Games are very often highly interactive with even some text adventures operating in real time. I thought it would be fun to go in the opposite direction and create a game with minimal interaction. So I settled on an outer space theme and had a text experiment of a probe travelling through the emptiness of space.
The next step was to create a graphical display and, of course, stars were the first order of business! I looked around at a few star field examples and ended up coding one for myself. Straightforward 2D scrolling is all I want - needs to be calm for the display. The class is nice and simple whilst the demo shows it off fairly well.
Exercise for the reader - can you make a layered demo? I'll share the code on a follow up post. Happy stargazing!
import random
import pygame
import sys
from pygame.locals import *
class starfield(object):
def __init__(self, pos , size, max, speed):
self.stars = []
self.pos = pos
self.size = size
self.max = max
self.speed = speed
self.box = True
self.color = (255,255,255)
self.bordercolor = Color(255,255,255)
self.backgroundcolor = Color(0,0,0)
for loop in range(0, max):
star = [random.randrange(0, size[0] - 1),
random.randrange(0, size[1] - 1)]
self.stars.append(star);
def draw(self, screen):
if self.box:
pygame.draw.rect(screen, self.backgroundcolor, Rect(self.pos[0], self.pos[1], self.size[0],self.size[1]), 0)
pygame.draw.rect(screen, self.bordercolor, Rect(self.pos[0], self.pos[1], self.size[0],self.size[1]), 1)
for loop in range(0, self.max):
p = (self.pos[0] + self.stars[loop][0], self.pos[1] + self.stars[loop][1] )
screen.set_at(p, self.color)
def update(self):
for loop in range(0, self.max):
self.stars[loop] = (self.stars[loop][0] + self.speed, self.stars[loop][1])
if self.stars[loop][0]>self.size[0]:
self.stars[loop] = (0, self.stars[loop][1])
# DEMO
sf = [starfield( (50,50), (550,410), 80, 1 ),
starfield( (80,150), (200,200), 33, 2 ),
starfield( (380,150), (200,200), 33, 3 ),
starfield( (5,5), (80,80), 12, 4 )
]
sf[1].color = (255,0,0)
sf[2].color = (0,255,0)
sf[3].color = (0,0,255)
TIMEREVENT = pygame.USEREVENT
UPDATEEVENT = pygame.USEREVENT+1
FPS = 50
pygame.init()
window = pygame.display.set_mode((640, 480))
background = None
background = pygame.Surface(window.get_size())
background.fill((0, 0, 0))
pygame.time.set_timer(TIMEREVENT, int(1000 / FPS))
pygame.time.set_timer(UPDATEEVENT, 50)
while True:
for event in pygame.event.get():
if event.type == TIMEREVENT:
background.fill((0,0,0))
for s in sf:
s.draw(background)
window.blit(background, (0, 0))
pygame.display.flip()
elif event.type == UPDATEEVENT:
for s in sf:
s.update()
# Move starfield
x = sf[3].pos[0] + 2
y = sf[3].pos[1] + 2
if x>640: x=-50
if y>480: y=-40
sf[3].pos = (x,y)
elif event.type == pygame.QUIT:
sys.exit()
