Blitter Vertical Fill

28 January 2014, 22:40

Hi,

I was wondering, is it possible to set the blitter so that it fills vertical lines instead of horizontal?

Cheers,
71M

Leffmann · 29 January 2014, 01:17

Yes, but it requires one Blitter pass per line and will be much slower. However, if you're on AGA then with this kind of vertical filling you can let both the CPU and the Blitter do the work, and it will theoretically be faster than doing regular horizontal filling with only the Blitter.

29 January 2014, 08:58

Wow, I never knew this existed! Could you point me at any docs for that please or is it noted in the Hardware Manual?

hooverphonique · 29 January 2014, 13:01

Do you mean if you can make the blitter fill from top to bottom instead of from right to left?

then the answer is yes and requires no special mode, you just need to set one source one line below the other and set the minterm to xor them.

29 January 2014, 14:27

Yup, that's the one.

Thanks for clarifying, seems so obvious!

Leffmann · 29 January 2014, 17:53

Quote:

Originally Posted by Leffmann

Yes, but it requires one Blitter pass per line and will be much slower. However, if you're on AGA then with this kind of vertical filling you can let both the CPU and the Blitter do the work, and it will theoretically be faster than doing regular horizontal filling with only the Blitter.

I realized earlier that you can actually do this in a single Blitter pass, because you typically use the same bitplane as both source and destination. It still takes up to 50% more time than regular horizontal filling though.

BroFistMcfury · 27 May 2016, 00:41

I've got vertical filling working! ...but, I'm seeing different results when using WinUAE quickstart to run the exe (see attachments)

Here's the routine I'm using...anyone know what I'm doing wrong?

Thanks a million!

;--------------------------------------
; a0 = address to fill
; d0 = area to fill
; d1 = fill width (in bytes)
; d2 = modulo
;--------------------------------------
BlitFillVertical:
bsr BlitWait
move.w d2,BLTAMOD(a5) ;set modulo A
move.w d2,BLTCMOD(a5) ;set modulo C
move.w d2,BLTDMOD(a5) ;set modulo D
move.w #SRCA|SRCC|DEST|A_XOR_C,BLTCON0(a5)
move.w #0,BLTCON1(a5) ;fill mode
move.l #-1,BLTAFWM(a5)
move.l a0,BLTAPT(a5) ;source A
add.l d1,a0
move.l a0,BLTCPT(a5) ;source C
move.l a0,BLTDPT(a5) ;destination D
move.w d0,BLTSIZE(a5)
rts

DanScott · 27 May 2016, 10:19

I am not 100% sure, but I may have been the first to do blitter vertical fill on the Amiga, in the Digital Innovation demo (the huge sine scroller)

BroFistMcfury · 27 May 2016, 11:06

Yay!

Maybe you know if the code is correct or what could cause the problem?

Muchos gracias!

DanScott · 28 May 2016, 22:26

move.l ScreenPtr,a0
lea 40(a0),a1

BlitWait_Inline

move.l #$0d140000,BLTCON0(a6)
move.l #$ffffffff,BLTAFWM(a6)
move.l a0,BLTBPTH(a6)
move.l a1,BLTAPTH(a6)
move.l a1,BLTDPTH(a6)
move.w #0,BLTAMOD(a6)
move.w #0,BLTBMOD(a6)
move.w #0,BLTDMOD(a6)
move.w #(255<<6)+20,BLTSIZE(a6)

BroFistMcfury · 30 May 2016, 13:57

Nice one, thanks Dan!

I tried with your version but same results

Attached is a simple hack test that should show the problem...

DanScott · 30 May 2016, 21:44

When I copy the test.exe to my virtual DH0: and run it in WinUAE from CLI, it runs fine (solid white rectangle)

If I drag the test.exe into the WinUAE window, I get the vertical lines patterned rectangle.

Not sure what is causing this..

If you disable the call to the BlitterVerticalFill, do you get dotted horizontal lines or solid horizontal lines?

Hannibal · 31 May 2016, 05:53

I think minterm should be $3c, not $14 - 14 assumes blitter c data is 0, and it looks like it is not

DanScott · 31 May 2016, 08:38

You could be right

But what about the OP's original version? It seems to have the same "effect" happening

Mrs Beanbag · 31 May 2016, 12:23

i have pondered this technique before, but it's a shame there is no "single pixel per column" line-drawing mode that would be required for doing filled polygons.

BroFistMcfury · 31 May 2016, 14:10

Quote:

Originally Posted by DanScott

If you disable the call to the BlitterVerticalFill, do you get dotted horizontal lines or solid horizontal lines?

I get a solid line...here's an exe with half the screen filled as an example.

BroFistMcfury · 31 May 2016, 14:11

Quote:

Originally Posted by Hannibal

I think minterm should be $3c, not $14 - 14 assumes blitter c data is 0, and it looks like it is not

Sorry, that was my fault merging the code incorrectly!

DanScott · 31 May 2016, 22:03

Minterm is $14 in the code I posted above, but it was really old code.. from 1991

BroFistMcfury · 03 June 2016, 20:30

So...do you think this is a WinUAE bug or something I'm doing wrong with my setup?

Lonewolf10 · 04 June 2016, 18:29

Which version of WinUAE are you using?

28 January 2014, 22:40	#1
71M Posts: n/a	Blitter Vertical Fill Hi, I was wondering, is it possible to set the blitter so that it fills vertical lines instead of horizontal? Cheers, 71M

27 May 2016, 00:41	#7
BroFistMcfury Registered User Join Date: May 2016 Location: London Posts: 14	I've got vertical filling working! ...but, I'm seeing different results when using WinUAE quickstart to run the exe (see attachments) Here's the routine I'm using...anyone know what I'm doing wrong? Thanks a million! ;-------------------------------------- ; a0 = address to fill ; d0 = area to fill ; d1 = fill width (in bytes) ; d2 = modulo ;-------------------------------------- BlitFillVertical: bsr BlitWait move.w d2,BLTAMOD(a5) ;set modulo A move.w d2,BLTCMOD(a5) ;set modulo C move.w d2,BLTDMOD(a5) ;set modulo D move.w #SRCA\|SRCC\|DEST\|A_XOR_C,BLTCON0(a5) move.w #0,BLTCON1(a5) ;fill mode move.l #-1,BLTAFWM(a5) move.l a0,BLTAPT(a5) ;source A add.l d1,a0 move.l a0,BLTCPT(a5) ;source C move.l a0,BLTDPT(a5) ;destination D move.w d0,BLTSIZE(a5) rts Attached Thumbnails Attached Images

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29 January 2014, 01:17	#2
Leffmann Join Date: Jul 2008 Location: Sweden Posts: 2,269	Yes, but it requires one Blitter pass per line and will be much slower. However, if you're on AGA then with this kind of vertical filling you can let both the CPU and the Blitter do the work, and it will theoretically be faster than doing regular horizontal filling with only the Blitter.

29 January 2014, 08:58	#3
71M Posts: n/a	Wow, I never knew this existed! Could you point me at any docs for that please or is it noted in the Hardware Manual?

29 January 2014, 13:01	#4
hooverphonique ex. demoscener "Bigmama" Join Date: Jun 2012 Location: Fyn / Denmark Posts: 1,624	Do you mean if you can make the blitter fill from top to bottom instead of from right to left? then the answer is yes and requires no special mode, you just need to set one source one line below the other and set the minterm to xor them.

29 January 2014, 14:27	#5
71M Posts: n/a	Yup, that's the one. Thanks for clarifying, seems so obvious!

27 May 2016, 10:19	#8
DanScott Lemon. / Core Design Join Date: Mar 2016 Location: Tier 5 Posts: 1,209	I am not 100% sure, but I may have been the first to do blitter vertical fill on the Amiga, in the Digital Innovation demo (the huge sine scroller)

27 May 2016, 11:06	#9
BroFistMcfury Registered User Join Date: May 2016 Location: London Posts: 14	Yay! Maybe you know if the code is correct or what could cause the problem? Muchos gracias!

28 May 2016, 22:26	#10
DanScott Lemon. / Core Design Join Date: Mar 2016 Location: Tier 5 Posts: 1,209	move.l ScreenPtr,a0 lea 40(a0),a1 BlitWait_Inline move.l #$0d140000,BLTCON0(a6) move.l #$ffffffff,BLTAFWM(a6) move.l a0,BLTBPTH(a6) move.l a1,BLTAPTH(a6) move.l a1,BLTDPTH(a6) move.w #0,BLTAMOD(a6) move.w #0,BLTBMOD(a6) move.w #0,BLTDMOD(a6) move.w #(255<<6)+20,BLTSIZE(a6)

30 May 2016, 21:44	#12
DanScott Lemon. / Core Design Join Date: Mar 2016 Location: Tier 5 Posts: 1,209	When I copy the test.exe to my virtual DH0: and run it in WinUAE from CLI, it runs fine (solid white rectangle) If I drag the test.exe into the WinUAE window, I get the vertical lines patterned rectangle. Not sure what is causing this.. If you disable the call to the BlitterVerticalFill, do you get dotted horizontal lines or solid horizontal lines?

31 May 2016, 05:53	#13
Hannibal Registered User Join Date: May 2015 Location: Kirkland, Washington, USA Posts: 56	I think minterm should be $3c, not $14 - 14 assumes blitter c data is 0, and it looks like it is not

31 May 2016, 08:38	#14
DanScott Lemon. / Core Design Join Date: Mar 2016 Location: Tier 5 Posts: 1,209	You could be right But what about the OP's original version? It seems to have the same "effect" happening

31 May 2016, 12:23	#15
Mrs Beanbag Glastonbridge Software Join Date: Jan 2012 Location: Edinburgh/Scotland Posts: 2,243	i have pondered this technique before, but it's a shame there is no "single pixel per column" line-drawing mode that would be required for doing filled polygons.

31 May 2016, 22:03	#18
DanScott Lemon. / Core Design Join Date: Mar 2016 Location: Tier 5 Posts: 1,209	Minterm is $14 in the code I posted above, but it was really old code.. from 1991

03 June 2016, 20:30	#19
BroFistMcfury Registered User Join Date: May 2016 Location: London Posts: 14	So...do you think this is a WinUAE bug or something I'm doing wrong with my setup?

04 June 2016, 18:29	#20
Lonewolf10 AMOS Extensions Developer Join Date: Jun 2007 Location: near Cambridge, UK Age: 44 Posts: 1,924	Which version of WinUAE are you using?

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