Feature wish: Replace single color backgrounds with multi-colored ones
 

Hi Toni,

can you please tell me if the following idea would be possible to implement and, if yes, how much effort do you think it would take to add this to WinUAE (and if you'd be willing to do it)?

Add the option to replace every pixel (in every drawn frame) of one specific color with the color of the respective line of a given "mask"-picture that we can select - a picture like one of these ("copper"-like backgrounds taken from Turrican II):

https://up.picr.de/44391874fs.png https://up.picr.de/44391875hv.png

So that we'd be able to replace the one-color backgrounds of e.g. Giana Sisters or Turrican I:

https://hol.abime.net/pic_full/scree...93_screen2.png https://hol.abime.net/pic_full/scree...33_screen4.png

...with the multiple colors from the selected "mask"-pic.

So that the result would look about like this:

https://up.picr.de/44391885qz.png

(drawn by Bubba'n'Stix 2 in this Lemon thread)

This feature could enrich games with one color backgrounds.

There could be a limit set for the lines to be affected so that the hud at the bottom wouldn't look weird in case it has some pixels of the same color as the playfield's background.


The implementation could be an enhancement of the existing mask-/overlay-feature in the filter settings where only the pixels of one specific color would be affected by the mask.

In the Hardware/Chipset menu, there is Genlock thing.
Turn it on, choose "image file (png)" then click on the ... and select a background picture.

It works in Workbench, it could work in games as well, if the color is right.

I'm digressing because it's not a WinUAE option

But I think it should be quite easy to add a rainbow background when modifying the copper list of a game like Great Giana because the scrolling is horizontal.
besides, maybe I'll try with an update of the slave whdload...

it's a little more complicated with a game like Turrican because the scolling is multi-directional.
But not impossible if you have enough free CHIP memory and you locate in memory the data relating to the Y position of the scrolling.

This is probably the right route.

Thank you, gonna give this a try after work.


That sounds great. If it makes it easier a fix background (from light to dark blue) for Turrican would already be an improvement. Though a vertically scrolling copper background like in Turrican II would be a dream come true.

You could make it anything you want within reason. Try some wild stuff let us see how it looks!

Wish I still had it, if anyone has please upload but I once took out the copper brackground of Turrican 2 because of the sickly colours. But agree Giana would look good.

And iirc member Gary? Once used a Genlock with real hardware maybe Star wars to put in some kind of background.

I guess going a bit far! Two Amigas and a Genlock you could get some perfect parallax.

I'm thinking about giana :nuts

I image well 2 optional copper backgrounds (one for the sky and for the cellars)
There may be enough CHIP memory available before address $1000 (if not used in game=>to check) and the game is not using the second copperlist. Which allows a fairly easy patch of the first copperlist........

I image 2 external files with just the list of colors for the levels with blue background and black background for easy modification & test;)
the custom copperlist should have a maximum size of 200*8 bytes
for one WAIT & MOVE command per line...
I'll think about it this weekend

Okay, tried the Genlock-way now with this png for Turrican:

https://up.picr.de/44401306uy.png

Sadly it's the black that gets replaced and not the blue:

https://up.picr.de/44401307bx.png


Cool, incl. the underground. Looking forward to what you'll be able to do.

Genlock doesn't work for Giana Sisters either.

For CarVup it works:

https://up.picr.de/44401371dd.png

Isn't there a way to select the colour?

No. I think it doesn't depend on a color, it's just the "background layer" that gets replaced I guess (don't know if that's the correct term).
Edit: I was wrong - it does depend on a color.

So Turrican's and Giana Sisters' background is not the system background layer (but CarVup's is).

Quite weird request but easily doable because ECS Denise (and AGA) supports configurable genlock color (each color palette entry has genlock transparency bit) and it is already emulated. Simple to make it config file only option.

Not sure what kind of config file entry should be because it should allow more than 1 palette entry index.

But don't expect this to work perfectly, for example scoreboard might use same color palette entry (but different color value) that shouldn't be transparent..

Glad to hear it's not difficult to implement. Config file option only is totally fine.

I know it's a quite unusual request but I'd be very happy if you'd add this option.

Should the scoreboard be affected I can just change the PNG to account for this (paint the usual color in that area).

Looking forward to seeing some excellent uses of pixel art backgrounds.

https://www.winuae.net/files/b/winuae.7z

Config file entry "genlock_effects=<numbers separated by comma>". number = color palette index that has genlock transparency bit set. p<number> = plane <number> is genlock mask. Both are ECS Denise new genlock features. (Originally genlock could only replace color 0). This feature "simply" reuses them.

For example "genlock_effects=3,15" (colors 3 and 15 will get replaced with genlock image)

ECS Denise is not required but genlock must be enabled (with some side-effects due to genlock, for example most programmed custom chipset display modes are not available in WB if genlock is enabled). Emulated genlock requirement probably will be gone in future update.

Thanks a bunch Toni! :great

https://s4.gifyu.com/images/t1copper.gif

Works pretty well (my png isn't optimal yet), but there's a problem with the main character:

https://up.picr.de/44407234rj.png

If someone else wants to try this, genlock_effects=5 is the right palette index for Turrican.

(I'm away tomorrow, will try again on Sunday.)

Fixed some sprite related genlock color selection bugs. Possibly fixes above problem.

I feel adding these backgrounds is legit as the system supported it.