From c9e0cd0a75f9f4106151843cf5572ddda9e570f6 Mon Sep 17 00:00:00 2001
From: "a.mantoni" <925171+eadmaster@users.noreply.github.com>
Date: Wed, 28 Dec 2022 07:03:21 +0100
Subject: [PATCH] replaced sound channel toggle with volume percent core
 options

---
 apu/bapu/dsp/SPC_DSP.cpp         |  10 +-
 libretro/libretro.cpp            |  31 ++++---
 libretro/libretro_core_options.h | 152 +++++++++++++++++++++++--------
 snes9x.h                         |   1 +
 4 files changed, 139 insertions(+), 55 deletions(-)

diff --git a/apu/bapu/dsp/SPC_DSP.cpp b/apu/bapu/dsp/SPC_DSP.cpp
index 6213b08b7..66b764958 100644
--- a/apu/bapu/dsp/SPC_DSP.cpp
+++ b/apu/bapu/dsp/SPC_DSP.cpp
@@ -860,7 +860,15 @@ inline void SPC_DSP::voice_output( voice_t const* v, int ch )
 	// Apply left/right volume
 	int amp = (m.t_output * (int8_t) VREG(v->regs,voll + ch)) >> 7;
 	amp *= ((stereo_switch & (1 << (v->voice_number + ch * voice_count))) ? 1 : 0);
-
+	
+	#ifdef __LIBRETRO__
+	// Apply user-set volume (if set)
+	if (Settings.ChannelsVolumePercent[v->voice_number] < 100)
+	{
+	    amp = amp * Settings.ChannelsVolumePercent[v->voice_number] / 100;
+	}
+	#endif
+	
 	// Add to output total
 	m.t_main_out [ch] += amp;
 	CLAMP16( m.t_main_out [ch] );
diff --git a/libretro/libretro.cpp b/libretro/libretro.cpp
index 0136b601b..3a62f27bc 100644
--- a/libretro/libretro.cpp
+++ b/libretro/libretro.cpp
@@ -371,19 +371,19 @@ static void update_variables(void)
     }
     else
         Settings.UpAndDown = false;
-
-    strcpy(key, "snes9x_sndchan_x");
+    
+    strcpy(key, "snes9x_sndchan_volume_x");
     var.key=key;
     for (int i=0;i<8;i++)
     {
-        key[strlen("snes9x_sndchan_")]='1'+i;
+        key[strlen("snes9x_sndchan_volume_")]='1'+i;
         var.value=NULL;
-        if (environ_cb(RETRO_ENVIRONMENT_GET_VARIABLE, &var) && !strcmp("disabled", var.value))
-            disabled_channels|=1<<i;
+        if (environ_cb(RETRO_ENVIRONMENT_GET_VARIABLE, &var))
+        {
+            Settings.ChannelsVolumePercent[i] = atoi(var.value);
+        }
     }
-    S9xSetSoundControl(disabled_channels^0xFF);
-
-
+    
     int disabled_layers=0;
     strcpy(key, "snes9x_layer_x");
     for (int i=0;i<5;i++)
@@ -1235,12 +1235,6 @@ bool retro_load_game(const struct retro_game_info *game)
             for(int lcv = 0; lcv < 0x20000; lcv++)
                 Memory.RAM[lcv] = rand() % 256;
         }
-
-        // restore disabled sound channels
-        if (disabled_channels)
-        {
-            S9xSetSoundControl(disabled_channels^0xFF);
-        }
     }
 
     if (!rom_loaded && log_cb)
@@ -1440,6 +1434,15 @@ void retro_init(void)
     Settings.CartBName[0] = 0;
     Settings.AutoSaveDelay = 1;
     Settings.DontSaveOopsSnapshot = TRUE;
+    Settings.ChannelsVolumePercent[0] = 100;
+    Settings.ChannelsVolumePercent[1] = 100;
+    Settings.ChannelsVolumePercent[2] = 100;
+    Settings.ChannelsVolumePercent[3] = 100;
+    Settings.ChannelsVolumePercent[4] = 100;
+    Settings.ChannelsVolumePercent[5] = 100;
+    Settings.ChannelsVolumePercent[6] = 100;
+    Settings.ChannelsVolumePercent[7] = 100;
+    Settings.ChannelsVolumePercent[8] = 100;
 
     CPU.Flags = 0;
 
diff --git a/libretro/libretro_core_options.h b/libretro/libretro_core_options.h
index d524d3620..c3ec5ed62 100644
--- a/libretro/libretro_core_options.h
+++ b/libretro/libretro_core_options.h
@@ -725,116 +725,188 @@ struct retro_core_option_v2_definition option_defs_us[] = {
       "enabled"
    },
    {
-      "snes9x_sndchan_1",
-      "Enable Sound Channel 1",
+      "snes9x_sndchan_volume_1",
+      "Volume % for Sound Channel 1",
       NULL,
       NULL,
       NULL,
       "advanced_av",
       {
-         { "enabled",  NULL },
-         { "disabled", NULL },
+         { "0",   NULL },
+         { "10",  NULL },
+         { "20",  NULL },
+         { "30",  NULL },
+         { "40",  NULL },
+         { "50",  NULL },
+         { "60",  NULL },
+         { "70",  NULL },
+         { "80",  NULL },
+         { "90",  NULL },
+         { "100", NULL },
          { NULL, NULL },
       },
-      "enabled"
+      "100"
    },
    {
-      "snes9x_sndchan_2",
-      "Enable Sound Channel 2",
+      "snes9x_sndchan_volume_2",
+      "Volume % for Sound Channel 2",
       NULL,
       NULL,
       NULL,
       "advanced_av",
       {
-         { "enabled",  NULL },
-         { "disabled", NULL },
+         { "0",   NULL },
+         { "10",  NULL },
+         { "20",  NULL },
+         { "30",  NULL },
+         { "40",  NULL },
+         { "50",  NULL },
+         { "60",  NULL },
+         { "70",  NULL },
+         { "80",  NULL },
+         { "90",  NULL },
+         { "100", NULL },
          { NULL, NULL },
       },
-      "enabled"
+      "100"
    },
    {
-      "snes9x_sndchan_3",
-      "Enable Sound Channel 3",
+      "snes9x_sndchan_volume_3",
+      "Volume % for Sound Channel 3",
       NULL,
       NULL,
       NULL,
       "advanced_av",
       {
-         { "enabled",  NULL },
-         { "disabled", NULL },
+         { "0",   NULL },
+         { "10",  NULL },
+         { "20",  NULL },
+         { "30",  NULL },
+         { "40",  NULL },
+         { "50",  NULL },
+         { "60",  NULL },
+         { "70",  NULL },
+         { "80",  NULL },
+         { "90",  NULL },
+         { "100", NULL },
          { NULL, NULL },
       },
-      "enabled"
+      "100"
    },
    {
-      "snes9x_sndchan_4",
-      "Enable Sound Channel 4",
+      "snes9x_sndchan_volume_4",
+      "Volume % for Sound Channel 4",
       NULL,
       NULL,
       NULL,
       "advanced_av",
       {
-         { "enabled",  NULL },
-         { "disabled", NULL },
+         { "0",   NULL },
+         { "10",  NULL },
+         { "20",  NULL },
+         { "30",  NULL },
+         { "40",  NULL },
+         { "50",  NULL },
+         { "60",  NULL },
+         { "70",  NULL },
+         { "80",  NULL },
+         { "90",  NULL },
+         { "100", NULL },
          { NULL, NULL },
       },
-      "enabled"
+      "100"
    },
    {
-      "snes9x_sndchan_5",
-      "Enable Sound Channel 5",
+      "snes9x_sndchan_volume_5",
+      "Volume % for Sound Channel 5",
       NULL,
       NULL,
       NULL,
       "advanced_av",
       {
-         { "enabled",  NULL },
-         { "disabled", NULL },
+         { "0",   NULL },
+         { "10",  NULL },
+         { "20",  NULL },
+         { "30",  NULL },
+         { "40",  NULL },
+         { "50",  NULL },
+         { "60",  NULL },
+         { "70",  NULL },
+         { "80",  NULL },
+         { "90",  NULL },
+         { "100", NULL },
          { NULL, NULL },
       },
-      "enabled"
+      "100"
    },
    {
-      "snes9x_sndchan_6",
-      "Enable Sound Channel 6",
+      "snes9x_sndchan_volume_6",
+      "Volume % for Sound Channel 6",
       NULL,
       NULL,
       NULL,
       "advanced_av",
       {
-         { "enabled",  NULL },
-         { "disabled", NULL },
+         { "0",   NULL },
+         { "10",  NULL },
+         { "20",  NULL },
+         { "30",  NULL },
+         { "40",  NULL },
+         { "50",  NULL },
+         { "60",  NULL },
+         { "70",  NULL },
+         { "80",  NULL },
+         { "90",  NULL },
+         { "100", NULL },
          { NULL, NULL },
       },
-      "enabled"
+      "100"
    },
    {
-      "snes9x_sndchan_7",
-      "Enable Sound Channel 7",
+      "snes9x_sndchan_volume_7",
+      "Volume % for Sound Channel 7",
       NULL,
       NULL,
       NULL,
       "advanced_av",
       {
-         { "enabled",  NULL },
-         { "disabled", NULL },
+         { "0",   NULL },
+         { "10",  NULL },
+         { "20",  NULL },
+         { "30",  NULL },
+         { "40",  NULL },
+         { "50",  NULL },
+         { "60",  NULL },
+         { "70",  NULL },
+         { "80",  NULL },
+         { "90",  NULL },
+         { "100", NULL },
          { NULL, NULL },
       },
-      "enabled"
+      "100"
    },
    {
-      "snes9x_sndchan_8",
-      "Enable Sound Channel 8",
+      "snes9x_sndchan_volume_8",
+      "Volume % for Sound Channel 8",
       NULL,
       NULL,
       NULL,
       "advanced_av",
       {
-         { "enabled",  NULL },
-         { "disabled", NULL },
+         { "0",   NULL },
+         { "10",  NULL },
+         { "20",  NULL },
+         { "30",  NULL },
+         { "40",  NULL },
+         { "50",  NULL },
+         { "60",  NULL },
+         { "70",  NULL },
+         { "80",  NULL },
+         { "90",  NULL },
+         { "100", NULL },
          { NULL, NULL },
       },
-      "enabled"
+      "100"
    },
    { NULL, NULL, NULL, NULL, NULL, NULL, {{0}}, NULL },
 };
diff --git a/snes9x.h b/snes9x.h
index e8d890e96..e19babaf6 100644
--- a/snes9x.h
+++ b/snes9x.h
@@ -307,6 +307,7 @@ struct SSettings
 	int	OneSlowClockCycle;
 	int	TwoClockCycles;
 	int	MaxSpriteTilesPerLine;
+	int	ChannelsVolumePercent[9];
 };
 
 struct SSNESGameFixes