Mode 15 PAL Blending?

[Mclaneinc]

Lovely demo, looks and moves great..

[José Pereira]

Hi. Merry Christmas to all.

 

What is the name of the gfx mode where you have interlace scanlines like this:

-> Hue using GTIA Gr.11

-> Luma using Gr.15

 

I also want a program to build a screen using this mode and could save it in '.xex'.

But no flicker mode.

Thanks.

[Synthpopalooza]

I know there was a mode called CIN which did 15+11, but it was a scanline interlace that did 160x192. Not useful for games as it requires 16k screen ram.

 

The same mode could be done using PAL blending at 160x96 which would be more like the 16 color mode, except that it'd be 64 colors. Downside is that horizontal scrolling would be 2 color clocks instead of one because of the halved chroma resolution.

[José Pereira]

Just to start with what I have in mind Memory is no problem as it would be 32Bytes wide screen, no scrolling, only 3 or 4 soft sprites 2x2chars and gfxs around 72tiles 2x1chars size.

All this maybee around 24KBs.

[Synthpopalooza]

This may help:

 

http://lepix.sourceforge.net/

 

Edits bitmap graphics in TIP, HIP, and CIN.

[José Pereira]

HI.

I know I have toget something from this that could be more easy to get something running using less cycles.

Problem with PAL Blending is that it only looks good if the resolution drops to half the scanlines where the seconline scanline gives the luminance.

It also need to use, like the previous, double the Hi-resolution pixels of the 16bit versions to get final a Gr.7/Gr.15 screen type.

This has the problem of double charsets/chars/Tiles according to wich mode you're using...

 

 

And more, doing each scanline DLIs/IRQs to the colour registers lots of cycles wasted.

Black always at all scanlines same BACKGROUND colour register it's good and I even propose to Xuel and it looks good that also the Blue (on his example) also use all scanlines same to get one less colour change and get the sky always blue.

It looks good but I wanted more.

 

 

 

This may not be for all games but at least for something like a vertical shooting like XENON or even a Horizontal scroller it works.

No need to, probably double the gfxs ratio.

And better, there's not any scanlines changing.

 

 

You have:

-> BACKGR.- Black (I use 0,2)

-> PF0 - Gray (0,8 )

-> PF1 - White (0,14)

(Other Grays and Black(s) possible)

 

Then you have:

PF2 - one colour at luminance 4

PF3 another colour at luminance 4

 

 

With thos you get:

-> 3 colours (PF0,PF1,BACKGR.): Dark/Gray/White

-> 4colours (PF2): own colour / Blending PF0 / Blending PF1 / Blending BACKGR.

-> 4colours (PF3): own colour / Blending PF0 / Blending PF1 / Blending BACKGR.

This is 11colours.

 

With this and Xenon like we could have the ground in PF2's colour&luminances Blending and the Building in the PF3 colours&luminances.

As we have Black, White and Gray as PF0,PF1&BACKGR. there's no conflict and we can have a solid 3colours for the Enemy ships.

2PMGs Multicolour 10pixels wide and we can have more 3colours ships (or ship with one weapon 'add-on').

 

 

 

But we can have more with less, we can, for CPU/cycles and if need for more soft sprites go into 32bytes wide:

 

And we can also have the DLI(s) in just Ground changing of PF2 and/or PF3, like, for example, Grass then Water,...:

 

 

And as on A8 we can, more simple get vertical srollers then we can 'DLIs' the ships and vertical shoots re-use the same ship PMG(s):

 

 

And even NTSC that, of course, couldn't get the PAL Blending (like PAL can't get the NTSC one) it even not look bad and I think that at some distance and old T.Vs. it may 'fool' our vision:

 

 

 

I just download all versions gfxs, screens, maps, sprites I could find of XENON and next would be: "How to build the Buildings and other gfxs?"

(of course it doesn't have to be XENON but this way I have the gfxs)

 

 

Doesn't this have some possible use? I think it can!...

(even a smaller version of R-Type or something around seems possible as we have the Grays for the Enemy ships and free 2Multicolour PMGs for 'our two ships'...)

[Creature XL]

And as on A8 we can, more simple get vertical srollers then we can 'DLIs' the ships and vertical shoots re-use the same ship PMG(s):

 

And what are "we" doing if we do not shoot down all enemy ships and they further down? Heavy flickering or do they just vanish?

DLI's are really great, however, they are tied to the Display-List. Of course they can be dynamically changed, but it is not so easy as you might think, considering you want them to change background AND PMG positions/colors. The C64-raster interrupt is (at least in my theoretically knowledge of its working) better suited to such things. Sure, we can use a POKEY-timer to do it. We would use one sound channel and must use 15KHz base-clock. Don't know if that is good or bad though

 

 

Generally, the PAL-blending thing is interesting, however, it doesn't give solid pixel. Additionally the resolution is halved vertically. Details in the graphics are very hard to recognize.

At least in the picture which Flash pixeled for the Morons-logo (see my current profile image). It looks different in the original 160x100 version on the ST.

 

For games I would like to develop it is maybe interesting to design some graphic tiles using this effect, but not as the basis for a whole game.

But that should not stop anyone to develop games in that mode. As awkward as it feels to play "GameBoy sized" games, they look colorful.

 

 

EDIT:

Using DLI's which change something on scanline basis in charmode is even more expansive, as you have to "sta WSYNC" until the correct scanline is reached.

Edited January 3, 2013 by Creature XL

[José Pereira]

CrtXL did you read what I write?

 

All enemys are soft sprites only: PF0,PF1,BACKGR White,Gray,Black on all screen scanlines.

 

Left ship PM0+PM1 Multicolour then [DLI]/re-use same PMGs for it's up shoting.

Right ship and it's shooting the same but with PM2+PM3.

[José Pereira]

More:

There isn't any DLI each scanline here as the colours are in PF2 and PF3 where the blending it's with White, Gray and Black / PF0, PF1 and PF2 that gives us solid 3colours for the enemys soft sprites only.

It's just a simple 5colours ANTIC4 screen.

[Creature XL]

CrtXL did you read what I write?

 

All enemys are soft sprites only: PF0,PF1,BACKGR White,Gray,Black on all screen scanlines.

 

Left ship PM0+PM1 Multicolour then [DLI]/re-use same PMGs for it's up shoting.

Right ship and it's shooting the same but with PM2+PM3.

 

Oopps. Sorry

[popmilo]

Doesn't this have some possible use? I think it can!...

(even a smaller version of R-Type or something around seems possible as we have the Grays for the Enemy ships and free 2Multicolour PMGs for 'our two ships'...)

Simply said: Yes

 

It's not a bad idea to choose high contrast shades of grey (including black and white) and add couple of colors to it.

Greys for enemies and colorful backgrounds and player ships can look good (specially for 'metalic' game like Xenon).

 

I wouldn't use these colors only for 'blending' of pixels that are one above other, more like dithering similar to what was used in 'Mayhem in monsterland'

 

Horizontal games included. Just look how "IO" on C64 (one of the best shooters ever Imho ) works with simple 4 color background and similar sprites...

 

For games I would like to develop it is maybe interesting to design some graphic tiles using this effect, but not as the basis for a whole game.

But that should not stop anyone to develop games in that mode. As awkward as it feels to play "GameBoy sized" games, they look colorful.

Well, I'm currently working right on that - designing 'gameboy-lookalike' tiles

And I do plan to use them for a whole game.

But because of massive amount of data on screen this will not be fast shooting game, more like rpg adventure type...

[+Stephen]

That C64 pic looks really nice. It is very cool how it can display a hi-res sprite over a med-res background.

[Synthpopalooza]

Don't forget, on NTSC you can do a scanline shift by altering the first line of the DLIST between 112 and 96. This shifts the screen up and down by a scanline and helps hide the blank scanlines better, and is very easy on the eyes (unlike in PAL).

[José Pereira]

Hi.

For today using again no DLIs lets see what we can get for an Horizontal scrolling shooter.

 

5colours with PAL Blending... Hmm->

The trick of have PF0/PF1/BACKGR. as Gray/White/Black it's still here but as we have an empty black sky instead of Ground/Walls/Buildings like on the Xenon example have us with no possible to have enemy ships in those 3colours (we would only have PF0/PF1 Gray/White) so we need to have the ships having a 3rd colour, ones as PF2 and others as PF3.

Or we can have the PF2 on the gfxs and PF3 on the soft sprites.

 

Just to see how it could look I decided to have PF2 and PF3 on gfxs but also on the soft sprites.

This way I would see how the two blend but also how they would look in soft sprites with Gray and White in solid shapes with no blending.

 

I take as an example a part of the un-released C16 game Xeo3.

The good on this is that we don't need to get hi-resolution games (2:1 ratio from other 8bits can also work) but I need to double expand the scanlines use.

This way I will never get anything from other Machines but I can build something from scratch.

(but I will try something with the same scanlines and try with the same size get the darker scanlines and blending but untill now no horizontal scroller like this one or Armalyte, or... seems good. Probably I need to design a new one)

 

 

I didn't reduce the sprites into 1:1 ratio but, of course, they could be. But, for good as I discouver that at ALTIRRA I also got some other Blending, even in in the solid soft sprites shapes.

(Please up-load the picture and see those 'almost no see' darker pixels and say me if that is correct on a real Machine, is it? Is it, probably Altirra simulating an old T.V. stretching?)

 

 

 

I have here:

-> PRIOR2

(PM0/PM1 -> All PFs -> PM2/PM3 -> BACKGR.)

-> PM0+PM1 Multicolour for our ship

-> P2/P3 Multicolour for the explosion (or it can be a second ship or even an 'add-on' gun)

-> M2/M3 on the Stars (that's why I used PRIOR2 so that stars goes behind the soft sprites and the gfxs)

[sack-c0s]

That C64 pic looks really nice. It is very cool how it can display a hi-res sprite over a med-res background.

 

it's actually a hires sprite over a med-res colour sprite to give the illusion of multicolour. Bit of a pain in that you burn 2 sprites instead of 1, but given that the player sprite is your main focal point it's a fair enough trade to make...

 

the fact you can mix highres and multicolour characters on the same screen is pretty neat though - you can give the impression of higher resolution that way if done carefully (IIRC the stars you collect are highres characters)

Edited January 4, 2013 by sack-c0s

[Heaven/TQA]

eeeeeeeehhh.... Mayhem has color clashes... speccy crap...

[analmux]

Tiled side-scroller demo using PAL blending:

 

http://youtu.be/09K95RlE14k

 

Binaries and source are on github.

This demo looks very interesting! Using the A800win debug I was looking at the DList at $3f00. I'm quite surprised how it works. If I'm correct you don't use IRQ or NMI, but you did use wsyncs and kernels instead?

 

1) I guess you used SINGLE (not double) scroll buffering. Am I correct?

 

2) I'm surprised about the 'lms' instructions: only $74 at the first DL line, and then only $54 commands. I'm totally surprised. My 8-direction scroller Always used $74 commands at any 'lms' line.

Edited August 18, 2014 by analmux

[Xuel]

This demo looks very interesting! Using the A800win debug I was looking at the DList at $3f00. I'm quite surprised how it works. If I'm correct you don't use IRQ or NMI, but you did use wsyncs and kernels instead?

 

1) I guess you used SINGLE (not double) scroll buffering. Am I correct?

 

2) I'm surprised about the 'lms' instructions: only $74 at the first DL line, and then only $54 commands. I'm totally surprised. My 8-direction scroller Always used $74 commands at any 'lms' line.

 

Thanks! Yes, this demo uses VCOUNT and WSYNC for all vertical and horizontal synchronization. All interrupts are disabled.

 

1) Everything is single buffered at 50 fps. All of the screen updates occur in the vertical blank since the CPU is fully utilized during the display kernel.

2) See this post from Rybag for an explanation of the VSCROL technique used here. It allows ANTIC mode 4 to be displayed for the the full 240 scan lines. (There's also a link in the README.md on github)

 

Also check out the tiles512 demo. The major difference there is that 4 character sets are used instead of one.

 

Also check out popmilo's WIP video.

[popmilo]

2) See this post from Rybag for an explanation of the VSCROL technique used here. It allows ANTIC mode 4 to be displayed for the the full 240 scan lines. (There's also a link in the README.md on github)

... Also check out popmilo's WIP video.

My demo is not using VSCROL, 'just' 3-4 LMSs and bitmap mode - Big thanks to Analmux and his MWP explanation!

ps. Glad to see you here Analmux!

[Heaven/TQA]

MWP... . another mysterium... for this thime being I am stuck to Fractalis

[analmux]

Thanks to Xuel & Popmilo. And yes, I had a long 'vacation'.

 

@ Xuel: I remember the tiles512 demo.

@ popmilo: Interesting software sprite techniques on YouTube.

[popmilo]

@ popmilo: Interesting software sprite techniques on YouTube.

Yeah, even more interesting trying to implement them in pal-blended mwp 8 directional scroll engine

 

Complex screen addressing, luma lines, chroma lines, shifting. masking, memory requirements... Uffghhh.....

[gorgh]

any progress with the game you showed Xuel?
I tooks very promising, and it would be a pity if the engine wasn't used anywhere

Edited June 17, 2017 by gorgh

[8bit-Dude]

Hey PopMilo, very interesting demo!

I know it's an old thread, but did you make the edit tools and asm code available for this mode?

Cheers, Tony

[8bit-Dude]

From what I gather, Atari Graphics Studio can load MCP+ images, and export as xex files.

But the export as ASM file function is not working... :-(