Testing the new Stella TIA core

[DirtyHairy]

I would suggest that we branch of a 5.0 release branch in git. That way, everybody who likes can continue developing and we can choose what we merge in to 5.0 (either by cherry picking or by developing stuff in feature branches).

[+stephena]

The last pre-release before 5.0 final (pre8) is now available for testing. In particular, this one has new phosphor emulation mode, which has been kicking around my inbox for the past 8 months or so. Please test and report any issues. Note that phosphor mode is currently broken when using Blargg effects (TV filtering), so make sure to switch that off before using it. This will be fixed before the final release.

 

https://github.com/stella-emu/stella/releases/tag/5.0.0-pre8

[Thomas Jentzsch]

The new phosphor code is quite simple. For each RGB value, the currently rendered value is blended (well actually they are not, see below) with the previously displayed value. The result becomes the new displayed value.

 

Here is the pseudo code:

; prev = previously displayed value
; curr = currently rendered value

prev *= Blend/100;
if (curr > prev) return curr; // raise (assumed immediate)  
else             return prev; // decay

You can see two cases:

• If the current value is larger than the decayed previous one, the previous display is ignored. Instead the current value is taken. This emulates an immediate raise of the CRT.
• If the current value is lower than the decayed previous one, the decayed value of the previous display is taken. So in this case, the new value is completely ignored. This emulates the phosphor effect of a decaying value.

I have experimented with a lot of other algorithms (e.g. not ignoring the current value in a decay case) and this one seemed best. But if anyone has a better one, please let us know.

 

BTW: We still have to experiment with the Blend values, the current default of 77 seems way too high. Any feedback here is welcome.

Edited May 29, 2017 by Thomas Jentzsch

[+stephena]

Test release pre-9 is now available, addressing some issues with the new phosphor mode.

 

https://github.com/stella-emu/stella/releases/tag/5.0.0-pre9

[+SpiceWare]

There's been a report of Draconian not working in pre-9, it appears to be stuck on the splash screen. It works on my Mac, as well as my 2600. Perhaps it's a Window's only issue? He's running 32-bit Windows 7.

false alarm. Looking closer I realized he was running an old build:

[TheHoboInYourRoom]

Will the debug colors be editable? Frankly, I'd gotten used to the old set and seeing that P1 and M1 use completely different hues and that PF and BL more or less swapped their colors is throwing me for a loop and is kinda disturbing.

[TheHoboInYourRoom]

Will the debug colors be editable? Frankly, I'd gotten used to the old set and seeing that P1 and M1 use completely different hues and that PF and BL more or less swapped their colors is throwing me for a loop and is kinda disturbing.

To expand on this, I quite like the scheme of [base color, lighter color] for marking the object pairs. My ideal fixed palette would be the pre-5.0 one with the ball color slightly darkened, but I don't see the point in scrapping a useful scheme just so you make a rainbow with the objects.

[+stephena]

The reason for the change was discussed at some detail in https://github.com/stella-emu/stella/issues/114. It wasn't just for the colours, but the fact that some of the objects inherit their colours from other objects, and they are laid out in the debugger in a certain way. While I'm not necessarily opposed to adding a toggle for the old colours, I won't be making them user-editable. That's too much work, both in the implementation and the error checking (ie, once something can be edited by the user, we also need error handling for the inevitable mistakes that users will make )

[TheHoboInYourRoom]

It wasn't just for the colours, but the fact that some of the objects inherit their colours from other objects

Exactly, which is why I much prefer each pair of colors to be from the same hue.

 

While I'm not necessarily opposed to adding a toggle for the old colours, I won't be making them user-editable. That's too much work, both in the implementation and the error checking (ie, once something can be edited by the user, we also need error handling for the inevitable mistakes that users will make )

That's understandable. A checkbox in the video settings (or wherever else appropriate) would be perfect.

[+Nathan Strum]

I have a couple of feature suggestions (I've brought these up before, but they've yet to make the cut) :

• In the Game List, being able to move to directories using Shift + (letter). For example, I keep my ROMs sorted by manufacturer, so being able to type Shift + P to jump to Parker Bros.
• Being able to save a game screenshot from the debugger with F12.

[Keatah]

..and consequently the search box should recognize a folder's brackets [Atari].

[+stephena]

Please post these as feature requests under 'Issues' at https://github.com/stella-emu/stella/issues. Otherwise they will probably be lost in these threads.

[+stephena]

You can currently save a snapshot in the debugger by right-clicking on the TIA image and selecting "Save snapshot". There is also a command in the debugger prompt to do the same thing. But I suppose adding a keyboard shortcut is easy enough.

[+Nathan Strum]

Please post these as feature requests under 'Issues' at https://github.com/stella-emu/stella/issues. Otherwise they will probably be lost in these threads.

 

 

Done and done. Didn't know about saving snapshots from the debugger - I thought there was a way to do it, but couldn't find it in the User's Guide.

[+iesposta]

Will the debug colors be editable? Frankly, I'd gotten used to the old set and seeing that P1 and M1 use completely different hues and that PF and BL more or less swapped their colors is throwing me for a loop and is kinda disturbing.

The only big change was making the Ball object blue. Then it all falls in line with the spectrum, plus the "b" in Ball is easy to remember "b"lue.

 

By the way, the latest build has a bug with Ball and Playfield debug colors swapped.

Bug report filed on GitHub.

 

Here are the old/new colors:

Original / New

[+Trebor]

Princess Rescue...

CRC32: 560DAC0C

MD5: 104468E44898B8E9FA4A1500FDE8D4CB

 

...is broke under Stella 5.0.0-pre8 and -pre9. It works fine under -pre4 thru -pre7.

 

Under -pre8 and pre9. The game appears to be running, it responds to joystick button presses to start the game, and you can hear Mario jumping, but the screen is black/blank the entire time.

 

Occurs both in a window and full screen Windows 10 64-bit, running Stella 64-bit versions for all trials:

 

[alex_79]

Turn off TV effects.

Currently the new phosphor mode doesn't work if those are enabled (and Princess Rescue has phosphor on by default)

https://github.com/stella-emu/stella/issues/75#issuecomment-304533016

[+stephena]

Turn off TV effects.

Currently the new phosphor mode doesn't work if those are enabled (and Princess Rescue has phosphor on by default)

https://github.com/stella-emu/stella/issues/75#issuecomment-304533016

 

You can quickly do this by pressing Alt-1. Then in other ROMs, press Alt-2,3,4,5 to turn it on again.

[+stephena]

Debug colours has been addressed https://github.com/stella-emu/stella/issues/162. Currently there's only a commandline option to change it; I will add a GUI item if I have time before the 5.0 release.

[+iesposta]

Debug colours has been addressed https://github.com/stella-emu/stella/issues/162. Currently there's only a commandline option to change it; I will add a GUI item if I have time before the 5.0 release.

Wow. Surprised you went with the Debug Colors: Red, Orange, Yellow, Green, Blue, Purple

But I am all for getting 5.0 out.

This Stella issue is closed, so we'll have to revisit it at a later date.

 

You can choose which object those colors belong to, but you can't change the colors, available through a commandline option (tia.dbgcolors).

 

I thought it was really going toward:

P0 _color_ M0 _lighter color_

P1 _color_ M1 _lighter color_

PF _color_ Ball _lighter color_

 

Or the original colors with P1's color (pea green) swapped with M1's (yellow)

 

Then on top of that, choosing your own colors would make everyone happy.

[Keatah]

I'd rather 5.0 bake for a long time. Then come out bursting with flavors and goodness

[Thomas Jentzsch]

IMO we shouldn't delay 5.0 by such details which can be solved for 5.1 (or later). There are a lot of changes waiting for a final release (especially the TIA emulation which has become so much better).

[DirtyHairy]

I'd much rather have us release 5.0 asap. Already now, there is a ton of changes piled up, and we will get much more exposure and feedback once we release it.

 

We are only talking about the debug colors here. I wager that 95% of Stella's user base don't even know that those exist or what they mean, and the remainder should be able to live with the change for the time being AND give feedback about how they would like this to be adressed in the future

Edited July 5, 2017 by DirtyHairy

[Keatah]

Well, whatever ya'll think works best.

 

I have no idea what they do, but, The new debug colors look ok. They have a lot of contrast and are spread more evenly and distinctly throughout the spectrum.

Edited July 5, 2017 by Keatah

[+stephena]

 

Wow. Surprised you went with the Debug Colors: Red, Orange, Yellow, Green, Blue, Purple

But I am all for getting 5.0 out.

This Stella issue is closed, so we'll have to revisit it at a later date.

 

You can choose which object those colors belong to, but you can't change the colors, available through a commandline option (tia.dbgcolors).

 

I thought it was really going toward:

P0 _color_ M0 _lighter color_

P1 _color_ M1 _lighter color_

PF _color_ Ball _lighter color_

 

Or the original colors with P1's color (pea green) swapped with M1's (yellow)

 

Then on top of that, choosing your own colors would make everyone happy.

 

The actual colours are the ones we discussed in https://github.com/stella-emu/stella/issues/114 and again in https://github.com/stella-emu/stella/issues/162. They were the ones we agreed on, yourself included I believe.

 

The ordering changed, but there is currently a commandline option to change it, and I will have a GUI option too in the next few days. Beyond that, we really need to get 5.0 done.