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CENTRON 3D - Title Screen Shot

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@Popmilo I read that to mean minimum CPU intervention, which gives me an idea.

 

So lets assume that a gun was put to my head, and I was forced to make a plasma in Pete's new Cmode (which none of us yet knows the trick for)... how will I fake it and keep my head.

 

With a Horzontal resolution of 80, the GTIA modes seem a good starting point. The usual blank line artifact from an APAC setup is missing, but thats okay I always liked Pryzm (alternate mode 9 and 11 in a VBI as opposed to per scanline with a DLI). Horizontal resolution appears to be 48 or 50 (depending on who counts) but that discrepancy doesn't matter, we can fake that with the old GTIA 9++ trick of setting VS for the modeline, and setting vscroll to trick Antic into repeating the last scanline 3 more times.

 

So that would give 80x48 (or 50!) at a perceived 256 colours, requiring a simple DLI once every 4 scanlines, a simple VBI, approximately 4k for the screen display, and 3 scanlines where Antics DMA would steal very few cycles from the CPU. Perfect for a plasma :D

 

Edit: "3 scanlines where Antics DMA would steal very few cycles from the CPU" should be read as for 75% (approximately) Antics DMA would steal very few cycles from the 6502.

Edited by Tonym1972
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Looks to me like flickering GTIA modes + VSCROL trick like this:

 

attachicon.gifbird.emu.pngattachicon.gifmetroid.emu.pngattachicon.gifsamus.emu.png

attachicon.gifbird.png.xexattachicon.gifmetroid.png.xexattachicon.gifsamus.png.xex

 

Though for my taste this flickers too much without frame blending enabled.

 

Code and more examples on github here.

 

I wasn't able to get these loaded on real hardware using SIDE Loader, or DOS 2.5 with SIO2PC. Are they targeted to a specific config?

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Looks to me like flickering GTIA modes + VSCROL trick like this:

 

attachicon.gifbird.emu.pngattachicon.gifmetroid.emu.pngattachicon.gifsamus.emu.png

attachicon.gifbird.png.xexattachicon.gifmetroid.png.xexattachicon.gifsamus.png.xex

 

Though for my taste this flickers too much without frame blending enabled.

 

Well, a lot of flicker modes look fine on real hardware, even when they don't look good in Altirra without frame blending enabled. But this has too much flicker even on real hardware, at least with the brightness values that are being used.

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There are other combinations possible using GTIA modes, with perhaps less flickering.

 

By using a Graphics 9 screen but changing the COLBK register between two opposite colors on the color wheel, you get 256 colors based out of a duo-shaded palette, which will flicker a lot less.

 

You can also mix Gr. 10 with 9 to get a RIP style effect of course at 144 colors.

 

You can also just use straight Graphics 10, and alternate pixels on differing scanlines with no register changes needed. When blended, you get 45 colors, but you can use checkerboard dithering to reduce alot of the flicker.

Edited by Synthpopalooza

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I am surprised no one has mentioned this before though: Blending PMG's atop of Graphics 9. Isn't there some setting (PRIOR=64) that allows the PMG's to mix atop Graphics 9, and also with each other to make new colors?

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@rpc_games

 

Okay! As promised: here are my truly meant apologies for my earlier behavior in the thread where you announced your game. This -indeed- is very promising, and looks like real quality work. Especially the picture with the vertical bars. It's amazing.

 

Sorry for being impatient. It's great to see what you are doing!

 

Greetz

Marius

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I don't know why and where I get these strange notions and I'm completely out of my league and absolutely incompetent when it comes to expressing such ideas, much less implementing them (that is, I really don't know if they are possible or not, but I indulge myself the idea, anyways), but while trying to wrap my head around the various experiments I've seen presented here on Atariage, with modes based on shifting memory from one mode to another, without clearing the registers, Synths Font-icized modes, notes on building screens from PMGs, GTIA transparency, use of PRIOR, etc, I've somehow locked onto this fantasy; that it might be possible to create and smoosh together a Font underlay monochrome layer, along with a built-up color screen layer on top; the luminance layer bleeding through and lending shading to the image. But somehow I instictively know that there wouldn't be enough cycles, however it is implemented, except for some very low-res samples, much less a full screen or an actual working game. *shakes head*

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I am surprised no one has mentioned this before though: Blending PMG's atop of Graphics 9. Isn't there some setting (PRIOR=64) that allows the PMG's to mix atop Graphics 9, and also with each other to make new colors?

 

That was what I thought first too. But I did not came to so many colors on one scan line then. When you have positioned a PM on one side, you can not position it again somewhere else (well, without flicker).

 

The Little Color Demo from High Teach Team uses that kind of technique. It's an old demo, which is pretty cool.

 

 

 

 

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I don't know why and where I get these strange notions and I'm completely out of my league and absolutely incompetent when it comes to expressing such ideas, much less implementing them (that is, I really don't know if they are possible or not, but I indulge myself the idea, anyways), but while trying to wrap my head around the various experiments I've seen presented here on Atariage, with modes based on shifting memory from one mode to another, without clearing the registers, Synths Font-icized modes, notes on building screens from PMGs, GTIA transparency, use of PRIOR, etc, I've somehow locked onto this fantasy; that it might be possible to create and smoosh together a Font underlay monochrome layer, along with a built-up color screen layer on top; the luminance layer bleeding through and lending shading to the image. But somehow I instictively know that there wouldn't be enough cycles, however it is implemented, except for some very low-res samples, much less a full screen or an actual working game. *shakes head*

 

I think Assembloids is using a hi-res + GTIA mode. They said the mode was new to the Atari...

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I am surprised no one has mentioned this before though: Blending PMG's atop of Graphics 9. Isn't there some setting (PRIOR=64) that allows the PMG's to mix atop Graphics 9, and also with each other to make new colors?

 

I believe that is because you can only mix the color of the missiles (acting as the fith player, so using the same color) against the gtia 9 luminances. So you can have something like this:

post-11240-0-95344600-1401166194_thumb.png

The 4 red and green zones are the missiles at 4x width (you can cover only that small area).

 

Sure, you could replicate the missiles and change their color with midline changes, but that takes a lot of time.

 

Well, with this I fall in the camp of non believers I suppose, because that looks like something with flickering, but with the flicker hide in some way (I'm assuming that this is a mode that could be used for gameplay, not just an static screen.. we have seen incredible pictures with RastaConverter already).

The only proof for me would be one of those pics in a file so everybody can test it in Altirra (or someone that we can absolutely trust, like Phaeron for example :) )

As much as I would like this to be true (a new mode that no one has ever seen), the idea that the flicker was hidden on purpose and the secretiveness behind this graphic mode (when the important thing should be the game), doesn't paint a nice picture in my mind.. please, prove me wrong x)

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On GR9 you'll get oring in the Missiles as 5th Player. They are one colour (take PF3) and over the 16shades of GR.9 they are now Missile colour and get the luminance of the pixel they are over.

Because they are 4 they can be at 4 different xPos but maximum per scanline will always be the 2colours/16+16luminances (GR.9+Missiles).

The 4Players are always 4colours and no mater to what PRIOR number you add into 64 it's always same: Players over GR.9 pixels (works like in other modes PRIOR1) and not a single oring.

Edited by José Pereira

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That's a really impressive demo that you've put out there Pete. Yes, you are blowing people away with your results which is fantastic. You have pleasantly surprised a lot of people.

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Video capture will usually do frame blending. It can also make modes like APAC look more "solid" than they actually are.

 

I get the feeling though that these pics use a flicker technique.

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Video capture will usually do frame blending. It can also make modes like APAC look more "solid" than they actually are.

 

I get the feeling though that these pics use a flicker technique.

 

Strangely enough, I was thinking exact the opposite. I thought: this look very stable, and although there is some fuzz in the signal, it looks extremely sharp.

 

I also can not believe -when I think of all the discussion rpcgames and a lot of members (including myself) had before- he would now release something (disappointing) with flicker.

 

Let's state it different: when it is with flicker, I would be disappointed; and I think I will give rpcgames the benefit of the doubt now. Until not is proven that there are some 'fake' tricks used, I believe him from now on. I really hope I will not have to change my mind (again). Atari is fun, and obviously not everything has discovered yet!

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as Rybags said... looking good in youtube but youtube does 25 frame blending... and I am 100% sure that this mode demo coders would use for ages when these 4x4 modes were top notch. VSCROL trick might reduce the DMA but for me when not flickering it's heavy on DLI while when flickering it will looking OK when colors choosen well and watching on old TVs (PAL worther than NTSC) but in emulators it will suck... ;)

 

but I am pationed to see what it is all about. :)

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Looks to me like flickering GTIA modes + VSCROL trick like this:

 

That's exactly what I thought, but I'm unsure about the VSCROL trick -

just simple LMS repeating fits better to the Basic based approach... ;)

 

But there are also good news: The company seems to be so big, that the manager cannot adjust/break its policies... :grin:

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Looks to me like flickering GTIA modes + VSCROL trick like this:

...

Though for my taste this flickers too much without frame blending enabled.

Kinda looks exactly like Altirra with blending enabled...

 

Well, we can always play it in Altirra if it flickers too much on Tv :)

 

@Pete: make it fast, make it explode stuff, make lots of sprites... Me happy :)

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Looks like GTIA Paletted (10) - the half-pixel shift is there. Check by hovering the mouse at the right of the text screen just before it transitions to a picture.

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I think you're right. Here's what it shows just as the load finishes:

post-3606-0-03336700-1401196863_thumb.jpg

post-3606-0-74618300-1401196876_thumb.jpg

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