py笔记25：生成动态心形

# -*-coding:utf-8-*-
import random
from math import sin, cos, pi, log
from tkinter import *

CANVAS_WIDTH = 640  # 画布的宽度
CANVAS_HEIGHT = 480  # 画布的高度
CANVAS_CENTER_X = CANVAS_WIDTH / 2  # 画布中心的X轴坐标
CANVAS_CENTER_Y = CANVAS_HEIGHT / 2  # 画布中心的y轴坐标
IMAGE_ENLARGE = 12  # 放大比例
HEART_COLOR = "#ff2121"  # 心的颜色


def heart_function(t, shrink_ratio: float = IMAGE_ENLARGE):
    """
    爱心函数生成器
    :param t: 参数
    :param shrink_ratio: 放大比例
    :return: 坐标
    心形函数表达式：r=a(1－sinθ)。又叫笛卡尔心形函数表达式;是个心形曲线
    """
    # 基础函数
    x = 16 * (sin(t) ** 3)
    y = -(13 * cos(t) - 5 * cos(2 * t) - 2 * cos(3 * t) - cos(4 * t))

    # 放大
    x *= shrink_ratio
    y *= shrink_ratio

    # 移动到画布中心
    x += CANVAS_CENTER_X
    y += CANVAS_CENTER_Y

    return int(x), int(y)


def scatter_inside(x, y, beta=0.15):
    """
    随机内部扩散
    :param x: 原x
    :param y: 原y
    :param beta: 强度
    :return: 新坐标
    """
    ratio_x = -beta * log(random.random())
    ratio_y = -beta * log(random.random())
    # 位移
    dx = ratio_x * (x - CANVAS_CENTER_X)
    dy = ratio_y * (y - CANVAS_CENTER_Y)

    return x - dx, y - dy


def shrink(x, y, ratio):
    """
    抖动
    :param x: 原x
    :param y: 原y
    :param ratio:比例
    :return: 新坐标
    """
    force = -1 / (((x - CANVAS_CENTER_X) ** 2 + (y - CANVAS_CENTER_Y) ** 2) ** 0.6)  # ?
    dx = ratio * force * (x - CANVAS_CENTER_X)
    dy = ratio * force * (y - CANVAS_CENTER_Y)
    return x - dx, y - dy


def curve(p):
    """
    自定义曲线函数，调整跳动周期
    :param p: 参数
    :return: 正弦
    """
    # 可以尝试其他动态函数
    # return 2*(2*sin(4*p))/(2*pi)
    return 2 * sin(4 * p) / pi


class Heart:
    """
    爱心类
    """

    def __init__(self, generate_frame=20):
        self.generate_frame = generate_frame
        self._points = set()  # 原始爱心坐标集合
        self._edge_diffusion_points = set()  # 边缘扩散效果点坐标集合
        self._center_diffusion_points = set()  # 中心扩散效果点坐标集合
        self.all_points = dict()  # 每帧动态点坐标

        self.build(2000)
        self.random_halo = 1000
        for frame in range(generate_frame):
            self.calc(frame)

    def build(self, number):
        # 爱心
        for _ in range(number):
            t = random.uniform(0, 2 * pi)  # 随机不到的地方造成爱心有缺口
            x, y = heart_function(t)
            self._points.add((x, y))

        point_list = list(self._points)
        # 爱心边缘扩散
        for _x, _y in point_list:
            for _ in range(3):
                x, y = scatter_inside(_x, _y, 0.05)
                self._edge_diffusion_points.add((x, y))

        # 爱心内再次扩散
        for _ in range(4000):
            x, y = random.choice(point_list)
            x, y = scatter_inside(x, y, 0.17)
            self._center_diffusion_points.add((x, y))

    @staticmethod
    def calc_position(x, y, ratio):
        # 调整缩放比例
        force = 1 / (((x - CANVAS_CENTER_X) ** 2 + (y - CANVAS_CENTER_Y) ** 2) ** 0.52)  # 魔法参数
        dx = ratio * force * (x - CANVAS_CENTER_X) + random.randint(-1, 1)
        dy = ratio * force * (y - CANVAS_CENTER_Y) + random.randint(-1, 1)
        return x - dx, y - dy

    def calc(self, generate_frame):
        val = generate_frame / 10 * pi
        ratio = 10 * curve(val)  # 圆滑的周期的缩放比例
        halo_radius = int(4 + 6 * (1 + curve(val)))
        halo_number = int(3000 + 4000 * abs(curve(val)))

        all_points = []

        # 光环
        heart_halo_point = set()  # 光环的点坐标集合
        for _ in range(halo_number):
            t = random.uniform(0, 2 * pi)
            x, y = heart_function(t, 11.6)  # 魔法参数
            x, y = shrink(x, y, halo_radius)
            if (x, y) not in heart_halo_point:
                # 处理新点
                heart_halo_point.add((x, y))
                x += random.randint(-14, 14)
                y += random.randint(-14, 14)
                size = random.choice((1, 2, 2))
                all_points.append((x, y, size))

        # 轮廓
        for x, y in self._points:
            x, y = self.calc_position(x, y, ratio)
            size = random.randint(1, 3)
            all_points.append((x, y, size))

        # 内容
        for x, y in self._edge_diffusion_points:
            x, y = self.calc_position(x, y, size)
            size = random.randint(1, 2)
            all_points.append((x, y, size))

        for x, y in self._center_diffusion_points:
            x, y = self.calc_position(x, y, size)
            size = random.randint(1, 2)
            all_points.append((x, y, size))

        self.all_points[generate_frame] = all_points

    def render(self, render_canvas, render_frame):
        for x, y, size in self.all_points[render_frame%self.generate_frame]:
            render_canvas.create_rectangle(x, y, x + size, y + size, width = 0, fill = HEART_COLOR)


# 绘画
def draw(main: Tk, render_canvas: Canvas, render_heart: Heart, render_frame=0):
    render_canvas.delete("all")
    render_heart.render(render_canvas, render_frame)
    main.after(160, draw, main, render_canvas, render_heart, render_frame + 1)


if __name__ =="__main__":
    root = Tk()  # 创建一个TK
    canvas = Canvas(root,bg="black",height=CANVAS_HEIGHT,width=CANVAS_WIDTH)
    canvas.pack()
    heart = Heart()  # 心
    draw(root,canvas, heart)  # 开始画画
    root.mainloop()