VGM Music Maker import

[techmetx11]

This is based off of reverse-engineered knowledge and may not be complete or accurate.

~~Only supports VGE files exported with VGM Music Maker v1.1 (file must start with VGEfmtV3) as of now.~~ Supports VGE files exported with any versions of VGM Music Maker.

• [x] VGEv1: VGMMM v1.0, v1.01, v1.02 (Pre-Release)
• [x] VGEv2: VGMMM v1.02
• [x] VGEv3: VGMMM v1.1
• [ ] Samples (gain for VGEv1, gain+pitch for the rest of the versions)
• [ ] PSG ADSR envelope and volumes
• [x] Special case for notes in PSG noise channel

[techmetx11]

Samples cannot be implemented due to the fact that Furnace cannot handle the possible amount of samples + FM instruments. VGM Music Maker has 256 FM instruments and 255 samples, and plays those samples using a special effect in FM 6 (while Furnace requires you to make a sample instrument for each sample, taking up space in the instrument list). In the case of a VGE file having more than (for example) 127 FM instruments and 127 sample instruments, it would cause the instrument list to overflow

[freq-mod]

is it alive?

[techmetx11]

is it alive?

PR blocked because I don't how to handle 1) Calculating PSG envelope from FM ADSR 2) If there are a combined more samples and FM instruments than the 256 instruments that Furnace can support