C++ Allegro 5 Made Easy Tutorial 32 - Fading [Camera Effects] Video Lecture | Allegro: A Complete Guide - Game Development

hello everybody and welcome to your 30
second Allegro 5 tutorial and in this
tutorial we're gonna be learning about
one last camera effect and that's fading
and now I never planned on making this
video but I just before I was gonna make
the loading time out this video for this
tutorial but I went on my website on the
forum and the user Albert Tito Lauren I
hope I pronounced that right he posted a
question that was regarding how to do
like fading and or like how to do a day
and night system and how to have like
certain things be brighter than other
things etc etc well so I decided to
teach you a fading system and with this
fading system you can use it to activate
day and night system etc etc so there's
many ways you can go about are fading
right you can change you could draw
excuse me sorry for that and we could
you could draw all you dudes like Al
draw tinted bitmap and you can all draw
a transparency for each image or a
global transparency where you want
everything to be drawn or tinted to
right but there is there is an easier
way some of you might like this way some
of you might not but by far this this is
a really just easy way to handle it
without much confusion so first of all I
made a black image like like so and it's
the screen size you can make it half of
the screen size since this is the
continuation from this play screen but
in reality you wanna you if you have all
if you're not doing split screen you're
gonna want to make it a size of the
screen itself okay so what we're gonna
do with this black image is that we're
going to first of all make it fully
transparent then we fade in we're going
to increase the transparency value and
therefore it's gonna kind of put like a
black cover over the screens gonna look
like everything is fading okay so you'll
see how we do so later so we have
now bitmap called fader I mean it fade
and we load in our our fade image now
before we continue and our cameras truck
- we have and we have our fade variable
right there
okay so at the top of our update we just
say fade is equal to the player numbers
cameras fade value and then after down
here we just said they press the F key
then we increase fade by one and they
press the G key they decrease the fade
by one right and don't forget to add
this code for the degrees I never iron
in previous tutorials but in the source
code which I will be updating this sort
of calling the website to incorporate
this as well so so yeah so once we once
we do that then we set the player
numbers fade the fade value equal to the
new fade value so once we do that
everything else remains the same and if
we go to our program what we want to do
if you want to draw our black image over
what we want in order to be transparent
so in this case the main player is going
to be able to fade but this other player
that is on that certain screen is not
going to be fading right and that's good
like say you have like torches or you
have a light something that stays lit up
or whatever all the time and you don't
want to fade and then you do this as
well so after I've drawn the the main
player and the background what I've done
is I said draw a tinted bitmap I draw
the fader bitmap and I do al map RGB a
and I set it to zero zero zero since
black and we set the we set the Alpha
value equal to the fade value of the
current camera and then we set our
position zero zero and we said that - no
now after that's when we draw the player
on the secondary player on that screen
so that secondary player is not gonna be
abs it's not gonna fade with the rest of
the game elements
and last but not least what I forgot to
do what I'm always forgetting to do is
we need to destroy our bitmap so bitmap
fader I didn't spell destroy properly so
I don't like a lot top sometimes I
rather mouse but yeah so if we run this
program right here and if we look right
if we look on the left screen that's our
screen as toggle right now by press f
you see everything center fade except
for our second player over here so
that's always taking it up so if you
have a good day and night system or
something and you want it to oh and you
want to go from day to night right we
can say that this is the day and when
you progress through the day whatever if
you had a nice system you just have it
slowly fade and have everything else
seem dark and then if you have torches
or something then you can have like
those lit up values whatever could
represent torches or whatever you could
have like a surrounding area where you
you put light or whatever whatever it
depends on me on you those weren't
wouldn't be the best for light effects
but if you want it like that and you
could so as you can see everything is
faded and so kind of looks like a night
in our in our world right and if I
toggle again right here I can fade it
and you fade it out so can make it we
can if we want to have like a fading
screen or something like that or
whatever like you want a PHA to
transition from one screen to another
you could use as well if you want to a
day and night cycle anything you want
you could do it with this so that is it
for this tutorial I hope you enjoyed it
thanks for watching and bye