MAMEWorld Forums - EmuChat - Re: CRT-aperture GLSL shader

> Vas is correct but let me elaborate one thing. The artifact from the camera is
> distinct from a rare but possible hum bar created by a ground loop problem. This hum
> bar is visible to the human eye and appears to move upward slowly.
>
> Another problem, not to be confused with the other two, is loss of sync signals. This
> will cause shuttering and bending.
>
> All of these things are undesirable and are not normal for CRTs.

I have never seen a "real" hum bar in my life and i have seen a lot CRT´s in my life. The only effect that comes near to a hum bar, is a very thin line (like 2 pixels that darkens the effected area) that moves up slowly, this was due to very long cables used. But this line was in no way, so noticeable like i.e. the hum bars in the youtube video.

Undesirable is a question of taste, because there are people that prefer a "moody/blurry" look for the screen, especially on arcade games, as it is how they remember them from their memories. This is due to the fact, that many arcade machines did run with no or low service support, often changed pcbs, running the games afterwards with wrong focus settings and what not. Those "undesirable" effects are exactly what makes HLSL so special and these effects actually really happened on the CRT screen and are something that was seen by everyone who stand in front of it.

And this is the only thing i dont like, regarding the hum bar. People with not enough knowledge, are tend to think that this effect "really" happened on CRT´s, like B2K24 for example.

> I'll have the final say in whether anikom's changes get merged in, and I will reject
> it if it strays too far from the look and feel of Jezze's shaders. I don't want the
> great work that Jezze has done to be broken or forgotten.
>
> What I would like to see is a more concentrated effort on bringing the BGFX features
> up to parity with the HLSL backend, so that Jezze's shaders can be accomplished
> identically. I unfortunately cannot volunteer that effort, because I'm working two
> jobs and am occupied 14 hours a day on weekdays, and only slightly less on weekends.
> Hopefully that will be lifting soon, but I'd really like to see someone else with a
> passion for graphics come in and do what I can't, in a modular and forward-looking
> way.
>
> Ultimately Direct3D 9 is a technological dead-end and is more than likely going to
> have its support increasingly restricted as time goes on, not by MAME, but by
> operating systems. I like Jezze's shaders, and I hope I'll like anikom's shaders, and
> I want a modern system where both can be supported, and more.

A job is a job and should have the highest priority... always. It is what makes any further effort and work for MAME developing even possible, not to mention any "real" life basis. No need to say, that i agree with all other mentioned arguments.

However i am sure, that you can contact Jezze for help, in a case where someone is getting stuck with a particular problem.

> The reason I ask is because the current implementation is an annoyance to me and
> doesn't fit well in the whole scheme.
>
> 'HDR monitor' probably means three things:
> 1. Good contrast
> 2. Wide gamut
> 3. Higher bit-depth
>

> I want to make a shader for artwork, the glow effect would have to go there, but
> that's probably a separate project right now.
>
> I can't make any improvements to the vector shader, but I can try to port it to BGFX.
> Porting is not as trivial as advertised unfortunately.

If you make HDR support possible, you will also improve vector rendering/shading. I think vector games will benefit visually the most of HDR implementation. It is a step further to realistic mimics of phosphor life and the brightness/ B&W levels of a CRT screen.

But making HDR possible is another story. Maybe it is better to wait and see, how the gaming industry will solve all the problems mentioned here, regarding HDR. I only know, that some games already support it and the next gen consoles will for sure. I just dont own a HDR supporting monitor, so i can be of no help here. But i know, that even without a HDR monitor, some effects calculated in 16bit per (RGB) channel, create much better results in my Adobe After Effects program and i think this could apply to MAME and shaders too (might be wrong here).