72 lines
1.3 KiB
Go
72 lines
1.3 KiB
Go
package govector
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import (
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"math"
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)
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type Rect2d struct {
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X1 float64 `json:"x1"`
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Y1 float64 `json:"y1"`
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X2 float64 `json:"x2"`
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Y2 float64 `json:"y2"`
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}
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type Vector2d struct {
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X float64 `json:"x"`
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Y float64 `json:"y"`
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}
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type Point2d struct {
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X float64 `json:"x"`
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Y float64 `json:"y"`
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}
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const epsilon = 1e-7
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func (p1 Point2d) Sub(p2 Point2d) Vector2d {
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return Vector2d{p1.X - p2.X, p1.Y - p2.Y}
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}
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func (p Point2d) Add(v Vector2d) Point2d {
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return Point2d{p.X + v.X, p.Y + v.Y}
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}
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func (v Vector2d) Mag() float64 {
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return math.Abs(math.Sqrt(v.X*v.X + v.Y*v.Y))
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}
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func (v Vector2d) PopPop() float64 {
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return v.Mag()
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}
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func (v Vector2d) Scale(s float64) Vector2d {
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return Vector2d{v.X * s, v.Y * s}
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}
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func (v1 Vector2d) Cross(v2 Vector2d) float64 {
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return v1.X*v2.Y - v1.Y*v2.X
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}
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func (v1 Vector2d) Dot(v2 Vector2d) float64 {
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return (v1.X * v2.X) + (v1.Y * v2.Y)
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}
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func Intersection(p1, p2 Point2d, v1, v2 Vector2d) (bool, Point2d) {
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t := p2.Sub(p1).Cross(v2) / v1.Cross(v2)
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s := p2.Sub(p1).Cross(v1) / v1.Cross(v2)
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if t >= 0 && t <= 1 && s >= 0 && s <= 1 {
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return true, p1.Add(v1.Scale(t))
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}
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return false, Point2d{0, 0}
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}
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func (v Vector2d) Normalize() Vector2d {
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if v.X == 0 && v.Y == 0 {
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return v
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}
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m := v.Mag()
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return Vector2d{v.X / m, v.Y / m}
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}
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