102 lines
2.1 KiB
Go
102 lines
2.1 KiB
Go
package geom
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import (
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"errors"
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"imposm3/element"
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"imposm3/geom/geos"
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)
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type GeomError struct {
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message string
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level int
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}
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func (e *GeomError) Error() string {
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return e.message
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}
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func (e *GeomError) Level() int {
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return e.level
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}
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func NewGeomError(message string, level int) *GeomError {
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return &GeomError{message, level}
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}
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var (
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ErrorOneNodeWay = NewGeomError("need at least two separate nodes for way", 0)
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ErrorNoRing = NewGeomError("linestrings do not form ring", 0)
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)
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func Point(g *geos.Geos, node element.Node) (*geos.Geom, error) {
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geom := g.Point(node.Long, node.Lat)
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if geom == nil {
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return nil, NewGeomError("couldn't create point", 1)
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}
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g.DestroyLater(geom)
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return geom, nil
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}
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func LineString(g *geos.Geos, nodes []element.Node) (*geos.Geom, error) {
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if len(nodes) < 2 {
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return nil, ErrorOneNodeWay
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}
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coordSeq, err := g.CreateCoordSeq(uint32(len(nodes)), 2)
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if err != nil {
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return nil, err
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}
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// coordSeq inherited by LineString
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for i, nd := range nodes {
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coordSeq.SetXY(g, uint32(i), nd.Long, nd.Lat)
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}
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geom, err := coordSeq.AsLineString(g)
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if err != nil {
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// coordSeq gets Destroy by GEOS
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return nil, err
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}
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g.DestroyLater(geom)
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return geom, nil
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}
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func Polygon(g *geos.Geos, nodes []element.Node) (*geos.Geom, error) {
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coordSeq, err := g.CreateCoordSeq(uint32(len(nodes)), 2)
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if err != nil {
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return nil, err
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}
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// coordSeq inherited by LinearRing, no destroy
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for i, nd := range nodes {
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err := coordSeq.SetXY(g, uint32(i), nd.Long, nd.Lat)
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if err != nil {
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return nil, err
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}
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}
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ring, err := coordSeq.AsLinearRing(g)
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if err != nil {
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// coordSeq gets Destroy by GEOS
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return nil, err
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}
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// ring inherited by Polygon, no destroy
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geom := g.CreatePolygon(ring, nil)
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if geom == nil {
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g.Destroy(ring)
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return nil, errors.New("unable to create polygon")
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}
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g.DestroyLater(geom)
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return geom, nil
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}
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func AsGeomElement(g *geos.Geos, geom *geos.Geom) (*element.Geometry, error) {
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wkb := g.AsEwkbHex(geom)
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if wkb == nil {
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return nil, errors.New("could not create wkb")
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}
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return &element.Geometry{
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Wkb: wkb,
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Geom: geom,
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}, nil
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}
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