vector.go

package simplify

import "math"

type Vector struct {
	X, Y, Z float64
}

func (a Vector) Less(b Vector) bool {
	if a.X != b.X {
		return a.X < b.X
	}
	if a.Y != b.Y {
		return a.Y < b.Y
	}
	return a.Z < b.Z
}

func (a Vector) Length() float64 {
	return math.Sqrt(a.X*a.X + a.Y*a.Y + a.Z*a.Z)
}

func (a Vector) Dot(b Vector) float64 {
	return a.X*b.X + a.Y*b.Y + a.Z*b.Z
}

func (a Vector) Cross(b Vector) Vector {
	x := a.Y*b.Z - a.Z*b.Y
	y := a.Z*b.X - a.X*b.Z
	z := a.X*b.Y - a.Y*b.X
	return Vector{x, y, z}
}

func (a Vector) Normalize() Vector {
	d := a.Length()
	return Vector{a.X / d, a.Y / d, a.Z / d}
}

func (a Vector) Add(b Vector) Vector {
	return Vector{a.X + b.X, a.Y + b.Y, a.Z + b.Z}
}

func (a Vector) Sub(b Vector) Vector {
	return Vector{a.X - b.X, a.Y - b.Y, a.Z - b.Z}
}

func (a Vector) MulScalar(b float64) Vector {
	return Vector{a.X * b, a.Y * b, a.Z * b}
}