Android Application Development Tutorial - 172 - Byte and Float Buffers Video Lecture | Android Application Development (Mobile App) - Software Development

what's up guys welcome to your 170
second Android tutorial for the new
Boston what we're gonna do is still work
with this you know GL triangle example
class and all we've done so far is just
basically set up a float you know a list
of floats and you know there's no
relation to OpenGL or anything like that
so the first thing that we need to do is
we need to set up something called a
float buffer because again a few
tutorials ago we use buffers and they
just sort a way that we can render stuff
to the screen so we're gonna call this
like our vertice vert buff maybe for a
vertice buffers and we're basically
going to relate these vertices later and
we want to set this again just to be a
private variable private variable for
now and a you know we have to add our
imports and you know also for this class
we're going to need a constructor
because again when we create an object
we want to call the constructor and set
everything up
so that's what we're going to set up
real quickly and this one's going to be
public so other classes can use this
constructor again when we create a
constructor has to be the same name as
our class name so triangle e^x and this
isn't gonna have any parameters within
it we could probably grow on that later
but we're just gonna set that up and
within this triangle what we're gonna
have to do is we're gonna have to create
a vertex buffer and in a byte buffer
because the bike buffer is gonna tell
our application how much you know space
we're using how many kilobytes or bytes
that we're using and for each float that
we use that takes up four bytes so our
float list here has six different floats
within it so we're gonna have to locate
24 bytes within our buffer so what we're
gonna do is we're gonna set up our byte
buffer I know it's kind of confusing
maybe a little bit for now but we're
just gonna set up that byte buffer we're
gonna call this be buff gonna set this
equal to the byte buffer class and use
the method dot of locate direct and
again we just have to it takes an INT of
the capacity that we're going to be
using so again
like I said it's 24 but in case we add
you know more vertices to this float
array we want to you know be able to
handle that and tell our you know update
our byte buffer and say hey we're using
more memory than just 24 so we're gonna
relate to our list that we created
called vertices and we're just gonna say
dot length that's gonna return how many
floats are within our list and as for
now there's six so that's gonna be six
and for each float we use 4 bytes so
we're just gonna times this by four so
that's basically telling our buffer you
know this is how much we're using which
is 24 bytes and then what we're going to
do is we're going to set up the order
within our byte buffer and so we're just
gonna say be buff dot order and you can
see as it takes within its parameters a
byte order so we're gonna click that one
know what we're gonna say is or we're
gonna relate to the byte order class so
byte order and we're just gonna say dot
native order and you know that's just
going to give us the native order for a
byte byte buffer so now what we need to
do is we need to relate to this vertice
buffer and you know kind of make the
connection as well so we're just gonna
say Verte buffer or vert buff I should
say we're gonna set this equal to our
byte buffer which we call B buff dot as
float because there's different types of
you know stuff that we or list that we
can have within a buffer the since we're
using floats we're gonna use this as a
float buffer and I spelled vert buff
wrong sorry so set that up and then what
we're gonna do is we're just gonna say
we need to put our list within this
vertice buffer so it knows that we're
working with floats as for now and we're
just gonna save vert buffer or vert buff
dot put and then we have to put our
float array in there which we called
vertices and then all we're going to do
is we're going to relate to our vert
buff
and tell what position we want to start
so vert buff dot position and we're
gonna start at position zero or the top
of our triangle so that's pretty much it
for this tutorial I know it's kind of
confusing as of now but it will it'll
sink in what we're actually doing in the
next few tutorials but I'll catch you
guys in and have a good one