Pygame (Python Game Development) Tutorial - 57 - Moving Tank Part 2 Video Lecture | Pygame (Python Game Development): Create Awesome Games - Front-End Programming

hello everybody and welcome to another
Piegan tutorial video in this video
we're gonna be talking about how we can
get our tank to move only when we press
a key so if you remember from our snake
game when you would basically only press
keys to change directions so as soon as
the game started we always wanted the
snake to move that was part of the
challenge of a snake game but this game
isn't that isn't the same we only want
the tank to move when we want to move it
and so we want to give the impression
that the arrow keys will actually move
the tank and like holding the arrow key
will keep the tank moving as opposed to
releasing it should stop the tank now in
games you're gonna find that a lot of
the things that we do in games are
really just kind of illusions or giving
a player the impression that something
is happening but if you know what's
going on behind the scenes it's a whole
different story it's not really the way
it seems the same thing is true for like
moving things around so what we do in
this event is when we you don't actually
as a player have to hold down the key
paganini doesn't have any register that
says player holding the key but instead
what it does have is you can have a key
down event but then you can also have
key up events so for example we could
say L if event dot type double equals
high game dot and all caps key up and
then we can ask if event dot key equals
double high game dot K underscore left
so if we lift it up the left key what
would we do but we would say tank move
equals zero we could also say if event
key double equals PI game K left or
event dot key and actually let me pull
this up a little bit event I key double
equals PI game dot K under
for all caps right tank move equals zero
so if the key up is the left arrow or
the right arrow we want to stop the tank
movement so what this is is its event so
Pi game again doesn't really register
the holding of anything it when it comes
to keys even though if you recall it
does register the holding of a mouse
button because it basically continues
spamming that like say your left key is
pressed the zeroeth element in that
tuple is 1 1 1 1 1 1 and then as soon as
you let it go at 0 but that is almost
because it's just kind of a different
thing I suppose but keydown doesn't it
it's an event it's a one single time
action so key down only corresponds to
the moment you press that key down it
does not hold like if you hold the key
down it's not like a new event of key
down every frame per second so the way
that we can give the illusion that it
moves as long as you hold the key down
even though as soon as you pull held the
key down it keeps that movement and
really the releasing of the key is the
trigger to stop that movement we give
kind of like the illusion that holding
the key actually matters it doesn't
you're just basically stopping the key
from coming up and creating an event not
releasing the key down event so that
should do it so let's go ahead and save
and run that and we'll go play and you
can see we can kind of tap it in the
tank moves cool but if we hold it it
also moves until we lift up the key so
it makes you feel like the holding of it
is actually continuing to move the tank
but that's not really the case and so
this is also just just in computer
programming gooeys and games in general
you're gonna find that there's a lot of
times where you give only the illusion
of something acting in such a way but it
doesn't actually act that way at all
it's just making the player or the user
feel like it's a fan it's no different
than buttons remember that button that
we programmed that's not a button it's
it's just
a square rectangle and then it just
changes the color as we hover over it
and it's it makes it feel interactive to
the person but it's not really so anyway
you're gonna see a lot of that in just
programming in general but anyways
that's it for moving the tank around now
the last thing that we want to do is for
its tank movement is concerned is when I
go to move the turret and actually we're
gonna find that's a little more
challenging than then just simply moving
the tank around because the length of a
line depending on the coordinates is
gonna change so there's no real easy way
to do it
so we'll probably end up hard-coding
various positions of the turret but
we'll get to that so anyways that's it
for this video hopefully you guys
enjoyed and you get your tank moving
around and stuff I said the next video
we'll do moving the I guess I said
turret but really the gun so stay tuned
for that and thanks for watching