# xy_line_dist.py

# xy_line_dist.py

# Python program to find the distance between
# a given point and a given line in 2D.

from Tkinter import *
import math

def XY(X,Y,r=50):
    return X-r,Y-r,X+r,Y+r
0
def dist(objA,objB):
    x1,y1 = objA
    x2,y2 = objB
    abs(x1-x2)+abs(y1-y2)
    return math.sqrt((x1-x2)**2+(y1-y2)**2)
0
def linetrack(segment, x2,y2, r=50,line_thickness=4): # x,y is the point
    xmin,ymin,xmax,ymax = segment
    w = abs(xmax-xmin)
    h = abs(ymax-ymin)
    if w>h:
        p = (x2-xmax+w)*1.0/w
    else:
        p = 1-(y2-ymax+h)*1.0/h
    y = ymin-(h*p)
    x = xmin+(w*p)
    x = max(xmin,min(xmax,x))
    y = max(ymax,min(ymin,y))
    canvas.coords(target,XY(x,y,5))
    d = dist((x,y),(x2,y2))

    if d > r + line_thickness:
        canvas.itemconfigure('circle',fill="red")
    else:
        canvas.itemconfigure('circle',fill="green")
0
def Click(event):
    X = event.x
    Y = event.y
    xmin,ymin,xmax,ymax = cv.xy
    cv.onTarget = False
    if xmin<X<xmax and ymin<Y<ymax: cv.onTarget = True
0
def Drag(event):
    X = event.x
    Y = event.y
    if cv.onTarget == True:
        if X<0: X=0
        elif X>L: X=L
        if Y<0: Y=0
        elif Y>H: Y=H
        cv.xy = XY(X,Y)

        linetrack(theline, X,Y)
        canvas.coords(circle,cv.xy)
0
root = Tk()
root.title("XY Line Distancing")

class Cv(): 0
cv = Cv()
cv.onTarget = False

L = 1000
H = 500
theline = [200,360,800,160]
cv.xy = XY(100,100)

canvas = Canvas(root,width=L,height=H,bg ='white')
circle = canvas.create_oval(cv.xy,tags='circle',fill='red')
canvas.create_line(theline,width=3,fill='gray')
target = canvas.create_oval(XY(L/2,H/2,5),fill='black')

canvas.bind('<Button-1>',Click)
canvas.bind('<B1-Motion>',Drag)

canvas.focus_set()
canvas.pack(padx=10,pady=10)

root.mainloop()
#