Pygame (Python Game Development) Tutorial - 12 - Boundaries Video Lecture | Pygame (Python Game Development): Create Awesome Games - Front-End Programming

what's going on everybody welcome to
another PI game tutorial video in this
video we're gonna be adding boundaries
to our games so like I was telling you
guys before you actually don't like PI
game doesn't know inherently that the
edge of the window is a boundary or when
you crash into a wall that you've
actually crashed into a wall it doesn't
just know that and it's not going to
impose that on your game you actually
have to code that into your game to say
hey if these two things cross over we've
got a crash or you know you've been hit
by a bullet or whatever you have to code
that in or you've gotten that coin or
whatever so what we're going to do in
this video is begin our first bit of
logical statements so like I was telling
you before you're going to have
basically a bunch of event handling and
then you'll have a group of logic
statements and then usually you'll have
a group of and the logic will sometimes
modify variables and stuff like that but
you'll have your event handling your
logic and then your graphics rendering
and then you'll update the display and
that's what happens every single frame
per second that you have set it's going
to run through all of that stuff and
that's kind of why we wanted to use
elif's instead of ifs to cut help cut
down on the amount of stuff that we have
that runs so now we have barriers and so
if we say we want to have barriers how
do how do we go about adding barriers to
the game so here's our game so how do we
tell pi game that like we've crossed
over this line here um game over or the
class over that line or that line or the
line over here how do we actually inform
PI game well the easiest way that we can
do that is by asking if we are over
those lines so for example what we can
ask is if um lead to underscore X is
greater than like let's say 800 pixels
okay but we want to say well we'd want
to say game exit equals true and like
that's game over so we can save and run
this and come over here and let's just
move our guy over there and now he's off
this
and so game exit was true the game ended
and we say we do want to exit so that's
cool so then of course you could say L
if lead X is less than zero game exit
Eagles true and so on well what really
mean what we really have to ask is these
the end result to any of these is game
over so instead of like making a bunch
of if and elif statements all about the
boundaries of you know running off the
screen what I suggest you do instead is
you can get rid of that and then we'll
say if lead X is greater than 800 game
out or you know game X it equals true
but you can say if lead X is greater
than 800 or lead X is less than zero or
lead Y is greater than 600 which was the
height or lead y is less than zero now
game exit equals true so now we can run
this statement like this and we see that
if we go up to high the game is over and
we'll check the bottom game over and
then if we go say left now it's a game
over now one of the things that can be a
problem though is like let's see if I
can get it to happen so we go like this
and then go Ashu I missed it hold on
hold on I'm gonna get this let's try it
this side then there we go see how I was
able to go off the screen that time I
failed again but I was a time able to
get off of the screen by going like this
up over there we go she did it again
obviously in snake you're not supposed
to be able to do that huh it's hard to
do it but I'm able to do it every now
and then and so what's the reason why is
it that we're able to go off the screen
like that well if we bring up our game
again though where is the location of
zero zero on this box it's right here
right at the top left
so zero zero on the surface right here
so we're asking if zero zero is greater
than this line well if it's equal to
that line like that that's okay right
that is not a problem because it's not
greater than it was only equal to so
obviously that's how we run into that
that problem the other side it can't
really be the case but it happens on
that side and also like so greater than
800 and all of that so how do we remedy
that's that problem well instead of just
being greater than 800 we would say
greater than or equal to 800 greater
than or equal to 600 okay
yeah so now let's say that around that
again and we can move our little guy
around and you see we can't cheat the
system anymore we're just not able to
get that to to go off and then come back
again and obviously um going up we were
never able to do that in the first place
because 0/0 was okay so anyway um that's
it we've added boundaries now with
basically one line of code I suppose two
lines calling the game exit but yeah
pretty simple and you're going to see
that we continue doing stuff like that
where basically we're asking about a
bunch of crossing over so when we find
apples for example it's going to be all
about crossing over the location of that
Apple and running into ourselves it's
going to be all about crossing over into
the location of ourselves that kind of
stuff so anyway stay tuned to that and
thanks for watching