rework noise readout, alter noise freq for specific feedback bits config

src/engine/platform/sid3.cpp

@@ -72,6 +72,19 @@ const char* regCheatSheetSID3[]={
   NULL
 };
 
+typedef struct
+{
+  uint32_t LFSRmask;
+  float freqScaling;
+} noiseFreqData;
+
+const noiseFreqData noiseInterestingWavesData[] = 
+{
+  {524288, 523.0f / 1675.0f}, //wave very close to SID2 noise mode 1 wave
+
+  {0, 0.0f}, //end marker
+};
+
 const char** DivPlatformSID3::getRegisterSheet() {
   return regCheatSheetSID3;
 }
@@ -490,6 +503,7 @@ void DivPlatformSID3::tick(bool sysTick)
     if (chan[i].std.ex7.had) { //noise LFSR feedback bits
       chan[i].noiseLFSRMask = chan[i].std.ex7.val & 0x3fffffff;
       updateNoiseLFSRMask(i);
+      chan[i].noiseFreqChanged = true;
     }
     if (chan[i].std.op[1].ar.had) { //1-bit noise / PCM mode for wavetable chan
       if(i == SID3_NUM_CHANNELS - 1) //wave chan
@@ -714,15 +728,27 @@ void DivPlatformSID3::tick(bool sysTick)
       if(chan[i].independentNoiseFreq)
       {
         chan[i].noiseFreq=parent->calcFreq(chan[i].baseFreq,chan[i].pitch,chan[i].noise_fixedArp?chan[i].noise_baseNoteOverride:chan[i].noise_arpOff,chan[i].noise_fixedArp,false,2,chan[i].noise_pitch2,chipClock,CHIP_FREQBASE * 64);
-
-        if (chan[i].noiseFreq<0) chan[i].noiseFreq=0;
-        if (chan[i].noiseFreq>0xffffff) chan[i].noiseFreq=0xffffff;
       }
       else
       {
         chan[i].noiseFreq = chan[i].freq;
       }
 
+      bool found = false;
+      int index = 0;
+      while(noiseInterestingWavesData != 0 && !found)
+      {
+        if(noiseInterestingWavesData[index].LFSRmask == chan[i].noiseLFSRMask)
+        {
+          chan[i].noiseFreq *= noiseInterestingWavesData[index].freqScaling;
+          found = true;
+        }
+        index++;
+      }
+
+      if (chan[i].noiseFreq<0) chan[i].noiseFreq=0;
+      if (chan[i].noiseFreq>0xffffff) chan[i].noiseFreq=0xffffff;
+
       updateNoiseFreq(i);
 
       chan[i].noiseFreqChanged = false;
@@ -1052,6 +1078,7 @@ int DivPlatformSID3::dispatch(DivCommand c) {
       chan[c.chan].noiseLFSRMask &= ~(0xffU << (8 * c.value2));
       chan[c.chan].noiseLFSRMask |= ((c.value & (c.value2 == 3 ? 0x3f : 0xff)) << (8 * c.value2));
       updateNoiseLFSRMask(c.chan);
+      chan[c.chan].noiseFreqChanged = true;
       break;
     case DIV_CMD_SID3_1_BIT_NOISE:
       if(c.chan == SID3_NUM_CHANNELS - 1) //wave chan
@@ -1250,7 +1277,7 @@ void DivPlatformSID3::reset() {
     chan[i].freq = chan[i].noiseFreq = 0;
     updatePanning(i);
 
-    chan[i].noiseLFSRMask = (1 << 29) | (1 << 5) | (1 << 3) | 1; //https://docs.amd.com/v/u/en-US/xapp052 for 30 bits: 30, 6, 4, 1
+    chan[i].noiseLFSRMask = 1 | (1 << 23) | (1 << 25) | (1 << 29); //https://docs.amd.com/v/u/en-US/xapp052 for 30 bits: 30, 6, 4, 1; but inverted since our LFSR is moving in different direction
 
     chan[i].pw_slide = 0;
 

src/engine/platform/sound/sid3.c

@@ -2254,7 +2254,16 @@ void sid3_clock_lfsr(sid3_channel* ch)
 
 uint16_t sid3_noise(uint32_t lfsr, bool one_bit) 
 {
-    return one_bit ? ((lfsr & 1) ? 0xffff : 0) : (lfsr & 0xffff);
+    return one_bit ? ((lfsr & 1) ? 0xffff : 0) : 
+    
+    ((((lfsr & 1) << 7) |
+    ((lfsr & 4) << 4) |
+    ((lfsr & 0x40) >> 1) |
+    ((lfsr & 0x200) >> 5) |
+    ((lfsr & 0x800) >> 8) |
+    ((lfsr & 0x8000) >> 13) |
+    ((lfsr & 0x40000) >> 17) |
+    ((lfsr & 0x100000) >> 20)) << 8); //bits like in SID
 }
 
 uint16_t sid3_special_wave(SID3* sid3, uint32_t acc, uint8_t wave) 
@@ -2353,8 +2362,8 @@ void sid3_reset(SID3* sid3)
     {
         memset(&sid3->chan[i], 0, sizeof(sid3_channel));
         sid3->chan[i].adsr.hold_zero = true;
-        sid3->chan[i].lfsr = 0x1;
+        sid3->chan[i].lfsr = 0x0ffffff; //three MSBs are left as 0
-        sid3->chan[i].lfsr_taps = (1 << 29) | (1 << 5) | (1 << 3) | 1; //https://docs.amd.com/v/u/en-US/xapp052 for 30 bits: 30, 6, 4, 1
+        sid3->chan[i].lfsr_taps = 1 | (1 << 23) | (1 << 25) | (1 << 29); //https://docs.amd.com/v/u/en-US/xapp052 for 30 bits: 30, 6, 4, 1; but inverted since our LFSR is moving in different direction
 
         for(int j = 0; j < SID3_NUM_FILTERS; j++)
         {
@@ -3044,7 +3053,7 @@ void sid3_clock(SID3* sid3)
                 {
                     ch->accumulator = 0;
                     ch->noise_accumulator = 0;
-                    ch->lfsr = 0x1;
+                    ch->lfsr = 0x0fffffff; //three MSBs are left as 0
                 }
             }
             else
@@ -3053,7 +3062,7 @@ void sid3_clock(SID3* sid3)
                 {
                     ch->accumulator = 0;
                     ch->noise_accumulator = 0;
-                    ch->lfsr = 0x1;
+                    ch->lfsr = 0x0fffffff; //three MSBs are left as 0
                 }
             }
         }
@@ -3315,7 +3324,7 @@ void sid3_write(SID3* sid3, uint16_t address, uint8_t data)
                 if(sid3->chan[channel].flags & SID3_CHAN_NOISE_PHASE_RESET)
                 {
                     sid3->chan[channel].noise_accumulator = 0;
-                    sid3->chan[channel].lfsr = 0x1;
+                    sid3->chan[channel].lfsr = 0x0fffffff; //three MSBs are left as 0
                 }
 
                 sid3->chan[channel].flags &= ~(SID3_CHAN_ENV_RESET | SID3_CHAN_NOISE_PHASE_RESET | SID3_CHAN_PHASE_RESET);

src/gui/insEdit.cpp

@@ -743,16 +743,16 @@ String macroHoverES5506FilterMode(int id, float val, void* u) {
   String mode="???";
   switch (((int)val)&3) {
     case 0:
-      mode="HP/K2, HP/K2";
+      mode=_("HP/K2, HP/K2");
       break;
     case 1:
-      mode="HP/K2, LP/K1";
+      mode=_("HP/K2, LP/K1");
       break;
     case 2:
-      mode="LP/K2, LP/K2";
+      mode=_("LP/K2, LP/K2");
       break;
     case 3:
-      mode="LP/K2, LP/K1";
+      mode=_("LP/K2, LP/K1");
       break;
     default:
       break;
@@ -797,10 +797,18 @@ String macroSID3SourceChan(int id, float val, void* u)
   }
   else
   {
-    return fmt::sprintf("Channel %d", (int)val + 1);
+    return fmt::sprintf(_("Channel %d"), (int)val + 1);
   }
 }
 
+String macroSID3NoiseLFSR(int id, float val, void* u) 
+{
+  return _("SID2 noise modes:\n\n"
+  "Mode 2: \n"
+  "Mode 3: \n"
+  "Mode 4: ");
+}
+
 String macroSID2WaveMixMode(int id, float val, void* u) 
 {
   if((int)val > 3) return "???";
@@ -2224,7 +2232,7 @@ void FurnaceGUI::drawMacroEdit(FurnaceGUIMacroDesc& i, int totalFit, float avail
       ImGui::SetNextItemWidth(availableWidth);
       String& mmlStr=mmlString[index];
       if (ImGui::InputText("##IMacroMML",&mmlStr)) {
-        decodeMMLStr(mmlStr,i.macro->val,i.macro->len,i.macro->loop,i.min,(i.isBitfield)?((1<<(i.isBitfield?i.max:0))-1):i.max,i.macro->rel,i.bit30);
+        decodeMMLStr(mmlStr,i.macro->val,i.macro->len,i.macro->loop,i.min,(i.isBitfield)?((1<<(i.isBitfield?(i.max):0))-1):i.max,i.macro->rel,i.bit30);
       }
       if (!ImGui::IsItemActive()) {
         encodeMMLStr(mmlStr,i.macro->val,i.macro->len,i.macro->loop,i.macro->rel,false,i.bit30);
@@ -6393,7 +6401,7 @@ void FurnaceGUI::drawInsSID3(DivInstrument* ins)
 
     if(!ins->sid3.doWavetable)
     {
-      macroList.push_back(FurnaceGUIMacroDesc(_("Noise LFSR bits"),&ins->std.ex7Macro,0,29,16 * 30,uiColors[GUI_COLOR_MACRO_NOISE],false,NULL,NULL,true));
+      macroList.push_back(FurnaceGUIMacroDesc(_("Noise LFSR bits"),&ins->std.ex7Macro,0,30,16 * 30,uiColors[GUI_COLOR_MACRO_NOISE],false,NULL,macroSID3NoiseLFSR,true));
       macroList.push_back(FurnaceGUIMacroDesc(_("1-Bit Noise"),&ins->std.opMacros[1].arMacro,0,1,32,uiColors[GUI_COLOR_MACRO_NOISE],false,NULL,NULL,true));
       macroList.push_back(FurnaceGUIMacroDesc(_("Wave Mix"),&ins->std.ex8Macro,0,4,64,uiColors[GUI_COLOR_MACRO_OTHER],false,NULL,macroSID3WaveMixMode));
     }