#----------------------------------------------------------------------
# Program to illustrate hierarchical image decomposition.
# 
# Copyright (C) October 30, 2017 -- Dr. William T. Verts
#----------------------------------------------------------------------

#----------------------------------------------------------------------
# Functions to plot centered circles and rectangles with both interior
# and exterior colors.
#----------------------------------------------------------------------
    
def addCircle (Canvas,Xc,Yc,R,InColor=white,OutColor=black):
    addOvalFilled(Canvas,Xc-R,Yc-R,2*R,2*R,InColor)
    addOval      (Canvas,Xc-R,Yc-R,2*R,2*R,OutColor)
    return
    
def addRectangle (Canvas,Xleft,Ytop,Width,Height,InColor=white,OutColor=black):
    addRectFilled(Canvas,Xleft,Ytop,Width,Height,InColor)
    addRect      (Canvas,Xleft,Ytop,Width,Height,OutColor)
    return

#----------------------------------------------------------------------
# Drawing a car the "hard way" by explicitly calling the rectangle or
# circle functions for every piece of geometry in the image.  What
# is necessary when moving a wheel or a window, or changing the color
# or size of a wheel or window?  (Short answer: you have to chase down
# every related function call and adjust the numbers appropriately.
# Possible, but very labor intensive, and easy to make errors.)
#----------------------------------------------------------------------
    
def addCar1 (Canvas,X,Y,NewColor=green):
    addRectangle(Canvas,X-20,Y-40,100,30,NewColor)      # Body
    addRectangle(Canvas,X+10,Y-70, 60,30,NewColor)      # Cab
    addRectangle(Canvas,X+20,Y-65, 20,20,blue)          # Left  Window
    addRectangle(Canvas,X+23,Y-62, 14,14,cyan)          # Left  Pane
    addRectangle(Canvas,X+45,Y-65, 20,20,blue)          # Right Window
    addRectangle(Canvas,X+48,Y-62, 14,14,cyan)          # Right Pane
    addCircle   (Canvas,X   ,Y-10, 10,black)            # Left  Tire
    addCircle   (Canvas,X   ,Y-10,  7,gray)             # Left  Hubcap
    addCircle   (Canvas,X+60,Y-10, 10,black)            # Right Tire
    addCircle   (Canvas,X+60,Y-10,  7,gray)             # Right Hubcap
    return
    
#----------------------------------------------------------------------
# Draw a car the sophisticated way.  In this case, functions Wheel and
# Window are ***local*** to the addCar2 function (not visible outside).
# In both Wheel and Window, their own X and Y are local, but Canvas is
# global to the inner functions (but local to addCar2).
#
# Changing a wheel's size or color is easy, as well as its position.
# This approach is much more complicated in terms of the code that must
# be written, but the complexity buys a certain simplicity in editing
# the graphical objects.
#----------------------------------------------------------------------

def addCar2 (Canvas,X,Y,NewColor=green):

    def Wheel(X,Y):
        addCircle(Canvas,X,Y,10,black)                  # Tire
        addCircle(Canvas,X,Y, 7,gray)                   # Hubcap
        return
        
    def Window(X,Y):
        addRectangle(Canvas,X,Y,20,20,blue)             # Outer Frame
        addRectangle(Canvas,X+3,Y+3,14,14,cyan)         # Inner Pane
        return
        
    addRectangle(Canvas,X-20,Y-40,100,30,NewColor)      # Body
    addRectangle(Canvas,X+10,Y-70, 60,30,NewColor)      # Cab
    Window(X+20,Y-65)                                   # Left  Window
    Window(X+45,Y-65)                                   # Right Window
    Wheel (X   ,Y-10)                                   # Left  Wheel
    Wheel (X+60,Y-10)                                   # Right Wheel
    return                    
    
#----------------------------------------------------------------------
# Plot the two cars
#----------------------------------------------------------------------

def Main():
    Canvas = makeEmptyPicture(600,400)
    addCar1 (Canvas,100,200)
    addCar2 (Canvas,300,200)
    show(Canvas)
    return