►
Description
Interactive live stream chat with the creator of PaddlePunks, the "underground fighting tennis" game written in Rust. Learn more about how the sausage is made, and ask your questions live!
https://rustfest.global/session/54-directors-commentary-paddlepunks/
A
Welcome
to
the
the
second
session
of
the
day,
something
that
I'm
also
like
really
really
looking
forward
to
with
me
here
is
felix:
hey
felix
hi
felix
is
a
student
from
finland
and
we'll
be
going
like
yeah
on
an
adventure,
because
felix
made
a
underground
tennis
battle
game
in
rust
and
we're
just
like
gonna
see
what
this
is
all
about,
I'll
be
like
felix.
He
would
just
like
start
playing
walk
through
the
game.
Tell
us
a
little
bit
about
it.
I
may
ask
them
questions.
A
B
Something
I
rendered
out
earlier
of
me
playing
with
a
friend
because
that
was
tricky
to
coordinate
to
happen
online.
So
it's
a
basically
it's
it's
a
sort
of
pawn
light
game
with
extra
steps.
The
sort
of
start
of
the
idea
was
that
I
actually
wanted
to
experiment
with
a
netcode
netcode
model
called
a
rollback
netcode,
and
I
figured
that
I
wanted
a
sort
of
a
simple
game
to
start
off
with.
You
know
something
something
easy.
B
So
I
figured
pong,
that's
nice,
a
simple
two-player
game
and
then
I
sort
of
kept
adding
elements
and
it
sort
of
got
out
of
control.
But
it's
it's
pretty
pleasant
to
play
now,
at
least
so.
I've
got
that
going
for
me,
it's
entirely
written
in
rust,
oh
yeah,
sorry
about
the
the
dress
code.
Actually,
the
thing
to
go
to
after
this
I'm
not
dressed
up
entirely
just
for
this,
although
it
is
very
exciting
to
be
here.
B
B
B
B
Yeah,
so
it's
it's
sort
of
modeled
after
like
fighting
games
where
you
have
a
pretty
diverse
roster
of
characters
with
different
sort
of
abilities,
and
I
knew
that
one
of
the
characters
that
I
wanted
to
have
early
on
was
somebody
who
just
doesn't
let
you
play
pong.
So
I
wanted
somebody
that
could
just.
B
I
had
in
mind,
and
in
general,
I've
been
trying
to
keep
keep
keep
it
possible,
keep
it
open
to
the
possibility
of
lots
of
different
sort
of
varied
abilities
that
break
the
game
in
different
ways.
I'm
pretty
sure
it's
not
balanced,
but
I'm
not
actually
sure
which
character
is
the
least
balanced
right
now,
so
it's
balanced
in
a
way,
at
least
so
yeah
there's
a
few
different
characters.
There's
an
ai
with
a
bunch
of
different
difficulty
levels,
there's
netplay,
which
is
quite
functional.
B
B
A
B
B
A
B
B
So
with
ropepak,
you
have
the
sort
of
speculative
execution
layer
on
top.
So,
instead
of
immediately
or
instead
of
having
to
wait
for
the
sort
of
input
to
come
from
your
opponent,
you
you
just
assume
that
the
opponent
is
gonna,
send
the
same
input
as
they
did
last
time,
and
then
you
just
simulate
with
that
assumption
in
mind.
B
B
If
your
game
runs
differently
on
different
computers,
I
mean
that's
a
no-go
from
the
start.
You
need
you
need.
People
to,
you
know,
run
the
same
game.
Otherwise,
you
put
in
the
same
inputs
and
you
get
divergence
immediately
and
that's
just
doesn't
work
and
the
other
thing
is
you
really
want
to
sort
of
separate
your
different
components
like
in
when
you
update
your
game?
You
can't
also
render
it
at
the
same
time
where
you'd
be
rendering
like
five
frames
or
whatever,
when
you
do.
B
B
So
I've
got
actually
a
trait
here,
and
this
is
all
I
need
to
sort
of
implements
a
game.
My
sort
of
network
layer
is
entirely
divorced
from
the
the
game
itself,
which
is
another
huge
benefit
of
this.
Like
most
games
when
you're
networking
things,
you
need
to
really
think
about
the
networking
for
all
the
different
abilities
like
how
should
just
this
be
shown
on
the
server.
How
should
this
be
predicted
locally
for
players?
B
If
the
game
is
over
is
like
a
convenience
thing,
it's
nice
to
know
when
the
game
should
end,
but
otherwise
it's
really
just
a
single
function,
that
sort
of
advances
the
game
state
and
returns
the
new
game
state.
I
put
in
inputs
and
I
get
a
new
game
state
out,
so
it's
it's
very
sort
of
functional.
In
that
sense,
yeah.
A
B
A
B
Saw
the
wizard
and
that's
a
hard
one,
because
I
mean
I
like
them
all
in
their
own
way.
Like
obviously
you
like
your
own,
you
like
your
own
babies
like
that's,
you
can't
pick,
but
if
I'm
gonna
do
I
mean
conceptually
like
default?
Is
maybe
the
least
interesting
like
she's
really
fun
to
play
as,
but
also,
this
is
like
literally
the
first.
B
B
There
we
go
so
this
is
actually
defaults
being
played
here.
You
can
tell
she's
got
the
curveballs,
which
she
still
has
make
that
a
bit
bigger
but
yeah.
The
visuals
here
aren't
quite
as
meaningful,
which
is
a
big
problem.
I
found
that
once
I
added
sprites,
the
game
made
a
lot
more
sense
to
people
different
colored
circles,
just
really
aren't
great
at
conveying
hitting
a
ball
or
being
hit
by
a
ball
things
like
that,
but
yeah.
B
B
A
mode
where
you
can
just
sort
of
mess
around
like
just
having
being
able
to
sort
of
set
up
whatever
scenarios
you
want,
it's
really
helpful
for
debugging
and
reproducing
things
so
this
one
you
can
sort
of
like
launch
these
arrows
and
then,
if
you
press
a
button
again,
you
relaunch
them.
Well
that
wasn't
supposed
to
happen.
B
B
Yeah
the
numbers
are
sort
of
numpad
notation
so
like.
If
you
look
at
a
number
pad,
you
can
see
that
okay,
three
is,
in
the
bottom
bottom
right
hand
corner
it's
a
convention
that
they
use
quite
often
for
fighting
games,
because
otherwise
it
gets
sort
of
wordy
talking
about
like
bottom
right
corners
and
like
a
quarter
circle
from
left
to
down
or
something
like
that.
B
B
B
B
B
Obviously,
I
suppose
it
depends
on
how
you
have
things
set
up,
but
it
does
cause
issues,
especially
when
you
want
your
game
state
to
be
very
copyable,
because
the
netcode
involves
storing
a
bunch
of
game
states
and
then
each
of
those
game
states
also
involves
storing,
like
the
500
past
game
states
before
it.
So
that
ends
up
multiplying
out
and
it's
a
lot
of
copying.
B
A
B
Yeah,
is
it
an
article
nope?
The
art
is
all
the
art
is
all
taken
from
itch.io.
It's
a
fantastic
website
for
people
making
indie
games
both
to
sort
of
share
them.
That's
where
the
game
is
hosted
right
now
they
have
a
really
nice
pipeline
for
deploying
to
it
too,
and
it's
also
a
marketplace
for
assets,
and
things
like
that.
B
So
there's
a
bunch
of
really
cool
stuff
on
there
and
basically
at
some
point
like
the
problem
was
you
usually,
I
do
a
lot
with
programmer
art
and
that's
mostly
fine,
but
for
this
I
really
needed
the
the
sort
of
conveyance
that
you
get
with
actual
sprites
and
it
really
does
help
the
game
a
lot.
I
do
intend
on
replacing
it
all
eventually,
but
for
now
I'm
quite
happy
with
it
like
you
can
really.
A
B
Kind
of
it's
it's
a
mix,
so
I
guess
the
first,
the
design
stuff,
I
guess.
Well,
maybe
I
just
start
with
finding
a
sprite.
I'm
not
sure
at
this
point
it's
a
mix.
I
do
have
like
some
sort
of
concepts
that
I
want
to
do,
but
what
I
end
up
doing
is,
I
do
have
basically
characters
are
config
files,
but
there's
also
a
lot
of
hard-coded
elements.
So
if
I
bring
up
say
what
do
we
have
wizard?
No,
that's
the
witch
we
could
do
the
witch.
B
So
I
use
a
ron
which
is
a
sort
of
I
think
it's
ron
rusty,
object,
notation,
which
is
a
sort
of
json-like
thing,
that's
more
in
line
with
the
rust
data
model,
so
it
has
like
native
representation,
forms
and
stuff.
You
also
don't
need
to
put
quotes
in
front
of
all
your
properties,
which
is
really
pleasant.
There's
trailing
commas,
you
can
add
comments
which
is
fantastic
if
you're
like
actually
doing
sort
of
significant
stuff
with
configs-
and
I
know
I
think,
review
at
least
also
uses
ron.
B
I
know
a
few
other
people
use
it,
I'm
a
big
fan.
So
I
do.
I
have
sort
of
basic
properties,
that's
sort
of
what
you'd
expect.
There's
some
accelerations
some
speeds
some
and
then
I
have
sort
of
this
animation
system,
which
is
really
a
sort
of
wild
scripting
system,
where
really
I'm
just
using
enums
for
everything.
I
I
step
through
a
list
of
enums
and
do
stuff
based
on
which
enum
is
the
sort
of
current
thing.
B
B
The
scripting
system
to
be
sort
of
simple
I
just
have
like
four,
I
think
registers.
So
if
I
want
to
do
an
attack
in
direction
one
I
just
set
the
first
register
to
be
45
and
then
execute
it,
and
it
uses
that
it's
it's
it's
silly,
but
it
works
quite
well,
but
yeah.
So
for
some
other
things,
it's
not
generic.
Like
I
don't
I,
like
writing
rust.
I
don't
really
want
to
use
a
scripting
language
unless
I
sort
of
have
to
for
things
like
showing
off
sprites
in
sequence.
B
Rust
is
really
not
a
natural
language
like
it's.
You
need
something
like
very
co-routiney
and
like
super
stateful,
to
be
able
to
handle
that.
So
for
that,
like
it's,
it's
a
nice
sort
of
thing,
but
for
things
that
are
sort
of
more
complex,
like
entity,
descriptions
and
like
what
spawning
entities
means
is,
I
just
add
a
new
sort
of
instruction
for
it.
B
So
the
spawn
dorito
thing
here,
which
is
what
the
witch
spawns
they're
not
really
dorito,
shaped
yet,
but
I
think
they
will
be
eventually
if
eventually
they'll
be
dorito
shaped
so
yeah
here
you
can
see
my
giant
list
of
genomes,
so
this
is
just
an
enum
case
which
takes
a
float
and
two
vects
two
vectors
and
another
float,
which
means
something.
I
should
probably
comment
that,
but
maybe
not
and.
B
B
You
need
to
show
off
some
stuff
at
the
top
and
bottom,
and
the
sort
of
initial
size
was
just
what
was
comfortable
to
show
on
my
screen
in
a
window
and
also
like
sort
of
just
arbitrary
values.
I
think
the
playing
field
was
800
no
400
by
200
no
800
by
400.
So
there's
like
two
400
by
400
sides
for
like
each
player,
which
was
comfortable
on
my
screen
and
also
is
really
terrible
to
like
multiply
to
anything
else.
B
So
nobody
makes
like
400
tall
screens
or
800
or
whatever.
So
I
ended
up
needing
to
resize
it
to
something
else,
and
I
went
to
a
lot
of
thinking
about
different
resolutions
like
there's.
There's
a
lot
of
options.
Well,
not
that
many
options,
but
there's
decent
options,
but
you
want
to
you
want
to
be
good
on
1080p,
and
you
also
want
to
look
good
on,
or
at
least
for
my
case.
B
B
So
if
you
rescale
the
entire
game
by
two-thirds,
I
think
it
was
that
has
some
unfortunate
effects
on
all
the
data
that
you've
already
done.
So
I
needed
to
go
through
and
change,
basically,
every
value
to
be
multiplied
by
two-thirds.
I
was
thinking
about
maybe
like
just
having
that
be
the
sort
of
internal
resolution
be
like
the
the
400
p
or
whatever
I
had.
I
suppose
it
was
like
600p
something
like
that.
It
was
very
silly,
but
I
decided
that
that
I
could
not
live
without
being
in
the
code
base.
B
So
I
just
had
an
evening
where
I
sat
and
went
through
every
single
script
and
multiplied
all
the
values
by
two-thirds
to
make
them
good,
and
I
missed
some
of
them
so
like
in
some
tutorials.
You
would
spawn
off
screen
until
somebody
thankfully
reported
it
to
me,
but
mostly
it
worked
out.
There
are
some
really
strange
values,
though
in
the
sort
of
configs.
B
Now,
as
a
result,
though,
like
I
would
not
normally
like,
I
don't
try
to
do
like
super
tight
balance
stuff,
I
do
pretty
extreme
things
and
then
sort
of
tweak
it
afterwards,
but
now
because
I
didn't
want
to
like
rebalance
things
as
I
rescaled
the
game,
there's
a
lot
of
things
that
are
like.
Oh,
this
thing
moves
at
5.66,
pixels
per
frame
and
that's
yeah.
A
A
B
B
I
do
have
some
people
in
mind
for
music
and
art
that
I
would
like
to
be
able
to
pay
to
do
that,
and
so
would
be
nice
and
I'd
like
to
I'd
like
to
try
and
support
it
to
get
as
decent
of
a
player
base
as
it
can
like.
It's
obviously
a
pretty
niche
thing,
it's
a
pond
with
extra
steps,
but
quite
a
few
people
who
have
played
it
have
enjoyed
it
quite
a
bit.
B
So
I'd
like
to
sort
of
make
it
easier
to
do
that,
but
that's
the
that's
the
sort
of
longer
term
plans.
I
don't
have
anything
like
sort
of
immediately
planned
it
is
it's
not
feature
complete,
it's
very
rough
still,
but
it's
it's
almost
there
like.
I
have
a
lot
of
the
sort
of
basic,
that's
working
quite
well,
it's
it's
a
lot
of
the
polish
and
then
art
and
music
and
sound.
That's
still
missing.
B
A
B
Yeah
frameworks
and
stuff
that
you
have
to
use
what
do
we
got
together?
There's
no
there's
no
frameworks
per
se,
it's
actually.
What
do
I
got?
The
the
sort
of
base
of
the
game
is
actually
it's
sdl
too,
for
a
sort
of
windowing
and
input
handling,
which
is
a
a
c
library,
but
the
bindings
are
quite
nice.
B
I've
heard
bad
things
about
this
sort
of
image
drawing
stuff,
but
I'm
not
doing
any
sort
of
rendering
with
it,
I'm
just
using
it
for
window
handling
and
that
all
seems
to
work
quite
nicely
and
that's
also
something
that
it
deploys
on
a
lot
of
platforms
like.
I
know,
for
example,
that
sdl2
works
on
the
switch.
B
B
The
rendering
is
done
via
gliam.
I
was
considering
doing
vulcan
for
a
while,
because
I
mean,
if
you're
doing,
cool
tech
stuff
in
rust,
like
vulcan,
is
a
pretty
obvious
choice.
That's
what
a
lot
of
people
do,
but
I
just
couldn't
justify
to
myself
knowing
the
sort
of
sprites
and
the
graphics
that
I
knew
that
I
was
going
to
do
like
I
would
be.
B
I
knew
that
I
would
spend
a
lot
of
time
to
draw
like
a
triangle
and
then
I
would
need
a
second
triangle
and
that'll,
be
it
like
all
the
it's
just
they're,
just
quads,
it's
very
unexciting
in
terms
of
rendering.
So
it's
so
I
just
went
for
glim
for
that,
because
it's
a
nice
opengl
wrapper
despite
the
warning
on
the
github
page,
and
I
had
some
familiarity
with
opengl
before
so
it's
it's
quite
nice.
What
else
have
I
got?
B
B
I
do
recommend
like
if
you
have
a
game
where
you're
making
a
game
engine
having
tools
built
in
for
sort
of
exporting,
video
and
stuff
from
the
game
is
very
helpful,
especially
if
it's
with
replays,
because
if
something
cool
happens,
you
don't
need
to
have
like
obs
or
whatever
running
as
you
as
you
sort
of
do
it
yeah.
You
can
just
go
in
afterwards
with
the
replay
viewer
and
sort
of
check
out
that
specific
part
also
good
for
debugging.
B
B
A
discord
in
tokyo
are
for
the
sort
of
discord
thing
that
pops
up.
I
had
a
user
ask
me
to
have
that
because
he
wanted
to
show
off
the
game,
which
was
fantastic
to
hear,
so
I
needed
to
spend
an
evening
doing
that
for
him
yeah
a
lot
of
a
lot
of
sort
of
different
things,
bin
code
great
for
sending
stuff
over
the
network-
maybe
probably
not
actually,
the
way
I
do
it,
but
it's
working
for
now
at
least
and
yeah
ron
ron
is
great.
B
This
is
a
weird
branch,
with
a
feature
that
I'm
using,
but
otherwise
yeah
ron
is
ron
is
fantastic.
Free
verb
is
well
reverb
thing
that
I'm
actually
not
using
at
all
right
now.
I've
made
an
audio
engine
for
something
else,
and
it's
part
of
that.
So
it's
it's
in
there
waiting
to
be
used
at
some
point.
There
will
be
different
atmospherics
for
different
places.