These two if statements are repeated frequently. I bet they can be optimized but for the life of me, I can’t think of an improvement.
5550 if acc < -128 then acc = -128
5560 if acc > 127 then acc = 127
Anyone?
5550 if acc < -128 then acc = -128
5560 if acc > 127 then acc = 127
Anyone?
DEF (https://www.c64-wiki.com/wiki/DEF) would be the way to do this, but I don’t see how to write a performant version in a single expression (you can’t use IF as an expression. You could cast to float, compute some specially chosen sigmoid function, and round to int, but that’s slow)
A USR function (https://www.c64-wiki.com/wiki/USR) would work, but that’s cheating.
I don’t think bit masking alone will get you there. You want to map anything over 0x80 to 0x7F.
I think you can do something like
x + (x < -127) * (x + 127) + (x > 127)) * (x - 127)
^^^^^^^^^^^^^^^^^^^^^^
That expression can be put in a DEF FN.