tile38/geojson/point.go

130 lines
3.5 KiB
Go

package geojson
import (
"github.com/tidwall/tile38/geojson/geo"
"github.com/tidwall/tile38/geojson/geohash"
"github.com/tidwall/tile38/geojson/poly"
)
// Point is a geojson object with the type "Point"
type Point struct {
Coordinates Position
BBox *BBox
bboxDefined bool
}
func fillSimplePointOrPoint(coordinates Position, bbox *BBox, err error) (Object, error) {
if coordinates.Z == 0 && bbox == nil {
return fillSimplePoint(coordinates, bbox, err)
}
return fillPoint(coordinates, bbox, err)
}
func fillPoint(coordinates Position, bbox *BBox, err error) (Point, error) {
bboxDefined := bbox != nil
if !bboxDefined {
cbbox := level1CalculatedBBox(coordinates, nil)
bbox = &cbbox
}
return Point{
Coordinates: coordinates,
BBox: bbox,
bboxDefined: bboxDefined,
}, err
}
// CalculatedBBox is exterior bbox containing the object.
func (g Point) CalculatedBBox() BBox {
return level1CalculatedBBox(g.Coordinates, g.BBox)
}
// CalculatedPoint is a point representation of the object.
func (g Point) CalculatedPoint() Position {
if g.BBox == nil {
return g.Coordinates
}
return g.CalculatedBBox().center()
}
// Geohash converts the object to a geohash value.
func (g Point) Geohash(precision int) (string, error) {
p := g.CalculatedPoint()
return geohash.Encode(p.Y, p.X, precision)
}
// MarshalJSON allows the object to be encoded in json.Marshal calls.
func (g Point) MarshalJSON() ([]byte, error) {
return g.appendJSON(nil), nil
}
func (g Point) appendJSON(json []byte) []byte {
return appendLevel1JSON(json, "Point", g.Coordinates, g.BBox, g.bboxDefined)
}
// JSON is the json representation of the object. This might not be exactly the same as the original.
func (g Point) JSON() string {
return string(g.appendJSON(nil))
}
// String returns a string representation of the object. This might be JSON or something else.
func (g Point) String() string {
return g.JSON()
}
// PositionCount return the number of coordinates.
func (g Point) PositionCount() int {
return level1PositionCount(g.Coordinates, g.BBox)
}
// Weight returns the in-memory size of the object.
func (g Point) Weight() int {
return level1Weight(g.Coordinates, g.BBox)
}
func (g Point) bboxPtr() *BBox {
return g.BBox
}
func (g Point) hasPositions() bool {
return true
}
// WithinBBox detects if the object is fully contained inside a bbox.
func (g Point) WithinBBox(bbox BBox) bool {
if g.bboxDefined {
return rectBBox(g.CalculatedBBox()).InsideRect(rectBBox(bbox))
}
return poly.Point(g.Coordinates).InsideRect(rectBBox(bbox))
}
// IntersectsBBox detects if the object intersects a bbox.
func (g Point) IntersectsBBox(bbox BBox) bool {
if g.bboxDefined {
return rectBBox(g.CalculatedBBox()).IntersectsRect(rectBBox(bbox))
}
return poly.Point(g.Coordinates).InsideRect(rectBBox(bbox))
}
// Within detects if the object is fully contained inside another object.
func (g Point) Within(o Object) bool {
return withinObjectShared(g, o)
}
// Intersects detects if the object intersects another object.
func (g Point) Intersects(o Object) bool {
return intersectsObjectShared(g, o)
}
// Nearby detects if the object is nearby a position.
func (g Point) Nearby(center Position, meters float64) bool {
return geo.DistanceTo(g.Coordinates.Y, g.Coordinates.X, center.Y, center.X) <= meters
}
// IsBBoxDefined returns true if the object has a defined bbox.
func (g Point) IsBBoxDefined() bool {
return g.bboxDefined
}
// IsGeometry return true if the object is a geojson geometry object. false if it something else.
func (g Point) IsGeometry() bool {
return true
}