Question about N64 combiner

[Orkin]

I'm working on an ARB_fragment_program combiner (which may eventually be expanded to do blending, alpha testing, texture coordinate wrap/mirror/clamp, and noise), but I need to know something about the N64's combiner so I can be sure I've got it 100% correct. Does anyone know if the N64 clamps color values between combiner stages? This never came up before because I didn't have the kind of control that fragment programs give me before.

In case nobody knows the answer to the question directly, here are a couple screenshots that someone might be able to help with.

Here's the new fragment program combiner with clamping between combiner stages enabled:
http://gln64.emulation64.com/clamped.jpg

And here it is with clamping disabled:
http://gln64.emulation64.com/non-clamped.jpg

Notice that with clamping disabled it goes to nearly black at the bottom of the N, but with it enabled it hits a medium green and stays there.

Can anyone with an N64 and OoT (or MM) handy tell me which is correct?

Thanks,
Orkin

[Knuckles]

You're lucky, I just had my N64 near me with the zoot catridge (I played some hours ago). I would say, the first one is the good one. but the shinning on the N64 logo should be with more brightness. there is no black part at the bottom when the N is spinning. Take a look at it in on glide64 (if you can).

[Shin_Gouki]

Soory orkin but IMO a color diffrence in those pics isn´t REALY noticeable by the human eye...
also the pics doesn´t show EXACTLY the same moment, or ami wrong?
perhaps a color histogramm would be good enough to find out what your looking for..
wbr Shin Gouki

[blight]

i also think the above one is the correct.... here are some shots from a real n64 connected to my tv input (i think it's a bit too bright, but it looks more like the upper one of yours)

--blight

[Orkin]

i also think the above one is the correct.... here are some shots from a real n64 connected to my tv input (i think it's a bit too bright, but it looks more like the upper one of yours)

--blight

Okay, thanks. It makes sense that it would clamp between combiner cycles.

I wonder if the extra-bright highlights on your shots are just from your TV caps being too bright, or if it's really supposed to be like that. If that's the way it's supposed to be, it looks like I still have some more work to do...

Orkin

[Shin_Gouki]

uh it seems as i was wrong there is a diffrence the one, blight mentioned.
if the light is no animation than the first of you your pics is truly brighter on the nintendo 64 font.
(especially good to see on the T )
if thats want you wanted to know ;)
wbr Shin Gouki

[gandalf]

Yep,it´s the correct brightness.I have the game,but any metod to "transfer" images from my N64 to PC :(

Keep your good job orkin!

(well,a little late to reply,but i like this plug-in!)

[Zuzma]

I agree that the first one looks the closest to it since the pic I took off my tuner looks similer to blights. The only difference is it does this stupid de-interlacing thing that looks weird but it does look almost the same.