RE: [GD-Consoles] what to do with little cash

[Mick W. <mi...@ne...>]

If you have little cash, you must invest wisely.
 
The devil is in the details however.  I'm sure many successful console
developers have complex class heirachies, and lots of virtual functions.
The virtual function overhead is reall not that bad, unless you are
talking about really low level rendering components (you would not want,
for example, to have a virtual "render" function for every polygon.  The
line has to be drawn, but it's open to experimentation.
 
I've got a related question:
 
(Assuming a PS2 style console)
 
Given that you have game objects that are composed of various components
(car = physics + collision + AI + script + sound, eg..).    Is it better
to process this "per-object" (where you iterate over the objects, and
updated all its components), or "per-component" (where for each type of
component, you iterate over each instance of the component type, and
update it)
 
Per-component might give you better usage of the I-Cache, but per-object
might give you better D-Cache usage.
 
Again, I suspect that "it depends", but has anyone thought about this?
Anyone tried restructuring code one way or the other?
 
Mick.
 

-----Original Message-----
From: gam...@li...
[mailto:gam...@li...] On Behalf Of
Raymond L. Maple
Sent: Monday, February 24, 2003 2:14 PM
To: gam...@li...
Subject: [GD-Consoles] what to do with little cash


Hello!  I have a question about programming a console that has a small
cache.  Now I'm new to this console so I don't know all the details
about it except I've read from other people on this group about how the
cache is very small and that you can stall the the system if you don't
watch out.  I was wondering if you could give me any tips and pointers
about what to watch out for in a engine framework or composition.  For
example, I heard you want to avoid virtual functions because the vtable
can cause a cache miss.  The problem is I do mostly c++ with a good deal
of virtual functions.  Does this mean I can't use an object heirarcy
with virtual or pure virtual functions?  My main concern is that my
engine layout is a pretty strict c++ implementation and I'm worried the
performance will suffer.  I've looked through the documention on the
website provided for the console and I didn't see anything specific to
my question but if you know of anything let me know.  I appreciate your
time and knowledge.
 
    Thanks,
    Raymond L. Maple
    WayForward Technologies