interesting effect

[Rybags]

Cool... I think it might look better with bigger, fewer crosses though.

[dmsc]

Hi!,

 

Cool... I think it might look better with bigger, fewer crosses though.

Second try, this has fewer crosses moving, with black ones moving in counter direction, I think that now is just like the original.

crosses2.atr

[José Pereira]

Hi. Thanks, seems great but sadly I can't see them now.

Are they rotating?

Can you please change to black and white to have a better distinct dark to bright and like the original? Just because most of A8 darkest luminance, the 0, are too bright (two good colours for luminance 0 that 'fool eyes' as an almost black are colour 9 and 14).

Edited January 16, 2016 by José Pereira

[kiwilove]

Something like this?

 

atari000.png

 

A little turbo basic XL program, run attached ATR image.

 

It's not exactly the same, but IMHO close enough

Altirra comes up with a corrupt error when trying to access/run that .atr file.

[Was using an Altirra 2.0 - changed up to 2.7 which runs it fine.}

 

Only looked at ver 2.0 --- I do think it looks good.

 

I wonder if it can be worked to include tessellations as such - to have it slowly changing into something else? Like Escher's fish into birds kind of thing. It won't be something easy to work on - but if you experiment with it, maybe it can lead to interesting animations and such like?

All kinds of interesting possibilities can open up or not?

 

Harvey

Edited January 16, 2016 by kiwilove

[Rybags]

I tried modifying for different modes but it's no good as it relies on inverse video.

 

Would be nice to see it in Gr. 2 albeit with the chunky pixels that come with it.. or bigger crosses in Gr. 0 but it might mean less angles due to character shortage.

[popmilo]

Hi!,

 

 

Second try, this has fewer crosses moving, with black ones moving in counter direction, I think that now is just like the original.

crosses2.atr

Awesome! Saved me a day

Would you share details about how many chars,angles you used and such?

[analmux]

Second try, this has fewer crosses moving, with black ones moving in counter direction, I think that now is just like the original.

Interesting.

 

What's the total size of your programm and data?

[Rybags]

You can break the program and list it and check the data stuff in Dos.

 

The TurboBasic program practically fits in one screen.

From memory the other stuff was 1K for the charset + about 205 sectors worth of data.

[analmux]

Yes, I found it. Data is 25600 bytes, and the TBB program is only appr. 1 kB at max.

 

@ dmsc

 

Simple, but interesting. It is possible to write the data table directly into memory as a binary file. You made a small TBB file, and you can write it from page 64. Then only change the 3 LMS indexes on the display list per frame.

[flashjazzcat]

Hi!,

 

 

Second try, this has fewer crosses moving, with black ones moving in counter direction, I think that now is just like the original.

crosses2.atr

 

Brilliant - elegantly done.

[w1k]

wow

[popmilo]

Yes, I found it. Data is 25600 bytes, and the TBB program is only appr. 1 kB at max.

 

@ dmsc

 

Simple, but interesting. It is possible to write the data table directly into memory as a binary file. You made a small TBB file, and you can write it from page 64. Then only change the 3 LMS indexes on the display list per frame.

Don't tell me it's animation !? I would be disappointed

 

I was on the way to make it with half Kb of animation data (for 8 angles) and rest done with code...

 

@ dmsc: You get a trophy for "first published"

[+JAC!]

Hi!,

 

 

Second try, this has fewer crosses moving, with black ones moving in counter direction, I think that now is just like the original.

crosses2.atr

Congrats. Very nicely done.

[w1k]

..not working on real hw

[dmsc]

I tried modifying for different modes but it's no good as it relies on inverse video.

 

Would be nice to see it in Gr. 2 albeit with the chunky pixels that come with it.. or bigger crosses in Gr. 0 but it might mean less angles due to character shortage.

Attached is a version with twice big crosses: disk.atr

 

Sadly, adding more angle steps uses more than 128 characters, so it is not possible with the current approach.

 

 

Awesome! Saved me a day

Would you share details about how many chars,angles you used and such?

Last one has 64 frames, with 12 angle steps for the quarter turn.

 

Yes, I found it. Data is 25600 bytes, and the TBB program is only appr. 1 kB at max.

 

@ dmsc

 

Simple, but interesting. It is possible to write the data table directly into memory as a binary file. You made a small TBB file, and you can write it from page 64. Then only change the 3 LMS indexes on the display list per frame.

Yes, but then you need to keep track of the 4k boundaries, so the program would be more complicated. I opted for the simpler approach

 

Attached is also the C++ program used to generate the animations. At the start you can try modifying the definitions to try different animations, the program also writes images with the frames. Note the if the character count is more than 128, the output is invalid.

gen.zip

[+CharlieChaplin]

And errm, a simple A8 picture-demo with optical illusions (pictures!) can be found e.g. here:

http://a8.fandal.cz/detail.php?files_id=6624

[w1k]

NOT WORKING ON REAL HW

[Roydea6]

NOT WORKING ON REAL HW

These ATR's are actually XFD files with NO atr header. So use Atari800 Plus Win emulator and convert to ATR files.

[w1k]

atari800win emulator is like living in year 1999...... now its 2016 - altirra

but real hw is real hw

[dmsc]

Hi!,

 

NOT WORKING ON REAL HW

Sorry, but I tested in my Atari 800XL before posting, so I know that works on real hw.

 

These ATR's are actually XFD files with NO atr header. So use Atari800 Plus Win emulator and convert to ATR files.

That could be the problem, didn't know the header was needed. I use sio2linux, there it works ok.

 

Here are the 3 ATR with proper headers.

crosses.atr

crosses2.atr

cross-big.atr

[popmilo]

Attached is also the C++ program used to generate the animations. At the start you can try modifying the definitions to try different animations, the program also writes images with the frames. Note the if the character count is more than 128, the output is invalid.

Thanks for that!

Excellent code. Much can be learned from such a small program.

[Kyle22]

Very nice. One thing to try is add line 68 POKE 710,0 to give a black background instead of blue.

[+Stephen]

Something like this?

 

atari000.png

 

A little turbo basic XL program, run attached ATR image.

 

It's not exactly the same, but IMHO close enough

Very slick.

[kiwilove]

And errm, a simple A8 picture-demo with optical illusions (pictures!) can be found e.g. here:

http://a8.fandal.cz/detail.php?files_id=6624

It's good to see these running. Thanks.

 

Harvey

[kiwilove]

I think both versions look very effective.

Maybe have an option to change the colours or go into random colour mode?

[it does change colours - if you leave it running long enough - but it would be good to have this happening sooner or manually changeable].

Have variable speed animation,

if possible? Random maybe.

 

Harvey

Edited January 16, 2016 by kiwilove