import tkinter as tk
from PIL import ImageTk
import PIL
import math

class EPoint:
  def __init__(self,x,y):
    self.x=x
    self.y=y
  
  def dist(self,a):
    return math.sqrt((self.x-a.x)**2+(self.y-a.y)**2)

class Application(tk.Frame):
  def __init__(self, master=None):
    self.corners=[]
    
    tk.Frame.__init__(self, master)
    self.pack()
    self.createWidgets()

  def createWidgets(self):
    self.hi_there = tk.Button(self)
    self.hi_there["text"] = "Hello World\n(click me)"
    self.hi_there["command"] = self.say_hi
    self.hi_there.pack(side="top")
    
    self.canvas=tk.Canvas(self)
    self.canvas.configure(width=480,height=360,background="#ff4444")
    imgOrig=PIL.Image.open("images/1.jpg")
    self.img=ImageTk.PhotoImage(imgOrig.resize((int(self.canvas['width']),int(self.canvas['height'])),resample=PIL.Image.BILINEAR))
    
    self.canvas.bind('<1>',lambda e: self.addCorner(e.x,e.y))
    self.canvas.create_image(2,2,anchor="nw",image=self.img)
    self.canvas.create_line(30,30,40,40,fill="#00ff00")
    self.canvas.create_line(30,40,40,30,fill="#00ff00")
    
    self.canvas.pack()

    self.QUIT = tk.Button(self, text="QUIT", fg="red", command=root.destroy)
    self.QUIT.pack(side="bottom")

  def say_hi(self):
    print("hi there, everyone!")
    
  def addCorner(self,x,y):
    a=EPoint(x,y)
    for i,c in enumerate(self.corners): # move an improperly placed point
      if a.dist(c)<20:
        self.corners[i]=a
        return
    
    if len(self.corners)<4: # add a new corner
      self.corners.append(a)
      return
    
    index,minDist=0,float('inf') # replace the corner closest to the clicked point
    for i,c in enumerate(self.corners):
      if a.dist(c)<minDist:
        index,minDist=i,a.dist(c)
    
    self.corners[index]=a
    
  def redrawGrid(self):
    pass

root = tk.Tk()
app = Application(master=root)
app.mainloop()