinate.x) / (tileSize.width * resolution));
}
var y;
if (this.ySouth_) {
y = Math.floor((origin.y - coordinate.y) / (tileSize.height * resolution));
} else {
y = Math.floor((coordinate.y - origin.y) / (tileSize.height * resolution));
}
return new ol.TileCoord(z, x, y);
};
/**
* @param {ol.TileCoord} tileCoord Tile coordinate.
* @return {goog.math.Coordinate} Tile center.
*/
ol.TileGrid.prototype.getTileCoordCenter = function(tileCoord) {
var origin = this.getOrigin(tileCoord.z);
var resolution = this.getResolution(tileCoord.z);
var tileSize = this.tileSize_;
var x;
if (this.xEast_) {
x = origin.x + (tileCoord.x + 0.5) * tileSize.width * resolution;
} else {
x = origin.x - (tileCoord.x + 0.5) * tileSize.width * resolution;
}
var y;
if (this.ySouth_) {
y = origin.y - (tileCoord.y + 0.5) * tileSize.height * resolution;
} else {
y = origin.y + (tileCoord.y + 0.5) * tileSize.height * resolution;
}
return new goog.math.Coordinate(x, y);
};
/**
* @param {ol.TileCoord} tileCoord Tile coordinate.
* @return {ol.Extent} Extent.
*/
ol.TileGrid.prototype.getTileCoordExtent = function(tileCoord) {
var origin = this.getOrigin(tileCoord.z);
var resolution = this.getResolution(tileCoord.z);
var tileSize = this.tileSize_;
var left, right;
if (this.xEast_) {
left = origin.x + tileCoord.x * tileSize.width * resolution;
right = left + tileSize.width * resolution;
} else {
right = origin.x - tileCoord.x * tileSize.width * resolution;
left = right - tileSize.height * resolution;
}
var top, bottom;
if (this.ySouth_) {
top = origin.y - tileCoord.y * tileSize.height * resolution;
bottom = top - tileSize.height * resolution;
} else {
bottom = origin.y + tileCoord.y * tileSize.height * resolution;
top = bottom + tileSize.height * resolution;
}
return new ol.Extent(top, right, bottom, left);
};
/**
* @param {ol.TileCoord} tileCoord Tile coordinate.
* @return {number} Tile resolution.
*/
ol.TileGrid.prototype.getTileCoordResolution = function(tileCoord) {
goog.asserts.assert(0 <= tileCoord.z && tileCoord.z < this.numResolutions_);
return this.resolutions_[tileCoord.z];
};
/**
* @return {goog.math.Size} Tile size.
*/
ol.TileGrid.prototype.getTileSize = function() {
return this.tileSize_;
};
/**
* @return {boolean} X East.
*/
ol.TileGrid.prototype.getXEast = function() {
return this.xEast_;
};
/**
* @return {boolean} Y South.
*/
ol.TileGrid.prototype.getYSouth = function() {
return this.ySouth_;
};
/**
* @param {number} resolution Resolution.
* @return {number} Z.
*/
ol.TileGrid.prototype.getZForResolution = function(resolution) {
var z;
for (z = 0; z < this.numResolutions_; ++z) {
if (this.resolutions_[z] == resolution) {
return z;
} else if (this.resolutions_[z] < resolution) {
if (z === 0) {
return z;
} else if (resolution - this.resolutions_[z] <=
this.resolutions_[z - 1] - resolution) {
return z;
} else {
return z - 1;
}
}
}
return this.numResolutions_ - 1;
};