VectorTileLayer.js
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(function (root, factory){
if (typeof define === 'function' && define.amd){ // AMD
define(factory);
} else if (typeof module !== 'undefined' && module.exports) { // Node.js
module.exports = factory();
} else { // Browser
root.VectorTileLayer = factory();
}
})(this, function () {
function VectorTileLayer(pbf, end) {
// Public
this.version = 1;
this.name = null;
this.extent = 4096;
this.length = 0;
// Private
this._pbf = pbf;
this._keys = [];
this._values = [];
this._features = [];
pbf.readFields(readLayer, this, end);
this.length = this._features.length;
}
function readLayer(tag, layer, pbf) {
if (tag === 15) layer.version = pbf.readVarint();
else if (tag === 1) layer.name = pbf.readString();
else if (tag === 5) layer.extent = pbf.readVarint();
else if (tag === 2) layer._features.push(pbf.pos);
else if (tag === 3) layer._keys.push(pbf.readString());
else if (tag === 4) layer._values.push(readValueMessage(pbf));
}
function readValueMessage(pbf) {
var value = null,
end = pbf.readVarint() + pbf.pos;
while (pbf.pos < end) {
var tag = pbf.readVarint() >> 3;
value = tag === 1 ? pbf.readString() :
tag === 2 ? pbf.readFloat() :
tag === 3 ? pbf.readDouble() :
tag === 4 ? pbf.readVarint64() :
tag === 5 ? pbf.readVarint() :
tag === 6 ? pbf.readSVarint() :
tag === 7 ? pbf.readBoolean() : null;
}
return value;
}
// return feature `i` from this layer as a `VectorTileFeature`
VectorTileLayer.prototype.feature = function(i) {
if (i < 0 || i >= this._features.length) throw new Error('feature index out of bounds');
this._pbf.pos = this._features[i];
var end = this._pbf.readVarint() + this._pbf.pos;
return new VectorTileFeature(this._pbf, end, this.extent, this._keys, this._values);
};
return VectorTileLayer;
});