added PSG channels volume core options (libretro#223)

eadmaster · Nov 30, 2020 · 0359e04 · 0359e04
1 parent 681f3cd
commit 0359e04
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Showing 3 changed files with 111 additions and 2 deletions.
diff --git a/core/sound/psg.c b/core/sound/psg.c
@@ -91,6 +91,7 @@ static struct
   int chanDelta[4][2];
   int chanOut[4][2];
   int chanAmp[4][2];
+  int chanUserVolume[4];
 } psg;
 
 static void psg_update(unsigned int clocks);
@@ -378,6 +379,14 @@ void psg_write(unsigned int clocks, unsigned int data)
   psg.regs[index] = data;
 }
 
+void psg_set_user_channel_volume(unsigned int channel, unsigned int volume)
+{
+    if(channel > 3 || volume > 100) return;  // invalid args
+    // else
+
+    psg.chanUserVolume[channel] = volume;
+}
+
 void psg_config(unsigned int clocks, unsigned int preamp, unsigned int panning)
 {
   int i;
@@ -398,8 +407,8 @@ void psg_config(unsigned int clocks, unsigned int preamp, unsigned int panning)
     int volume = psg.regs[i*2+1];
 
     /* update channel stereo amplification */
-    psg.chanAmp[i][0] = preamp * ((panning >> (i + 4)) & 1);
-    psg.chanAmp[i][1] = preamp * ((panning >> (i + 0)) & 1);
+    psg.chanAmp[i][0] = preamp * (psg.chanUserVolume[i]/100) * ((panning >> (i + 4)) & 1);
+    psg.chanAmp[i][1] = preamp * (psg.chanUserVolume[i]/100) * ((panning >> (i + 0)) & 1);
 
     /* tone channels */
     if (i < 3)

diff --git a/libretro/libretro.c b/libretro/libretro.c
@@ -1540,6 +1540,26 @@ static void check_variables(bool first_run)
     }
   }
 
+   char sound_channel_volume_base_str[] = "genesis_plus_gx_psg_channel_0_volume";
+   var.key = sound_channel_volume_base_str;
+   for (unsigned c = 0; c < 4; c++) {
+       sound_channel_volume_base_str[28] = c+'0';
+       if (environ_cb(RETRO_ENVIRONMENT_GET_VARIABLE, &var))
+       {
+            psg_set_user_channel_volume(c, atoi(var.value));
+            // need to recall config to have the settings applied
+            if ((system_hw & SYSTEM_PBC) == SYSTEM_MD)
+            {
+              psg_config(0, config.psg_preamp, 0xff);
+            }
+            else
+            {
+              psg_config(0, config.psg_preamp, io_reg[6]);
+            }
+       }
+   }
+
+
   var.key = "genesis_plus_gx_fm_preamp";
   environ_cb(RETRO_ENVIRONMENT_GET_VARIABLE, &var);
   {

diff --git a/libretro/libretro_core_options.h b/libretro/libretro_core_options.h
@@ -588,6 +588,86 @@ struct retro_core_option_definition option_defs_us[] = {
       },
       "disabled"
    },
+   {
+      "genesis_plus_gx_psg_channel_0_volume",
+      "PSG Tone Channel 0 Volume %",
+      "",
+      {
+         { "0",   NULL },
+         { "10",  NULL },
+         { "20",  NULL },
+         { "30",  NULL },
+         { "40",  NULL },
+         { "50",  NULL },
+         { "60",  NULL },
+         { "70",  NULL },
+         { "80",  NULL },
+         { "90",  NULL },
+         { "100", NULL },
+         { NULL, NULL },
+      },
+      "100"
+   },
+   {
+      "genesis_plus_gx_psg_channel_1_volume",
+      "PSG Tone Channel 1 Volume %",
+      "",
+      {
+         { "0",   NULL },
+         { "10",  NULL },
+         { "20",  NULL },
+         { "30",  NULL },
+         { "40",  NULL },
+         { "50",  NULL },
+         { "60",  NULL },
+         { "70",  NULL },
+         { "80",  NULL },
+         { "90",  NULL },
+         { "100", NULL },
+         { NULL, NULL },
+      },
+      "100"
+   },
+   {
+      "genesis_plus_gx_psg_channel_2_volume",
+      "PSG Tone Channel 2 Volume %",
+      "",
+      {
+         { "0",   NULL },
+         { "10",  NULL },
+         { "20",  NULL },
+         { "30",  NULL },
+         { "40",  NULL },
+         { "50",  NULL },
+         { "60",  NULL },
+         { "70",  NULL },
+         { "80",  NULL },
+         { "90",  NULL },
+         { "100", NULL },
+         { NULL, NULL },
+      },
+      "100"
+   },
+   {
+      "genesis_plus_gx_psg_channel_3_volume",
+      "PSG Noise Channel 3 Volume %",
+      "",
+      {
+         { "0",   NULL },
+         { "10",  NULL },
+         { "20",  NULL },
+         { "30",  NULL },
+         { "40",  NULL },
+         { "50",  NULL },
+         { "60",  NULL },
+         { "70",  NULL },
+         { "80",  NULL },
+         { "90",  NULL },
+         { "100", NULL },
+         { NULL, NULL },
+      },
+      "100"
+   },
    { NULL, NULL, NULL, {{0}}, NULL },
 };