Pygame (Python Game Development) Tutorial - 7 - Moving Rectangle Video Lecture | Pygame (Python Game Development): Create Awesome Games - Front-End Programming

hey guys what is going on welcome to the
seventh high game tutorial video from
centex for Bucky at the new boss and
where we left off we've got the idea of
how we can draw things to the screen but
we want this game to be a snake game and
we want to be able to move the snake
around so generally when people first do
this stuff this is like the most
exciting thing is when we can actually
like move things with our keyboard so
that's what we're going to be doing
today so what we're going to do now is
add a few things so first of all in
order to move things we in order to move
it and kind of work with some logic
let's specify some new variables we need
some starting variables and then we can
edit those variables and then each time
we basically just draw those variables
and so each time we draw them they'll be
different based on input that changes
the variables so that doesn't make too
much sense don't worry this should make
a lot more sense so first of all we have
game X 8 equals false then we're going
to go ahead and specify a couple
variables here the first one will be
lead underscore X and lead X will equal
300 and then lead underscore Y will
equal 300 now why we calling these lead
X and lead Y lead will be the leader of
the group of blocks so to speak that
would be the number one block so
basically where's the first block and
then all the other blocks behind it so
because we're going to make a snake and
the snake is going to be built in
sections and where each section will be
a block so this is the variables for x
and y for the x and y locations of those
first x and y blocks so the head of the
snake so we're starting at 300 300 and
then now we come down into our while
loop and so again these are the this is
the events part of our loop so well
first we're going to need an event that
will move the snake and the event is
going to be the pressing of arrow key so
first we'll do left and right and then
we can start to incorporate up-and-down
and all that so first let's just do the
left and right keep things simple
so for event in PI game dot event I get
now we're going to run through those
events so we're just going to keep this
for loop because this is our like event
handling loop here so if it's a quit
then we quit obviously but then we're
going to specify some new events so I'm
going to say if the event dot type
equals and that's a double equals sun-hi
game dot and then all caps now key down
what do we want to do well we want to go
well now we need to know first of all
what key was that so that could be a
queue it could be a one three or narrow
so we need to make sure that these were
an arrow and then specify which arrow so
then we can kind of way we can handle
the specific arrows so if it was a key
down what we want to do we're going to
ask the question if event dot key and
then double equals sign equals PI game
dot k capital underscore and then all
caps left so if they hit that left arrow
key what do we want to do well we in
theory would like to do lead underscore
X and then since they want to move left
that would be minus equals so minus
equals I'd be a subtraction of X right
we'd want to like go down X so minus
equals and then we're going to move it
by 10 because our block is 10 wide and
tall we want to also move it by segments
of 10 so there so we can make our script
a little bit easier to code and you'll
see why later on but we'll we'll do that
for now and then we also need to ask
that's how move it left but then we also
need to ask if event dot key equals PI
game dot K underscore all caps right if
it was right then we want to add to the
X variable so it was a lead underscore X
plus equals 10 and that would change the
location of the lead X and lead y so
then we come down here we fill we're
drawing our rectangle
we don't want this red rectangle anymore
so I'm gonna go ahead and get rid of
that so we don't need that anymore and
let's bring up our update and now we're
going to put a lead underscore X and
then lead underscore Y in the creation
of this rectangle this black rectangle
on our white background and then we
update the displace so let's bring this
out to you so we have that condense
space here and that should be everything
we're going to see this works a little
finicky and we'll have to have to fix
that let's go ahead and run that see
where we stand
save and run and just for anybody who's
wondering if you're not familiar with
saving and running things I just press
f5 and then ask me if I want to save it
because I need to save it so I hit f5
enter and it brings it up you can also
just go to run and then run module and
you see that it says f5 there but just
letting you guys know so anyway we got
our object level
rectangle here and we can hit the arrow
keys and we see it moves but if we hold
the arrow key it doesn't continue moving
and that's kind of annoying but also
more importantly for a snake game we
actually want to be it has to continue
moving that's part of what makes the
snake game challenging is you have to
think kind of fast so as soon as you
enter a direction it holds that
direction and continues that direction
so this doesn't actually stand it won't
be able to continue working even though
our objective is snake I would like to
show you guys how you can do something
where you hold the arrow key you release
the arrow key and it will keep moving
while you're holding it and stop moving
you release it it is kind of useful so I
still want to show you guys that before
we go to our snake game because most
games are actually probably I mean more
so like they want to move until you
release the key so that's what we do in
the next video stay tuned for that