tile38/geojson/multilinestring.go

173 lines
4.4 KiB
Go

package geojson
import (
"github.com/tidwall/tile38/geojson/geohash"
)
// MultiLineString is a geojson object with the type "MultiLineString"
type MultiLineString struct {
Coordinates [][]Position
BBox *BBox
bboxDefined bool
linestrings []LineString
}
func fillMultiLineString(coordinates [][]Position, bbox *BBox, err error) (MultiLineString, error) {
linestrings := make([]LineString, len(coordinates))
if err == nil {
for i, ps := range coordinates {
linestrings[i], err = fillLineString(ps, nil, nil)
if err != nil {
break
}
}
}
bboxDefined := bbox != nil
if !bboxDefined {
cbbox := mlCalculatedBBox(linestrings, nil)
bbox = &cbbox
}
return MultiLineString{
Coordinates: coordinates,
BBox: bbox,
bboxDefined: bboxDefined,
linestrings: linestrings,
}, err
}
func mlCalculatedBBox(linestrings []LineString, bbox *BBox) BBox {
if bbox != nil {
return *bbox
}
var cbbox BBox
for i, g := range linestrings {
if i == 0 {
cbbox = g.CalculatedBBox()
} else {
cbbox = cbbox.union(g.CalculatedBBox())
}
}
return cbbox
}
// CalculatedBBox is exterior bbox containing the object.
func (g MultiLineString) CalculatedBBox() BBox {
return mlCalculatedBBox(g.linestrings, g.BBox)
}
// CalculatedPoint is a point representation of the object.
func (g MultiLineString) CalculatedPoint() Position {
return g.CalculatedBBox().center()
}
// Geohash converts the object to a geohash value.
func (g MultiLineString) Geohash(precision int) (string, error) {
p := g.CalculatedPoint()
return geohash.Encode(p.Y, p.X, precision)
}
// PositionCount return the number of coordinates.
func (g MultiLineString) PositionCount() int {
return level3PositionCount(g.Coordinates, g.BBox)
}
// Weight returns the in-memory size of the object.
func (g MultiLineString) Weight() int {
return level3Weight(g.Coordinates, g.BBox)
}
// MarshalJSON allows the object to be encoded in json.Marshal calls.
func (g MultiLineString) MarshalJSON() ([]byte, error) {
return g.appendJSON(nil), nil
}
func (g MultiLineString) appendJSON(json []byte) []byte {
return appendLevel3JSON(json, "MultiLineString", 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 MultiLineString) JSON() string {
return string(g.appendJSON(nil))
}
// String returns a string representation of the object. This might be JSON or something else.
func (g MultiLineString) String() string {
return g.JSON()
}
func (g MultiLineString) bboxPtr() *BBox {
return g.BBox
}
func (g MultiLineString) hasPositions() bool {
if g.bboxDefined {
return true
}
for _, c := range g.Coordinates {
if len(c) > 0 {
return true
}
}
return false
}
func (g MultiLineString) getLineString(index int) LineString {
if index < len(g.linestrings) {
return g.linestrings[index]
}
return LineString{Coordinates: g.Coordinates[index]}
}
// WithinBBox detects if the object is fully contained inside a bbox.
func (g MultiLineString) WithinBBox(bbox BBox) bool {
if g.bboxDefined {
return rectBBox(g.CalculatedBBox()).InsideRect(rectBBox(bbox))
}
if len(g.Coordinates) == 0 {
return false
}
for i := range g.Coordinates {
if !g.getLineString(i).WithinBBox(bbox) {
return false
}
}
return true
}
// IntersectsBBox detects if the object intersects a bbox.
func (g MultiLineString) IntersectsBBox(bbox BBox) bool {
if g.bboxDefined {
return rectBBox(g.CalculatedBBox()).IntersectsRect(rectBBox(bbox))
}
for i := range g.Coordinates {
if g.getLineString(i).IntersectsBBox(bbox) {
return true
}
}
return false
}
// Within detects if the object is fully contained inside another object.
func (g MultiLineString) Within(o Object) bool {
return withinObjectShared(g, o)
}
// Intersects detects if the object intersects another object.
func (g MultiLineString) Intersects(o Object) bool {
return intersectsObjectShared(g, o)
}
// Nearby detects if the object is nearby a position.
func (g MultiLineString) 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 MultiLineString) IsBBoxDefined() bool {
return g.bboxDefined
}
// IsGeometry return true if the object is a geojson geometry object. false if it something else.
func (g MultiLineString) IsGeometry() bool {
return true
}