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don't use geom collection, instead diff geom per feature

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This commit is contained in:
Dane Springmeyer 2015-02-23 11:43:32 -08:00
parent 20e7340699
commit 568d3cbf41
1 changed files with 24 additions and 18 deletions
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42
plugins/input/templates/helloworld/hello_featureset.cpp
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@ -11,7 +11,10 @@ hello_featureset::hello_featureset(mapnik::box2d<double> const& box, std::string
: box_(box),
feature_id_(1),
tr_(new mapnik::transcoder(encoding)),
ctx_(std::make_shared<mapnik::context_type>()) { }
ctx_(std::make_shared<mapnik::context_type>()) {
// add known field names to attributes schema
ctx_->push("key");
}
hello_featureset::~hello_featureset() { }
@ -19,33 +22,38 @@ mapnik::feature_ptr hello_featureset::next()
{
if (feature_id_ == 1)
{
// let us pretend it just has one column/attribute name
std::string attribute("key");
// the featureset context needs to know the field schema
ctx_->push(attribute);
// create a new feature
mapnik::feature_ptr feature(mapnik::feature_factory::create(ctx_,feature_id_));
// increment the count so that we only return one feature
// increment the count
++feature_id_;
// create an attribute pair of key:value
mapnik::value_unicode_string ustr = tr_->transcode("hello world!");
feature->put(attribute,ustr);
feature->put("key",tr_->transcode("hello world point!"));
// we need a geometry to display so just for fun here
// we take the center of the bbox that was used to query
// since we don't actually have any data to pull from...
// take the center of the bbox that was used to query
// to dynamically generate a fake point
mapnik::coord2d center = box_.center();
// create a new point geometry
feature->set_geometry(mapnik::new_geometry::point(center.x,center.y));
// A feature usually will have just one geometry of a given type
// but mapnik supports many geometries per feature of any type
// so here we draw a line around the point
// return the feature!
return feature;
}
else if (feature_id_ == 2)
{
// create a second feature
mapnik::feature_ptr feature(mapnik::feature_factory::create(ctx_,feature_id_));
// increment the count
++feature_id_;
// create an attribute pair of key:value
feature->put("key",tr_->transcode("hello world line!"));
// take the outer ring of the bbox that was used to query
// to dynamically generate a fake line
mapnik::new_geometry::line_string line;
line.reserve(4);
line.add_coord(box_.minx(),box_.maxy());
@ -53,8 +61,6 @@ mapnik::feature_ptr hello_featureset::next()
line.add_coord(box_.maxx(),box_.miny());
line.add_coord(box_.minx(),box_.miny());
feature->set_geometry(std::move(line));
// return the feature!
return feature;
}