package main

import (
	"image/color"
	"math"
)

type Function interface {
	Func(float64) uint16
}

type ColorArray struct {
	img []color.Color
}

func NewColorArray() *ColorArray {
	ca := &ColorArray{make([]color.Color, screenWidth*screenHeight)}
	ca.Clear(color.Black)
	return ca
}

func (ca *ColorArray) Clear(c color.Color) {
	for i := 0; i < len(ca.img); i++ {
		ca.img[i] = c
	}
}

func (ca *ColorArray) At(x, y int) color.Color {
	position := x + (y * screenHeight)
	if position > len(ca.img) || position < 0 {
		return color.Black
	} else {
		return ca.img[position]
	}
}

func (ca *ColorArray) Set(x, y int, c color.Color) {
	position := x + (y * screenHeight)
	if position < len(ca.img) && position >= 0 {
		ca.img[position] = c
	}
}

type Position struct {
	X int
	Y int
}

func (p *Position) Length() float64 {
	return math.Sqrt(float64(p.X)*float64(p.X) + float64(p.Y)*float64(p.Y))
}

func (p *Position) Dist(P *Position) float64 {
	return (&Position{p.X - P.X, p.Y - P.Y}).Length()
}