flext - C++ layer for Max/MSP and pd (pure data) externals

Copyright (c) 2001-2023 Thomas Grill (gr@grrrr.org)
For information on usage and redistribution, and for a DISCLAIMER OF ALL
WARRANTIES, see the file, "license.txt," in this distribution.

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VARIOUS NOTES:

Platform specific:
- Pd does not allow signal and message to go into the same inlet (except leftmost inlet)
- Pd: with DSP objects all float messages to the leftmost inlet are converted to signal

Restrictions in compatibility mode:
- Max allows only 9 float/int inlets

Porting to new compilers/platforms:
- enums must be int-sized!!!
- compiler must support bool type
- an STL implementation must exist
- C++ exceptions and RTTI must be enabled

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KNOWN BUGS:
- Some few external libraries have troubles with flext's global new and delete overloadings.
  In these cases one can switch back to the C library memory operators by defining the FLEXT_NOGLOBALNEW macro before
  inclusion of the flext.h header file (e.g. as a -D compiler option)

- Pd: floats into the leftmost inlet of DSP objects can't be used as messages
  even if there's no signal inlet at all

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TODO LIST:

- optimizations for object initialization and messaging
- speed up message handling (usage of other containers?)
- SIMD for gcc
- lock-free code for old AMD 64-bit architectures

- update documentation
- add log messages for debugging version
- use Pd's t_float and t_int types (or comparable for 32-bit safety)

- add double handlers
- add signal in/out connection query function

- support for Max qelem style

- flext::post and flext::error should print via a worker thread (and should be unlimited in characters)

- manage running threads individually (stop, isrunning?, priority etc.)

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TESTS TO DO:

- Pd: problems with timed buffer redrawing (takes a lot of cpu time)
- hard thread termination upon object destruction doesn't seem to work properly -> crash
- Max rounding bug ... buffer resize could be one sample less!

- Pd: figure out what "pointer" messages do and whether they are correctly implemented in flext

- Max buffer~ resize: flext_base::buffer::Frames(): must we use buffer or system sample rate?

- check whether m_dsp gets called upon deletion of a used buffer (Pd and MaxMSP may behave differently).
	-> Pd does call m_dsp, Max/MSP does not
