tidwall 6257ddba78 Faster point in polygon / GeoJSON updates
The big change is that the GeoJSON package has been completely
rewritten to fix a few of geometry calculation bugs, increase
performance, and to better follow the GeoJSON spec RFC 7946.

GeoJSON updates

- A LineString now requires at least two points.
- All json members, even foreign, now persist with the object.
- The bbox member persists too but is no longer used for geometry
  calculations. This is change in behavior. Previously Tile38 would
  treat the bbox as the object's physical rectangle.
- Corrections to geometry intersects and within calculations.

Faster spatial queries

- The performance of Point-in-polygon and object intersect operations
  are greatly improved for complex polygons and line strings. It went
  from O(n) to roughly O(log n).
- The same for all collection types with many children, including
  FeatureCollection, GeometryCollection, MultiPoint, MultiLineString,
  and MultiPolygon.

Codebase changes

- The pkg directory has been renamed to internal
- The GeoJSON internal package has been moved to a seperate repo at
  https://github.com/tidwall/geojson. It's now vendored.

Please look out for higher memory usage for datasets using complex
shapes. A complex shape is one that has 64 or more points. For these
shapes it's expected that there will be increase of least 54 bytes per
point.
2018-10-13 04:30:48 -07:00

80 lines
1.3 KiB
Go

package collection
import (
"encoding/json"
"github.com/tidwall/geojson"
"github.com/tidwall/geojson/geometry"
)
// String ...
type String string
var _ geojson.Object = String("")
// Spatial ...
func (s String) Spatial() geojson.Spatial {
return geojson.EmptySpatial{}
}
// ForEach ...
func (s String) ForEach(iter func(geom geojson.Object) bool) bool {
return iter(s)
}
// Empty ...
func (s String) Empty() bool {
return true
}
// Rect ...
func (s String) Rect() geometry.Rect {
return geometry.Rect{}
}
// Center ...
func (s String) Center() geometry.Point {
return geometry.Point{}
}
// AppendJSON ...
func (s String) AppendJSON(dst []byte) []byte {
data, _ := json.Marshal(string(s))
return append(dst, data...)
}
// String ...
func (s String) String() string {
return string(s)
}
// JSON ...
func (s String) JSON() string {
return string(s.AppendJSON(nil))
}
// Within ...
func (s String) Within(obj geojson.Object) bool {
return false
}
// Contains ...
func (s String) Contains(obj geojson.Object) bool {
return false
}
// Intersects ...
func (s String) Intersects(obj geojson.Object) bool {
return false
}
// NumPoints ...
func (s String) NumPoints() int {
return 0
}
// Distance ...
func (s String) Distance(obj geojson.Object) float64 {
return 0
}