raytrace

import pygame
import math

# 屏幕尺寸
WIDTH, HEIGHT = 800, 600

# 初始化 Pygame
pygame.init()
screen = pygame.display.set_mode((WIDTH, HEIGHT))

# 定义一个球体类
class Sphere:
    def __init__(self, center, radius, color):
        self.center = center
        self.radius = radius
        self.color = color

    def intersect(self, ray_origin, ray_direction):
        oc = ray_origin - self.center
        a = ray_direction.dot(ray_direction)
        b = 2.0 * oc.dot(ray_direction)
        c = oc.dot(oc) - self.radius * self.radius
        discriminant = b*b - 4*a*c
        if discriminant < 0:
            return None
        else:
            t = (-b - math.sqrt(discriminant)) / (2.0 * a)
            if t > 0:
                return t
        return None

# 创建一个球体
sphere = Sphere((400, 300), 100, (255, 0, 0))

# 主渲染循环
running = True
while running:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            running = False

    screen.fill((0, 0, 0))

    # 简单的光线追踪
    for x in range(WIDTH):
        for y in range(HEIGHT):
            # 计算光线方向
            ray_direction = pygame.math.Vector2(x - WIDTH / 2, y - HEIGHT / 2).normalize()
            ray_origin = pygame.math.Vector2(WIDTH / 2, HEIGHT / 2)

            t = sphere.intersect(ray_origin, ray_direction)
            if t is not None:
                color = sphere.color
            else:
                color = (0, 0, 0)

            screen.set_at((x, y), color)

    pygame.display.flip()

pygame.quit()