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mapnik/plugins/input/tiles/tiles_datasource.cpp
Artem Pavlenko ce9a3172a3 Pass 'filter_factor' (raster_tiles_featureset)
2025-06-23 14:06:59 +01:00

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/*****************************************************************************
*
* This file is part of Mapnik (c++ mapping toolkit)
*
* Copyright (C) 2025 Artem Pavlenko
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
*****************************************************************************/
#include "tiles_datasource.hpp"
#include "vector_tiles_featureset.hpp"
#include "raster_tiles_featureset.hpp"
#include "pmtiles_source.hpp"
#include "mbtiles_source.hpp"
#include "vector_tile_projection.hpp"
#include <mapnik/geom_util.hpp>
#include <mapnik/util/fs.hpp>
#include <mapnik/unicode.hpp>
#include <mapnik/datasource_plugin.hpp>
#include <mapnik/well_known_srs.hpp>
#include <string>
#include <algorithm>
#include <thread>
DATASOURCE_PLUGIN_IMPL(tiles_datasource_plugin, tiles_datasource);
DATASOURCE_PLUGIN_EXPORT(tiles_datasource_plugin);
DATASOURCE_PLUGIN_EMPTY_AFTER_LOAD(tiles_datasource_plugin);
DATASOURCE_PLUGIN_EMPTY_BEFORE_UNLOAD(tiles_datasource_plugin);
tiles_datasource::tiles_datasource(mapnik::parameters const& params)
: datasource(params)
, desc_(tiles_datasource::name(), *params.get<std::string>("encoding", "utf-8"))
{
init(params);
}
tiles_datasource::~tiles_datasource() {}
mapnik::datasource::datasource_t tiles_datasource::type() const
{
return datasource::Vector;
}
const char* tiles_datasource::name()
{
return "tiles";
}
mapnik::layer_descriptor tiles_datasource::get_descriptor() const
{
return desc_;
}
std::optional<mapnik::datasource_geometry_t> tiles_datasource::get_geometry_type() const
{
return mapnik::datasource_geometry_t::Collection;
}
mapnik::box2d<double> tiles_datasource::envelope() const
{
return extent_;
}
void tiles_datasource::init(mapnik::parameters const& params)
{
std::optional<std::string> file = params.get<std::string>("file");
if (!file)
{
throw mapnik::datasource_exception("Tiles Plugin: missing <file> parameter");
}
std::optional<std::string> base = params.get<std::string>("base");
if (base)
{
database_path_ = *base + "/" + *file;
}
else
{
database_path_ = *file;
}
if (!mapnik::util::exists(database_path_))
{
throw mapnik::datasource_exception("Tiles Plugin: " + database_path_ + " does not exist");
}
if (database_path_.ends_with(".pmtiles"))
{
source_ptr_ = std::make_shared<mapnik::pmtiles_source>(database_path_);
}
else if (database_path_.ends_with(".mbtiles"))
{
source_ptr_ = std::make_shared<mapnik::mbtiles_source>(database_path_);
}
else
{
throw mapnik::datasource_exception("Unexpected file extension in tiles source: " + database_path_);
}
if (!source_ptr_->is_raster())
{
std::optional<std::string> layer = params.get<std::string>("layer");
try
{
layer_ = layer.value();
}
catch (std::bad_optional_access&)
{
throw mapnik::datasource_exception("Tiles Plugin: parameter 'layer' is missing.");
}
}
minzoom_ = source_ptr_->minzoom();
maxzoom_ = source_ptr_->maxzoom();
extent_ = source_ptr_->extent();
// overwrite envelope with user supplied
std::optional<std::string> ext = params.get<std::string>("extent");
if (ext && !ext->empty())
{
extent_.from_string(*ext);
}
if (!extent_.valid())
{
throw mapnik::datasource_exception("Tiles Plugin: " + database_path_ + " extent is invalid.");
}
// Bounds are specified in EPSG:4326, therefore transformation is required.
mapnik::lonlat2merc(extent_.minx_, extent_.miny_);
mapnik::lonlat2merc(extent_.maxx_, extent_.maxy_);
auto metadata = source_ptr_->metadata();
if (!source_ptr_->is_raster())
{
auto layers = metadata.at("vector_layers");
bool found = false;
for (auto const& layer : layers.as_array())
{
std::string id = layer.at("id").as_string().c_str();
if (id == layer_)
{
found = true;
if (auto const* p = layer.as_object().if_contains("minzoom"))
{
minzoom_ = std::max(minzoom_, p->as_int64());
}
if (auto const* p = layer.as_object().if_contains("maxzoom"))
{
maxzoom_ = std::min(maxzoom_, p->as_int64());
}
for (auto const& field : layer.at("fields").as_object())
{
std::string name{field.key_c_str()};
if (field.value() == "String")
{
desc_.add_descriptor(mapnik::attribute_descriptor(name, mapnik::String));
}
else if (field.value() == "Number")
{
desc_.add_descriptor(mapnik::attribute_descriptor(name, mapnik::Float));
}
else if (field.value() == "Boolean")
{
desc_.add_descriptor(mapnik::attribute_descriptor(name, mapnik::Boolean));
}
}
break;
}
}
if (!found)
{
throw mapnik::datasource_exception("Requested layer '" + layer_ + "' not found.");
}
}
}
mapnik::context_ptr tiles_datasource::get_context_with_attributes() const
{
mapnik::context_ptr context = std::make_shared<mapnik::context_type>();
std::vector<mapnik::attribute_descriptor> const& desc_ar = desc_.get_descriptors();
for (auto const& attr_info : desc_ar)
{
context->push(attr_info.get_name());
}
return context;
}
mapnik::context_ptr tiles_datasource::get_query_context(mapnik::query const& q) const
{
mapnik::context_ptr context = std::make_shared<mapnik::context_type>();
std::vector<mapnik::attribute_descriptor> const& desc_ar = desc_.get_descriptors();
for (auto const& name : q.property_names())
{
for (auto const& attr_info : desc_ar)
{
if (name == attr_info.get_name())
{
context->push(name);
break;
}
}
}
return context;
}
namespace {
constexpr double scales[] = {279541132.014, 139770566.007, 69885283.0036, 34942641.5018, 17471320.7509, 8735660.37545,
4367830.18772, 2183915.09386, 1091957.54693, 545978.773466, 272989.386733, 136494.693366,
68247.3466832, 34123.6733416, 17061.8366708, 8530.9183354, 4265.4591677, 2132.72958385,
1066.36479192, 533.182395962, 266.59119798, 133.29559899, 66.6477994952};
std::int64_t scale_to_zoom(double scale, std::int64_t minzoom, std::int64_t maxzoom)
{
for (std::int64_t zoom = 0; zoom < 22; ++zoom)
{
if (scale > std::ceil(scales[zoom]))
return std::min(zoom, minzoom);
else if (scale < std::ceil(scales[zoom]) && scale > std::ceil(scales[zoom + 1]))
{
return std::min(zoom, maxzoom);
}
}
return maxzoom;
}
} // namespace
std::unordered_map<std::string, std::string>& tiles_datasource::tile_cache()
{
static thread_local std::unordered_map<std::string, std::string> vector_tile_cache;
return vector_tile_cache;
}
mapnik::featureset_ptr tiles_datasource::features(mapnik::query const& q) const
{
#ifdef MAPNIK_STATS
mapnik::progress_timer __stats__(std::clog, "tiles_datasource::features");
#endif
auto& vector_tile_cache = tile_cache();
if (vector_tile_cache.size() > 16)
{
vector_tile_cache.clear();
}
auto datasource_hash = std::hash<std::string>{}(database_path_);
mapnik::box2d<double> bbox = q.get_bbox().intersect(extent_);
auto zoom = scale_to_zoom(q.scale_denominator(), minzoom_, maxzoom_);
mapnik::context_ptr context = get_query_context(q);
if (source_ptr_->is_raster())
{
return std::make_shared<raster_tiles_featureset>(source_ptr_,
context,
zoom,
bbox,
layer_,
vector_tile_cache,
datasource_hash,
q.get_filter_factor());
}
else
{
return std::make_shared<vector_tiles_featureset>(source_ptr_,
context,
zoom,
bbox,
layer_,
vector_tile_cache,
datasource_hash);
}
}
mapnik::featureset_ptr tiles_datasource::features_at_point(mapnik::coord2d const& pt, double tol) const
{
#ifdef MAPNIK_STATS
mapnik::progress_timer __stats__(std::clog, "tiles_datasource::features_at_point");
#endif
mapnik::filter_at_point filter(pt, tol);
mapnik::context_ptr context = get_context_with_attributes();
auto datasource_hash = std::hash<std::string>{}(database_path_);
int tile_count = 1 << maxzoom_;
auto tile_x =
static_cast<int>((pt.x + mapnik::EARTH_CIRCUMFERENCE / 2) * (tile_count / mapnik::EARTH_CIRCUMFERENCE));
auto tile_y =
static_cast<int>(((mapnik::EARTH_CIRCUMFERENCE / 2) - pt.y) * (tile_count / mapnik::EARTH_CIRCUMFERENCE));
double x0 = tile_x * (mapnik::EARTH_CIRCUMFERENCE / tile_count) - 0.5 * mapnik::EARTH_CIRCUMFERENCE;
double y0 = -tile_y * (mapnik::EARTH_CIRCUMFERENCE / tile_count) + 0.5 * mapnik::EARTH_CIRCUMFERENCE;
double x1 = (tile_x + 1) * (mapnik::EARTH_CIRCUMFERENCE / tile_count) - 0.5 * mapnik::EARTH_CIRCUMFERENCE;
double y1 = -(tile_y + 1) * (mapnik::EARTH_CIRCUMFERENCE / tile_count) + 0.5 * mapnik::EARTH_CIRCUMFERENCE;
auto query_bbox = mapnik::box2d<double>{x0, y0, x1, y1};
if (!source_ptr_->is_raster())
return std::make_shared<vector_tiles_featureset>(source_ptr_,
context,
maxzoom_,
query_bbox,
layer_,
tile_cache(),
datasource_hash);
return mapnik::featureset_ptr();
}
#if !defined(_MSC_VER)
// Boost.Json header only
#include <boost/json/src.hpp>
#endif
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