forked from arne-cl/tile38
/
featurecollection.go
250 lines (227 loc) 路 5.68 KB
/
featurecollection.go
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package geojson
import (
"github.com/tidwall/gjson"
"github.com/quesurifn/tile38/pkg/geojson/geohash"
)
// FeatureCollection is a geojson object with the type "FeatureCollection"
type FeatureCollection struct {
Features []Object
BBox *BBox
bboxDefined bool
}
func fillFeatureCollectionMap(json string) (FeatureCollection, error) {
var g FeatureCollection
res := gjson.Get(json, "features")
switch res.Type {
default:
return g, errInvalidFeaturesMember
case gjson.Null:
return g, errFeaturesMemberRequired
case gjson.JSON:
if !resIsArray(res) {
return g, errInvalidFeaturesMember
}
v := res.Array()
g.Features = make([]Object, len(v))
for i, res := range v {
if res.Type != gjson.JSON {
return g, errInvalidFeature
}
o, err := objectMap(res.Raw, fcoll)
if err != nil {
return g, err
}
g.Features[i] = o
}
}
var err error
g.BBox, err = fillBBox(json)
if err != nil {
return g, err
}
g.bboxDefined = g.BBox != nil
if !g.bboxDefined {
cbbox := g.CalculatedBBox()
g.BBox = &cbbox
}
return g, err
}
// Geohash converts the object to a geohash value.
func (g FeatureCollection) Geohash(precision int) (string, error) {
p := g.CalculatedPoint()
return geohash.Encode(p.Y, p.X, precision)
}
// CalculatedPoint is a point representation of the object.
func (g FeatureCollection) CalculatedPoint() Position {
return g.CalculatedBBox().center()
}
// CalculatedBBox is exterior bbox containing the object.
func (g FeatureCollection) CalculatedBBox() BBox {
if g.BBox != nil {
return *g.BBox
}
var bbox BBox
for i, g := range g.Features {
if i == 0 {
bbox = g.CalculatedBBox()
} else {
bbox = bbox.union(g.CalculatedBBox())
}
}
return bbox
}
// PositionCount return the number of coordinates.
func (g FeatureCollection) PositionCount() int {
var res int
for _, g := range g.Features {
res += g.PositionCount()
}
if g.BBox != nil {
return 2 + res
}
return res
}
// Weight returns the in-memory size of the object.
func (g FeatureCollection) Weight() int {
var res int
for _, g := range g.Features {
res += g.Weight()
}
return res
}
// MarshalJSON allows the object to be encoded in json.Marshal calls.
func (g FeatureCollection) MarshalJSON() ([]byte, error) {
return g.appendJSON(nil), nil
}
func (g FeatureCollection) appendJSON(json []byte) []byte {
json = append(json, `{"type":"FeatureCollection","features":[`...)
for i, g := range g.Features {
if i != 0 {
json = append(json, ',')
}
json = append(json, g.JSON()...)
}
json = append(json, ']')
if g.bboxDefined {
json = appendBBoxJSON(json, g.BBox)
}
return append(json, '}')
}
// JSON is the json representation of the object. This might not be exactly the same as the original.
func (g FeatureCollection) JSON() string {
return string(g.appendJSON(nil))
}
// String returns a string representation of the object. This might be JSON or something else.
func (g FeatureCollection) String() string {
return g.JSON()
}
// Bytes is the bytes representation of the object.
func (g FeatureCollection) Bytes() []byte {
return []byte(g.JSON())
}
func (g FeatureCollection) bboxPtr() *BBox {
return g.BBox
}
func (g FeatureCollection) hasPositions() bool {
if g.BBox != nil {
return true
}
for _, g := range g.Features {
if g.hasPositions() {
return true
}
}
return false
}
// WithinBBox detects if the object is fully contained inside a bbox.
func (g FeatureCollection) WithinBBox(bbox BBox) bool {
if g.bboxDefined {
return rectBBox(g.CalculatedBBox()).InsideRect(rectBBox(bbox))
}
if len(g.Features) == 0 {
return false
}
for _, g := range g.Features {
if !g.WithinBBox(bbox) {
return false
}
}
return true
}
// IntersectsBBox detects if the object intersects a bbox.
func (g FeatureCollection) IntersectsBBox(bbox BBox) bool {
if g.bboxDefined {
return rectBBox(g.CalculatedBBox()).IntersectsRect(rectBBox(bbox))
}
for _, g := range g.Features {
if g.IntersectsBBox(bbox) {
return true
}
}
return false
}
// Within detects if the object is fully contained inside another object.
func (g FeatureCollection) Within(o Object) bool {
return withinObjectShared(g, o,
func(v Polygon) bool {
if len(g.Features) == 0 {
return false
}
for _, f := range g.Features {
if !f.Within(o) {
return false
}
}
return true
},
)
}
// WithinCircle detects if the object is fully contained inside a circle.
func (g FeatureCollection) WithinCircle(center Position, meters float64) bool {
if len(g.Features) == 0 {
return false
}
for _, feature := range g.Features {
if !feature.WithinCircle(center, meters) {
return false
}
}
return true
}
// Intersects detects if the object intersects another object.
func (g FeatureCollection) Intersects(o Object) bool {
return intersectsObjectShared(g, o,
func(v Polygon) bool {
if len(g.Features) == 0 {
return false
}
for _, f := range g.Features {
if f.Intersects(o) {
return true
}
}
return false
},
)
}
// IntersectsCircle detects if the object intersects a circle.
func (g FeatureCollection) IntersectsCircle(center Position, meters float64) bool {
for _, feature := range g.Features {
if feature.IntersectsCircle(center, meters) {
return true
}
}
return false
}
// Nearby detects if the object is nearby a position.
func (g FeatureCollection) Nearby(center Position, meters float64) bool {
return nearbyObjectShared(g, center.X, center.Y, meters)
}
// IsBBoxDefined returns true if the object has a defined bbox.
func (g FeatureCollection) IsBBoxDefined() bool {
return g.bboxDefined
}
// IsGeometry return true if the object is a geojson geometry object. false if it something else.
func (g FeatureCollection) IsGeometry() bool {
return true
}