bw_voice_alloc

Basic voice allocator with low/high note priority.

Examples

Here you can download one or more example VST3 plugins for Windows, macOS and Linux. Source code of the audio engine(s) is included in the archive(s).

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API

Module type: Utility

bw_voice_alloc_priority

typedef enum {
	bw_voice_alloc_priority_low,
	bw_voice_alloc_priority_high
} bw_voice_alloc_priority;

Note priority:

• bw_voice_alloc_priority_low: low note priority;
• bw_voice_alloc_priority_high: high note priority.

bw_voice_alloc_opts

typedef struct {
	bw_voice_alloc_priority priority;

	void (*note_on)(
		void * BW_RESTRICT voice,
		unsigned char      note,
		float              velocity);

	void (*note_off)(
		void * BW_RESTRICT voice,
		float              velocity);

	unsigned char (*get_note)(
		const void * BW_RESTRICT voice);

	char (*is_free)(
		const void * BW_RESTRICT voice);
} bw_voice_alloc_opts;

Voice allocation options:

• priority: note priority;
• note_on: note on callback, where voice is an opaque pointer to the chosen voice, note is the note number, and velocity is the note velocity in [0.f, 1.f] or otherwise negative to indicate unknown / not available;
• note_off: note off callback, where voice is an opaque pointer to the chosen voice and velocity is the note velocity in [0.f, 1.f] or otherwise negative to indicate unknown / not available;
• get_note: callback that returns the note number associated to the given voice;
• is_free: callback that returns whether the given voice is free (non-0) or not (0);

bw_voice_alloc()

static inline void bw_voice_alloc(
	const bw_voice_alloc_opts * BW_RESTRICT opts,
	bw_note_queue * BW_RESTRICT             queue,
	void * BW_RESTRICT const * BW_RESTRICT  voices,
	size_t                                  n_voices);

It performs voice allocation according to opts and using the events in queue.

voices is the array of opaque voice pointers and n_voices indicates the number of elements in voices.

Changelog

• Version 1.1.0:
  • Added static inline to bw_voice_alloc().
  • Added support for BW_INCLUDE_WITH_QUOTES and BW_CXX_NO_EXTERN_C.
• Version 1.0.1:
  • Now using BW_NULL.
• Version 1.0.0:
  • Specified that velocity can be negative in bw_voice_alloc_opts.
  • Now using size_t instead of BW_SIZE_T.
  • Added const and BW_RESTRICT where needed to callback types in bw_voice_alloc_opts and to bw_voice_alloc().
  • Removed usage of reserved identifiers.
• Version 0.6.0:
  • Now using BW_SIZE_T to count voices in bw_voice_alloc().
  • Added debugging code.
  • Removed dependency on bw_config.
• Version 0.5.0:
  • First release.