from math import factorial
import sys, pygame, random
pygame.init()

mouse = 0
temp = pygame.display.list_modes(0)
size = width, height = temp[0]
cSpeed = [random.choice([-1, 1]), random.choice([-1, 1]), random.choice([-1, 1])]
black = 0, 0, 0
####red = 255, 0 , 0####
delta = 0.01
lineColor = [random.randrange(1,254), random.randrange(1,254), random.randrange(1,254)]

if len(sys.argv) == 3:
    numCurves = int(sys.argv[1])
    
    if numCurves < 1: numCurves = 1

    numPoints = 3 * numCurves + 1
    nm1 = numPoints - 2
    n = 3

    speed = [random.choice([-1, 1]) * int(sys.argv[2]), random.choice([-1, 1]) * int(sys.argv[2])]
    i = 1
    
    while i < numPoints:
        speed += [random.choice([-1, 1]) * int(sys.argv[2]), random.choice([-1, 1]) * int(sys.argv[2])]
        i += 1
else:
    print("Bounces a bezier curve with a given number of points.")
    print("")
    print("Usage:")
    print("    bez.py numCurves speed")
    print("")
    print("    numCurves   Specifies how many bezier curves to use in the loop")
    print("                -Value must be at least 1")
    print("    speed       Specifies the speed at which bezier bounces around the screen")
    print("                -Value must be an integer greater than 0")
    sys.exit()

p = [0, 0] * numPoints

def midPoints():
    if numCurves > 1:
        p[0] = (p[2] + p[nm1 * 2]) / 2
        p[1] = (p[3] + p[nm1 * 2 + 1]) / 2
        i = 3

        while i < numPoints - 1:
            p[2 * i] = (p[2 * (i - 1)] + p[2 * (i + 1)]) / 2
            p[2 * i + 1] = (p[2 * (i - 1) + 1] + p[2 * (i + 1) + 1]) / 2
            i += 3

        p[2 * i] = p[0]
        p[2 * i + 1] = p[1]


def Bezier():
    c = 0
    
    while c < numCurves:
        """####
        i = 0
        while i < numPoints - 1:
            pygame.draw.line(screen, red, (p[2*i],p[2*i+1]), (p[2*i+2],p[2*i+3]), i+1)
            i+=1
        i = 0
        ####"""
        mu = delta
        pA = [p[6 * c], p[6 * c + 1]]
        
        while mu <= 1.001:
            i = 0
            node = 3 * c
            pB = [0, 0]
        
            while node <= ((3 * c) + 3):
                pB[0] += p[2 * node] * pow(mu, i) * pow(1 - mu, n - i) * (factorial(n) / (factorial(i) * factorial(n - i)))
                pB[1] += p[2 * node + 1] * pow(mu, i) * pow(1 - mu, n - i) * (factorial(n) / (factorial(i) * factorial(n - i)))
                i += 1
                node += 1
            
            pygame.draw.line(screen, lineColor, pA, pB, 1)
            
            pA = pB
            mu += delta

        c += 1

i = 0

while i < numPoints:
    p[2 * i] = random.randrange(1, width - 1)
    p[2 * i + 1] = random.randrange(1, height - 1)
    i += 1

midPoints()

screen = pygame.display.set_mode((0,0),pygame.FULLSCREEN)
pygame.mouse.set_visible(0)

while 1:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            pygame.mouse.set_visible(1)
            sys.exit()
        elif event.type == pygame.MOUSEBUTTONUP:
            pygame.mouse.set_visible(1)
            sys.exit()
        elif event.type == pygame.MOUSEMOTION:
            mouse += 1
            if mouse == 5:
                pygame.mouse.set_visible(1)
                sys.exit()
    
    cColor = random.randrange(0,4)
    if cColor == 1:
        lineColor[0] += cSpeed[0]
        if lineColor[0] < 1 or lineColor[0] > 254: cSpeed[0] = -cSpeed[0]
    if cColor == 2:
        lineColor[1] += cSpeed[1]
        if lineColor[1] < 1 or lineColor[1] > 254: cSpeed[1] = -cSpeed[1]
    if cColor == 3:
        lineColor[2] += cSpeed[2]
        if lineColor[2] < 1 or lineColor[2] > 254: cSpeed[2] = -cSpeed[2]
    
    i = 0
    
    while i < numPoints:
        p[2 * i] += speed[2 * i]
        if p[2 * i] < 1 or p[2 * i] > width - 1: speed[2 * i] = -speed[2 * i]
        p[2 * i + 1] += speed[2 * i + 1]
        if p[2 * i + 1] < 1 or p[2 * i + 1] > height - 1: speed[2 * i + 1] = -speed[2 * i + 1]
        i += 1

    midPoints()
    screen.fill(black)
    Bezier()
    pygame.display.flip()