[fluid-dev] Fluidsynth internal structures

[jimmy]

Hi folks,

I know Miguel(???) was working on a reimplementation of FS using CPP.  Plus, 
some folks here are looking to modularize FS.  You may want to use some kind of 
dictionary, or table look up for some of the structures (objects) used in FS.  
Hopefully for a more efficient and a little faster real-time look up.

For what it's worth, I have been tracing through some of the FS code and find 
that the structure:

   fluid_sfont_t

can be a virtual pointer to a font structure of type:

   fluid_defsfont_t

which contains a pointer to a "preset" structure:

   fluid_preset_t

There is a preset for each prog_num in each soundbank(s) of a soundfont.  As 
used in

   fluid_defsfont.c : fluid_defsfont_get_preset()

The fluid_preset_t is a link-list structure pointing to the next fluid_preset_t 
structure.  Basically, that function walks through consecutive presets:

   preset for bank 0 prog 0
   preset for bank 0 prog 1
   preset for bank 0 prog 2
   . . .
   preset for bank 0 prog 128

follow by presets for any additional instrument bank(s), and drum bank 128.  
This lookup is used for every prog_change.

That's a simple and straigh forward way to implement the system using linear 
link-list, but can be very inefficient for look up time.

Best regards,

Jimmy