Terminal-based snake game: input thread manipulates output
- by enlightened
I'm writing a snake game for the terminal, i.e. output via print.
The following works just fine:
while status[snake_monad] do
print to_string draw canvas, compose_all([
frame,
specs,
snake_to_hash(snake[snake_monad])
])
turn! snake_monad, get_dir
move! snake_monad, specs
sleep 0.25
end
But I don't want the turn!ing to block, of course. So I put it into a new Thread and let it loop:
Thread.new do
loop do
turn! snake_monad, get_dir
end
end
while status[snake_monad] do
...
# no turn! here
...
end
Which also works logically (the snake is turning), but the output is somehow interspersed with newlines. As soon as I kill the input thread (^C) it looks normal again.
So why and how does the thread have any effect on my output?
And how do I work around this issue? (I don't know much about threads, even less about them in ruby. Input and output concurrently on the same terminal make the matter worse, I guess...)
Also (not really important): Wanting my program as pure as possible, would it be somewhat easily possible to get the input non-blockingly while passing everything around?
Thank you!
