gotcha: wd77 writing into samplebank memory

[pachuco]

During trying to set up multiple instances of websynth d-77(via MemoryModule), I naively used a single pointer to the soundbank.
D77_InitializeDataFile() fails on 2nd init.

If it's a thin check, requesting patching out.
If it's a deeper transformation, screw it and God have mercy.

[pachuco]

Doesn't look good at first glance. I'll go get my prayer beads.

[M-HT]

In the future, spare me the drama, please.
The pointer in D77_InitializeDataFile is explicitly not const, because the data is modified.
I took a quick look at it and I should be able to patch the code to not modify the data.

[M-HT]

Upon closer look, the data is modified more than I first thought, so I won't patch it to not modify the data.
But it seems that the data is modified only in function D77_InitializeDataFile, so I patched the function to work if the data was already modified in another instance.
This way you can use a single pointer to the datafile in multiple instances, with a minor caveat that initialization in the first instance can't run in parallel with initialization in other instances.

[pachuco]

My theory of what kind of changes it did is turning indexes/offsets to pointers inside bank, as an optimization.

[M-HT]

That's what I thought at first and I could deal with that, but there are also other changes which I don't know how to deal with.