Making the rays travel faster

Question

So I started a new project where I am tying to imitate this. It is a pseudo 3d world where a ray in cast in a 2d world and the farther away the ray travels, the smaller the walls, giving the illusion of 3d. I stared by writing rays. The way I thought of doing this is:

Initialize a whole load of rays going from player's angle - player's FOV/2 to player's angle + player's FOV/2. This is basically the player field of view.
Shoot the rays in the specified direction. However, my problem is that that rays are too slow and I cant think of anything to make it go faster.

Here is the code:

import pygame
from math import sin, cos, tan, radians
pygame.init()

SW = 1200
SH = 600
WIN = pygame.display
D = WIN.set_mode((SW, SH))

class Ray:
    def __init__(self, x, y, theta):
        self.x = x
        self.y = y
        self.theta = theta

    # draw only for debugging 
    def draw(self):
        pygame.draw.circle(D, (255, 255, 0), (int(self.x), int(self.y)), 1)

class Player:
    def __init__(self, x, y):
        self.fov = 1.5
        self.x = x
        self.y = y
        self.theta = 0

player = Player(600, 300)

class Sim:
    def __init__(self):
        self.rays = []
        #lower end is 
        lowerEnd = player.theta - player.fov/2
        previous = 0
        # fov is 1.5 rads(90 degrees), so
        # i want there to be 900 rays
        # in 90 degrees so that every pixel
        # is covered (90/0.1) becasue rays
        # seem to diverge as they get farther
        # away
        while len(self.rays) < 900:
            previous += radians(0.1)# 0.1 in radians
            self.rays.append(Ray(player.x, player.y, lowerEnd + previous))

sim = Sim()
            
while True:
    #D.fill(0)
    keys = pygame.key.get_pressed()
    events = pygame.event.get()
    for event in events:
        if event.type == pygame.QUIT:
            pygame.quit()

    #print(self.rays[0].x, self.rays[0].y)
    for ray in sim.rays:
        ray.x += cos(ray.theta) 
        ray.y -= sin(ray.theta) 
        ray.draw()
        
    pygame.display.flip()

Running the code, you will be able to see that that all the pixels are covered, but it almost takes 2 seconds for the rays to get from the centre to the edge. I could force the rays to travel faster by skipping pixels, but that may bring unwanted problems later.

for ray in self.rays:
    ray.x += cos(ray.theta) * 20
    ray.y -= sin(ray.theta) * 20

I suspect that it might be faster when the rays are not drawn, but I cant think of a way to test this because printing the position values would also make it slow. Thanks for any help.

Making the rays travel faster

0 Answers