Returned SDL calls from apu.c to emulator.c

src/apu.c

@@ -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 Device *devapu;
-
-extern SDL_AudioDeviceID audio_id;
-int error(char *msg, const char *err);
 
 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) {
+				if(apu->queue->i == apu->queue->n) {
-					q->i = q->n = 0;
+					apu->queue->i = apu->queue->n = 0;
-					if(!q->ends) {
+					if(!apu->queue->finishes) {
-						u->ram.dat[id_addr] = note_i;
+						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->end_value = (Sint16)apu->queue->dat[apu->queue->i++];
-				wv->period = (30 << 4) * q->dat[q->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
+void
-play_all_notes(void *u, Uint8 *stream, int len)
+apu_render(Apu *apu, Uxn *u, Sint16 *samples, int n_samples)
 {
 	int i;
-	SDL_memset(stream, 0, len);
+	for(i = 0; i < n_samples * 2; ++i)
-	for(i = 0; i < n_notes; ++i)
+		samples[i] = 0;
-		if(notes[i].playing) play_note(u, i, (Sint16 *)stream, len >> 2);
+	for(i = 0; i < apu->n_notes; ++i)
-	q = NULL;
+		if(apu->notes[i].playing) render_note(apu, u, i, samples, n_samples);
+	apu->queue = NULL;
 }
 
-static Note *
+void
-get_note(Uint8 i)
+apu_play_note(Note *note, Uint16 wave_vector, Uint16 envelope_vector, Uint8 volume, Uint8 pitch)
 {
-	if(i >= n_notes) notes = SDL_realloc(notes, (i + 1) * sizeof(Note));
-	while(i >= n_notes) SDL_zero(notes[n_notes++]);
-	return &notes[i];
-}
-
-static Uint8
-audio_poke(Uxn *u, Uint16 ptr, Uint8 b0, Uint8 b1)
-{
-	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->volume[i] = 0xf & (volume >> 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[i].queue.finishes = 0;
 	}
-		note->wv[0].advance = note_advances[m[0x9] % 12] >> (8 - m[0x9] / 12);
+	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;
-	} 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;
-	}
-	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;
 }

src/apu.h

@@ -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);

src/emulator.c

@@ -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))
+	devapu = portuxn(&u, 0x08, "audio", audio_poke);
-		return 1;
 	portuxn(&u, 0x09, "midi", ppnil);
 	portuxn(&u, 0x0a, "datetime", datetime_poke);
 	portuxn(&u, 0x0b, "---", ppnil);