utils.go

package main

func Clamp(v, a, b int) int {
	if v < a {
		return a
	}
	if v > b {
		return b
	}
	return v
}

type Vector2d struct {
	x, y int
}

func (v *Vector2d) Negate() *Vector2d {
	return &Vector2d{-v.x, -v.y}
}

var V = struct {
	Zero     Vector2d
	Identity Vector2d
	Left     Vector2d
	Right    Vector2d
	Up       Vector2d
	Down     Vector2d
	Equal    func(Vector2d, Vector2d) bool
	Negate   func(Vector2d) Vector2d
	Sum      func(Vector2d, Vector2d) Vector2d
	Multiply func(Vector2d, int) Vector2d
	Divide   func(Vector2d, int) Vector2d
}{
	Zero:     Vector2d{0, 0},
	Identity: Vector2d{1, 1},
	Left:     Vector2d{-1, 0},
	Right:    Vector2d{1, 0},
	Up:       Vector2d{0, -1},
	Down:     Vector2d{0, 1},
	Equal: func(a Vector2d, b Vector2d) bool {
        return a.x == b.x && a.y == b.y
	},
	Negate: func(a Vector2d) Vector2d {
		return Vector2d{
			-a.x,
			-a.y,
		}
	},
	Sum: func(a Vector2d, b Vector2d) Vector2d {
		return Vector2d{
			a.x + b.x,
			a.y + b.y,
		}
	},
	Multiply: func(a Vector2d, b int) Vector2d {
		return Vector2d{
			a.x * b,
			a.y * b,
		}
	},
	Divide: func(a Vector2d, b int) Vector2d {
		return Vector2d{
			a.x / b,
			a.y / b,
		}
	},
}