Ah, good ole RB closed a topic which raised certain points, and I want to comment some of the issues. Yup, sorry.
>and all it teaches us is that Pete should keep his mouth shut in public ;-)
Ehehe, sometimes Pete forgets that his hobby takes place in a global kindergarten, where kids love to build, defend and destroy virtual sandcastles...
Anyway, a few words (harhar, understatement) about software gpus <> hardware/accel. gpus and open source <> closed source license issues, and, yeah, MAME ZiNc plugins.
About the different gpu approaches (software<>hw/accel): emulation-wise an hw/accel plugin is not "worse" than a software gpu. It simply offers a different kind of display (and often better speed). And yes, certain things are harder to emulate properly in a hw/accel gpu, so glitches are more likely, but that's not the point: I dare to say that currently all psx gpu emulation approaches (be it my D3D/OpenGL/OGL2 plugins, Lewpy's Glide, my P.E.Op.S. or smf's software renderers) have their own special glitches, issues and general advantages/disadvantages.
I can understand opinions like "I don't like this special type of rendering, because (enter your visual reason here)". But I don't like statements like "this type of gpu emulation is superior because (...), and therefore there is no reason at all for the existence of other approaches". But maybe that's only because I am german, and all I can say that this kind of arrogance didn't do us much good 60 years ago.
Yes, changing the internal rendering resolution (that's what most hw/accel psx gpu emulations are doing... you can play in the native psx resolution in my OGL2 plugin, though, if you like that better), isn't "pure". But doing a stretched blit without keeping the native aspect ratio in a soft gpu isn't very "pure" as well. Or adding visual scanlines. Or applying any sort of post-process filter (to make the image sharper, or even the bilinear filtering most nowadays cards do automatically when doing a DirectDraw streched blit). Or frame skipping. And And And. So, imho, even nowadays MAME has settings and options to tweak the display (and sound and input) into "non-pure" modes, and I could easily play devil's advocate and ask why, harhar (hey, "MAME isn't about playing games").
Now, about open source, closed source, and licenses.
In the PSX emu scene there are freeware closed source emus, GPL open source emus, freeware closed source plugins, GPL open source plugins... a colorful mix, and nearly all of them are compatible to each other (thanks to the visions of the PSEmu Pro Vision Thing team 7 years ago, ehehe).
Of course that leads sometimes to questions like: how can a GPL emu avoid to get "tainted" by a closed source plugin? How can a closed source emu dare to use an holy GPL plugin?
The answer is very easy: emus and plugins are not distributed together. The GPL (and out of my mind the MAME license is not different in that) is controlling the distribution, but not the private usage. A user can get a GPL thingie, and he can get a non-GPL thingie, and - grasp - he can _use_ them together, if he likes to do that. Again, not distribute them together. But use them.
Therefore an open source MAME derivate, containing a gpu plugin interface, is (imho) no license problem as long as the MAME main emu and the plugins are not bundled together.
But... surprise, surprise, even if there is no real license problem (as far as I can see), and even if I think that a "hw/accel gpu enhanced hi-res display" is not a bad thing by itself (I prefer it myself over "pure" soft rendering for playing games anytime), I also don't support the "MAME zinc plugin" idea anymore (yeah, prolly I started it, that's life), but for a different reason:
I don't think that smf is pissed off because he gets no praise or emu fame or whatever (as far as I can see smf's work on MAME is highly regarded everywhere).
He just wants to realize his own ideas, without having to worry about plugins, or anything else which may limit the ways he wants to go. And I can understand that. Do we need a second ZiNc (MAME + plugins)? Not really, if ZiNc 1.0 gets released, users can choose whatever they prefer. And who knows, if smf continues his great work, maybe I will finally see a psx emulation (MESS) which can handle SPU IRQs perfectly. Personally I would like that