@@ -1,5 +1,3 @@

-#include <SDL2/SDL.h>

-

 /*

 Copyright (c) 2021 Devine Lu Linvega

 Copyright (c) 2021 Andrew Alderwick

@@ -13,11 +11,9 @@ WITH REGARD TO THIS SOFTWARE.

 */

 #include "uxn.h"

+#include "apu.h"

-#define SAMPLE_FREQUENCY 48000

-

-extern SDL_AudioDeviceID audio_id;

-int error(char *msg, const char *err);

+extern Device *devapu;

 static Uint32 note_advances[12] = {

 	0x82d01286 / (SAMPLE_FREQUENCY / 30), /* C7 */

@@ -34,55 +30,33 @@ static Uint32 note_advances[12] = {

 	0xf6f11003 / (SAMPLE_FREQUENCY / 30) /* B7 */

 };

-typedef struct {

-	Uint16 *dat;

-	Uint8 i, n, sz, ends;

-} Queue;

-

-typedef struct {

-	Uint32 count, advance, period;

-	Uint16 vector;

-	Sint16 start_value, end_value;

-	Queue queue;

-} WaveformGenerator;

-

-typedef struct {

-	WaveformGenerator wv[2];

-	Sint8 volume[2], playing;

-} Note;

-

-static Note *notes = NULL;

-static int n_notes = 0;

-static Queue *q;

-static Uint16 id_addr;

-

 static void

-play_note(Uxn *u, int note_i, Sint16 *samples, int n_samples)

+render_note(Apu *apu, Uxn *u, int note_i, Sint16 *samples, int n_samples)

 {

 	int i;

-	Note *note = &notes[note_i];

+	Note *note = &apu->notes[note_i];

 	while(n_samples--) {

 		Sint32 sample = 1;

 		for(i = 0; i < 2; ++i) {

 			WaveformGenerator *wv = &note->wv[i];

-			q = &wv->queue;

+			apu->queue = &wv->queue;

 			wv->count += wv->advance;

 			while(wv->count > wv->period) {

 				wv->count -= wv->period;

 				wv->start_value = wv->end_value;

-				if(q->i == q->n) {

-					q->i = q->n = 0;

-					if(!q->ends) {

-						u->ram.dat[id_addr] = note_i;

+				if(apu->queue->i == apu->queue->n) {

+					apu->queue->i = apu->queue->n = 0;

+					if(!apu->queue->finishes) {

+						u->ram.dat[devapu->addr + 0xa] = note_i;

 						evaluxn(u, wv->vector);

 					}

 				}

-				if(!q->n) {

+				if(!apu->queue->n) {

 					note->playing = 0;

 					return;

 				}

-				wv->end_value = (Sint16)q->dat[q->i++];

-				wv->period = (30 << 4) * q->dat[q->i++];

+				wv->end_value = (Sint16)apu->queue->dat[apu->queue->i++];

+				wv->period = (30 << 4) * apu->queue->dat[apu->queue->i++];

 			}

 			if(wv->period >> 9)

 				sample *= wv->start_value + (Sint32)(wv->end_value - wv->start_value) * (Sint32)(wv->count >> 10) / (Sint32)(wv->period >> 10);

@@ -94,70 +68,31 @@ play_note(Uxn *u, int note_i, Sint16 *samples, int n_samples)

 	}

 }

-static void

-play_all_notes(void *u, Uint8 *stream, int len)

+void

+apu_render(Apu *apu, Uxn *u, Sint16 *samples, int n_samples)

 {

 	int i;

-	SDL_memset(stream, 0, len);

-	for(i = 0; i < n_notes; ++i)

-		if(notes[i].playing) play_note(u, i, (Sint16 *)stream, len >> 2);

-	q = NULL;

-}

-

-static Note *

-get_note(Uint8 i)

-{

-	if(i >= n_notes) notes = SDL_realloc(notes, (i + 1) * sizeof(Note));

-	while(i >= n_notes) SDL_zero(notes[n_notes++]);

-	return &notes[i];

+	for(i = 0; i < n_samples * 2; ++i)

+		samples[i] = 0;

+	for(i = 0; i < apu->n_notes; ++i)

+		if(apu->notes[i].playing) render_note(apu, u, i, samples, n_samples);

+	apu->queue = NULL;

 }

-static Uint8

-audio_poke(Uxn *u, Uint16 ptr, Uint8 b0, Uint8 b1)

+void

+apu_play_note(Note *note, Uint16 wave_vector, Uint16 envelope_vector, Uint8 volume, Uint8 pitch)

 {

-	Uint8 *m = u->ram.dat + ptr;

 	int i;

-	if(b0 == 0xa) {

-		Note *note = get_note(b1);

-		note->playing = 1;

-		for(i = 0; i < 2; ++i) {

-			note->volume[i] = 0xf & (m[0x8] >> 4 * (1 - i));

-			note->wv[i].vector = (m[0x0 + i * 2] << 8) + m[0x1 + i * 2];

-			note->wv[i].count = note->wv[i].period = 0;

-			note->wv[i].end_value = 0;

-			note->wv[i].queue.n = note->wv[i].queue.i = 0;

-			note->wv[i].queue.ends = 0;

-		}

-		note->wv[0].advance = note_advances[m[0x9] % 12] >> (8 - m[0x9] / 12);

-		note->wv[1].advance = (30 << 20) / SAMPLE_FREQUENCY;

-	} else if(b0 == 0xe && q != NULL) {

-		if(q->n == q->sz) {

-			q->sz = q->sz < 4 ? 4 : q->sz * 2;

-			q->dat = SDL_realloc(q->dat, q->sz * sizeof(*q->dat));

-		}

-		q->dat[q->n++] = (m[0xb] << 8) + m[0xc];

-		q->dat[q->n++] = (m[0xd] << 8) + b1;

-	} else if(b0 == 0xf && q != NULL) {

-		q->ends = 1;

+	note->playing = 1;

+	for(i = 0; i < 2; ++i) {

+		note->volume[i] = 0xf & (volume >> 4 * (1 - i));

+		note->wv[i].count = note->wv[i].period = 0;

+		note->wv[i].end_value = 0;

+		note->wv[i].queue.n = note->wv[i].queue.i = 0;

+		note->wv[i].queue.finishes = 0;

 	}

-	return b1;

-}

-

-int

-initapu(Uxn *u, Uint8 id)

-{

-	SDL_AudioSpec as;

-	SDL_zero(as);

-	as.freq = SAMPLE_FREQUENCY;

-	as.format = AUDIO_S16;

-	as.channels = 2;

-	as.callback = play_all_notes;

-	as.samples = 2048;

-	as.userdata = u;

-	audio_id = SDL_OpenAudioDevice(NULL, 0, &as, NULL, 0);

-	if(!audio_id)

-		return error("Audio", SDL_GetError());

-	id_addr = portuxn(u, id, "audio", audio_poke)->addr + 0xa;

-	SDL_PauseAudioDevice(audio_id, 0);

-	return 1;

+	note->wv[0].vector = wave_vector;

+	note->wv[0].advance = note_advances[pitch % 12] >> (8 - pitch / 12);

+	note->wv[1].vector = envelope_vector;

+	note->wv[1].advance = (30 << 20) / SAMPLE_FREQUENCY;

 }

new file mode 100644

@@ -0,0 +1,46 @@

+/*

+Copyright (c) 2021 Devine Lu Linvega

+Copyright (c) 2021 Andrew Alderwick

+

+Permission to use, copy, modify, and distribute this software for any

+purpose with or without fee is hereby granted, provided that the above

+copyright notice and this permission notice appear in all copies.

+

+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES

+WITH REGARD TO THIS SOFTWARE.

+*/

+

+typedef unsigned char Uint8;

+typedef signed char Sint8;

+typedef unsigned short Uint16;

+typedef signed short Sint16;

+typedef unsigned int Uint32;

+typedef signed int Sint32;

+

+#define SAMPLE_FREQUENCY 48000

+

+typedef struct {

+	Uint16 *dat;

+	Uint8 i, n, sz, finishes;

+} Queue;

+

+typedef struct {

+	Uint32 count, advance, period;

+	Uint16 vector;

+	Sint16 start_value, end_value;

+	Queue queue;

+} WaveformGenerator;

+

+typedef struct {

+	WaveformGenerator wv[2];

+	Sint8 volume[2], playing;

+} Note;

+

+typedef struct {

+    Queue *queue;

+    Note *notes;

+    int n_notes;

+} Apu;

+

+void apu_render(Apu *apu, Uxn *u, Sint16 *samples, int n_samples);

+void apu_play_note(Note *note, Uint16 wave_vector, Uint16 envelope_vector, Uint8 volume, Uint8 pitch);

@@ -15,15 +15,18 @@ WITH REGARD TO THIS SOFTWARE.

 #include "uxn.h"

 #include "ppu.h"

+#include "apu.h"

 int initapu(Uxn *u, Uint8 id);

-SDL_AudioDeviceID audio_id;

+static SDL_AudioDeviceID audio_id;

 static SDL_Window *gWindow;

 static SDL_Renderer *gRenderer;

 static SDL_Texture *gTexture;

 static Ppu ppu;

+static Apu apu;

 static Device *devsystem, *devscreen, *devmouse, *devkey, *devctrl;

+Device *devapu;

 #pragma mark - Helpers

@@ -41,6 +44,12 @@ error(char *msg, const char *err)

 	return 0;

 }

+static void

+audio_callback(void *u, Uint8 *stream, int len)

+{

+	apu_render(&apu, (Uxn *)u, (Sint16 *)stream, len >> 2);

+}

+

 void

 redraw(Uint32 *dst, Uxn *u)

 {

@@ -86,8 +95,9 @@ quit(void)

 }

 int

-init(void)

+init(Uxn *u)

 {

+	SDL_AudioSpec as;

 	if(!initppu(&ppu, 48, 32, 16))

 		return error("PPU", "Init failure");

 	if(SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO) < 0)

@@ -103,6 +113,17 @@ init(void)

 		return error("Texture", SDL_GetError());

 	SDL_StartTextInput();

 	SDL_ShowCursor(SDL_DISABLE);

+	SDL_zero(as);

+	as.freq = SAMPLE_FREQUENCY;

+	as.format = AUDIO_S16;

+	as.channels = 2;

+	as.callback = audio_callback;

+	as.samples = 2048;

+	as.userdata = u;

+	audio_id = SDL_OpenAudioDevice(NULL, 0, &as, NULL, 0);

+	if(!audio_id)

+		return error("Audio", SDL_GetError());

+	SDL_PauseAudioDevice(audio_id, 0);

 	return 1;

 }

@@ -258,6 +279,27 @@ file_poke(Uxn *u, Uint16 ptr, Uint8 b0, Uint8 b1)

 	return b1;

 }

+static Uint8

+audio_poke(Uxn *u, Uint16 ptr, Uint8 b0, Uint8 b1)

+{

+	Uint8 *m = u->ram.dat + ptr;

+	if(b0 == 0xa) {

+		if(b1 >= apu.n_notes) apu.notes = SDL_realloc(apu.notes, (b1 + 1) * sizeof(Note));

+		while(b1 >= apu.n_notes) SDL_zero(apu.notes[apu.n_notes++]);

+		apu_play_note(&apu.notes[b1], (m[0x0] << 8) + m[0x1], (m[0x2] << 8) + m[0x3], m[0x8], m[0x9]);

+	} else if(b0 == 0xe && apu.queue != NULL) {

+		if(apu.queue->n == apu.queue->sz) {

+			apu.queue->sz = apu.queue->sz < 4 ? 4 : apu.queue->sz * 2;

+			apu.queue->dat = SDL_realloc(apu.queue->dat, apu.queue->sz * sizeof(*apu.queue->dat));

+		}

+		apu.queue->dat[apu.queue->n++] = (m[0xb] << 8) + m[0xc];

+		apu.queue->dat[apu.queue->n++] = (m[0xd] << 8) + b1;

+	} else if(b0 == 0xf && apu.queue != NULL) {

+		apu.queue->finishes = 1;

+	}

+	return b1;

+}

+

 Uint8

 midi_poke(Uxn *u, Uint16 ptr, Uint8 b0, Uint8 b1)

 {

@@ -367,7 +409,7 @@ main(int argc, char **argv)

 		return error("Boot", "Failed");

 	if(!loaduxn(&u, argv[1]))

 		return error("Load", "Failed");

-	if(!init())

+	if(!init(&u))

 		return error("Init", "Failed");

 	devsystem = portuxn(&u, 0x00, "system", system_poke);

@@ -378,8 +420,7 @@ main(int argc, char **argv)

 	devkey = portuxn(&u, 0x05, "key", ppnil);

 	devmouse = portuxn(&u, 0x06, "mouse", ppnil);

 	portuxn(&u, 0x07, "file", file_poke);

-	if(!initapu(&u, 0x08))

-		return 1;

+	devapu = portuxn(&u, 0x08, "audio", audio_poke);

 	portuxn(&u, 0x09, "midi", ppnil);

 	portuxn(&u, 0x0a, "datetime", datetime_poke);

 	portuxn(&u, 0x0b, "---", ppnil);