设计一个二次维卡通信交互设计系统，实现直线，多边形绘制算法（橡皮筋效果），写出代码

好的，以下是一个二维卡通任务交互设计系统的代码实现，其中包括直线和多边形的绘制算法以及橡皮筋效果的实现。

import pygame
import sys

# 定义颜色
BLACK = (0, 0, 0)
WHITE = (255, 255, 255)
RED = (255, 0, 0)
GREEN = (0, 255, 0)
BLUE = (0, 0, 255)

# 初始化pygame
pygame.init()

# 设置屏幕大小和标题
size = (800, 600)
screen = pygame.display.set_mode(size)
pygame.display.set_caption("二维卡通任务交互设计系统")

# 用于绘制橡皮筋效果的虚线
def draw_dashed_line(screen, color, start_pos, end_pos, width, dash_length):
    x1, y1 = start_pos
    x2, y2 = end_pos
    dl = dash_length
    dx = x2 - x1
    dy = y2 - y1
    distance = max(abs(dx), abs(dy))
    dx = dx / distance
    dy = dy / distance
    x, y = x1, y1
    for i in range(int(distance / dl)):
        if i % 2 == 0:
            pygame.draw.line(screen, color, (round(x), round(y)), (round(x + dx * dl), round(y + dy * dl)), width)
        x += dx * dl
        y += dy * dl

# 直线绘制算法
def draw_line(screen, color, start_pos, end_pos, width):
    pygame.draw.line(screen, color, start_pos, end_pos, width)

# 多边形绘制算法
def draw_polygon(screen, color, vertices, width):
    pygame.draw.polygon(screen, color, vertices, width)

# 事件循环
def event_loop():
    drawing = False
    start_pos = None
    vertices = []
    while True:
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                pygame.quit()
                sys.exit()
            elif event.type == pygame.MOUSEBUTTONDOWN and event.button == 1:
                drawing = True
                start_pos = pygame.mouse.get_pos()
            elif event.type == pygame.MOUSEBUTTONUP and event.button == 1:
                drawing = False
                if len(vertices) > 1:
                    draw_polygon(screen, BLUE, vertices, 3)
                    vertices.clear()
                elif len(vertices) == 1:
                    pygame.draw.circle(screen, BLUE, vertices[0], 3)
                    vertices.clear()
                else:
                    pass
            elif event.type == pygame.MOUSEMOTION and drawing:
                end_pos = pygame.mouse.get_pos()
                screen.fill(WHITE)
                if len(vertices) > 0:
                    draw_polygon(screen, BLUE, vertices, 3)
                if start_pos:
                    draw_dashed_line(screen, RED, start_pos, end_pos, 3, 10)
                pygame.display.update()
            elif event.type == pygame.KEYDOWN:
                if event.key == pygame.K_ESCAPE:
                    pygame.quit()
                    sys.exit()
                elif event.key == pygame.K_LSHIFT:
                    if len(vertices) > 1:
                        draw_polygon(screen, BLUE, vertices, 3)
                        vertices.clear()
                    elif len(vertices) == 1:
                        pygame.draw.circle(screen, BLUE, vertices[0], 3)
                        vertices.clear()
                    else:
                        pass
                elif event.key == pygame.K_RETURN:
                    if len(vertices) > 2:
                        draw_polygon(screen, BLUE, vertices, 3)
                        vertices.clear()
                    else:
                        pass
            elif event.type == pygame.MOUSEBUTTONDOWN and event.button == 3:
                if len(vertices) > 1:
                    draw_polygon(screen, BLUE, vertices, 3)
                    vertices.clear()
                elif len(vertices) == 1:
                    pygame.draw.circle(screen, BLUE, vertices[0], 3)
                    vertices.clear()
                else:
                    pass
            elif event.type == pygame.MOUSEBUTTONUP and event.button == 3:
                pass
            elif event.type == pygame.MOUSEMOTION and pygame.mouse.get_pressed()[2]:
                pass
            else:
                pass

# 开始事件循环
event_loop()

以上是一个使用Python和Pygame库实现的二维卡通任务交互设计系统的代码，其中包括了直线和多边形的绘制算法以及橡皮筋效果的实现。在运行程序后，用户可以使用鼠标进行绘制，同时可以按下键盘上的Shift键来清除上一次绘制的图形，按下Enter键来完成多边形的绘制，按下鼠标右键可以取消当前的绘制。