mirror of https://github.com/tidwall/tile38.git
147 lines
4.0 KiB
Go
147 lines
4.0 KiB
Go
package geojson
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import "github.com/tidwall/tile38/geojson/geohash"
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// LineString is a geojson object with the type "LineString"
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type LineString struct {
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Coordinates []Position
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BBox *BBox
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bboxDefined bool
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}
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func fillLineString(coordinates []Position, bbox *BBox, err error) (LineString, error) {
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if err == nil {
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if len(coordinates) < 2 {
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err = errLineStringInvalidCoordinates
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}
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}
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bboxDefined := bbox != nil
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if !bboxDefined {
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cbbox := level2CalculatedBBox(coordinates, nil)
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bbox = &cbbox
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}
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return LineString{
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Coordinates: coordinates,
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BBox: bbox,
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bboxDefined: bboxDefined,
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}, err
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}
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// CalculatedBBox is exterior bbox containing the object.
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func (g LineString) CalculatedBBox() BBox {
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return level2CalculatedBBox(g.Coordinates, g.BBox)
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}
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// CalculatedPoint is a point representation of the object.
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func (g LineString) CalculatedPoint() Position {
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return g.CalculatedBBox().center()
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}
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// Geohash converts the object to a geohash value.
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func (g LineString) Geohash(precision int) (string, error) {
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p := g.CalculatedPoint()
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return geohash.Encode(p.Y, p.X, precision)
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}
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// PositionCount return the number of coordinates.
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func (g LineString) PositionCount() int {
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return level2PositionCount(g.Coordinates, g.BBox)
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}
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// Weight returns the in-memory size of the object.
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func (g LineString) Weight() int {
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return level2Weight(g.Coordinates, g.BBox)
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}
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func (g LineString) appendJSON(json []byte) []byte {
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return appendLevel2JSON(json, "LineString", g.Coordinates, g.BBox, g.bboxDefined)
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}
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// MarshalJSON allows the object to be encoded in json.Marshal calls.
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func (g LineString) MarshalJSON() ([]byte, error) {
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return g.appendJSON(nil), nil
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}
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// JSON is the json representation of the object. This might not be exactly the same as the original.
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func (g LineString) JSON() string {
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return string(g.appendJSON(nil))
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}
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// String returns a string representation of the object. This might be JSON or something else.
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func (g LineString) String() string {
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return g.JSON()
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}
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func (g LineString) bboxPtr() *BBox {
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return g.BBox
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}
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func (g LineString) hasPositions() bool {
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return g.bboxDefined || len(g.Coordinates) > 0
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}
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// WithinBBox detects if the object is fully contained inside a bbox.
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func (g LineString) WithinBBox(bbox BBox) bool {
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if g.bboxDefined {
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return rectBBox(g.CalculatedBBox()).InsideRect(rectBBox(bbox))
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}
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return polyPositions(g.Coordinates).InsideRect(rectBBox(bbox))
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}
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// IntersectsBBox detects if the object intersects a bbox.
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func (g LineString) IntersectsBBox(bbox BBox) bool {
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if g.bboxDefined {
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return rectBBox(g.CalculatedBBox()).IntersectsRect(rectBBox(bbox))
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}
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return polyPositions(g.Coordinates).IntersectsRect(rectBBox(bbox))
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}
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// Within detects if the object is fully contained inside another object.
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func (g LineString) Within(o Object) bool {
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return withinObjectShared(g, o,
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func(v Polygon) bool {
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return polyPositions(g.Coordinates).Inside(polyExteriorHoles(v.Coordinates))
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},
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func(v MultiPolygon) bool {
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for _, c := range v.Coordinates {
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if !polyPositions(g.Coordinates).Inside(polyExteriorHoles(c)) {
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return false
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}
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}
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return true
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},
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)
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}
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// Intersects detects if the object intersects another object.
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func (g LineString) Intersects(o Object) bool {
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return intersectsObjectShared(g, o,
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func(v Polygon) bool {
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return polyPositions(g.Coordinates).LineStringIntersects(polyExteriorHoles(v.Coordinates))
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},
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func(v MultiPolygon) bool {
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for _, c := range v.Coordinates {
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if polyPositions(g.Coordinates).LineStringIntersects(polyExteriorHoles(c)) {
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return true
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}
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}
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return false
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},
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)
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}
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// Nearby detects if the object is nearby a position.
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func (g LineString) Nearby(center Position, meters float64) bool {
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return nearbyObjectShared(g, center.X, center.Y, meters)
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}
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// IsBBoxDefined returns true if the object has a defined bbox.
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func (g LineString) IsBBoxDefined() bool {
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return g.bboxDefined
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}
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// IsGeometry return true if the object is a geojson geometry object. false if it something else.
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func (g LineString) IsGeometry() bool {
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return true
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}
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