From 952f5526016226e04defaa5fb130bd9fc2af5d8e Mon Sep 17 00:00:00 2001
From: JJ Bliss <jj@infinity.garden>
Date: Tue, 7 Jul 2026 17:44:14 -0400
Subject: [PATCH] Added audio.ha

---
 uxn/audio.ha | 169 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 169 insertions(+)
 create mode 100644 uxn/audio.ha

diff --git a/uxn/audio.ha b/uxn/audio.ha
new file mode 100644
index 0000000..05b7645
--- /dev/null
+++ b/uxn/audio.ha
@@ -0,0 +1,169 @@
+use fmt;
+use sdl3;
+
+def SAMPLE_FREQUENCY = 44100;
+def POLYPHONY = 4;
+def NOTE_PERIOD = (SAMPLE_FREQUENCY * 0x4000 / 11025);
+def ADSR_STEP = (SAMPLE_FREQUENCY / 0xf);
+
+export fn init_audio() void = {
+	let aspec = sdl3::AudioSpec {
+		format = sdl3::AudioFormat::S16,
+		channels = 2,
+		freq = SAMPLE_FREQUENCY,		
+	};
+	// sdl3::zero(as);
+	// as.freq = SAMPLE_FREQUENCY;
+	// as.format = AUDIO_S16SYS;
+	// as.channels = 2;
+	// as.callback = audio_callback;
+	// as.samples = 512;
+	// as.userdata = NULL;
+	// sdl3::OpenAudioDeviceStream(null,0,&as,null,0);
+	const device = *(sdl3::GetAudioPlaybackDevices(&1)!);
+	const audio_id = sdl3::OpenAudioDeviceStream(device,&aspec,&audio_callback,null);
+};
+
+fn audio_callback(userdata: nullable *opaque,stream: nullable *sdl3::AudioStream, additional_amount: int, total_amount: int) void = {
+
+	// int instance, running = 0;
+	let instance = 0;
+	let running = 0;
+	// Sint16 *samples = (Sint16 *)stream;
+	match(stream) {
+		case let s: *sdl3::AudioStream =>
+			const samples = (s: *[*]i16)[0..additional_amount];//TODO verify this makes sense
+			for(let instance = 0; instance < POLYPHONY; instance+=1){
+				running += audio_render(instance,samples);	
+			};
+
+		case null =>
+			return;
+	};
+	// USED(u);
+	// SDL_memset(stream, 0, len);
+	// for(instance = 0; instance < POLYPHONY; instance++)
+	// 	running += audio_render(instance, samples, samples + len / 2);
+	// if(!running)
+	// 	SDL_PauseAudioDevice(audio_id, 1);
+};
+
+// static void
+// audio_finished_handler(int instance)
+// {
+// 	SDL_Event event;
+// 	event.type = audio0_event + instance;
+// 	SDL_PushEvent(&event);
+// }
+
+// static Sint32
+// envelope(UxnAudio *c, Uint32 age)
+// {
+// 	if(!c->r) return 0x0888;
+// 	if(age < c->a) return 0x0888 * age / c->a;
+// 	if(age < c->d) return 0x0444 * (2 * c->d - c->a - age) / (c->d - c->a);
+// 	if(age < c->s) return 0x0444;
+// 	if(age < c->r) return 0x0444 * (c->r - age) / (c->r - c->s);
+// 	c->advance = 0;
+// 	return 0x0000;
+// }
+
+
+// int
+// audio_render(int instance, Sint16 *sample, Sint16 *end)
+// {
+// 	UxnAudio *c = &uxn_audio[instance];
+// 	Sint32 s;
+// 	if(!c->advance || !c->period) return 0;
+// 	while(sample < end) {
+// 		c->count += c->advance;
+// 		c->i += c->count / c->period;
+// 		c->count %= c->period;
+// 		if(c->i >= c->len) {
+// 			if(!c->repeat) {
+// 				c->advance = 0;
+// 				break;
+// 			}
+// 			c->i %= c->len;
+// 		}
+// 		s = (Sint8)(c->addr[c->i] + 0x80) * envelope(c, c->age++);
+// 		*sample++ += s * c->volume[0] / 0x180;
+// 		*sample++ += s * c->volume[1] / 0x180;
+// 	}
+// 	if(!c->advance) audio_finished_handler(instance);
+// 	return 1;
+// }
+fn audio_render(instance: int, samples: []i16) int = {
+	return 0;	
+};
+
+
+// static void
+// audio_start(int instance, Uint8 *d)
+// {
+// 	UxnAudio *c = &uxn_audio[instance];
+// 	Uint8 pitch = d[0xf] & 0x7f;
+// 	Uint16 addr = peek2(d + 0xc);
+// 	Uint16 adsr = peek2(d + 0x8);
+// 	c->len = peek2(d + 0xa);
+// 	if(c->len > 0x10000 - addr)
+// 		c->len = 0x10000 - addr;
+// 	c->addr = &ram[addr];
+// 	c->volume[0] = d[0xe] >> 4;
+// 	c->volume[1] = d[0xe] & 0xf;
+// 	c->repeat = !(d[0xf] & 0x80);
+// 	if(pitch < 108 && c->len)
+// 		c->advance = advances[pitch % 12] >> (8 - pitch / 12);
+// 	else {
+// 		c->advance = 0;
+// 		return;
+// 	}
+// 	c->a = ADSR_STEP * (adsr >> 12);
+// 	c->d = ADSR_STEP * (adsr >> 8 & 0xf) + c->a;
+// 	c->s = ADSR_STEP * (adsr >> 4 & 0xf) + c->d;
+// 	c->r = ADSR_STEP * (adsr >> 0 & 0xf) + c->s;
+// 	c->age = 0;
+// 	c->i = 0;
+// 	if(c->len <= 0x100) /* single cycle mode */
+// 		c->period = NOTE_PERIOD * 337 / 2 / c->len;
+// 	else /* sample repeat mode */
+// 		c->period = NOTE_PERIOD;
+// }
+
+// static void
+// audio_play(int instance, Uint8 *d)
+// {
+// 	SDL_LockAudioDevice(audio_id);
+// 	audio_start(instance, d);
+// 	SDL_UnlockAudioDevice(audio_id);
+// 	SDL_PauseAudioDevice(audio_id, 0);
+// }
+
+// Uint8
+// audio_get_vu(int instance)
+// {
+// 	int i;
+// 	UxnAudio *c = &uxn_audio[instance];
+// 	Sint32 sum[2] = {0, 0};
+// 	if(!c->advance || !c->period) return 0;
+// 	for(i = 0; i < 2; i++) {
+// 		if(!c->volume[i]) continue;
+// 		sum[i] = 1 + envelope(c, c->age) * c->volume[i] / 0x800;
+// 		if(sum[i] > 0xf) sum[i] = 0xf;
+// 	}
+// 	return (sum[0] << 4) | sum[1];
+// }
+
+// Uint16
+// audio_get_position(int instance)
+// {
+// 	return uxn_audio[instance].i;
+// }
+
+fn audio_pitch(device: u8, state: *uxn) void = {
+	if(device > 3){
+		fmt::fatal("Trying to use non-existant audio device!");
+	};
+	
+	return;
+};