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Hypex 
Re: Bit Plane Technology
Posted on 21-Jul-2018 15:13:22
#21 ]
Elite Member
Joined: 6-May-2007
Posts: 11180
From: Greensborough, Australia

@saimo

Quote:
Wrong: it's precisely the fact that there are (mostly) indipendent planes that allows full screen parallax scrolling.


As I stated it also had the scroll offset for each field. Two planes of 4-bit packed pixels with their own palette and scroll offsets could have easily been used the same way for a hardware dual playfield. Collisions and plane priorities are another related matter.

Quote:
The Dual Playfield mode is possible precisely thanks to the bitplanes, so again it's the fact that the graphics are based on bitplanes that makes parallax scrolling easy.


You've got scroll offsets and plane pointers. So, likewise, there could be two scroll offsets and plane pointers for two planes. Two fields with one plane each. Make a special packed mode and those two seperate planes go from being a bitmap to a packmap.

Quote:
Wrong: the kind of filling that you're talking about is possible thanks to the fact that it's possible to have "movable" rasters bigger than the display. It's here that bitplanes are irrevelant.


It still allows you to chose how to fill up the bitmap by selecting what planes to use. For a packed mode you'd need to write to the total colour depth. But for planar you only fill in what planes you need.

Quote:
1. The C64 does not have chunky pixels.


Wrong. It does have chunky pixels in MCM mode. We could call it super low res compared to the Amiga. Each byte has four colours across in packed format. It's 2-bit chunky. But as you would be aware the bitmap or packmap, as it were, was not linear across. It was formatted as a text matrix with 8 sequential bytes going down 8 lines to form a character block then starting at the top for the next block.

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Hypex 
Re: Bit Plane Technology
Posted on 21-Jul-2018 15:35:54
#22 ]
Elite Member
Joined: 6-May-2007
Posts: 11180
From: Greensborough, Australia

@RodTerl

Quote:
8 bit planes per each R, G, B colour channel, then tested a range of compression algorithms, or entropy functions, per bit plane.


So IOW a 24-bit bitplane? I think bitplanes beyond the 8-bit depth are diminished for their return. I know this was planned for AAA with 24-bit or 16-bit planar modes but I think that is taking the idea too far. Fine for CLUT modes but not beyond that.

In any case, what I'd be interested in is RGB data formatted in different planes. That is, each colour channel in its own plane with packed data, so three planes of each RGB byte.

Same could be done for 12-bit data in 4096 colours. 3x4-bit packed planes of RGB data.

Could also be done for 8-bit depth but bit mapped and packed 8-bit needs a CLUT so would be in different format and result.

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saimo 
Re: Bit Plane Technology
Posted on 21-Jul-2018 15:43:32
#23 ]
Elite Member
Joined: 11-Mar-2003
Posts: 2450
From: Unknown

@Hypex

Quote:

Hypex wrote:
@saimo

Quote:
Wrong: it's precisely the fact that there are (mostly) indipendent planes that allows full screen parallax scrolling.


As I stated it also had the scroll offset for each field. Two planes of 4-bit packed pixels with their own palette and scroll offsets could have easily been used the same way for a hardware dual playfield. Collisions and plane priorities are another related matter.

The matter is not what other possibilities are there to obtain parallax scrolling. Of course there are, but the initial question is whether it's thanks to the bitplanes that the Amiga does parallax scrolling, and your statement "It was said because of the planar format why the Amiga was good at parallax scrolling. However, I don't think the pixel format really has any bearing on this", which was supposed to be an answer to the question, is wrong because bitplanes are the key to obtain parallax scrolling (and the Dual Playfield) on the Amiga.
Your statement rather answers the question "Are bitplanes necessary to obtain parallax scrolling?".

Quote:
Quote:
The Dual Playfield mode is possible precisely thanks to the bitplanes, so again it's the fact that the graphics are based on bitplanes that makes parallax scrolling easy.


You've got scroll offsets and plane pointers.

Sure, those are features that allow scrolling in first place. But how does that counter the fact that it's the bitplanes-based architecture that allows parallax scrolling in the Amiga?

Quote:
So, likewise, there could be two scroll offsets and plane pointers for two planes. Two fields with one plane each. Make a special packed mode and those two seperate planes go from being a bitmap to a packmap.

Again, neither I nor the OP were talking about alternatives.

Quote:
Quote:
Wrong: the kind of filling that you're talking about is possible thanks to the fact that it's possible to have "movable" rasters bigger than the display. It's here that bitplanes are irrevelant.


It still allows you to chose how to fill up the bitmap by selecting what planes to use. For a packed mode you'd need to write to the total colour depth. But for planar you only fill in what planes you need.

Yes, but that's a totally different story from your initial statement, which is: "But, because it was planar, it could fill in blocks on the edge incrementally until they came into view. Such as blitting 16x16 blocks at a time. The blitter was made for transferring images of different sizes onto a full screen bitmap " and which was supposed to be an answer to the OP question.

Quote:
Quote:
1. The C64 does not have chunky pixels.


Wrong. It does have chunky pixels in MCM mode. We could call it super low res compared to the Amiga. Each byte has four colours across in packed format. It's 2-bit chunky. But as you would be aware the bitmap or packmap, as it were, was not linear across. It was formatted as a text matrix with 8 sequential bytes going down 8 lines to form a character block then starting at the top for the next block.

I stand corrected: I was thinking of byte-chunky pixels only.
(Yes, I know how the C64 works, I make games for it.)

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saimo 
Re: Bit Plane Technology
Posted on 21-Jul-2018 16:39:02
#24 ]
Elite Member
Joined: 11-Mar-2003
Posts: 2450
From: Unknown

@Trekiej

Quote:
Does the A1000 have an 8 or 16 bit data bus?

I've never had an A1000 nor I have ever read any specific document about it, but I guess that it was 16-bit.

Quote:
Does the shift registers rotate or end up being all zeros when done?

I guess you are again thinking of scrolling - in that case, the answer is as follows.
There are no shifter registers at all. The BPLCON1 register holds the delay that has to be applied to pixels before being output. Given that the rasterlines are output from left to right, the BPLCON1 register basically indicates how many pixels to the right the bitmap data is scrolled. The effect of having pixels enter from the left side is obtained by telling the system (by means of the DDFSTRT register) to start fetching data before the horizontal display start point (which is dictated by the DIWSTRT/DIWHIGH registers) is reached: this way, if BPLCON1 specifies a delay, the bits of the pre-fetched words are used.
I have a faint memory that if data is not fetched earlier, what one gets is the background color or color 0, but it might well be that whatever was left in the BPLxDAT registers is used instead - I can't remember exactly.

Quote:
There was video card that plugged in to video output that was chunky.
How did that work?
I think it made by Newtek.

A number of graphic cards has been produced by several manufacturers. I have never owned one, so I can only guess: they connect through the expansion ports/slots and have their separate video out, and can be accessed only by the CPU.

Quote:
Also, is it possible to send data through the RGB port during blanking interval?

The CPU and the Copper can write to the BPLxDAT registers (normally automatically loaded with the data coming from the bitplanes) anytime, but that would produce no result (other than keeping the processor performing the writes busy), given that the data in those registers gets combined to address the COLORxx registers only when the pixels are being drawn.
Fancy note: the closest one can get to writing directly to the video out is enabling the BYPASS bit in the BPLCON0 register, which disables the COLORxx lookup and makes the data in BPLxDAT, after having been combined, go to the video out as a red intensity value (this works on AGA Amigas only, or at least it's supposed to according to what the docs floating around say - I have never tried it myself).

Last edited by saimo on 21-Jul-2018 at 04:50 PM.

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Trekiej 
Re: Bit Plane Technology
Posted on 21-Jul-2018 17:47:07
#25 ]
Cult Member
Joined: 17-Oct-2006
Posts: 890
From: Unknown

@saimo

Here is one.
http://www.bigbookofamigahardware.com/bboah/product.aspx?id=498

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fishy_fis 
Re: Bit Plane Technology
Posted on 21-Jul-2018 17:56:39
#26 ]
Elite Member
Joined: 29-Mar-2004
Posts: 2156
From: Australia

@ppcamiga1

Quote:
c64 has chunky pixels and hardware scrolling also work


Wrong. The c64 doesnt use chunky pixels.

Quote:
Hardware scrolling was not added to chunky pixel modes on pc, because in 1990+ nobody need this crap


Wrong. Most vga graphics cards from the early to mid 90's have specific hardware for "scrolling", along with blitters .

Quote:
Bitplanes are nothing special, everyone use bitplanes before 1990


Wrong. Firstly a lot of earlier hardware uses a predefined palette, and second, many use chunky pixel formats without the ability to move entire bitplanes with a single adjustment to adresses.


Once again you prove what an absolute moron you are. Absolutely zero clues.

You do understand that bullshit doesnt stop being bullshit just because you write it on a forum right?

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cdimauro 
Re: Bit Plane Technology
Posted on 21-Jul-2018 18:01:27
#27 ]
Elite Member
Joined: 29-Oct-2012
Posts: 3621
From: Germany

Some interesting threads finally here. :)

@Trekiej

Quote:

Trekiej wrote:
Hello.
Is Bit Plane Technology why the Amiga is good a Parallax Scrolling?

No: you can do it also with packed (chunky) data.
Quote:
Also, do modern cards use Bit Plane Tech?
Thanks.

Still, yes: the old EGA and VGA modes continue to support bitplanes (BTW: they supported hardware scrolling, as well as vertical blank interrupts).

To extend a bit the topic, packed/chunky data is almost always better than bitplane data from a space and bandwidth point-of-view (I've mathematically proved it in an old amigacoding.de thread, some years ago; unfortunately the site is down from some months).
The only case where bitplanes are better is if you need to access only one or a few bitplanes (less than the total), which isn't a very common case.

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Karlos 
Re: Bit Plane Technology
Posted on 21-Jul-2018 20:52:55
#28 ]
Elite Member
Joined: 24-Aug-2003
Posts: 4394
From: As-sassin-aaate! As-sassin-aaate! Ooh! We forgot the ammunition!

@saimo

Yeah it was the horizontal scroll offset I was thinking about. Its fair to say that what made the Amiga so good at scrolling was just the general flexibility of the hardware in general. I remember various tricks you could get up to with AGA in which you can essentially scroll a lowres pixel mode screen by superhigh res increments, giving sub-pixel horizontal scroll. It has been a long time.

I guess all this stuff is very fresh in your mind right now ;)

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saimo 
Re: Bit Plane Technology
Posted on 21-Jul-2018 21:52:22
#29 ]
Elite Member
Joined: 11-Mar-2003
Posts: 2450
From: Unknown

@cdimauro

Quote:
Quote:

Trekiej wrote:
Hello.
Is Bit Plane Technology why the Amiga is good a Parallax Scrolling?

No: you can do it also with packed (chunky) data.

You are not answering Trekiej's question, but a different one (same mistake done by others here). The question asks "Are bitplanes what allows *the Amiga* to achieve parallax scrolling easily?" and if we took yours as a proper answer to exactly that question, then your answer would mean: "No, the Amiga achieves parallax scrolling also in chunky modes (hence, there is some other feature that makes the effect possible)" - but, of course, the Amiga doesn't even have a chunky mode, so such an answer would be totally bogus.
Yours is a reply to the more general question: "Are bitplanes strictly necessary to achieve parallax scrolling?"

Edit: sorry everybody if I keep on hammering on this, but it would be no good to let a misconception spread and confuse Trekiej's ideas.

Last edited by saimo on 21-Jul-2018 at 09:54 PM.

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saimo 
Re: Bit Plane Technology
Posted on 21-Jul-2018 22:14:18
#30 ]
Elite Member
Joined: 11-Mar-2003
Posts: 2450
From: Unknown

Quote:
Yeah it was the horizontal scroll offset I was thinking about.

Indeed I had imagined that, but I wanted to clarify things as this thread already contained quite a lot of confusing/erroneous information.

Quote:
Its fair to say that what made the Amiga so good at scrolling was just the general flexibility of the hardware in general.

Yep, it's true. In my answers I just tried to focus on the relationship between bitplanes and parallax scrolling in order to provide a good answer and limit the noise.

Quote:
I remember various tricks you could get up to with AGA in which you can essentially scroll a lowres pixel mode screen by superhigh res increments, giving sub-pixel horizontal scroll. It has been a long time.

Yep, that's easily achieved thanks to the extra bits in BPLCON1, which bring the delay granularity to 35 ns (i.e. 1 SHRES pixel = 1/4 of LORES pixel).

Quote:
I guess all this stuff is very fresh in your mind right now ;)

Well, the concepts have always been crystal clear since the day I learned them the first time, but indeed towards the end of 2017, after many years, I returned to programming the classic Amigas precisely to have fun with a parallax scrolling engine, so, yes, even the details are fresh in my mind

I guess that not everybody knows about it, but since that engine actually makes for a good example relatively to the subject, let me show the latest preview video of the game I'm developing on it:

https://www.youtube.com/watch?v=jApqi3DVgls

Scrolling-wise, the video shows:
* 3 parallax layers scrolling at variable speed;
* 1 fixed layer for the HUD and laser beams;
* real transparencies (each color can have any 8 bit degree of transparency).

All of that it possible precisely thanks to the bitplanes (of course I use various other features as well, but still the fact that, on the Amiga, bitplanes are crucial to achieve parallax scrolling holds true).

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saimo 
Re: Bit Plane Technology
Posted on 21-Jul-2018 22:34:52
#31 ]
Elite Member
Joined: 11-Mar-2003
Posts: 2450
From: Unknown

@Trekiej

Quote:
Here is one.
http://www.bigbookofamigahardware.com/bboah/product.aspx?id=498

Cool! I didn't know a device of such a kind had been made. Thanks for the pointer.

Last edited by saimo on 21-Jul-2018 at 10:35 PM.

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fishy_fis 
Re: Bit Plane Technology
Posted on 21-Jul-2018 22:46:21
#32 ]
Elite Member
Joined: 29-Mar-2004
Posts: 2156
From: Australia

Wow, I've never seen a black Grafitti, only white.

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Trekiej 
Re: Bit Plane Technology
Posted on 21-Jul-2018 23:31:54
#33 ]
Cult Member
Joined: 17-Oct-2006
Posts: 890
From: Unknown

@saimo

That is listed as a non-RTG video card.
The video slot in an Amiga 2000 has to connectors.
One is an RGB slot with audio and the other is a Centronics Parallel port.
I got this information from the Amiga 2000 Hardware Reference Manual.
I could be wrong.

The Opal vision uses this slot.

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Trekiej 
Re: Bit Plane Technology
Posted on 21-Jul-2018 23:35:37
#34 ]
Cult Member
Joined: 17-Oct-2006
Posts: 890
From: Unknown

@Trekiej

Looking back at the time that I was pondering Bit Planes, it looks like this technology could use a very wide data bus.


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Trekiej 
Re: Bit Plane Technology
Posted on 21-Jul-2018 23:39:43
#35 ]
Cult Member
Joined: 17-Oct-2006
Posts: 890
From: Unknown

@Trekiej

If I have a bit-map in ram, do I shift the data in ram or do I shift a pointer to data?
I prefer the later.
The first could be for something like a photo editor and the second for a game.

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cdimauro 
Re: Bit Plane Technology
Posted on 22-Jul-2018 5:15:10
#36 ]
Elite Member
Joined: 29-Oct-2012
Posts: 3621
From: Germany

@saimo

Quote:

saimo wrote:
@cdimauro

You are not answering Trekiej's question, but a different one (same mistake done by others here). The question asks "Are bitplanes what allows *the Amiga* to achieve parallax scrolling easily?" and if we took yours as a proper answer to exactly that question, then your answer would mean: "No, the Amiga achieves parallax scrolling also in chunky modes (hence, there is some other feature that makes the effect possible)" - but, of course, the Amiga doesn't even have a chunky mode, so such an answer would be totally bogus.
Yours is a reply to the more general question: "Are bitplanes strictly necessary to achieve parallax scrolling?"

Edit: sorry everybody if I keep on hammering on this, but it would be no good to let a misconception spread and confuse Trekiej's ideas.

I've already read all messages (included yours) before writing mine.

From what I've understood, Trekiej wanted to talk not only about parallax, but more generally about bitplanes. In fact the title is "Bit Plane Technology", and his first message talked about modern cards too (which usually do NOT use bitplanes, albeit they are still there for backward-compatibility, as I reported).

He also has written other comments which aren't related to parallax: #19 (which was before that I've written my message), and you can also see the last ones.

Finally, yes, usually Amiga uses bitplanes, Dual Playfields and BPLCONs for achieving parallax.
But when I added parallax scrolling to Fightin' Spirit (to the bottom 64 lines of the screen, to look like Street Fighter 2 and others similar Beat'em ups), I haven't used DP and BPLCONs, but only bitplanes with the Blitter, and it was a pain: a packed/chunky mode would have made my life MUCH easier...

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cdimauro 
Re: Bit Plane Technology
Posted on 22-Jul-2018 5:20:13
#37 ]
Elite Member
Joined: 29-Oct-2012
Posts: 3621
From: Germany

@Trekiej

Quote:

Trekiej wrote:
@Trekiej

Looking back at the time that I was pondering Bit Planes, it looks like this technology could use a very wide data bus.

And that was the big problem of bitplanes as well: it required a wider data bus, which wasted space and bandwidth (take a look at the enormous alignment requirements of AGA).

The (not so) funny thing is that the Blitter was kept using a 16-bit bus, so dramatically cutting the potential to handle a massive amount of graphic data.

Quote:

Trekiej wrote:
@Trekiej

If I have a bit-map in ram, do I shift the data in ram or do I shift a pointer to data?
I prefer the later.
The first could be for something like a photo editor and the second for a game.

Depends. For Fightin' Spirit parallax scrolling I had to do the first, and it was a game...

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saimo 
Re: Bit Plane Technology
Posted on 22-Jul-2018 9:37:02
#38 ]
Elite Member
Joined: 11-Mar-2003
Posts: 2450
From: Unknown

@cdimauro

Quote:
I've already read all messages (included yours) before writing mine.

From what I've understood, Trekiej wanted to talk not only about parallax, but more generally about bitplanes. In fact the title is "Bit Plane Technology", and his first message talked about modern cards too (which usually do NOT use bitplanes, albeit they are still there for backward-compatibility, as I reported).

He also has written other comments which aren't related to parallax: #19 (which was before that I've written my message), and you can also see the last ones.

So it's like I said: you answered a different question from the one he asked But the way you did it didn't help, and actually confused things.
He asked two very specific questions, and those should be answered correctly in first place. Look again at the Q&A and you'll see that the answer is plain wrong:

Quote:
Quote:
Is Bit Plane Technology why the Amiga is good a Parallax Scrolling?
No: you can do it also with packed (chunky) data.

Straight question, straight answer. Look at it from the point of view of who has only a shallow or no knowledge of the Amiga hardware and you'll see that what he would learn is that:
* Amiga has bitplanes;
* Amiga is good at parallax scrolling;
* Amiga has chunky modes;
* bitplanes are not the reason why Amiga is good at parallax scrolling.

This just had to be corrected.

Quote:
Finally, yes, usually Amiga uses bitplanes, Dual Playfields and BPLCONs for achieving parallax.
But when I added parallax scrolling to Fightin' Spirit (to the bottom 64 lines of the screen, to look like Street Fighter 2 and others similar Beat'em ups), I haven't used DP and BPLCONs, but only bitplanes with the Blitter, and it was a pain: a packed/chunky mode would have made my life MUCH easier...

Just for clarity: I never said that parallax can only be achieved by moving bitplanes (actually, I've explicitly said that other techiniques are possible and even mentioned the floor parallax in my first post here). Also, yes, of course bitplanes make horizontal alignment more complex and inefficient (but then again I never said the opposite, as I restricted my observations just the parallax subject).

I didn't know (or remember?) that you were the coder of Fightin' Spirit, which, BTW, is a great technical achievement in all departments (I don't know about the gameplay though, as I've never played it, nor I'm a fan on the genre).
Regarding your choice, it's interesting because it very RAM-intensive, and you already have big bobs moving on a 6 planes screen. I guess that the reason why you used Blitter is being able to blit the bobs in one go, given that, if BPLCON1 were used instead, bitplanes would have had increasing widths at the floor level (i.e. as many different Blitter modulos, and therefore blits, would have been needed). Please let me ask: did you consider going the BPLCON1+Copper route and performing multiple blits to draw just the parts of the characters at floor level? Given that the characters (I guess) would never reach the bottommost line, less and shorter lines would have needed to be blitted, i.e. quite some CHIP RAM bandwidth would have been saved. Or, did you consider using BPLCON1+Copperfor just the lines below the lowest point reached by the characters (to avoid at least the last blits)? Or did you go the full Blitter route for simplicity's sake, given that you didn't need or couldn't make use of the extra RAM bandwidth?

Last edited by saimo on 22-Jul-2018 at 10:42 AM.

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Karlos 
Re: Bit Plane Technology
Posted on 22-Jul-2018 11:09:14
#39 ]
Elite Member
Joined: 24-Aug-2003
Posts: 4394
From: As-sassin-aaate! As-sassin-aaate! Ooh! We forgot the ammunition!

@saimo

I think all the noise in the thread is just that people like to think about different approaches. I'm sure that if the Amiga had supported packed pixel formats (e.g. 2, 4 and 8 bits per pixel) most of the features we ascribe to bit plane graphics could still have worked just fine, given that scrolling was achieved by setting horizontal offsets and not by actually moving any data around.

As a historical footnote, Jay Minor once said that in hindsight, the choice to use planar was a mistake. I don't have the reference to hand but it's on YouTube somewhere. Personally I would have loved to have packed pixel modes but only in addition to fully supporting planar modes too.

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cdimauro 
Re: Bit Plane Technology
Posted on 22-Jul-2018 12:20:49
#40 ]
Elite Member
Joined: 29-Oct-2012
Posts: 3621
From: Germany

@saimo

Quote:

saimo wrote:
@cdimauro

I didn't know (or remember?) that you were the coder of Fightin' Spirit, which, BTW, is a great technical achievement in all departments (I don't know about the gameplay though, as I've never played it, nor I'm a fan on the genre).

I was the additional coder. I worked to the low-level graphic routines.
Quote:
Regarding your choice, it's interesting because it very RAM-intensive, and you already have big bobs moving on a 6 planes screen. I guess that the reason why you used Blitter is being able to blit the bobs in one go, given that, if BPLCON1 were used instead, bitplanes would have had increasing widths at the floor level (i.e. as many different Blitter modulos, and therefore blits, would have been needed).

Yes, the idea was to prepare the screen first, and after that drawing whatever we wanted.

Unfortunately I couldn't draw BOBs in one go, because they used only 32 colors (instead of the 64 available with the EBH). The first 16 color entries in the CLUT were reserved to the backgroud, and changed all the times. So, drawing BOBs required 6 blits...
Quote:
Please let me ask: did you consider going the BPLCON1+Copper route and performing multiple blits to draw just the parts of the characters at floor level? Given that the characters (I guess) would never reach the bottommost line, less and shorter lines would have needed to be blitted, i.e. quite some CHIP RAM bandwidth would have been saved. Or, did you consider using BPLCON1+Copperfor just the lines below the lowest point reached by the characters (to avoid at least the last blits)? Or did you go the full Blitter route for simplicity's sake, given that you didn't need or couldn't make use of the extra RAM bandwidth?

I've considered both solutions, but the required effort wouldn't have payed the bandwidth saving.

The big BOBs were split in very small rectangles (usually squares) in order to reuse as much as possible the graphic for the animations, basically acting like tiles. So, we already had to do several blits (repeated 6 times, as I've said before), and introducing the BPLCON1 + Copper would have complicated a lot the code (which had to deal with the double buffer and the special horizontal scrolling too).

Unfortunately only a few bottom lines are usually not affected by BOBs, but it wasn't a general rule, as you can see here: https://www.youtube.com/watch?v=K4jdNPsbdow&t=14m07s where you can see at the bottom left that some background animation covered the last lines of the screen.

Anyway, at the end my parallax code didn't went in production because the graphic artist refused to change again all background screens.
He also refused to change the backgrounds to accomodate the idea which I had for special lighting of the night scenarios.

It was a pity, because Fightin' Spirit could have been much better technically (and visually) speaking, but we were youngs at the time, and made a lot of mistakes.
@Karlos

Quote:


Karlos wrote:
@saimo

I think all the noise in the thread is just that people like to think about different approaches. I'm sure that if the Amiga had supported packed pixel formats (e.g. 2, 4 and 8 bits per pixel) most of the features we ascribe to bit plane graphics could still have worked just fine, given that scrolling was achieved by setting horizontal offsets and not by actually moving any data around.

It depends on the pixel "size" (screen depth). For example, a 16 colors packed display would have required in any case the BPLCON1 to properly shift some bits.
Quote:
As a historical footnote, Jay Minor once said that in hindsight, the choice to use planar was a mistake. I don't have the reference to hand but it's on YouTube somewhere.

Strange to "hear" it, but I fully agree.
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Personally I would have loved to have packed pixel modes but only in addition to fully supporting planar modes too.

It doesn't make sense. With packed pixels you can do everything that you usually do with bitplanes, but with less space and bandwidth wasted; except for the specific case which I've talked before (e.g.: addressing a single plane / "bit").

Supporting both packed and bitplane displays would have complicated the display controller.

Better have had only packed graphics.

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