added per-sound channel individual volume core options (#166)

libgambatte/include/gambatte.h

@@ -24,6 +24,7 @@
 #include "serial_io.h"
 #endif
 #include "gbint.h"
+#include "sound.h"
 #include <string>
 #include <cstddef>
 
@@ -140,6 +141,7 @@ class GB {
    void *rombank1_ptr() const;
    void *zeropage_ptr() const;
    void *oamram_ptr() const;
+   PSG *getPSG() const;
 #endif
 
 private:

libgambatte/libretro/libretro.cpp

@@ -1144,6 +1144,17 @@ static void check_variables(void)
 
    /* Interframe blending option has its own handler */
    check_frame_blend_variable();
+
+   char sound_channel_volume_base_str[] = "gambatte_channel_1_volume";
+   var.key = sound_channel_volume_base_str;
+   for (unsigned c = 0; c < 4; c++) {
+       sound_channel_volume_base_str[17] = c+'1';
+       if (environ_cb(RETRO_ENVIRONMENT_GET_VARIABLE, &var) && var.value)
+       {
+           gb.getPSG()->setSoChanVolume(unsigned(atoi(var.value)), c);
+       }
+   }
+
 
 #ifdef HAVE_NETWORK
 

libgambatte/libretro/libretro_core_options.h

@@ -322,6 +322,86 @@ struct retro_core_option_definition option_defs_us[] = {
       },
       "10"
    },
+   {
+      "gambatte_channel_1_volume",
+      "Square 1 Channel volume %",
+      "Modify Square 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"
+   },
+   {
+      "gambatte_channel_2_volume",
+      "Square 2 Channel volume %",
+      "Modify Square 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"
+   },
+   {
+      "gambatte_channel_3_volume",
+      "Wave Channel volume %",
+      "Modify Wave 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"
+   },
+   {
+      "gambatte_channel_4_volume",
+      "Noise Channel volume %",
+      "Modify Noise 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"
+   },
 #ifdef HAVE_NETWORK
    {
       "gambatte_show_gb_link_settings",

libgambatte/src/gambatte-memory.h

@@ -62,6 +62,7 @@ class Memory {
    void *rombank1_ptr() const { return cart_.romdata(0) + 0x4000; }
    void *zeropage_ptr() const { return (void*)(ioamhram_ + 0x0180); }
    void *oamram_ptr() const { return (void*)ioamhram_; }
+   PSG *psg_ptr() const { return (PSG*)&psg_; }
 #else
    void loadSavedata() { cart_.loadSavedata(); }
    void saveSavedata() { cart_.saveSavedata(); }

libgambatte/src/gambatte.cpp

@@ -219,6 +219,10 @@ void *GB::zeropage_ptr() const {
 void *GB::oamram_ptr() const {
  return p_->cpu.oamram_ptr();
 }
+
+PSG *GB::getPSG() const {
+  return p_->cpu.mem_.psg_ptr();
+}
 #endif
 
 }

libgambatte/src/sound.cpp

@@ -51,6 +51,11 @@ namespace gambatte
       ,  rsum_(0x8000) // initialize to 0x8000 to prevent borrows from high word, xor away later
       ,  enabled_(false)
    {
+       // init as full volume
+       setSoChanVolume(100, 0);
+       setSoChanVolume(100, 1);
+       setSoChanVolume(100, 2);
+       setSoChanVolume(100, 3);
    }
 
    void PSG::init(const bool cgb)
@@ -98,10 +103,10 @@ namespace gambatte
       uint_least32_t *const buf = buffer_ + bufferPos_;
 
       std::memset(buf, 0, cycles * sizeof(uint_least32_t));
-      ch1_.update(buf, soVol_, cycles);
-      ch2_.update(buf, soVol_, cycles);
-      ch3_.update(buf, soVol_, cycles);
-      ch4_.update(buf, soVol_, cycles);
+      ch1_.update(buf, (soChVol_[0] * soVol_ * 0x1999999A) >> 32, cycles);
+      ch2_.update(buf, (soChVol_[1] * soVol_ * 0x1999999A) >> 32, cycles);
+      ch3_.update(buf, (soChVol_[2] * soVol_ * 0x1999999A) >> 32, cycles);
+      ch4_.update(buf, (soChVol_[3] * soVol_ * 0x1999999A) >> 32, cycles);
    }
 
    void PSG::generateSamples(unsigned long const cycleCounter, bool const doubleSpeed)
@@ -180,6 +185,14 @@ namespace gambatte
       soVol_ = (((nr50      & 0x7) + 1) * so1Mul 
             +  ((nr50 >> 4 & 0x7) + 1) * so2Mul) * 64;
    }
+
+   void PSG::setSoChanVolume(const unsigned percent, const unsigned ch)
+   {
+      if( ch > 3 || percent > 100 )
+        return; // invalid arg
+
+      soChVol_[ch] = int(percent / 10);
+   }
 
    void PSG::mapSo(const unsigned nr51)
    {

libgambatte/src/sound.h

@@ -71,6 +71,7 @@ class PSG {
 	void setNr44(unsigned data) { ch4_.setNr4(data); }
 
 	void setSoVolume(unsigned nr50);
+	void setSoChanVolume(unsigned percent, unsigned ch);
 	void mapSo(unsigned nr51);
 	unsigned getStatus() const;
 
@@ -83,6 +84,7 @@ class PSG {
 	std::size_t bufferPos_;
 	unsigned long lastUpdate_;
 	unsigned long soVol_;
+	unsigned long soChVol_[4];
 	uint_least32_t rsum_;
 	bool enabled_;