009. connect the dots

import helper

firststr=helper.readFile(".\\Data\\009\\first.txt")
secondstr=helper.readFile(".\\Data\\009\\second.txt")

firstlist=[int(x.strip()) for x in firststr.split(',')]
secondlist=[int(x.strip()) for x in secondstr.split(',')]

import turtle
import tkinter

tk=tkinter.Tk()
tk.title("Challenge009")
canvas=tkinter.Canvas(tk, width=500, height=500)
canvas.pack(expand=1,fill="both")
pen=turtle.RawPen(canvas)
pen.hideturtle()

def drawPoints(plist):
    points=list(map(lambda x: (x[0]-250, 250-x[1]), zip(plist[::2], plist[1::2])))
    pen.up()
    pen.goto(points[0])
    pen.down()
    for x,y in points:
        pen.goto(x,y)

drawPoints(firstlist)
drawPoints(secondlist)
tk.mainloop()

function GetPoints {
    param (
        [string[]]
        $strs
    )

    [System.Collections.Generic.List[System.Drawing.Point]]$list=New-Object System.Collections.Generic.List[System.Drawing.Point]

    for ($i=0; $i -lt $strs.Length; $i+=2) {
        $x=[System.Convert]::ToInt32($strs[$i].Trim())
        $y=[System.Convert]::ToInt32($strs[$i+1].Trim())
        [System.Drawing.Point]$point=New-Object System.Drawing.Point $x,$y
        $list.Add($point)
    }

    return $list
}

$firststr=(Get-Content ".\\Data\\009\\first.txt" -Raw).Replace("`r`n","").Split(',',[System.StringSplitOptions]::RemoveEmptyEntries)
$secondstr=(Get-Content ".\\Data\\009\\second.txt" -Raw).Replace("`r`n","").Split(',',[System.StringSplitOptions]::RemoveEmptyEntries)

[System.Collections.Generic.List[System.Drawing.Point]]$firstline=GetPoints -strs $firststr
[System.Collections.Generic.List[System.Drawing.Point]]$secondline=GetPoints -strs $secondstr

[void][System.Reflection.Assembly]::LoadWithPartialName("System.Drawing")
$img=New-Object System.Drawing.Bitmap 500,500
$graphics=[System.Drawing.Graphics]::FromImage($img)
$graphics.Clear([System.Drawing.Color]::White)
$pen=[System.Drawing.Pens]::Black

$graphics.DrawLines($pen, $firstline.ToArray())
$graphics.DrawLines($pen, $secondline.ToArray())

. .\Code\PowerShell\helper.ps1
Show-Image -Title "Challenge009" -Image $img

$img.Dispose()

package main

import(
	"image"
	"image/color"
	"image/draw"
	"strings"
	"strconv"
)

func (c *Challenge) Challenge009() {
	firststr := ReadFile(".\\Data\\009\\first.txt")
	secondstr := ReadFile(".\\Data\\009\\second.txt")

	bg := image.White
	pen := color.Black

	rgba :=  image.NewRGBA(image.Rect(0, 0, 500, 500))
	draw.Draw(rgba, rgba.Bounds(), bg, image.ZP, draw.Over)

	firstline := getPoints(firststr)
	secondline := getPoints(secondstr)

	drawPoints(rgba, pen, firstline)
	drawPoints(rgba, pen, secondline)

	pngfile := ".\\Data\\009\\go.png"
	SaveImage(pngfile, rgba, "png")

	ShowImage(pngfile)
}

func getPoints(str string) []image.Point {
	var points []image.Point
	strlist := strings.Split(str, ",")
	for i := 0; i < len(strlist); i+=2 {
		x,_ := strconv.Atoi(strings.Trim(strlist[i], "\r\n "))
		y,_ := strconv.Atoi(strings.Trim(strlist[i+1], "\r\n "))
		points = append(points, image.Pt(x,y))
	}

	return points
}

func drawPoints(rgba *image.RGBA, color color.Color, points []image.Point) {
	for i := 0; i < len(points)-1; i++ {
		drawLine(points[i].X, points[i].Y, points[i+1].X, points[i+1].Y, rgba, color)
	}
}

func drawLine(x0, y0, x1, y1 int, rgba *image.RGBA, color color.Color) {
	dx := abs(x1 - x0)
	dy := abs(y1 - y0)

	sx, sy := 1, 1
	if x0>=x1 {
		sx = -1
	}
	if y0>=y1 {
		sy = -1
	}
	err := dx-dy

	for {
		rgba.Set(x0, y0, color)
		if x0 == x1 && y0 == y1 {
			return
		}
		e2 := err * 2
		if e2 > -dy {
			err -= dy
			x0 += sx
		}
		if e2 < dx {
			err += dx
			y0 += sy
		}
	}
}

func abs(x int) int {
	if x>=0 {
		return x
	} else {
		return -x
	}
}