'''
Show a ball bouncing off the sides of the window.
'''

from graphics import *
import time, math

HEIGHT=400
WIDTH=400
SIDE=200
VSIDE=140		# visible length of side
AMPLITUDE=20
CORNERS=[]
SHOWCORNERS=False
CSIDE = 60		# corner side


def animate(win, hline1, hline2, vline1, vline2, rate):
    ''' Animate a shape moving in jumps (dx, dy), bouncing when
    its center reaches the low and high x and y coordinates.
    '''
    global SHOWCORNERS
    oldsin=0		# for horizontal lines, moving vertically
    oldcos=1		# for vertical lines, moving horizontally
    vsum=0
    delay = .05
    for t in range(1, 6000):
        newsin = math.sin(rate*t)
        newcos = math.cos(rate*t)
        vchange= AMPLITUDE*(newcos - oldcos)
        hchange= AMPLITUDE*(newsin - oldsin)
        hline1.move(0, vchange)
        hline2.move(0, vchange)
        vline1.move(hchange, 0)
        vline2.move(hchange, 0)
        oldsin = newsin
        oldcos = newcos
        #vsum += vchange
        #if t % 20 == 0: print('vsum={}'.format(vsum))
        p = win.checkMouse()
        if p != None:
             SHOWCORNERS = not SHOWCORNERS
             corners(SHOWCORNERS, win)
        time.sleep(delay)

def getRandomPoint(xLow, xHigh, yLow, yHigh):
    '''Return a random Point with coordinates in the range specified.'''
    x = random.randrange(xLow, xHigh+1)
    y = random.randrange(yLow, yHigh+1)
    return Point(x, y)

def makesquare(x,y, r):
    #x = center.getX()
    #y = center.getY()
    sqr = Rectangle(Point(x-r, y-r), Point(x+r, y+r))
    sqr.setFill("green")
    return sqr

def corners(makeVisible, win):
    if makeVisible:
        for s in CORNERS: s.draw(win)
    else:
        for s in CORNERS: s.undraw()

def main(rate):
    '''create lines and start animation'''
    global CORNERS
    win = GraphWin('Illusion', WIDTH, HEIGHT)
    midX = WIDTH/2
    midY = HEIGHT/2
    hs = SIDE/2		# half side
    hv = VSIDE/2	# half visible side

    DEFAULT_CONFIG["width"] = 3

    hlineupper = Line(Point(midX - hv,midY-hs), Point(midX + hv, midY -hs))
    hlinelower = Line(Point(midX - hv,midY+hs), Point(midX + hv, midY +hs))

    vlineleft  = Line(Point(midX - hs,midY-hv), Point(midX - hs, midY+hv))
    vlineright = Line(Point(midX + hs,midY-hv), Point(midX + hs, midY+hv))

    hlineupper.move(0,AMPLITUDE)
    hlinelower.move(0,AMPLITUDE)

    hlineupper.draw(win)
    hlinelower.draw(win)
    vlineleft.draw(win)
    vlineright.draw(win)

    CORNERS.append(makesquare(midX-hs, midY-hs, CSIDE/2))
    CORNERS.append(makesquare(midX+hs, midY-hs, CSIDE/2))
    CORNERS.append(makesquare(midX+hs, midY+hs, CSIDE/2))
    CORNERS.append(makesquare(midX-hs, midY+hs, CSIDE/2))


    animate(win, hlineupper, hlinelower, vlineleft, vlineright,rate)
    #pld win.close()


main(0.16)