From 864ac1d6a68fd6c7212781b3e914bb03a6521cca Mon Sep 17 00:00:00 2001
From: kub <derkub@gmail.com>
Date: Sat, 18 May 2024 11:35:22 +0200
Subject: [PATCH] sound, don't reinitialize after menu if not needed

---
 pico/sound/sn76496.c | 12 +++++++++--
 pico/sound/sn76496.h |  1 +
 pico/sound/sound.c   | 49 +++++++++++++++++++++++++-------------------
 pico/sound/ym2612.c  |  5 +++++
 4 files changed, 44 insertions(+), 23 deletions(-)

diff --git a/pico/sound/sn76496.c b/pico/sound/sn76496.c
index 0837839c..1624d136 100644
--- a/pico/sound/sn76496.c
+++ b/pico/sound/sn76496.c
@@ -279,6 +279,15 @@ static void SN76496_set_gain(struct SN76496 *R,int gain)
 }
 
 
+//static
+void SN76496_set_clockrate(int clock,int sample_rate)
+{
+	struct SN76496 *R = &ono_sn;
+
+	R->SampleRate = sample_rate;
+	SN76496_set_clock(R,clock);
+}
+
 //static
 int SN76496_init(int clock,int sample_rate)
 {
@@ -287,8 +296,7 @@ int SN76496_init(int clock,int sample_rate)
 
 	//R->Channel = stream_create(0,1, sample_rate,R,SN76496Update);
 
-	R->SampleRate = sample_rate;
-	SN76496_set_clock(R,clock);
+	SN76496_set_clockrate(clock,sample_rate);
 
 	for (i = 0;i < 4;i++) R->Volume[i] = 0;
 
diff --git a/pico/sound/sn76496.h b/pico/sound/sn76496.h
index 707bb5dd..8677ea93 100644
--- a/pico/sound/sn76496.h
+++ b/pico/sound/sn76496.h
@@ -4,6 +4,7 @@
 void SN76496Write(int data);
 void SN76496Update(short *buffer,int length,int stereo);
 void SN76496Config(int panning);
+void SN76496_set_clockrate(int clock,int sample_rate);
 int  SN76496_init(int clock,int sample_rate);
 
 #endif
diff --git a/pico/sound/sound.c b/pico/sound/sound.c
index edf9c896..2150f68d 100644
--- a/pico/sound/sound.c
+++ b/pico/sound/sound.c
@@ -33,7 +33,6 @@ static int (*PsndFMUpdate)(s32 *buffer, int length, int stereo, int is_buf_empty
 
 // ym2413
 static OPLL *opll = NULL;
-static OPLL old_opll;
 static struct {
   uint32_t adr;
   uint8_t reg[sizeof(opll->reg)];
@@ -152,6 +151,10 @@ static int YM2612UpdateONE(s32 *buffer, int length, int stereo, int is_buf_empty
   return YM2612UpdateOne(buffer, length, stereo, is_buf_empty);
 }
 
+static int ymclock;
+static int ymrate;
+static int ymopts;
+
 // to be called after changing sound rate or chips
 void PsndRerate(int preserve_state)
 {
@@ -159,54 +162,58 @@ void PsndRerate(int preserve_state)
   int target_fps = Pico.m.pal ? 50 : 60;
   int target_lines = Pico.m.pal ? 313 : 262;
   int sms_clock = Pico.m.pal ? OSC_PAL/15 : OSC_NTSC/15;
+  int ym2413_rate = (sms_clock + 36) / 72;
   int ym2612_clock = Pico.m.pal ? OSC_PAL/7 : OSC_NTSC/7;
   int ym2612_rate = YM2612_NATIVE_RATE();
-  int ym2413_rate = (sms_clock + 36) / 72;
+  int ym2612_init = !preserve_state;
 
-  if (preserve_state) {
+  // don't init YM2612 if preserve_state and no parameter changes
+  ym2612_init |= ymclock != ym2612_clock || ymopts != (PicoIn.opt & (POPT_DIS_FM_SSGEG|POPT_EN_FM_DAC));
+  ym2612_init |= ymrate != (PicoIn.opt & POPT_EN_FM_FILTER ? ym2612_rate : PicoIn.sndRate);
+  ymclock = ym2612_clock;
+  ymrate = (PicoIn.opt & POPT_EN_FM_FILTER ? ym2612_rate : PicoIn.sndRate);
+  ymopts = PicoIn.opt & (POPT_DIS_FM_SSGEG|POPT_EN_FM_DAC);
+
+  if (preserve_state && ym2612_init) {
     state = malloc(0x204);
     if (state == NULL) return;
     ym2612_pack_state();
     memcpy(state, YM2612GetRegs(), 0x204);
-
-    if (opll != NULL)
-       memcpy(&old_opll, opll, sizeof(OPLL)); // remember old state
   }
+
   if (PicoIn.AHW & PAHW_SMS) {
     OPLL_setRate(opll, ym2413_rate);
-    OPLL_reset(opll);
+    if (!preserve_state)
+      OPLL_reset(opll);
     YMFM_setup_FIR(ym2413_rate, PicoIn.sndRate, 0);
     PsndFMUpdate = YM2413UpdateFIR;
   } else if ((PicoIn.opt & POPT_EN_FM_FILTER) && ym2612_rate != PicoIn.sndRate) {
     // polyphase FIR resampler, resampling directly from native to output rate
-    YM2612Init(ym2612_clock, ym2612_rate,
+    if (ym2612_init)
+      YM2612Init(ym2612_clock, ym2612_rate,
         ((PicoIn.opt&POPT_DIS_FM_SSGEG) ? 0 : ST_SSG) |
         ((PicoIn.opt&POPT_EN_FM_DAC)    ? ST_DAC : 0));
     YMFM_setup_FIR(ym2612_rate, PicoIn.sndRate, PicoIn.opt & POPT_EN_STEREO);
     PsndFMUpdate = YM2612UpdateFIR;
   } else {
-    YM2612Init(ym2612_clock, PicoIn.sndRate,
+    if (ym2612_init)
+      YM2612Init(ym2612_clock, PicoIn.sndRate,
         ((PicoIn.opt&POPT_DIS_FM_SSGEG) ? 0 : ST_SSG) |
         ((PicoIn.opt&POPT_EN_FM_DAC)    ? ST_DAC : 0));
     PsndFMUpdate = YM2612UpdateONE;
   }
-  if (preserve_state) {
+
+  if (preserve_state && ym2612_init) {
     // feed it back it's own registers, just like after loading state
     memcpy(YM2612GetRegs(), state, 0x204);
     ym2612_unpack_state();
-
-    if (opll != NULL) {
-      memcpy(&opll->adr, &old_opll.adr, sizeof(OPLL)-20); // restore old state
-      OPLL_forceRefresh(opll);
-    }
+    free(state);
   }
 
-  if (preserve_state) memcpy(state, sn76496_regs, 28*4); // remember old state
-  SN76496_init(Pico.m.pal ? OSC_PAL/15 : OSC_NTSC/15, PicoIn.sndRate);
-  if (preserve_state) memcpy(sn76496_regs, state, 28*4); // restore old state
-
-  if (state)
-    free(state);
+  if (preserve_state)
+    SN76496_set_clockrate(Pico.m.pal ? OSC_PAL/15 : OSC_NTSC/15, PicoIn.sndRate);
+  else
+    SN76496_init(Pico.m.pal ? OSC_PAL/15 : OSC_NTSC/15, PicoIn.sndRate);
 
   // calculate Pico.snd.len
   Pico.snd.len = PicoIn.sndRate / target_fps;
diff --git a/pico/sound/ym2612.c b/pico/sound/ym2612.c
index f8a18625..f0e60b42 100644
--- a/pico/sound/ym2612.c
+++ b/pico/sound/ym2612.c
@@ -193,6 +193,8 @@ UINT16 ym_tl_tab2[13*TL_RES_LEN];
 /* sin waveform table in 'decibel' scale (use only period/4 values) */
 static UINT16 ym_sin_tab[256];
 
+static int ym_init_tab;
+
 /* sustain level table (3dB per step) */
 /* bit0, bit1, bit2, bit3, bit4, bit5, bit6 */
 /* 1,    2,    4,    8,    16,   32,   64   (value)*/
@@ -1467,6 +1469,9 @@ static void init_tables(void)
 	signed int n;
 	double o,m;
 
+	if (ym_init_tab) return;
+	ym_init_tab = 1;
+
 	for (i=0; i < 256; i++)
 	{
 		/* non-standard sinus */
-- 
2.39.2