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43 lines
1.4 KiB
43 lines
1.4 KiB
import pygame as pg
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import random
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WHITE = (255,)*3
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def snap(x, scale):
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return int(x//scale)*scale
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class Starfield:
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def __init__(self,
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screen,
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inv_density=10,
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grid_step=31,
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paralax = 2,
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star_color=WHITE,
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star_size = 1):
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self.rng = random.Random()
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self.screen = screen
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self.inv_density = inv_density
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self.paralax = paralax
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self.grid_step = grid_step
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self.star_color = star_color
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self.star_size = star_size
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def draw(self, screen, map_pos, map_period):
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sky_pos = pg.math.Vector2((map_pos.x, map_pos.y))/self.paralax
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xstart = snap(sky_pos.x, self.grid_step)
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ystart = snap(sky_pos.y, self.grid_step)
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srect = screen.get_rect()
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xstop = xstart + srect.width
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ystop = ystart + srect.height
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for x in range(xstart, xstop, self.grid_step):
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for y in range(ystart, ystop, self.grid_step):
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self.rng.seed(hash((
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x % map_period[0], y % map_period[1])))
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if self.rng.randint(0, self.inv_density) == 0:
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xoff = self.rng.randint(0, self.grid_step)
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yoff = self.rng.randint(0, self.grid_step)
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cx = x + xoff - sky_pos.x
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cy = y + yoff - sky_pos.y
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pg.draw.circle(screen, self.star_color, (cx,cy), self.star_size)
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