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move vector tile parsing to separate class + iterators

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This commit is contained in:
Konstantin Käfer
2014-01-28 13:53:59 +01:00
parent edf2a532af
commit 31fca20c16
6 changed files with 277 additions and 128 deletions
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141
src/map/tile.cpp
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@@ -10,7 +10,6 @@
#include <llmr/geometry/geometry.hpp>
#include <llmr/renderer/fill_bucket.hpp>
#include <llmr/style/style.hpp>
#include <llmr/style/value.hpp>
#include <cmath>
using namespace llmr;
@@ -95,10 +94,8 @@ bool Tile::parse() {
}
try {
pbf tile(data, bytes);
// fprintf(stderr, "[%p] parsing tile [%d/%d/%d]...\n", this, z, x, y);
parseLayers(tile, style.layers);
tile = VectorTile(pbf(data, bytes));
parseStyleLayers(style.layers);
} catch (const std::exception& ex) {
fprintf(stderr, "[%p] exception [%d/%d/%d]... failed: %s\n", this, id.z, id.x, id.y, ex.what());
cancel();
@@ -114,12 +111,12 @@ bool Tile::parse() {
return true;
}
void Tile::parseLayers(const pbf& data, const std::vector<LayerDescription>& layers) {
void Tile::parseStyleLayers(const std::vector<LayerDescription>& layers) {
for (const LayerDescription& layer_desc : layers) {
if (layer_desc.child_layer.size()) {
// This is a layer group.
// TODO: create framebuffer
parseLayers(data, layer_desc.child_layer);
parseStyleLayers(layer_desc.child_layer);
// TODO: render framebuffer on previous framebuffer
} else {
// This is a singular layer. Check if this bucket already exists. If not,
@@ -130,7 +127,7 @@ void Tile::parseLayers(const pbf& data, const std::vector<LayerDescription>& lay
if (bucket_it != style.buckets.end()) {
// Only create the new bucket if we have an actual specification
// for it.
std::shared_ptr<Bucket> bucket = createBucket(data, bucket_it->second);
std::shared_ptr<Bucket> bucket = createBucket(bucket_it->second);
if (bucket) {
// Bucket creation might fail because the data tile may not
// contain any data that falls into this bucket.
@@ -146,30 +143,17 @@ void Tile::parseLayers(const pbf& data, const std::vector<LayerDescription>& lay
}
}
std::shared_ptr<Bucket> Tile::createBucket(const pbf& data, const BucketDescription& bucket_desc) {
pbf tile(data);
// TODO: remember data locations in tiles for faster parsing so that we don't
// have to go through the entire vector tile all the time.
while (tile.next()) {
if (tile.tag == 3) { // layer
pbf layer = tile.message();
while (layer.next()) {
if (layer.tag == 1) {
std::string name = layer.string();
if (name == bucket_desc.source_layer) {
if (bucket_desc.type == BucketType::Fill) {
return createFillBucket(layer, bucket_desc);
} else {
// TODO: create other bucket types.
}
}
} else {
layer.skip();
}
}
std::shared_ptr<Bucket> Tile::createBucket(const BucketDescription& bucket_desc) {
auto layer_it = tile.layers.find(bucket_desc.source_layer);
if (layer_it != tile.layers.end()) {
const VectorTileLayer& layer = layer_it->second;
if (bucket_desc.type == BucketType::Fill) {
return createFillBucket(layer, bucket_desc);
} else {
tile.skip();
// TODO: create other bucket types.
}
} else {
// The layer specified in the bucket does not exist. Do nothing.
}
return NULL;
@@ -182,99 +166,14 @@ enum geom_type {
Polygon = 3
};
std::shared_ptr<Bucket> Tile::createFillBucket(const pbf data, const BucketDescription& bucket_desc) {
pbf layer;
std::shared_ptr<Bucket> Tile::createFillBucket(const VectorTileLayer& layer, const BucketDescription& bucket_desc) {
std::shared_ptr<FillBucket> bucket = std::make_shared<FillBucket>(fillBuffer);
int32_t key = -1;
std::set<uint32_t> values;
// If we filter further by field/value, parse the key/value indices first
// because protobuf doesn't mandate a particular key order.
if (bucket_desc.source_field.size()) {
uint32_t key_id = 0;
uint32_t value_id = 0;
// Find out what key/value IDs we need.
layer = data;
while (layer.next()) {
if (layer.tag == 3) { // keys
if (layer.string() == bucket_desc.source_field) {
// We found the key
key = key_id;
}
key_id++;
} else if (layer.tag == 4) { // values
Value value = parseValue(layer.message());
if (std::find(bucket_desc.source_value.begin(), bucket_desc.source_value.end(), value) != bucket_desc.source_value.end()) {
values.insert(value_id);
}
value_id++;
} else {
layer.skip();
}
}
if (key < 0 || values.empty()) {
// There are no valid values that we could possibly find. Abort early.
return bucket;
}
}
// Now parse the features and optionally filter by key/value IDs.
layer = data;
while (layer.next()) {
if (layer.tag == 2) { // feature
pbf feature = layer.message();
pbf geometry;
geom_type type = Unknown;
bool skip = false;
while (!skip && feature.next()) {
if (feature.tag == 2) { // tags
if (key < 0) {
// We want to parse the entire layer anyway
feature.skip();
} else {
// We only want to parse some features.
skip = true;
// tags are packed varints. They should have an even length.
pbf tags = feature.message();
while (tags) {
uint32_t tag_key = tags.varint();
if (tags) {
uint32_t tag_val = tags.varint();
// Now check if the tag_key/tag_val pair is included
// in the set of key/values that we are looking for.
if (key == tag_key && values.find(tag_val) != values.end()) {
skip = false;
break;
}
} else {
// This should not happen; otherwise the vector tile
// is invalid.
throw std::runtime_error("uneven number of feature tag ids");
}
}
}
} else if (feature.tag == 3) { // geometry type
type = (geom_type)feature.varint();
if (type != Polygon) {
skip = true;
break;
}
} else if (feature.tag == 4) { // geometry
geometry = feature.message();
} else {
feature.skip();
}
}
if (!skip && geometry) {
bucket->addGeometry(geometry);
}
} else {
layer.skip();
FilteredVectorTileLayer filtered_layer(layer, bucket_desc);
for (pbf feature : filtered_layer) {
while (feature.next(4)) { // geometry
pbf geometry_pbf = feature.message();
bucket->addGeometry(geometry_pbf);
}
}