"Gunlock" has the brightness too high

[CharlesProfessional]

When playing the game "Gunlock", during the Area 5 boss, you are descending down a vertical shaft

This effect is done by using the same sprite and scaling it repeatedly

However, the brightness is too high and you can see the bottom edge of the sprite

As seen from this person's direct PCB capture, this should not happen, and the sprite should appear black at the bottom and top parts

This indicates to me that the brightness of the game's sprites is too high, and should be turned down

[barbudreadmon]

I found this pcb video : https://youtu.be/dhwe3qEWgZE?t=1205

It seems the stage should be far darker indeed, especially the grey parts

[dinkc64]

taito f3 video is a beast, if you can accomplish that without breaking anything else, by all means, do it :)

[dinkc64]

I actually think this might have something to do with a non-linear gamma-like effect that happens when using a real pcb and video signals as opposed to perfect pixels coming through an lcd from an emulator.

[dinkc64]

I did some experimenting, changing just the brightness - it doesn't help. I think its a combination of brightness + contrast or saturation, maybe? hmm...

[dinkc64]

what I came up with to get close, (in irfanview): it needs gamma correction of 0.53 saturation of -88 and contrast of -37

In the past I wrote palette lut calculators for doing brightness and contrast, but not saturation and gamma. Will try to work those out soon.

best regards,

• dink

[dinkc64]

(in an experiment) got it looking close in fbneo! will post pics soon

[dinkc64]

this is as close as I can get it: (none of the code is available to try yet) With a gamma (new code in d_taitof3) of 0.53. With bi-linear filterting to smooth the image (built into the fbneo blitter)

problems: 1: the colors are a little too saturated (can be fixed with more work) 2: I can't totally make the stuff disappear further down the tunnel (can't fix this)

It took a huge amount of time to get it this far, though, what do you think?

left side: youtube video from pcb / right side: fbneo running some test-code

best regards,

• dink

[CharlesProfessional]

How do I change the brightness, contrast, saturation, and gamma? There is no option to do so in FBNeo's interface

[dinkc64]

this is test code/project i'm working on, its not available yet - but it will be when I'm happy with the results :)

[y-ack]

generally i would consider anything related to brightness in taito f3 invalid until the line ram 6200 blending side is figured out, because a lot of games are using that for brightening/darkening in subtle or not so subtle ways.

another pcb recording here: https://youtu.be/iZ1x6N74_Y4?t=2905

[dinkc64]

y-ack, I totally agree, this will just be a little dip hack/option for the time being though :) p.s. I love the work you've been doing lately! Great job! :)

[dinkc64]

@CharlesProfessional The new code is in, go into the game's DIPs and set the "GammaBrightness hack" to On & restart or reset the game. If you want smoothing: in the Enhanced blitter, it's "Video -> Blitter options -> Enable Bi-linear filtering" in either DirectX9 blitters, it's "Linear Filtering" under Blitter options The Basic Blitter has bi-linear filtering on (its not an option)

best regards,

• dink