39 lines
1.1 KiB
Go
39 lines
1.1 KiB
Go
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package upath
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import "math"
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import "image"
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// P creates a path fom a list of integers that form X-Y pairs.
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func P (data ...int) []image.Point {
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result := make([]image.Point, len(data) / 2)
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for index := range result {
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result[index].X = data[index * 2]
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result[index].Y = data[index * 2 + 1]
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}
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return result
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}
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// Lerp linearally interpolates between two paths. If the paths differ in
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// length, the returned path will only be as long as the smaller one.
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func Lerp (fac float64, start, end []image.Point) []image.Point {
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result := make([]image.Point, len(start))
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for index, startPt := range start {
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if index >= len(end) { return result[:index] }
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endPt := end[index]
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result[index] = image.Pt (
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lerp(fac, startPt.X, endPt.X),
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lerp(fac, startPt.Y, endPt.Y))
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}
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return result
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}
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// Distance returns the distance between two points.
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func Distance (start, end image.Point) float64 {
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delta := start.Sub(end)
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return math.Sqrt(float64(delta.X * delta.X) + float64(delta.Y * delta.Y))
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}
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func lerp (fac float64, x, y int) int {
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return int(float64(x) * fac + float64(y) * (1.0 - fac))
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}
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