English Amiga Board


Go Back   English Amiga Board > Main > Retrogaming General Discussion

 
 
Thread Tools
Old 29 January 2021, 23:49   #201
DanScott
Lemon. / Core Design

DanScott's Avatar
 
Join Date: Mar 2016
Location: Tier 5
Posts: 955
You could even scroll the screen vertically, and do a vertical perspective effect with it too

Now THAT would look cool for a unique Amiga fighting game, rather than trying to convert SFII
DanScott is offline  
Old 30 January 2021, 00:01   #202
ross
Defendit numerus

ross's Avatar
 
Join Date: Mar 2017
Location: Crossing the Rubicon
Age: 50
Posts: 3,213
There is however something very optimistic about the video: it relies heavily on BPLCON4 split.
Ok, simple to do vertically, as well as the horizontal and vertical multiplex of the sprites.
But how to easily couple the horizontal multiplex of the sprites with the horizontal colors split using BPLCON4?

Last edited by ross; 30 January 2021 at 00:07. Reason: I no longer remembered if it was BPLCON3 or 4 :D
ross is offline  
Old 30 January 2021, 00:17   #203
roondar
Registered User

 
Join Date: Jul 2015
Location: The Netherlands
Posts: 2,755
Yeah, I saw that too. Asked the author about it on YouTube, he told me that the last bit with BPLCON4 rectangular areas was a kind of "prototype" made on modern hardware, some things were not final about that.

Anyway, he's apparently using the automatic sprite multiplexing that AGA offers, where sprites repeat after 256 pixels by themselves.
roondar is online now  
Old 30 January 2021, 00:25   #204
ross
Defendit numerus

ross's Avatar
 
Join Date: Mar 2017
Location: Crossing the Rubicon
Age: 50
Posts: 3,213
Quote:
Originally Posted by roondar View Post
Anyway, he's apparently using the automatic sprite multiplexing that AGA offers, where sprites repeat after 256 pixels by themselves.
Does not appear that way from the video, observe how many times the clouds are replicated. With sscan2 you can have only two copies and using more sprites..

Moreover, a so close colors split for the passengers of the boat is very complicated, the copper is not so fine (and need to compete with the BPL DMA).
A way could be to 'alternating grouping' it with different colors of the palette, but that way you should reduce them considerably, or simply space out the people.
ross is offline  
Old 30 January 2021, 00:27   #205
DanScott
Lemon. / Core Design

DanScott's Avatar
 
Join Date: Mar 2016
Location: Tier 5
Posts: 955
It would appear that the video is just showing mainly some ideas, and not an actual Amiga AGA implementation. I fear that they WILL have some issues and have to backtrack on some things perhaps...

However they ARE thinking along the same lines as I've been thinking about a few things here and there
DanScott is offline  
Old 30 January 2021, 00:34   #206
roondar
Registered User

 
Join Date: Jul 2015
Location: The Netherlands
Posts: 2,755
Quote:
Originally Posted by ross View Post
Does not appear that way from the video, observe how many times the clouds are replicated. With sscan2 you can have only two copies and using more sprites..
As I understood the video, he just used all 8 sprites for the clouds etc and reused them that way, but maybe I'm mistaken here.

Quote:
Moreover, a so close colors split for the passengers of the boat is very complicated, the copper is not so fine (and need to compete with the BPL DMA). A way could be to grouping it and 'alternate' it with different colors of the palette, but that way you should reduce them considerably, or simply space out the people
Yeah, this is the bit that he pre-viewed on PC. I pointed out on YT that BLPCON4 changes could be delayed by up to 16 pixels due to DMA and he said that the current version is just a preview and that the end result would likely have more space between the passengers.

Anyway, it's still a very interesting result and one that shows that with lots of time and passion AGA can do very neat stuff
roondar is online now  
Old 30 January 2021, 00:44   #207
ross
Defendit numerus

ross's Avatar
 
Join Date: Mar 2017
Location: Crossing the Rubicon
Age: 50
Posts: 3,213
Yes, I absolutely do not want to be in contrast with the attempt (quite the opposite!), the ideas are good, and as Dan says these ideas have crossed various mind.
I know AGA can do great things. But better not to overdo the expectations
ross is offline  
Old 30 January 2021, 05:58   #208
saimon69
J.M.D - Bedroom Musician

 
Join Date: Apr 2014
Location: los angeles,ca
Posts: 1,787
Quote:
Originally Posted by ross View Post
Yes, I absolutely do not want to be in contrast with the attempt (quite the opposite!), the ideas are good, and as Dan says these ideas have crossed various mind.
I know AGA can do great things. But better not to overdo the expectations
To be crazy in my opinion they could even do a decent ECS version, but will need to redo the player bobs in cel shaded style characters similarly to Shadow Fighter to have proper 8 colors... at that point, though, indeed will NOT be an arcade perfect port but rather an interesting reinterpretation...

[ Show youtube player ]
saimon69 is offline  
Old 30 January 2021, 07:38   #209
Steril707
Tigerskunk!

Steril707's Avatar
 
Join Date: Sep 2016
Location: Amiga Island
Posts: 1,977
Quote:
Originally Posted by ross View Post
Moreover, a so close colors split for the passengers of the boat is very complicated, the copper is not so fine (and need to compete with the BPL DMA).
A way could be to 'alternating grouping' it with different colors of the palette, but that way you should reduce them considerably, or simply space out the people.
That was my observation as well.
I am not sure the copper can change so many colors in line this fast.
Also, while it's certainly possible to switch colors in line, it's a HUGE PAIN IN THE ASS while scrolling the whole scenery.

Writing that copper list dynamically each frame with palette swaps AND sprites being multiplexed as well horizontally will take some resources that he is not talking about in the video. And some crazy coding.

I experimented with this stuff a lot in my beginnings of my engine when it was still dual playfield and I was looking for ways to get more than 7 colours in the foreground, and I decided not to do it.

So, great video, but in the end it's simplifying things a bit too much too make it look more clever than it actually is.
Steril707 is offline  
Old 30 January 2021, 08:58   #210
aros-sg
Registered User

 
Join Date: Nov 2015
Location: Italy
Posts: 69
Quote:
Originally Posted by Toni Wilen View Post
Perhaps it is possible to have almost all sprites by taking advantage of bitplane DMA overrun situation (http://eab.abime.net/showthread.php?p=1144664)

Btw, what about hires/superhires? 64 superhires pixels look like 16 lores pixels. Do all sprites work on a standard non scrolling superhires resolution?


Superhires needs to "load" 64 pixels in 4 times shorter time. Could this be abused by switching from lores to superhires to lores in each scanline?
aros-sg is offline  
Old 30 January 2021, 09:53   #211
chb
Registered User

 
Join Date: Dec 2014
Location: germany
Posts: 320
Quote:
Originally Posted by aros-sg View Post
Superhires needs to "load" 64 pixels in 4 times shorter time. Could this be abused by switching from lores to superhires to lores in each scanline?
No, the DMA slots for sprites are fixed, and they always load the same amount of data to the sprite registers for all sprite and display resolutions - just depending on the sprite width/fetchmode.
chb is offline  
Old 30 January 2021, 10:21   #212
ross
Defendit numerus

ross's Avatar
 
Join Date: Mar 2017
Location: Crossing the Rubicon
Age: 50
Posts: 3,213
Quote:
Originally Posted by aros-sg View Post
Superhires needs to "load" 64 pixels in 4 times shorter time. Could this be abused by switching from lores to superhires to lores in each scanline?
There had been a user attempt for something like this.
Also for changing FMODE during the line.
I seem to remember that the attempts had not gone so well...
ross is offline  
Old 30 January 2021, 10:27   #213
ross
Defendit numerus

ross's Avatar
 
Join Date: Mar 2017
Location: Crossing the Rubicon
Age: 50
Posts: 3,213
Quote:
Originally Posted by chb View Post
No, the DMA slots for sprites are fixed, and they always load the same amount of data to the sprite registers for all sprite and display resolutions - just depending on the sprite width/fetchmode.
The main idea here is only to 'anticipate' the pixels to video, a shift of 64 in shires is only 16 pixels, so even with DDFSTRT=$38 you do not have to use a big DIWSTRT.
Then switch to lores during line.
But I see it as difficult or impossible to implement for different reasons
ross is offline  
Old 30 January 2021, 12:45   #214
chb
Registered User

 
Join Date: Dec 2014
Location: germany
Posts: 320
Quote:
Originally Posted by ross View Post
The main idea here is only to 'anticipate' the pixels to video, a shift of 64 in shires is only 16 pixels, so even with DDFSTRT=$38 you do not have to use a big DIWSTRT.
Then switch to lores during line.
But I see it as difficult or impossible to implement for different reasons
I think I understood the question wrong - I thought it was about shires sprites, but it wasn't. Thanks for pointing that out.

BTW, you were at some point investigating the possibility to compensate the 64 pix shift to the right by fiddling with the hsstrt/hsstop registers, IIRC? In theory one should be able to do that, but it might be necessary to have a higher value for hsstop than for hsstop to compensate a full 64 pixels. Did you have some success with that approach?
chb is offline  
Old 30 January 2021, 13:11   #215
ross
Defendit numerus

ross's Avatar
 
Join Date: Mar 2017
Location: Crossing the Rubicon
Age: 50
Posts: 3,213
Quote:
Originally Posted by chb View Post
BTW, you were at some point investigating the possibility to compensate the 64 pix shift to the right by fiddling with the hsstrt/hsstop registers, IIRC? In theory one should be able to do that, but it might be necessary to have a higher value for hsstop than for hsstop to compensate a full 64 pixels. Did you have some success with that approach?
Yes, I did it many years ago when I still had a real A1200.
I definitely have some test code.
I don't remember exactly the results and the disadvantages but surely something worked
I would need a real AGA machine..
ross is offline  
Old 30 January 2021, 17:56   #216
vulture
Registered User
 
Join Date: Oct 2007
Location: Athens , Greece
Posts: 1,235
There's a mention of a Mortal Kombat AGA demo by a french coder, anybody knows more about this?
vulture is offline  
Old 30 January 2021, 18:30   #217
Toni Wilen
WinUAE developer
 
Join Date: Aug 2001
Location: Hämeenlinna/Finland
Age: 46
Posts: 24,692
Quote:
Originally Posted by ross View Post
Well, Toni is needed

DDFSTRT=$36 seems the right value but it fail to overrun (maybe not emulated?)
DDFSTRT=$38 works but it destroy SPR1 and SPR2 that's bad because you loose 2 16 colors sprite (you maintain 2 x 4 colors + 2 x 16 colors)
DDFSTRT=$34 is what you see in previous message (3 x 16 colors sprites + 1 x 1 color, loss 1 channel audio)
I don't think emulation is perfect yet, nothing is guaranteed This is quite special edge without any good real world test cases.

But at least check DMA debugger (v-command) to see which cycles overrun bitplane cycles use. (v <line> to see the beginning, for example v <line> 160 to see the end).
Toni Wilen is online now  
Old 30 January 2021, 20:56   #218
ross
Defendit numerus

ross's Avatar
 
Join Date: Mar 2017
Location: Crossing the Rubicon
Age: 50
Posts: 3,213
Quote:
Originally Posted by Toni Wilen View Post
I don't think emulation is perfect yet, nothing is guaranteed This is quite special edge without any good real world test cases.

But at least check DMA debugger (v-command) to see which cycles overrun bitplane cycles use. (v <line> to see the beginning, for example v <line> 160 to see the end).
HARDDIS work in WinUAE only if coupled with a variable beam counter bit active. (example: BEAMCON0=$4020 doesn't enable it)
Is this an expected behavior?

EDIT:
An observation.. I have always assumed (but not found written confirmation) that the possible deactivation of the sprites DMA is from the value in DDFSTRT, this even if the bitplanes activated in BPLCON0 did not 'compete' with the used sprites channels (this is even more unfortunate in AGA where the fetch is blocky, so many DMA slots are possibily unused..).
This is why the DMA overrun would allow high numbered sprites to eventually work (the comparison for deactivation is not reached because DDFSTRT > of the fetch position for the sprites).
Is this right?

Last edited by ross; 30 January 2021 at 21:37.
ross is offline  
Old 31 January 2021, 11:26   #219
redblade
Zone Friend

redblade's Avatar
 
Join Date: Mar 2004
Location: Middle Earth
Age: 37
Posts: 1,685
Quote:
Originally Posted by vulture View Post
There's a mention of a Mortal Kombat AGA demo by a french coder, anybody knows more about this?
Yes it is on the French Amiga site. obligement.fr (I think that is the word) under the Assembler section.

Quote:
Originally Posted by saimon69 View Post
To be crazy in my opinion they could even do a decent ECS version, but will need to redo the player bobs in cel shaded style characters similarly to Shadow Fighter to have proper 8 colors... at that point, though, indeed will NOT be an arcade perfect port but rather an interesting reinterpretation...

[ Show youtube player ]
I never knew that the fighters were 8 colour sprites. It's great to see how they used the sprite for the energy bar at the top.

I really liked that game, If it was released in 93 they would have sold a lot more copies. Some good techno songs on that as well.
redblade is offline  
Old 31 January 2021, 14:35   #220
kremiso
Registered User
 
Join Date: Dec 2020
Location: Italy
Posts: 168
Another randomly find that could be useful to share here.
I'm trying a longplay with Bubble & Squeak AGA atm, and i have reached the 'Neon City' set of levels, imo nice upgraded despite the standard Amiga version, expecially for the use of some changing colors effects.
Prolly those levels were lastly developed, seems a little better dedicated work;
i can't find any video on tube, i'll share some pictures here, but obviously they can't return the changing effect;
little shame also because, due the game difficulty, that environment has prolly been explored by not too much players

This is the standard Amiga longplay, and the correct level starts at 1.18.40 (Neon City part2) :
[ Show youtube player ]

This instead is the longplay of that level alone, but on Megadrive;
i must say, even more effects, but less colors than AGA
(strangely on Megadrive is called Neon City part 3) :
[ Show youtube player ]

At last, two screenshots taken from the AGA release :
Attached Thumbnails
Click image for larger version

Name:	b&s.PNG
Views:	114
Size:	230.1 KB
ID:	70697   Click image for larger version

Name:	b&s2.PNG
Views:	102
Size:	257.8 KB
ID:	70698  
kremiso is offline  
 


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Similar Threads
Thread Thread Starter Forum Replies Last Post
Bordersprites restrictions (AGA chipset) dissident Coders. Asm / Hardware 22 01 February 2019 23:37
Money Matters 4 (AGA chipset issue) Zarnal support.WinUAE 2 31 May 2018 19:10
How to detect AGA chipset installed from C? earok Coders. C/C++ 3 04 June 2016 02:31
Best way of detecting the AGA chipset? Steve Coders. Asm / Hardware 13 25 January 2014 22:08
EHB sprites with AGA chipset ? FrenchShark Coders. General 4 17 September 2009 06:37

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +2. The time now is 14:29.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, vBulletin Solutions Inc.
Page generated in 0.10618 seconds with 14 queries