Being one of my favourite topics... the Wolfenstein algorithm is
actually incredibly inefficient. It's a linear search for every column
and then a couple of multiplies, an add and a divide to get scale.

If you instead used a combination forward/backward renderer with
portals and convex sectors, you could do significantly better for any
sort of geometry you'd expect on that level of device.

Assuming I've thought this through, costs Wolfenstein doesn't incur
would be: per visible sector you'd end up at a quadrant test, a divide
and a small table lookup per vertex, a divide, two multiplies and
three adds per visible wall. But you'd then be looking at (much the
same) two multiplies and an add every 8 or 16 columns and just two
adds per column. So you're spending a little on setup to save a lot
per column.

You'd draw front to back, zero overdraw for the world. Sprites would
be sorted per sector and I guess you'd want to walk back to the front
in sector order to paint them in, making it a stack-type thing rather
than merely a queue.

Walls could be any angle, and costs would increase as geometry
complexity increased, whereas in Wolfenstein they increase as your
rooms get larger. But freely angle walls would probably allow you to
keep the geometry simple.

Disadvantages would be indeterminate, and usually larger, level data
sizes, and the need to create a proper editor rather than just editing
in TextEdit or Notepad or whatever.

So, yes, I'm good at bluster.

On 24 April 2012 23:18,  <war...@wdlee.co.uk> wrote:
> Just been having a quick play!! Love that it works so fast. :-) very cool to
> see another new SAM game. How many is that now, in the last few months? Dave
> Invaders, Garden Centre of the Universe and now XOR... :-) What next??? :-D
> Those making them, should see about getting them mentioned in Retro Gamer
> magazine. They've got a section in the magazine about new games for all the
> old machines, with mini-reviews etc. Definitely worth a bit of free
> promotion and seeing your game in print on the shop shelves. :-)
>
> I agree with the discussion that we all concentrated on emulating the 16bit
> machines too much instead of working within the limitations to create other
> stuff, but such is the way of things. We all wanted to do what the big-boys
> could. Then again, that pushed a lot of the games further than a lot of
> people expected anyway. I suppose that's another area where the SAM was like
> the Spectrum. It wasn't technically as advanced as say the c64 in many ways,
> but competed by sheer versatility and creativity. Such was the SAM to the
> Amigas and STs. I think over the years the SAM has certainly proved it could
> do great stuff, when pushed to its limits. Who originally thought Lemmings
> would work? It's a shame we didn't see more games that weren't as limited by
> speed, like Dizzy/Flashback types.
>
>
> I'd love to see a basic test of a wolfenstein game running! :-) It'd really
> be a nice show-piece. Having said that, if someone managed to get it
> working, once the pseudo 3D engine of that was running, why not create the
> SAM's own first FPS? (Like Colin was planning with Chrome) No need to use
> the existing Wolfenstein graphics and such, when we can create our own for
> the SAM, and our own level designs, story, creatures, etc?
>
> Warren
>
>
>
>
> Quoting James R Curry <8...@itdoesntsuck.com>:
>
>> I remember ordering the original from one of those ZX Spectrum mail order
>> places.  They were never able to deliver it, for some reason, and offered
>> me the choice of another game, instead.
>>
>> No idea what I wound up buying.
>>
>> Now I can finally play it.  Looks good!  Is it in Mode 4?
>>
>> On Tue, Apr 24, 2012 at 8:21 PM, Thomas Harte
>> <tomh.retros...@gmail.com>wrote:
>>
>>> I played it for five minutes and it all looked very impressive. That
>>> being said, I don't actually know the original game so I was quite
>>> lost. Looking at the incredibly sparse World of Spectrum inlay scan
>>> though, I think I'm meant to work things out for myself?
>>>
>>> On 24 April 2012 18:00, Balor Price <toberm...@cookingcircle.co.uk>
>>> wrote:
>>> > Hello everybody
>>> >
>>> > I'm proud to present my conversion of the 1987 Spectrum game XOR.  I
>>> finally
>>> > kept my promise to my teenage self to finish a SAM game!
>>> >
>>> > You can download it for free from the revived
>>> > http://cookingcircle.co.uk
>>> >
>>> > I hope you enjoy it (and yell in frustration).  It's 25 years old and
>>> still
>>> > as rock-hard as I remember.
>>> >
>>> > Any feedback/initial bugs found would be greatly appreciated.  :D
>>> >
>>> > Cheers
>>> > Howard
>>>
>>
>>
>>
>> --
>> James R Curry
>> 8...@itdoesntsuck.com
>>
>
>
>

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