112 lines
1.7 KiB
Go
112 lines
1.7 KiB
Go
package gg
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import (
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//"github.com/hajimehoshi/ebiten/v2"
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"math"
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)
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var (
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ZV = V2(0)
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)
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type Vector struct {
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X, Y Float
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}
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func (v Vector) XY() (Float, Float) {
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return v.X, v.Y
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}
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type Point = Vector
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//type Vertex = Vector
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type Vectors []Vector
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type Points []Point
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func V(x, y Float) Vector {
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return Vector{x, y}
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}
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func V2(v Float) Vector {
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return V(v, v)
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}
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func (v Vector) Div(o Vector) Vector {
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return V(
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v.X / o.X,
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v.Y / o.Y,
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)
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}
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func (v Vector) Scale(o Vector) Vector {
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return V(
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v.X * o.X,
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v.Y * o.Y,
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)
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}
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func (v Vector) Eq(o Vector) bool {
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return v.X == o.X && v.Y == o.Y
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}
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// Returns the vector with the matrix applied
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func (v Vector) Apply(m Matrix) Vector {
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x, y := m.Apply(v.X, v.Y)
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return Vector{x, y}
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}
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// Adds the vector to other one returning the result.
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func (v Vector) Add(a ...Vector) Vector {
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for _, r := range a {
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v.X += r.X
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v.Y += r.Y
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}
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return v
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}
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// Returns the subtraction of all the vectors from the current one.
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func (v Vector) Sub(s ...Vector) Vector {
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for _, r := range s {
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v.X -= r.X
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v.Y -= r.Y
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}
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return v
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}
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// Returns the negative version of the vector.
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func (v Vector) Neg() Vector {
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return Vector{
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-v.X,
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-v.Y,
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}
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}
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// Returns the vector rotated by "a" angle in radians.
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func (v Vector) Rotate(a Float) Vector {
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m := Matrix{}
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m.Rotate(a)
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return v.Apply(m)
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}
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// Returns the normalized vector.
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func (v Vector) Norm() Vector {
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l := math.Sqrt(v.X*v.X + v.Y*v.Y)
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return V(v.X / l, v.Y / l)
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}
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func (pts Points) Contained(c PointContainer) Points {
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ret := make([]Point, 0, len(pts))
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for _, pt := range pts {
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if c.ContainsPoint(pt) {
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ret = append(ret, pt)
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}
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}
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return ret
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}
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func (pts Points) Len() int {
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return len(pts)
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}
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