gopatterns/pkg/util/point.go

package util

import (
	"fmt"
	"math"
)

// Point represents a 2 dimensional Point
type Point struct {
	X, Y float64
}

// Abs returns a Point with the absolute value of X and Y.
// Should not be confused with Magnitude due to its notation ||A||.
func (p Point) Abs() Point {
	return Point{
		math.Abs(p.X),
		math.Abs(p.Y),
	}
}

// Add returns a Point with the value of Point p plus Point q.
func (p Point) Add(q Point) Point {
	return Point{
		p.X + q.X,
		p.Y + q.Y,
	}
}

// Subtract returns a Point with the value of Point p minus Point q.
func (p Point) Subtract(q Point) Point {
	return Point{
		X: p.X - q.X,
		Y: p.Y - q.Y,
	}
}

// Multiply returns a Point with the value of Point p multiplied by f.
func (p Point) Multiply(f float64) Point {
	return Point{X: p.X * f, Y: p.Y * f}
}

// Divide returns a Point with the value of Point p divided by f.
func (p Point) Divide(f float64) Point {
	return Point{X: p.X / f, Y: p.Y / f}
}

// Round returns a Point with the rounded value of Point p.
func (p Point) Round() Point {
	return Point{X: math.Round(p.X), Y: math.Round(p.Y)}
}

// Floor returns a Point with the floored value of Point p.
func (p Point) Floor() Point {
	return Point{X: math.Floor(p.X), Y: math.Floor(p.Y)}
}

// Ceil returns a Point with the rounded up value of Point p.
func (p Point) Ceil() Point {
	return Point{X: math.Ceil(p.X), Y: math.Ceil(p.Y)}
}

// Scale returns a Point with the values of Point p scaled up by the values of Point q.
func (p Point) Scale(q Point) Point {
	return Point{
		X: p.X * q.X,
		Y: p.Y * q.Y,
	}
}

// ScaleDown returns a Point with the values of Point p scaled down by the values of Point q.
func (p Point) ScaleDown(q Point) Point {
	return Point{
		X: p.X / q.X,
		Y: p.Y / q.Y,
	}
}

// Min returns a Point with the smallest values of X and Y for Point p and q.
func (p Point) Min(q Point) Point {
	return Point{
		X: math.Min(p.X, q.X),
		Y: math.Min(p.Y, q.Y),
	}
}

// Max returns a Point with the largest values of X and Y for Point p and q.
func (p Point) Max(q Point) Point {
	return Point{
		X: math.Max(p.X, q.X),
		Y: math.Max(p.Y, q.Y),
	}
}

// String returns a string with comma separated values of Point p.
func (p Point) String() string {
	return fmt.Sprintf("%v,%v", p.X, p.Y)
}

// Magnitude returns a float64 with the length/magnitude of Point p.
func (p Point) Magnitude() float64 {
	return math.Sqrt(math.Pow(p.X, 2) + math.Pow(p.Y, 2))
}

func (p Point) Unit() Point {
	return p.Divide(p.Magnitude())
}

func (p Point) Rotate(a float64) Point {
	return Point{
		X: math.Cos(a)*p.X - math.Sin(a)*p.Y,
		Y: math.Sin(a)*p.X + math.Cos(a)*p.Y,
	}
}

func (p Point) Distance(q Point) float64 {
	return p.Subtract(q).Magnitude()
}

func (p Point) Above(l float64) Point {
	return p.Subtract(Point{Y: l})
}

func (p Point) Below(l float64) Point {
	return p.Add(Point{Y: l})
}

func (p Point) Right(l float64) Point {
	return p.Add(Point{X: l})
}

func (p Point) Left(l float64) Point {
	return p.Subtract(Point{X: l})
}