- Don't look for PkgConfig on Win32.
- Don't force glib and gthread on Win32.
- Support finding libsndfile with vcpkg.
- Add enable-static-msvcrt option to use the static VC runtime library.
- Add stubs that define glib functions to Win32 equivalents.
This PR moves mixing of LADSPA effects in fluid_rvoice_mixer_process_fx() before mixing of the internal reverb and chorus effects.
Currently, if a user sets synth.audio-groups >1, LADSPA effects can be applied to specific MIDI channels only. The user can then follow @mawe42's great suggestion from the mailing list and use a zero-gain amp effect to mix the LADSPA buffers back to the first host port for output to the sound card (This seems like the most proper way to do this IMO - the LADSPA subsystem shouldn't have to figure out what FluidSynth's audio output channels are on its own).
However, since the internal reverb and chorus are applied first and don't care about synth.audio-groups, the LADSPA effects will appear in the internal effects buffers regardless of which audio_group the currently-playing MIDI channels are part of. Increasing synth.effects-groups is not ideal since it adds a lot of processing load, and also would seem to require that effects-groups always be equal to audio-groups. A user could disable the internal reverb and chorus and add them as LADSPA effects, but it's nice to be able to have backing instruments or tracks from MIDI files play "normally" (i.e. according to the soundfonts' reverb and chorus settings), while a user plays lead with interesting effects that don't alter the backing voices.
Resolves#1117.
This common setting was ignored by the PulseAudio driver.
It doesn't change the synthesis buffer size, which is still
the number of frames specified by audio.period-size, but
the number of periods may be raised to request a higher latency
amount, unless audio.pulseaudio.adjust-latency is 1 (the
default). In turn, PulseAudio will grant or not this latency
request. See: [PulseAudio Latency
Control](https://www.freedesktop.org/wiki/Software/PulseAudio/Documentation/Developer/Clients/LatencyControl/).
