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Could the Jag Do Decent Ports of NeoGeo and CPS-2


christo930

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In the meantime there is no evidence out there that lb for lb the Jag won't smoke the Falcon.

 

 

I don't see Quake running on the Jaguar, do you?

 

Please, go find some proof, otherwise "I believe" is just that.

 

[Edit] Comment removed due to the offence it might cause potatoes.

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There hasn't been anyone skilled enough to tackle such a job in this community.

 

But if there was, lb for lb it should smoke the Falcon at that as well.

 

That's like saying you are only allowed out because you haven't met a psychologist yet ;)

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PC memory requirements, Robinson's Requiem. 4mb. Voxel landscape.

 

Falcon version, voxels.

 

Jag version, textured polygons 2mb memory.

 

I believe it's the same programmer for Falcon and Jag.

 

Well, shit. that's certainly conclusive proof. Case closed, Detecting Genius JagChris has cracked it, lads.

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Aren't all those Falcon games actually not using the FP coprocessor ?

 

What I'm saying is that Falcon's DSP+Coprocessor+68030 should come very close to jag's 68000+GPU, but only in 3D, as coprocessor is basically useless in 2D bitmap games. You spend one full frame on FP, just computing all transformations and texturing coefficients, and then spend next few frames on DSP just driving Falcon's Blitter to draw scanlines.

 

If we're talking just Falcon's 68030+DSP, then the performance gap is much wider.

 

Also depends on what kind of pipeline stages Falcon's DSP adheres to.

 

I'm glad I resisted the temptation to unbox the Falcon I got 6 months ago...

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PC memory requirements, Robinson's Requiem. 4mb. Voxel landscape.

Falcon version, voxels.

Jag version, textured polygons 2mb memory.

I believe it's the same programmer for Falcon and Jag.

Dear God...

 

The Jaguar version is done in polygons because the hardware isn't suited to the PC Voxel Engine...

 

 

"It was quickly realized that the dumb and wicked port on the 68000 was not enough , in fact at the base Robinson uses the voxel, a pseudo 3D managed in 2D. The jaguar was not strong enough to handle that.

 

At the same time as me, another programmer (David Ingels) was developing the 3DO version and had the same problems as me. So we decided to replace the voxel with real 3D faces. Any time, we have each developed our engine specifically dedicated to our respective machines."

 

http://mleguludec.free.fr/dossiers/interview/jc_interview_cyril_cogordan.htm

 

That's before you look at clipping issue's on Jaguar version..draw distance..simplified 2D objects like trees etc.

 

You cannot just say behold Jaguar version uses textured polygons so it's more powerful than engine used on Falcon..

 

It took 30 secs to find that interview..

Edited by Lost Dragon
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Will do.

In the meantime there is no evidence out there that lb for lb the Jag won't smoke the Falcon.

While everyone is waiting we can look at the available evidence.

Towers II, letterboxed on the Falcon compared to full screen on Jag.

Doom, quick and dirty port on the Jag, 15fps fullscreen.

After years of work on Falcon, Doom is 9-13fps, letterboxed.

Doom on Jaguar a quick and dirty port?

 

Bloody hell..

 

Sure Carmack would be delighted to hear it described as that..

 

Sure he admits coding it again from scratch would result in better frame rate, lighting effects and resolution..but the quick and dirty ports were 32X,3DO and Pal Saturn

 

 

The latter being a result of him not letting Jim Bagley use Saturn hardware in manner he wanted.

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Yeah LD i interviewed him too. They changed it because they didn't like the look of the voxels.

 

http://www.3do.cdinteractive.co.uk/viewtopic.php?f=14&t=3375&hilit=Cogordan

 

It's a good thing you've found out the system wasn't suited for voxels. Don't tell those who enjoy fallen Angels or Phase Zero.

 

You guys ignore evidence right in front of everyones faces for years and then call those who don't imbeciles.

 

Not gonna dig up the numerous statements Carmack has made that it is the PC DOOM engine bolted into the Jaguar.

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I just read that interview and the guy admits that the initial voxel engine on jag was just a quick and dirty port from PC. Of course it didn't run very smooth on 68000 as a quick port.

 

What is however mindblowing is that in the end he wrote a 3d texturing polygonal engine, which is like, easily - at the very least- 2 orders of magnitude more work than getting a simple voxel engine to run well...

 

The viewport on jag version looks to be roughly 256x150 pixels. There's no way 68000+Blitter wouldn't be able to handle voxels in a reasonable framerate. Let alone with DSP, which he eventually used.

 

So, there are other reasons why they went with writing a polygonal engine. I would wager a bet Atari pushed him (like they did with everybody) for the polygonal engine.

 

 

BTW, there are voxel engines running fullscreen on 1.79 MHz 6502.Certainly a 13.3 MHz 68000 with Blitter could pull off at least 10 fps in the 256x150 viewport.

 

He certainly has the skills. We just don't know whole story.

 

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Yeah LD i interviewed him too. They changed it because they didn't like the look of the voxels.

 

http://www.3do.cdinteractive.co.uk/viewtopic.php?f=14&t=3375&hilit=Cogordan

Just read this. Thanks.

 

The google translation of the French interview made it appear as the other coder was working on 3DO port, but this here explicitly mentions that they both were working on jaguar port. So, it wasn't just a single-person coding endeavor, as I originally thought.

 

They just thought the voxels looked ugly. Not Atari pushing for textured polygons. That's nice to hear, for a change...

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Aren't all those Falcon games actually not using the FP coprocessor ?

 

What I'm saying is that Falcon's DSP+Coprocessor+68030 should come very close to jag's 68000+GPU, but only in 3D, as coprocessor is basically useless in 2D bitmap games. You spend one full frame on FP, just computing all transformations and texturing coefficients, and then spend next few frames on DSP just driving Falcon's Blitter to draw scanlines.

 

If we're talking just Falcon's 68030+DSP, then the performance gap is much wider.

 

Also depends on what kind of pipeline stages Falcon's DSP adheres to.

 

I'm glad I resisted the temptation to unbox the Falcon I got 6 months ago...

 

 

The guy that's doing Quake for the Atari Falcon030 isn't using a 68882 FPU at all. He said it's too slow and he's using the 68030 and the Motorola DSP for the heavy lifting.

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:-))

Yeah LD i interviewed him too. They changed it because they didn't like the look of the voxels.

http://www.3do.cdinteractive.co.uk/viewtopic.php?f=14&t=3375&hilit=Cogordan

It's a good thing you've found out the system wasn't suited for voxels. Don't tell those who enjoy fallen Angels or Phase Zero.

You guys ignore evidence right in front of everyones faces for years and then call those who don't imbeciles.

Not gonna dig up the numerous statements Carmack has made that it is the PC DOOM engine bolted into the Jaguar.

That makes your earlier post even more curious...

 

You could of used quotes from your interview to make a case,yet instead jumped in with a vague statement about..Yeah..developers..

 

Now having read your interview coder said:

 

If I remember correctly, the voxel version was pretty ugly... David worked on the 3do version at same time and he tried a 3D test of the land with better results, so we decided to do same on Jaguar and then we worked together on a polygons version of the render engine. The hardest part was to code it on the dsp/gpu. With time, I think that wasn't my best code, but it works..

 

 

So..he admits his memory might not be that great..understandable due to number of years passed..

 

Decision to ditch voxels was based on cosmetic choice and due to work done on 3DO version.. not because of smoking raw powa of the Jaguar.

 

And your interview has him contradicting comments he made in an earlier interview to boot.

 

If your still in contact with him..you could ask him if Atari pushed him to go for polygon engine..just to clear up any speculation.

Edited by Lost Dragon
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The guy that's doing Quake for the Atari Falcon030 isn't using a 68882 FPU at all. He said it's too slow and he's using the 68030 and the Motorola DSP for the heavy lifting.

That's not however a fair comparison by any stretch of imagination, as he's using fixed-point calculations on DSP. Of course, fixed-point will be faster than floating-point!

 

The point I am making is, that even with the floating-point being slower, you have a separate chip that allows for free parallel execution. So, it doesn't matter if it's a bit slower, as it's simply free (minus the bandwidth to store results) - it runs in parallel with DSP and 68030 doing other stuff.

 

But ID Software didn't design Quake engine on a PC around parallel computation of floats. Of course, it's not going to work like that on Falcon version without major rearchitecture around performance characteristics of FPU.

 

You have to design the engine around the HW from scratch. In this case, this means that FPU is simply computing next frame's data, while 68030+DSP is rendering using last frame's data (computed on FPU).

With a frame rate of ~10 fps, that's 60/10 = 6 full frames worth of FPU time. That's a lot of performance that's just being thrown away.

 

 

That's basically like saying - we have 68000 in jaguar ! Why use another chip - some funny GPU malarkey - blah !

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This is quite literally the same "shut the 68k" logic that has been spread last 2 decades in jaguar land.

 

Is 68k slower than GPU on jag ? Sure ! But 68k can do a hell-of-lot of functionality in 2 frames (30 fps). For free, in parallel, while GPU is rendering the 3D scene.

 

Guess what, when you shut the 68k off, all that code has to run somewhere. So, now you halt GPU, stop rendering and start running all that gameplay/input/ai code.

 

This means loosing more framerate.

 

But wait, it won't fit within the 4 KB of GPU, as 3D engine was there.

 

So you start paging gameplay and other code back and forth.

 

This means loosing more framerate. Why ? Because not only are you wasting the system's bandwidth for transfers, the GPU is IDLE while the code is being copied. That idle time alone is much more performance lost than you ever lost by using 68k.

 

And you do it every few frames.

 

 

 

Now, as a corner case, yes - it's absolutely possible to design a very simple/primitive 8-bit game, that will either:

- actually fit all functionality into 4 KB of GPU

- OR will be so technologically simple (e.g. platformer), that the lost performance on code blits does not matter

 

Might as well dust off that Atari 2600 !

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@Jagchris, the falcon's DSP is a RISC chip and it's faster than the Jaguar's DSP's. Also, it has more memory. The real strength of the jaguar is the Object Processor.

 

Edit: The real reason the Falcon isn't a better gaming platform is the 16-bit bus. But seeing that the jag demoscene is very small, we'll never know what it's limit was.

Edited by Christos
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@Jagchris, the falcon's DSP is a RISC chip and it's faster than the Jaguar's DSP's. Also, it has more memory. The real strength of the jaguar is the Object Processor.

Yes, we're not questioning the 2D powah of jag. We're trying to assess how close in 3D engine Falcon is.

 

 

The real reason the Falcon isn't a better gaming platform is the 16-bit bus.

Well, we're not going to attempt 3D rasterizing in highres <768x200 - 1536x200> on Falcon, that's for sure.

 

But, even 16-bit bus is usable in something like 256x200 - 320x200. Hell, DML is using 256x128 framebuffer. 16-bit is adequate there.

 

Let's not forget that I have (via compile-time switch) options to switch between 8/16/32-bit blitting (on the SW rasterizer codepath), so I know very well the impact of just 16-bit writes.

 

And it's not as drastic as people make it out to be.

 

 

But seeing that the jag demoscene is very small, we'll never know what it's limit was.

Not necessarily :)

While at this time I don't want another distraction from jag coding, I will unbox my Falcon next year and port my 3D engine there.

 

When I last checked the DSP 56000, the instruction set is (obviously) very similar (it's a RISC after all). My 68000 code should run straight without any modifications on 68030.

 

So, the port should be very straightforward. 2-3 weeks at most, I suspect, after I get the build environment up&running.

 

 

Then we'll have exact, fully comparable, benchmarks on differences between the two platforms in 3D arena :)

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But seeing that the jag demoscene is very small, we'll never know what it's limit was.

Have you seen his latest raymarching demos ?

 

I would argue that he pushes the Falcon HW pretty darn well :)

 

But you are correct - the more people are active, the more are HW limits pushed.

 

Patience, my friend :)

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