New Atari STE Blitter objects demo (24 Bobs)

[Anima]

Two years later and after some optimizations here's a new attempt on drawing 32 x 32 pixel Bobs on an Atari STE:

https://www.youtube.com/watch?v=x1ekLXdo-2c

Disk image, program and sources here:
http://atomic-skulls.de/temp/atari/fastbobs.zip

[GokMasE]

Cool, that looks incredibly smooth!

I can't helt wondering though, where ever did you find enough room for code improvements compared to the 23 bobs demo..?

[Cyprian]

@Anima great
one more sprite and opened border? how did you reach that?

[Anima]

I can't helt wondering though, where ever did you find enough room for code improvements compared to the 23 bobs demo..?

Well, it was mainly the elimination of empty endmasks (ENDMASK = $0000) which were responsible for a gain of 48 cycles each. Also, the object clearing routine has been improved as well.

[Anima]

@Anima great
one more sprite and opened border? how did you reach that?

Thanks!

I've chosen the 320 x 256 display size because AFAIK this demo cannot be reproduced ("beaten") on the Amiga 500 even when hardware sprites will be used.

I can't helt wondering though, where ever did you find enough room for code improvements compared to the 23 bobs demo..?

Well, it was mainly the elimination of empty endmasks (ENDMASK = $0000) which were responsible for a gain of 48 cycles each. Also, the object clearing routine has been improved as well.

[masteries]

Excelent Anima!

Incredible work,

At Metal Slug port, using DML´s EMX2 (that comes from your sprites format if I remember well)
I reached up to 18 32x32 pixels bob at 50 Hz, custom clearing, with 3 voices at 12.5 KHz audio mixer running.

But 24 bobs with audio playback, almost all screen filled


I am sure that following your demo sprite procedure,
20 bobs could be displayed with the audio mixer running.

[Anima]

Excelent Anima!

Incredible work,

At Metal Slug port, using DML´s EMX2 (that comes from your sprites format if I remember well)
I reached up to 18 32x32 pixels bob at 50 Hz, custom clearing, with 3 voices at 12.5 KHz audio mixer running.

But 24 bobs with audio playback, almost all screen filled


I am sure that following your demo sprite procedure,
20 bobs could be displayed with the audio mixer running.

Thanks.

I'll prepare a version with proper background restoration. I am not sure how many Bobs will survive but we'll see...

[TheNameOfTheGame]

Superb!

[Eero Tamminen]

Looks great, and works also with EmuTOS! Is there pouet.net or demozoo entry yet for this?

[keops]

Nice. Thanks for including the source code. I'll probably have a look at it if I ever find some time to play with STE features

[Anima]

Superb!

Looks great, and works also with EmuTOS! Is there pouet.net or demozoo entry yet for this?

Thanks.

Well, no. I haven‘t published anything on those sites yet.

[Anima]

Nice. Thanks for including the source code. I'll probably have a look at it if I ever find some time to play with STE features

You‘re welcome.

[Eero Tamminen]

When testing under Hatari, it does not appear to work with ST + blitter or TT. Blitting is broken with MegaSTE. With Falcon / ST-low, blitting works, but sound is broken. Any idea how blitting can work fine with STE + Falcon, but be broken under MegaSTE?

[Cyprian]

When testing under Hatari, it does not appear to work with ST + blitter or TT. Blitting is broken with MegaSTE. With Falcon / ST-low, blitting works, but sound is broken. Any idea how blitting can work fine with STE + Falcon, but be broken under MegaSTE?

it could be connected with the fact that Mega STE's BLiTTER takes 1 more bus cycle (4 CPU 8Mhz cycles) per every pass

[EvilFranky]

Nice work Anima!

When testing under Hatari, it does not appear to work with ST + blitter or TT.

Is that not down to the demo using STE sound? And no blitter in the TT?

[metalages]

Would it be possible to use the full 336x273 "easily" accessible surface ?

[stormy]

.

Anima I've always wanted to ask you, with Cho-Ren-Sha-68k, while it is amazing it would be even more amazing with music. What if you used the YM chip in the Falcon to make music without any CPU overhead?

I appreciate this is an old project, but just wondering!

[Eero Tamminen]

When testing under Hatari, it does not appear to work with ST + blitter or TT.

Is that not down to the demo using STE sound? And no blitter in the TT?

Ah, I did not realize it using STE sound, but that does make sense as it uses less cycles. And I forgot that TT lacks a blitter (I guess it would be slower than CPU, so that makes sense too).

[Anima]

Ah, I did not realize it using STE sound, but that does make sense as it uses less cycles. And I forgot that TT lacks a blitter (I guess it would be slower than CPU, so that makes sense too).

Besides the Atari STE sound the "linewid" register is being used as well so unfortunately it's a bit more work to fix it to get it working for the Atari ST.

[Anima]

Anima I've always wanted to ask you, with Cho-Ren-Sha-68k, while it is amazing it would be even more amazing with music. What if you used the YM chip in the Falcon to make music without any CPU overhead?

I think the Atari Falcon deserves a bit more than the YM sound...

But seriously: the best would be a X68000 sound chip emulation running on the DSP but thats quite much IMHO.

[Anima]

Would it be possible to use the full 336x273 "easily" accessible surface ?

Uh yes... Well, why not!? Probably quite easy to implement!? I'll have to check that...

[metalages]

Would it be possible to use the full 336x273 "easily" accessible surface ?

Uh yes... Well, why not!? Probably quite easy to implement!? I'll have to check that...

If you have 256 pixels available vertically I suppose you have opened both upper and low border ? (on STe if I well understand the resolution is 273 when vertical borders are opened)

In order to open left additionnal 16 pixels you just have to write just once (in a shifter "safe" place) something like :
move.b #1,ffff8265.w
clr.b ffff8264.w

[Anima]

If you have 256 pixels available vertically I suppose you have opened both upper and low border ? (on STe if I well understand the resolution is 273 when vertical borders are opened)

In order to open left additionnal 16 pixels you just have to write just once (in a shifter "safe" place) something like :
move.b #1,ffff8265.w
clr.b ffff8264.w

Thanks. Yes, that works. Here's a screenshot @ 336 x 273:

[metalages]

If you have 256 pixels available vertically I suppose you have opened both upper and low border ? (on STe if I well understand the resolution is 273 when vertical borders are opened)

In order to open left additionnal 16 pixels you just have to write just once (in a shifter "safe" place) something like :
move.b #1,ffff8265.w
clr.b ffff8264.w

Thanks. Yes, that works. Here's a screenshot @ 336 x 273:

Pretty cool
That's more than 10% additionnal display

[shoggoth]

This stuff makes me tingly.