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Old 23 September 2015, 23:13   #1
Photon
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OCS demo, Blu Sky

Long overdue, I've been busy with another prod. I even forgot to post the release on scoopex1988.org, which says something. Will try to correct that now

Blu Sky by Scoopex
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Old 24 September 2015, 21:06   #2
Fell
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Loved it, honoured to be in the same compo (and beaten by it)

Anything for TRSAC or would that be a secret? Just trying to get an idea if an Amiga compo could be had..
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Old 25 September 2015, 19:52   #3
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Beautiful dentro.
We find well the spirit of old production on Amiga.
Thank you for this journey.
Can be that if the demo had been a little longer we would have been able to have a better demo but sometimes the quality is better than the quantity.
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Old 26 September 2015, 19:53   #4
ReadOnlyCat
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Short but nice!

Nice use of HAM to avoid filling polygons.
I guess you must pre-fill the background with a HAM constant blue color?

Have you measured how many such polygons this allows you to draw per frame? I guess that's solely limited by blitter line drawing speed?
I often find myself wishing the Amiga had a variable bitplanes HAM mode.
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Old 27 September 2015, 20:56   #5
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Nice one, and a really great opening with the sweeping logo!
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Old 02 October 2015, 00:00   #6
Photon
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Thanks, I appreciate it

Quote:
Originally Posted by ReadOnlyCat View Post
Short but nice!

Nice use of HAM to avoid filling polygons.
I guess you must pre-fill the background with a HAM constant blue color?

Have you measured how many such polygons this allows you to draw per frame? I guess that's solely limited by blitter line drawing speed?
I often find myself wishing the Amiga had a variable bitplanes HAM mode.
Yes and yes

I chose HAM5 to draw a little less lines, because the line count escalates. The break-even point just to save the polygon filling comes pretty soon. But with the right application and object, perhaps something could be done.
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Old 02 October 2015, 16:03   #7
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Quote:
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Thanks, I appreciate it


Yes and yes

I chose HAM5 to draw a little less lines, because the line count escalates. The break-even point just to save the polygon filling comes pretty soon. But with the right application and object, perhaps something could be done.
I see.
Can line mode use a pattern? If it could I guess you could save a bit of setup time by using interleaved bit planes for the first 4 planes and drawing a single patterned line.
This said, I seem to recall that line mode cannot draw patterns.
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Old 02 October 2015, 20:48   #8
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It certainly can! Unfortunately, a single line loses you time if it's 4x as long, since you couldn't skip drawing into some bitplanes. Darnit!
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Old 02 October 2015, 23:43   #9
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Quote:
Originally Posted by Photon View Post
It certainly can! Unfortunately, a single line loses you time if it's 4x as long, since you couldn't skip drawing into some bitplanes. Darnit!
I think it's possible to find a kind of compromise allowing to make this still "profitable". I'll post it when I'm back at home.

Update: Actually, after thinking about it I think the idea I had is not valid.

The principle would have been to count and sort the lines to be drawn by their color (== bitplane pattern) so as to know which bitplanes are the ones which most often need to be written to.
Once that is known, the copper would then be used instead of the modulos to invert the bitplanes order (at each line) so that the bitplanes which need to be written to the most are first in memory (but not necessarily for determining the color index). (*)
Then, you can draw each line, either by batches of 1, 2 or 4 depending on that line's color, thus choosing the most efficient blit(s) for each line.

It would be great if this worked with three but unfortunately drawing the line over three interleaved bitplanes would result in unaligned pixels between the planes.

Maybe this system would be worth activating on some frames depending on the types of lines to draw but I am not sure if this is viable in general.

Sorry.

(*) Actually that might not be necessary, reordering the colors in the palette might be enough depending on the method you use to select the luminosity of each polygon.

Last edited by ReadOnlyCat; 03 October 2015 at 08:04. Reason: Added mentioned idea. Re-clarified.
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Old 26 August 2017, 06:42   #10
Steril707
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Supernice...
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Old 26 August 2017, 08:48   #11
Crown
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HI Photon,

this is a great release, love it.

Could you send me the music in .mod format? would be cool

take care
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