Mode 15 PAL Blending?

[NRV]

Would this be workable in Antic 4 mode to get the PF3 combinations, and 23 colors instead of 16?

Yes, but (normally) you would have the same restriction of selecting the new color for all the character.

I would use it as a new color in the "hue" lines and would leave the same 4 values for the "luma" lines (set PF3 equal to PF2 there), so that you get 20 colors instead of 16.

I think you can change the use of PF3 per line, but I don't remember how that works.

Also using chars can complicate the timing to use DLI's (or IRQ's) but it should be doable.

[José Pereira]

If using Antic4/GR.12 it'll be perhaps not because other than a static image there will be no cpu/cycles to move anything on the badlines because remember that in these and all on the screen for each scanline you have to change 4 colour registers (PF0/PF1/PF2/PF3).

In here like now using bitmap mode GR.15 you don't have the badlines and even less one colour change because there's not PF3.

[NRV]

If using Antic4/GR.12 it'll be perhaps not because other than a static image there will be no cpu/cycles to move anything on the badlines because remember that in these and all on the screen for each scanline you have to change 4 colour registers (PF0/PF1/PF2/PF3).

In here like now using bitmap mode GR.15 you don't have the badlines and even less one colour change because there's not PF3.

You also need to change the charset every couple of lines probably..

 

But not having cycles available in the bad lines doesn't prevent you from changing the graphics anywhere, or using this for a game.. I don't follow your logic here.

Obviously, if doing a game I would try to use one IRQ every two lines (not one big DLI over the whole screen), but I need to test if this works well changing 4 registers.

[popmilo]

All this time I didn't think about using charmode to get one more color

 

25 cycles free in badline should be enough for 4 register changes and plenty remain from non-bad lines so should be doable.

 

That char based color would look great in tile based gfx for some tiles like walls, water etc. (Something that sprites can' get over). So it would be safe from mixing colors.

Good idea!

 

ps. NRV is right about charset change... Can't make much different tiles+sprites with only 128 characters...

[Rybags]

VScrol tricks can be used to get rid of badlines though a kernal is still needed and you need to keep changing CHBASE, and the memory usage can potentially be wasteful.

[José Pereira]

All this time I didn't think about using charmode to get one more color

 

25 cycles free in badline should be enough for 4 register changes and plenty remain from non-bad lines so should be doable.

 

That char based color would look great in tile based gfx for some tiles like walls, water etc. (Something that sprites can' get over). So it would be safe from mixing colors.

Good idea!

 

ps. NRV is right about charset change... Can't make much different tiles+sprites with only 128 characters...

Maybe going with the Interleaved charset.

Think that, for example, that the game has [2x2] chars tiles sizes and is from a computer version that has a 256chars charset. Most of the times this interleaved in charsets 1,2,1,2,... would be around 128chars per each or less.

Depending on the version you're converting you could even go to interleaved 1,2,3,4,1,2,3,4,... that seems the way for these GameBoy and others like hi-res multicolour gfxs and sprites of NES games.

Edited October 18, 2017 by José Pereira

[Synthpopalooza]

You can also set up the mode like C64 low res ... DLI character set change every three lines, poke into the character set memory to plot pixels, inverse wherever you want to use PF3.

[Synthpopalooza]

OK, here's some interesting thoughts to consider ...

 

First, what happens if we changed the color selection from the usual luma on one line and chroma on the other. I did this sample color palette up in my ICE font editor:

 

 

This is using Super IRG 2 mode, which basically blends two fonts full frame with color palette changes full screen to get an Antic 4/5 mode at 23 colors. Changing the colors every scanline is pretty much the same concept, but without the full frame flickering.

 

With the color palette I used above, you can unlock additional colors which are outside of the normal 256 color palette on the Atari. You can also get greys and off greys from blending colors on the opposite side of the color wheel. The above color palette looks very useful. I chose a variety of colors and luminances which allow for a wide selection of blending possibilities. This actually looks fairly close to the C-64 palette.

 

The other interesting thought: Could ICE be used to design fonts to be used in the PAL blending mode? The concept is the same, an Antic 5 font would have the same aspect ratio. We'd just have to rearrange the data. For example, here is the ICE format for Super IRG 2:

 

Byte 1: graphics mode identifier (2 for Super IRG 2)

9 bytes follow, arranged as such: BAK, PF0a, PF0b, PF1a, PF1b, PF2a, PF2b, PF3a, PF3b (the colors on alternate frames with a steady background)

1024 bytes of font a

1024 bytes of font b

 

We'd need to rearrange the font data to end up with two 1K fonts, of 128 characters each, each character being essentially 4x4 blended pixels.

 

I am attaching the .ATR for the font editor here, along with the sample font if anyone wants to have a play with it or see about displaying it in the PAL blending mode. From the ICE screen type "L" and load up the SCRPFNT2.ICE file that is in the zip file.

iceirg.atr

ice font.zip

Edited October 23, 2017 by Synthpopalooza

[Synthpopalooza]

Yes it's old but not neglected

 

Here is one recent experiment:

rvr.png

 

Source:

mixgraphicmodes.asm

 

Executable:

mixgraphicmodes.xex

 

Binary for image:

rvr.bin

 

So only thing missing for you to experiment with is python converter... I have a gui version that's kinda easy to work with, but one important part still need manual value editing in source - color mapping from 16 color pc bitmap image to PalBlending 16 "colors". When I figure that out I'll upload exe or source in python, what ever people want to use...

 

ps. If anyone has ideas on how best to handle color mapping automatically or semi-auto please feel free to write !

Question: How is the data in your .bin laid out? Is it a sequence of 40 bytes of chroma followed by 40 bytes of luma? If so, I may have a play with your code and see if I can modify it to import ICE Super IRG 2 fonts.

[popmilo]

Question: How is the data in your .bin laid out? Is it a sequence of 40 bytes of chroma followed by 40 bytes of luma? If so, I may have a play with your code and see if I can modify it to import ICE Super IRG 2 fonts.

It's pure bitmap format. So yes it's 192 lines of 40 bytes. Think it's like you said, even lines are chroma, odd lines are luma.

Try it and you'll see if it's right

[mono]

Hello, guys!

Inspired by FlashJazzcat's message I've been working on something over last couple of days.

 

First line 160 pixels in one of 4 hues (black, red, green, blue).

Second line 160 pixels in one of 4 lumas (0, 6, 10,14).

 

As Rybags said it's much better (brighter) if color-line has luma 2 instead of 0.

 

Should be tested with different hues and lumas but overall for an quick'n'dirty weekend job it doesn't look that bad

 

Ps. If anyone has a nice 160x96 colorfull image and would like to see it on A8 just send it to me!

@Popmilo: Could you provide me original picture of mixcolorsmode2.png (not screenshot, but original image transformed by you) which was presented in http://atariage.com/forums/topic/197450-mode-15-pal-blending/?p=2609821? I would like to make experiment and I've found this picture best fit to my purposes.

Edited December 22, 2018 by mono

[popmilo]

@Popmilo: Could you provide me original picture of mixcolorsmode2.png (not screenshot, but original image transformed by you) which was presented in http://atariage.com/forums/topic/197450-mode-15-pal-blending/?p=2609821? I would like to make experiment and I've found this picture best fit to my purposes.

Ufff... That was long time ago

 

If you're referring to this picture:

 

It's from here:

 

Of course, I cropped it, resized, reduced number of colors to 16 (all this using Gimp).

Then I hand mapped those 16 colors to 16 pal blending color combinations and converted it with python script.

 

Exe:

mixcolorsmode2.xex

[mono]

Thank you very much. That's it!

[xxl]

On 11/13/2012 at 5:17 AM, Xuel said:

@José Pereira

 

Here's your swap-only-two-colors-per-line scheme:

 

chroma: 2 blue6 red4 green4

luma: 2 blue6 10 14

 

tiles-pal-jose.xex 33.35 kB · 96 downloads

 

Here's a variation of your scheme with the following mods:

 

chroma: 2 blue6 red4 green4

luma: 2 blue6 8 12

 

tiles-pal-jose-alt.xex 33.35 kB · 95 downloads

 

Another variation:

 

chroma: 0 blue4 red4 green4

luma: 0 blue4 8 12

 

tiles-pal-jose-alt2.xex 33.35 kB · 102 downloads

 

deep necro bump... but what's going on with this project?

 

[José Pereira]

3 hours ago, xxl said:

 

deep necro bump... but what's going on with this project?

 

I think that @Xuel was only doing this just as a show and don't remember in any of ours talks he saying he intended to turn it into a real game.

Good old times when after X:8 was Ransack then Bhad to Bomber but he stop things on the future due to own life things but still is here allways helpfull.

Sadly we also didn't finish X:8 adding large bosses on the levels end, shoot and destroy ground cannons,...

[xxl]

a great pity because these "tests" look and work better than any scrolling platformer game on Atari.

[emkay]

1 hour ago, xxl said:

a great pity because these "tests" look and work better than any scrolling platformer game on Atari.

Of course.

But people seem to not like what tha Atari could do best.

Drop the resolution down and push the fire to every game and gameplay.  

[+Stephen]

3 hours ago, emkay said:

Of course.

But people seem to not like what tha Atari could do best.

Drop the resolution down and push the fire to every game and gameplay.  

I understand "gameplay above graphics", but it's also nice to see things like PoP and Albert, etc.  Games that don't look like 1970s chunk resolution or 4 colours.

[GravityWorm]

On 7/16/2021 at 3:09 AM, Stephen said:

I understand "gameplay above graphics", but it's also nice to see things like PoP and Albert, etc.  Games that don't look like 1970s chunk resolution or 4 colours.

 PoP and Albert look great!