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sqlite plugin: add features_at_point() impl

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This commit is contained in:
Dane Springmeyer 2011-04-02 04:54:26 +00:00
parent 5a1842aad1
commit f891b0f61f
1 changed files with 59 additions and 0 deletions
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59
plugins/input/sqlite/sqlite_datasource.cpp
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@ -375,6 +375,65 @@ featureset_ptr sqlite_datasource::features_at_point(coord2d const& pt) const
{
if (!is_bound_) bind();
if (dataset_)
{
// TODO - need tolerance
mapnik::box2d<double> const e(pt.x,pt.y,pt.x,pt.y);
std::ostringstream s;
s << "SELECT " << geometry_field_ << "," << key_field_;
std::vector<attribute_descriptor>::const_iterator itr = desc_.get_descriptors().begin();
std::vector<attribute_descriptor>::const_iterator end = desc_.get_descriptors().end();
while (itr != end)
{
std::string fld_name = itr->get_name();
if (fld_name != key_field_)
s << ",\"" << itr->get_name() << "\"";
++itr;
}
s << " FROM ";
std::string query (table_);
if (use_spatial_index_)
{
std::ostringstream spatial_sql;
spatial_sql << std::setprecision(16);
spatial_sql << " WHERE " << key_field_ << " IN (SELECT pkid FROM idx_" << geometry_table_ << "_" << geometry_field_;
spatial_sql << " WHERE xmax>=" << e.minx() << " AND xmin<=" << e.maxx() ;
spatial_sql << " AND ymax>=" << e.miny() << " AND ymin<=" << e.maxy() << ")";
if (boost::algorithm::ifind_first(query, "WHERE"))
{
boost::algorithm::ireplace_first(query, "WHERE", spatial_sql.str() + " AND ");
}
else if (boost::algorithm::ifind_first(query, geometry_table_))
{
boost::algorithm::ireplace_first(query, table_, table_ + " " + spatial_sql.str());
}
}
s << query ;
if (row_limit_ > 0) {
s << " LIMIT " << row_limit_;
}
if (row_offset_ > 0) {
s << " OFFSET " << row_offset_;
}
#ifdef MAPNIK_DEBUG
std::clog << "Sqlite Plugin: " << s.str() << std::endl;
#endif
boost::shared_ptr<sqlite_resultset> rs (dataset_->execute_query (s.str()));
return featureset_ptr (new sqlite_featureset(rs, desc_.get_encoding(), format_, multiple_geometries_));
}
return featureset_ptr();
}