Flickery Graphics

[snicklin]

 

If I may say, you should definitely get a graphician, maybe Irgendwer volunteers

It makes a big difference. And personally, when I spend my time coding a game I would like it to look (and sound) good as well.

 

That's ok, I have what some call "programmers graphics" and I know it.

 

And as for the sound, Miker has that sorted.

[snicklin]

I am reading this thread now since you started it and it gives me lot's and lot's of ideas how to do things. Thank you for that!

 

I've also had a look at RPG from peteym5 ...

 

I'm glad that it is of help. With regards to the games ideas, I take some inspiration from kiwilove that you need to do things which others haven't seen before.

 

As for the graphical techniques, there has been a lot of helpful information on here.

 

And as for RPG, yes, I didn't notice flicker in this game and it is well handled. That is what I look for.

[Synthpopalooza]

One of the reasons that RPG's flicker isn't bad is because of Super IRG. Unlike other flicker modes (e.g. Space Harrier) there are no color palette changes, so you can checkerboard the colors to make an interlacing effect, while the primary pf colors themselves do not flicker.

 

In other flicker modes, like PCIN (12+10 with no color changes) this can also be done in a more limited fashion, where the pf colors blend on both frames.

 

If you are only designing with LCD TVs in mind, you could use all sorts of flicker mode combos. The tradeoff is it won't look that good on CRT monitors, especially in PAL systems.

[Synthpopalooza]

Here is an example of Super IRG-type modes taken to their extreme ...

 

http://atariage.com/forums/topic/203052-puzzle-bobble-on-a8-using-pcin-character-mode/?p=2608324

 

I did a series of Puzzle Bobble screens in a mode I called PCIN (Palette CIN) ... it's a Graphics 12+10 full-frame flicker mode without color palette changes. It involves a character set swap, plus a swap of the BAK register to allow for extra colors and to ensure a non-flickering border. You can get 35 colors (30 per char cell) at once, but there is a bit more flicker here ... you can have solid colors where the same PF color blends on both frames, and dithered colors when blending PF colors like in Super IRG, but blending with the PM1-PM3 and the 9th (BAK mode 10) color require full-frame flicker.

 

It's also a tricky mode in that you have to swap display lists (Antic 4 and Antic 2) every VBLANK, and you also have to set the Antic 2 to horizontal scrolling and store a 13 in HSCROL, this gets the Antic 2 characters to slide over one color clock and line up with the mode 10 graphics. It also is not recommended for PMG usage, they will flicker because they don't show up in mode 10, plus PM0 would be invisible anyway (it's the BG color).

 

I also had a bit of a brainstorm tonight ... would it be possible to combine a 160x96 PAL blending mode in Antic 4, with a Super IRG-style character set swap? I think it would be possible to get 126 colors onscreen at this resolution using this method, and you could checkerboard dither the colors like in Super IRG to reduce flicker. So, line one would be the color part of the display, and for line 2, you'd have luma 2 at PF3, lumas 4, 6, 8, sequentially from PF0 to PF2. When you blend lumas, make them within two steps of each other. This would get you 14 chromas by 9 lumas, roughly.

 

And if you used this same method in APAC (9+11) but using text mode, I think you could get something north of 4,096 colors at 80x96. The key is, when blending the Gr. 9 lines, make sure each blended luminance is within one step of the next. This would get you 136 chroma x 31 lumas.

Edited January 27, 2015 by Synthpopalooza

[snicklin]

Well, it seems like that there are plenty of options. I remember seeing the Puzzle Bobble screens a while ago and thought that they looked good.

 

Has anyone ever documented all of these mode combinations anywhere (other than in the forum)?

[Synthpopalooza]

The closest there is, likely, is a series of articles I wrote for the Atari User mag in 2011, covering the most useful of these modes. I wrote 3 articles, and I will try to see if I can find those tonight.

[TheNameOfTheGame]

The closest there is, likely, is a series of articles I wrote for the Atari User mag in 2011, covering the most useful of these modes. I wrote 3 articles, and I will try to see if I can find those tonight.

 

That would be great!

 

Would be nice to get all the newest techniques put into the Ironman Atari document so it was up to date...

[Synthpopalooza]

Just realised, I am going to have to rewrite some of that article. Seems that one of the modes I described (PCIN low res, graphics 12+12.10) described inaccurate behaviour of Graphics 10 under Antic 4, which the emulator I had at the time rendered incorrectly. A lot of work to do. Agreed, it'd be great to have this info on the Wiki. I have been considering also, a "Super IRG and ICE editor for beginners" wiki article, to give tips for people new to doing graphics in these modes.

Edited January 28, 2015 by Synthpopalooza

[Synthpopalooza]

For anyone who's interested, I found those articles I wrote for Atari User ... all three are in a zip file. A couple of caveats:

 

I haven't covered all the possible combinations of Super IRG modes (there are nearly 20, not counting the Graphics 1 Super IRG modes which came about after this article).

 

Also, the description for the hardware mode Graphics 12.10 (Antic 4 with GPRIOR set to $80 for Graphics 10), and the resulting low res PCIN mode (PCIN 12/13) are inaccurate. You can blame emulation for this, prior to Altirra 2.0, there were no emulators which showed this mode properly. The culprits are color patterns 1000 (both normal and inverse chars), and 1100 inverse (or ATASCII>127). On a real Atari these return the BAK (712) color, but on the emulator they incorrectly displayed PF0 (708) instead. I will need to rewrite this section.

 

I'm also going to write up documentation for the Graphics 1 modes as well, including full documentation of GTIA mode behavior when using Graphics 1 and 2.

 

These were written as "type-in" examples, just like the old COMPUTE! days. I may still have the ATR's around somewhere.

super irg modes.zip