62 lines
1.1 KiB
Go
62 lines
1.1 KiB
Go
package geo
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import (
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"math"
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)
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type Route []*Point
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func (route Route) Length() float64 {
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l := 0.
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for i := 0; i < len(route)-1; i++ {
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l += EuclideanDistance(
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route[i].X, route[i].Y,
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route[i+1].X, route[i+1].Y,
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)
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}
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return l
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}
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// return the point at _distance_ along the route, and the index of the segment it's on
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func (route Route) GetPointAtDistance(distance float64) (*Point, int) {
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remaining := distance
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for i := 0; i < len(route)-1; i++ {
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curr, next := route[i], route[i+1]
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length := EuclideanDistance(curr.X, curr.Y, next.X, next.Y)
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if remaining <= length {
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t := remaining / length
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// point t% of the way between curr and next
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return NewPoint(
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curr.X*(1.0-t)+next.X*t,
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curr.Y*(1.0-t)+next.Y*t,
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), i
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}
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remaining -= length
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}
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return nil, -1
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}
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func (route Route) GetBoundingBox() (tl, br *Point) {
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minX := math.Inf(1)
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minY := math.Inf(1)
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maxX := math.Inf(-1)
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maxY := math.Inf(-1)
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for _, p := range route {
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if p.X < minX {
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minX = p.X
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}
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if p.X > maxX {
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maxX = p.X
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}
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if p.Y < minY {
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minY = p.Y
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}
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if p.Y > maxY {
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maxY = p.Y
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}
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}
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return NewPoint(minX, minY), NewPoint(maxX, maxY)
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}
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