VectorTileFeature::VectorTileFeature(pbf feature, const VectorTileLayer& layer) {
while (feature.next()) {
if (feature.tag == 1) { // id
id = feature.varint<uint64_t>();
} else if (feature.tag == 2) { // tags
// tags are packed varints. They should have an even length.
pbf tags = feature.message();
while (tags) {
uint32_t tag_key = tags.varint();
if (layer.keys.size() <= tag_key) {
throw std::runtime_error("feature referenced out of range key");
}
if (tags) {
uint32_t tag_val = tags.varint();
if (layer.values.size() <= tag_val) {
throw std::runtime_error("feature referenced out of range value");
}
properties.emplace(layer.keys[tag_key], layer.values[tag_val]);
} else {
throw std::runtime_error("uneven number of feature tag ids");
}
}
} else if (feature.tag == 3) { // type
type = (FeatureType)feature.varint();
} else if (feature.tag == 4) { // geometry
geometry = feature.message();
} else {
feature.skip();
}
}
}
VectorTile::VectorTile(pbf tile) {
while (tile.next()) {
if (tile.tag == 3) { // layer
VectorTileLayer layer(tile.message());
layers.emplace(layer.name, std::forward<VectorTileLayer>(layer));
} else {
tile.skip();
}
}
}
VectorTileFeature::VectorTileFeature(pbf feature_pbf, const VectorTileLayer& layer_)
: layer(layer_) {
while (feature_pbf.next()) {
if (feature_pbf.tag == 1) { // id
id = feature_pbf.varint<uint64_t>();
} else if (feature_pbf.tag == 2) { // tags
tags_pbf = feature_pbf.message();
} else if (feature_pbf.tag == 3) { // type
type = (FeatureType)feature_pbf.varint();
} else if (feature_pbf.tag == 4) { // geometry
geometry_pbf = feature_pbf.message();
} else {
feature_pbf.skip();
}
}
}
Value parseValue(pbf data) {
while (data.next())
{
switch (data.tag)
{
case 1: // string_value
return data.string();
case 2: // float_value
return static_cast<double>(data.float32());
case 3: // double_value
return data.float64();
case 4: // int_value
return data.varint<int64_t>();
case 5: // uint_value
return data.varint<uint64_t>();
case 6: // sint_value
return data.svarint<int64_t>();
case 7: // bool_value
return data.boolean();
default:
data.skip();
break;
}
}
return false;
}
VectorTileLayer::VectorTileLayer(pbf layer) : data(layer) {
std::vector<std::string> stacks;
while (layer.next()) {
if (layer.tag == 1) { // name
name = layer.string();
} else if (layer.tag == 3) { // keys
keys.emplace_back(layer.string());
key_index.emplace(keys.back(), keys.size() - 1);
} else if (layer.tag == 4) { // values
values.emplace_back(std::move(parseValue(layer.message())));
} else if (layer.tag == 5) { // extent
extent = layer.varint();
} else {
layer.skip();
}
}
}