Export audio-backend and audio-device?; SIGIL_AUDIO

Message

(audio-backend) answers the backend miniaudio picked as a symbol ('pulseaudio, 'alsa, 'jack, 'wasapi, 'dsound, 'winmm, 'coreaudio, 'null; #f before audio-setup); (audio-device?) is #t when a real device is open. audio-initialized? keeps its meaning (audio-setup ran; the mixer and the streams work on every backend), as under sokol_audio where an invalid device was silent but initialized: code that gated pushes on it keeps working, and the new predicate names the new fact.

SIGIL_AUDIO_BACKEND=<name> makes ma_context_init try that backend only, so the suite runs once as it falls and once forced to null; the drain test checks the symbol is known, that audio-device? is #t exactly when the backend is not null, that a forced name is honoured, and that both answer #f after audio-shutdown. Sabotaged (audio-device? made #t on every backend): the forced-null run failed that check.

Changed

 CHANGELOG.md               | 17 +++++++++++++++++
 README.md                  |  4 +++-
 src/c/audio-device.h       | 10 ++++++++++
 src/c/audio.c              | 37 +++++++++++++++++++++++++++++++++++++
 src/c/miniaudio-impl.c     | 47 ++++++++++++++++++++++++++++++++++++++++++++++-
 src/sigil/audio.sgl        |  2 +-
 test/test-device-drain.sgl | 16 ++++++++++++++++
 7 files changed, 130 insertions(+), 3 deletions(-)

Diff

CHANGELOG.mdmodified

@@ -33,6 +33,23 @@ and this project adheres to [Semantic Versioning](https://semver.org/).

for the test that opens a device (`test/test-device-drain.sgl`, which

proves the device thread drains a stream).

+36

### Added

+37

+38

- `(audio-backend)`: the backend the device runs on as a symbol

+39

(`'pulseaudio`, also on a PipeWire desktop through pipewire-pulse;

+40

`'alsa`, `'jack`, `'wasapi`, `'dsound`, `'winmm`, `'coreaudio`, or

+41

`'null` when frames are consumed in silence), `#f` before `audio-setup`.

+42

- `(audio-device?)`: `#t` when a real (non-null) device is open, i.e.

+43

when sound can reach a listener. `audio-initialized?` keeps its meaning

+44

(`audio-setup` ran; the mixer and streams work on every backend), as it

+45

had under sokol_audio where an invalid device was silent but

+46

initialized; the new predicate names the new fact.

+47

+48

one backend instead of miniaudio's priority walk (tests run the suite

+49

with `null` too; a desktop whose first choice misbehaves can pin one).

+50

- `test/test-device-drain.sgl`: opens the real device and proves the

+51

device thread drains a stream, and checks the two predicates agree.

+52

### Removed

- `vendor/sokol` (sokol_audio.h, sokol_log.h) and `src/c/sokol-audio.c`.

README.mdmodified

@@ -29,7 +29,9 @@ sigil-desktop's, see `src/c/DL-SEARCH-ORIGIN.md`): `SIGIL_LIBRARY_PATH`,

the active `guix shell` / `nix-shell`, then the user and system profiles

of both. With no backend library anywhere miniaudio's Null backend runs

the mixer in silence and one line on stderr says so.

−32

`SIGIL_AUDIO_VERBOSE=1` prints the backend, the device and every

+32

`(audio-backend)` answers the backend as a symbol and `(audio-device?)`

+33

whether it is a real one; `SIGIL_AUDIO_BACKEND=null` (or a backend name)

+34

pins the choice. `SIGIL_AUDIO_VERBOSE=1` prints the backend, the device and every

resolver hit. A run manifest for a game on Guix adds `pulseaudio` (the

client library, 187 MiB of closure) or `alsa-lib` (3 MiB; untested here, and the ALSA

route would go through the machine's ALSA configuration to reach PipeWire) to

src/c/audio-device.hmodified

@@ -19,4 +19,14 @@ void sigil_audio_device_close(void);

* "WASAPI", "Core Audio", ...), or NULL when no device is open. */

const char *sigil_audio_device_backend(void);

+22

/* The backend as a lowercase symbol name for Scheme ("pulseaudio", "alsa",

+23

* "jack", "wasapi", "dsound", "winmm", "coreaudio", "null", "other"), or

+24

* NULL when no device is open. PipeWire desktops answer "pulseaudio"

+25

* (pipewire-pulse): miniaudio has no PipeWire backend of its own. */

+26

const char *sigil_audio_device_backend_symbol(void);

+27

+28

/* 1 when a device is open on a real backend, 0 on the Null backend (frames

+29

* are consumed in silence) or with no device. */

+30

int sigil_audio_device_real(void);

+31

#endif /* SIGIL_AUDIO_DEVICE_H */

src/c/audio.cmodified

@@ -304,6 +304,37 @@ static Value native_audio_initialized(SigilVM *vm, int argc, Value *args)

304

return g_audio_initialized ? SIGIL_TRUE : SIGIL_FALSE;

305

}

306

+307

/*

+308

* (audio-backend) -> symbol or #f

+309

*

+310

* The backend the device runs on: 'pulseaudio (also on a PipeWire desktop,

+311

* through pipewire-pulse), 'alsa, 'jack, 'wasapi, 'dsound, 'winmm,

+312

* 'coreaudio, or 'null when no backend library or server was usable and

+313

* frames are consumed in silence; #f before audio-setup.

+314

*/

+315

static Value native_audio_backend(SigilVM *vm, int argc, Value *args)

+316

{

+317

(void)argc; (void)args;

+318

const char *name = sigil_audio_device_backend_symbol();

+319

if (!name) return SIGIL_FALSE;

+320

return sigil_intern_symbol(vm, name, strlen(name));

+321

}

+322

+323

/*

+324

* (audio-device?) -> boolean

+325

*

+326

* #t when sound can reach a listener: a device is open on a real backend.

+327

* (audio-initialized?) stays #t after audio-setup whatever the backend,

+328

* because the mixer and the streams work either way (as under sokol_audio,

+329

* where an invalid device was silent but initialized); this predicate

+330

* names the new fact a game may want: whether to bother with sound.

+331

*/

+332

static Value native_audio_device(SigilVM *vm, int argc, Value *args)

+333

{

+334

(void)vm; (void)argc; (void)args;

+335

return sigil_audio_device_real() ? SIGIL_TRUE : SIGIL_FALSE;

+336

}

+337

338

/* ============================================================

339

* NATIVE FUNCTIONS - SOUNDS

340

* ============================================================ */

@@ -590,6 +621,10 @@ void sigil__init_sigil_audio_module(SigilVM *vm)

621

SIGIL_ARITY_EXACT(0), "Initialize audio");

622

sigil_module_register_native(vm, "audio-shutdown", native_audio_shutdown,

623

SIGIL_ARITY_EXACT(0), "Shutdown audio");

+624

sigil_module_register_native(vm, "audio-backend", native_audio_backend,

+625

SIGIL_ARITY_EXACT(0), "The audio backend in use, as a symbol, or #f");

+626

sigil_module_register_native(vm, "audio-device?", native_audio_device,

+627

SIGIL_ARITY_EXACT(0), "Is a real (non-null) audio device open?");

628

sigil_module_register_native(vm, "audio-initialized?", native_audio_initialized,

629

SIGIL_ARITY_EXACT(0), "Is audio initialized?");

630

@@ -631,6 +666,8 @@ void sigil__init_sigil_audio_module(SigilVM *vm)

666

sigil_module_export(vm, "audio-setup");

667

sigil_module_export(vm, "audio-shutdown");

668

sigil_module_export(vm, "audio-initialized?");

+669

sigil_module_export(vm, "audio-backend");

+670

sigil_module_export(vm, "audio-device?");

671

sigil_module_export(vm, "load-sound");

672

sigil_module_export(vm, "sound?");

673

sigil_module_export(vm, "play-sound");

src/c/miniaudio-impl.cmodified

@@ -106,7 +106,31 @@ int sigil_audio_device_open(int sample_rate, int channels, int buffer_frames,

106

log = &g_log;

107

}

108

cc.pLog = log;

−109

if (ma_context_init(NULL, 0, &cc, &g_context) != MA_SUCCESS) {

+109

/* SIGIL_AUDIO_BACKEND=pulseaudio|alsa|jack|wasapi|coreaudio|null picks one

+110

* backend instead of miniaudio's priority walk: for tests (null is a

+111

* silent device that still consumes frames in real time) and for a

+112

* desktop where the first choice misbehaves. An unknown name is

+113

* reported and ignored. */

+114

ma_backend forced[1];

+115

ma_backend *backends = NULL;

+116

ma_uint32 backend_count = 0;

+117

const char *want = getenv("SIGIL_AUDIO_BACKEND");

+118

if (want && *want) {

+119

static const struct { const char *name; ma_backend backend; } table[] = {

+120

{ "pulseaudio", ma_backend_pulseaudio }, { "alsa", ma_backend_alsa },

+121

{ "jack", ma_backend_jack }, { "wasapi", ma_backend_wasapi },

+122

{ "coreaudio", ma_backend_coreaudio }, { "null", ma_backend_null },

+123

};

+124

size_t i;

+125

for (i = 0; i < sizeof table / sizeof table[0]; i++) {

+126

if (strcmp(want, table[i].name) == 0) {

+127

forced[0] = table[i].backend; backends = forced; backend_count = 1;

+128

break;

+129

}

+130

}

+131

        if (!backends) fprintf(stderr, "sigil-audio: SIGIL_AUDIO_BACKEND=%s is not one of pulseaudio, alsa, jack, wasapi, coreaudio, null; ignored\n", want);

+132

}

+133

if (ma_context_init(backends, backend_count, &cc, &g_context) != MA_SUCCESS) {

134

fprintf(stderr, "sigil-audio: no audio backend could be initialised\n");

135

return -1;

136

}

@@ -181,3 +205,24 @@ const char *sigil_audio_device_backend(void)

205

if (!g_device_ready) return NULL;

206

return ma_get_backend_name(g_context.backend);

207

}

+208

+209

const char *sigil_audio_device_backend_symbol(void)

+210

{

+211

if (!g_device_ready) return NULL;

+212

switch (g_context.backend) {

+213

case ma_backend_pulseaudio: return "pulseaudio";

+214

case ma_backend_alsa: return "alsa";

+215

case ma_backend_jack: return "jack";

+216

case ma_backend_wasapi: return "wasapi";

+217

case ma_backend_dsound: return "dsound";

+218

case ma_backend_winmm: return "winmm";

+219

case ma_backend_coreaudio: return "coreaudio";

+220

case ma_backend_null: return "null";

+221

default: return "other";

+222

}

+223

}

+224

+225

int sigil_audio_device_real(void)

+226

{

+227

return g_device_ready && g_context.backend != ma_backend_null;

+228

}

src/sigil/audio.sglmodified

@@ -30,7 +30,7 @@

(sigil time))

;; Native functions exported directly by audio.c:

−33

;; audio-setup, audio-shutdown, audio-initialized?

+33

;; audio-setup, audio-shutdown, audio-initialized?, audio-backend, audio-device?

;; load-sound, sound?, play-sound, stop-all-sounds

;; play-music, stop-music, pause-music, resume-music

;; music-playing?, set-music-volume

test/test-device-drain.sglmodified

@@ -10,6 +10,7 @@

(import (sigil core)

(sigil time)

+13

(sigil process)

(sigil audio))

(define failures 0)

@@ -30,6 +31,19 @@

(audio-setup)

(check "audio initialized" (audio-initialized?) #t)

+34

;; the backend, as the game sees it; SIGIL_AUDIO_BACKEND=null forces the

+35

;; silent backend, and the two predicates must agree about it

+36

(let ((backend (audio-backend)))

+37

(display " backend: ") (display backend) (newline)

+38

(check "audio-backend is a symbol" (symbol? backend) #t)

+39

(check "audio-backend is a known backend"

+40

(and (memq backend '(pulseaudio alsa jack wasapi dsound winmm coreaudio null other)) #t) #t)

+41

(check "audio-device? is #t exactly when the backend is not null"

+42

(audio-device?) (not (eq? backend 'null)))

+43

(let ((forced (getenv "SIGIL_AUDIO_BACKEND")))

+44

(when forced

+45

(check "SIGIL_AUDIO_BACKEND picked the backend" (symbol->string backend) forced))))

+46

(let* ((frames 22050) ; half a second at 44100

(s (open-audio-stream channels: 2 buffer-frames: 32768))

(bv (make-bytevector (* frames 2 4) 0))

@@ -45,6 +59,8 @@

(close-audio-stream! s))

(audio-shutdown)

+62

(check "no backend after shutdown" (audio-backend) #f)

+63

(check "no device after shutdown" (audio-device?) #f)

(check "audio shut down" (audio-initialized?) #f)

(if (= failures 0)