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package gg
import "math"
func quadratic(x0, y0, x1, y1, x2, y2, t float64) (x, y float64) {
u := 1 - t
a := u * u
b := 2 * u * t
c := t * t
x = a*x0 + b*x1 + c*x2
y = a*y0 + b*y1 + c*y2
return
}
func QuadraticBezier(x0, y0, x1, y1, x2, y2 float64) []Point {
l := (math.Hypot(x1-x0, y1-y0) +
math.Hypot(x2-x1, y2-y1))
n := int(l + 0.5)
if n < 4 {
n = 4
}
d := float64(n) - 1
result := make([]Point, n)
for i := 0; i < n; i++ {
t := float64(i) / d
x, y := quadratic(x0, y0, x1, y1, x2, y2, t)
result[i] = Point{x, y}
}
return result
}
func cubic(x0, y0, x1, y1, x2, y2, x3, y3, t float64) (x, y float64) {
u := 1 - t
a := u * u * u
b := 3 * u * u * t
c := 3 * u * t * t
d := t * t * t
x = a*x0 + b*x1 + c*x2 + d*x3
y = a*y0 + b*y1 + c*y2 + d*y3
return
}
func CubicBezier(x0, y0, x1, y1, x2, y2, x3, y3 float64) []Point {
l := (math.Hypot(x1-x0, y1-y0) +
math.Hypot(x2-x1, y2-y1) +
math.Hypot(x3-x2, y3-y2))
n := int(l + 0.5)
if n < 4 {
n = 4
}
d := float64(n) - 1
result := make([]Point, n)
for i := 0; i < n; i++ {
t := float64(i) / d
x, y := cubic(x0, y0, x1, y1, x2, y2, x3, y3, t)
result[i] = Point{x, y}
}
return result
}
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