Add vibrato, portamento and appregio events

[sikthehedgehog]

'nuff said. You can currently fake them with set frequency events, at the expense of wasting lots of memory.

[marcb0t]

Yes, yes, yes, yes, yes... and double yes!

[sikthehedgehog]

The big problem here is the math. Tones are not linear, so the Z80 would have to do some logarithm stuff or something like that, and look-up tables may take too much space (I need to be careful with RAM usage if I don't want to be stuck unable to add anything else). And even interpolating linearly between semitones may not be that trivial :P

I know everybody will yell at me if it isn't 100% accurate though. I already got yelled for not having dedicated tables for NTSC and PAL >_>

[marcb0t]

I know everybody will yell at me if it isn't 100% accurate though. I already got yelled for not having dedicated tables for NTSC and PAL >_>

Haha! I will not "yell" at you for anything. But as I've said before, I'm willing to test and give my constructive critique and analysis in order to help you make this feature the best you can.

And when you've done your personal best, what does it matter what other people say? I have confidence in your ability to make this feature shine! :D

[sikthehedgehog]

Implemented an alternate version of the $3x events that takes up a semitone instead of a frequency. Not a proper alternative to this, but still worth noting since it takes up 2/3 the space (i.e. instead of taking up 180 bytes per second per channel, it takes up 120). Will show up in the next version.

[sikthehedgehog]

For what's worth it, XGM is actually worse than Echo at this even with the old-style events since XGM stores raw register writes :/ So pressure for this may be lower priority than I think.