A89: Re: Re: Scroller Engine

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A89: Re: Re: Scroller Engine





>
> Hi!
>
> | All Characters, Enemies, Turrets, Bosses are inside an object structure
>
> Hehe, OOP.  Please download the source to my syntax editor if you want to
> see some _real_ OOP. :-)  But on calculators, it would probably just be
some
> structure definitions and variable-sized arrays.

I generally program C++, so I felt I would apply the idea to standard C to
help in organization.

> | All Projectiles like bullets and powerups are in their own objects to
save
> | space(they don't need as much data).
>
> I guess here's where the object-oriented concept would go, if there was
one:
> You'd have a hierarchy like:
>
> TVisualObject
>           |
> TFlyingObject
>      |              |
> TBullet     TCharacter    ... and so on ...
>
> I can only make suggestions, since I've never programmed such a game, but
> there is a technique I've seen in Macs in my computer science class, and I
> thought it was pretty neat:  Each of these is, of course, a structure
type.
> Let's say the first byte of TVisualObject tells what kind of object this
is,
> and there is also an x and y coordinate, size, maybe a pointer to a
sprite,
> etc.  Then TFlyingObject needs the same things as well.  What you can do
is
> let the _first_ field of TFlyingObject be something of type TVisualObject.
> That way you can cast a pointer to a TFlyingObject to a pointer to a
> TVisualObject, and pass it to your drawing function, for example.  Tell me
> if you need more info.

Lemme think about that one, have to see what your talking about :)

> | All objects are organized into a variable pointer 'database'(char* or
> void*
> | not sure)that has the addresses where all the character objects are
> located.
>
> For the database, I would have a pointer to a variable-sized array.

Like char *objectdatabase[]; ?

> | An Integer variable would say how many objects are active(on screen)at a
> | time, ditto for projectiles.
>
> You don't need information about how _many_ there are, but which object is
> on the screen and which isn't.  In fact, you may either go through the
> entire array, or you can make a second array that tells which ones are on
> the screen.
>
> The problem with this is that there have to be a lot of reallocation
> functions.  Maybe someone should make a system similar to Delphi's, where
> space is allocated on a specific alignment (e.g. always four or eight
array
> elements are allocated at once).

never used delphi, so I'm kinda vague on what your talking about :)

> | Object Database will be cleaned every level,
> | projectiles dynamically(when they leave the screen)
>
> Sounds good to me, but again, I can only guess.
>
> | I'm thinking of using a frame based system running at about 30fps...
every
> x
> | milliseconds a function is ran which draws the background, reads the
> | database for objects, runs code based on that(AI, etc.), updates
> projectile
> | data, and garbage collects projectiles if needed.
>
> That seems much too complicated for me.  You can be sure that the
> calculators always run at about the same speed, unless they're overclocked
> or the batteries are almost empty.  Therefore I would rather leave all
> timing out completely.  You have to see, though, what happens if a lot of
> objects are on the screen.  If you do it in grayscale, and have your
screen
> additionally double-buffered, the flipping of buffers should take much
more
> time that the updating of objects, I think.  But I might be completely
wrong
> here.

I was just thinking of having the function run, then having it wait, then
again. If i just have the function recurse itself over and over, then I
would assume you would see speed differences... I'll check into that one.

> | What do you guys think of this? I'm not sure because I borrow alot of
> ideas
> | >from more advanced engines(QuakeIII comes to mind).
>
> How do you know about the engines used in that game?

I write little things for Quake III in C and Unreal Tournament in
UnrealScript from time to time... Quake II for example is a frame based
game, every 50ms all the objects are updated internally, etc. I don't know
how it  *exactly* works as I've never seen the engine source with my own
eyes, but you get the deal quickly just browsing the game source.

> One question to all: Why does _everyone_ put a '>' in front of every
'from'?
> Just curious.

where did that come >from? :)

Josh
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