add phase invesrion for left/right channel and feedback

src/engine/instrument.cpp

@@ -269,6 +269,8 @@ bool DivInstrumentSID3::operator==(const DivInstrumentSID3& other) {
     _C(separateNoisePitch) &&
     _C(special_wave) &&
     _C(doWavetable) &&
+    _C(phaseInv) &&
+    _C(feedback) &&
     _C(filt[0]) &&
     _C(filt[1]) &&
     _C(filt[2]) &&

src/engine/instrument.h

@@ -874,6 +874,8 @@ struct DivInstrumentSID3
   bool separateNoisePitch;
   unsigned char special_wave;
   bool doWavetable;
+  unsigned char phaseInv;
+  unsigned char feedback;
 
   struct Filter 
   {
@@ -940,7 +942,9 @@ struct DivInstrumentSID3
     oneBitNoise(false),
     separateNoisePitch(false),
     special_wave(0),
-    doWavetable(false)
+    doWavetable(false),
+    phaseInv(0),
+    feedback(0)
     {
       filt[0].mode = 16 | 32; //default settings so filter just works, connect to input and channel output
       filt[0].output_volume = 0xff;

src/engine/platform/sid3.cpp

@@ -308,6 +308,10 @@ void DivPlatformSID3::tick(bool sysTick)
       panChanged = true;
       chan[i].panRight = chan[i].std.panR.val & 0xff;
     }
+    if (chan[i].std.op[2].ar.had) { //channel signal inversion
+      chan[i].phaseInv = chan[i].std.op[2].ar.val & 3;
+      rWrite(SID3_REGISTER_PHASE_INVERSION + i * SID3_REGISTERS_PER_CHANNEL, chan[i].phaseInv);
+    }
     if (chan[i].std.op[0].am.had) { //key on/off
       chan[i].gate = chan[i].std.op[0].am.val & 1;
       flagsChanged = true;
@@ -330,6 +334,10 @@ void DivPlatformSID3::tick(bool sysTick)
       chan[i].phaseSrc = chan[i].std.fb.val & 0xff;
       rWrite(SID3_REGISTER_PHASE_MOD_SRC + i * SID3_REGISTERS_PER_CHANNEL, chan[i].phaseSrc);
     }
+    if (chan[i].std.op[3].ar.had) { //feedback
+      chan[i].feedback = chan[i].std.op[3].ar.val & 0xff;
+      rWrite(SID3_REGISTER_FEEDBACK + i * SID3_REGISTERS_PER_CHANNEL, chan[i].feedback);
+    }
     if (chan[i].std.phaseReset.had) {
       chan[i].phaseReset = chan[i].std.phaseReset.val & 1;
 
@@ -517,6 +525,9 @@ void DivPlatformSID3::tick(bool sysTick)
         rWrite(SID3_REGISTER_SYNC_SRC + i * SID3_REGISTERS_PER_CHANNEL, chan[i].syncSrc); //hard sync source
         rWrite(SID3_REGISTER_PHASE_MOD_SRC + i * SID3_REGISTERS_PER_CHANNEL, chan[i].phaseSrc); //phase mod source
 
+        rWrite(SID3_REGISTER_PHASE_INVERSION + i * SID3_REGISTERS_PER_CHANNEL, chan[i].phaseInv); //signal inversion
+        rWrite(SID3_REGISTER_FEEDBACK + i * SID3_REGISTERS_PER_CHANNEL, chan[i].feedback); //feedback
+
         updateEnvelope(i);
 
         updateFlags(i, false); //gate off TODO: make it properly?
@@ -677,9 +688,13 @@ int DivPlatformSID3::dispatch(DivCommand c) {
 
         chan[c.chan].ringSrc = ins->sid3.ring_mod_source;
         chan[c.chan].syncSrc = ins->sid3.sync_source;
+        chan[c.chan].phaseSrc = ins->sid3.phase_mod_source;
 
         chan[c.chan].independentNoiseFreq = ins->sid3.separateNoisePitch;
 
+        chan[c.chan].phaseInv = ins->sid3.phaseInv;
+        chan[c.chan].feedback = ins->sid3.feedback;
+
         for(int j = 0; j < SID3_NUM_FILTERS; j++)
         {
           if(ins->sid3.filt[j].init)

src/engine/platform/sid3.h

@@ -76,6 +76,9 @@ class DivPlatformSID3: public DivDispatch {
     unsigned long long dacPos;
     int dacSample;
 
+    unsigned char phaseInv;
+    unsigned char feedback;
+
     void handleArpNoise(int offset=0) 
     {
       DivMacroStruct& m = this->std.op[3].am;
@@ -164,14 +167,16 @@ class DivPlatformSID3: public DivDispatch {
       panRight(0xff),
       noiseFreq(0),
       independentNoiseFreq(false),
-      noiseLFSRMask((1 << 29) | (1 << 5) | (1 << 3) | 1),
+      noiseLFSRMask((1 << 29) | (1 << 5) | (1 << 3) | 1), //https://docs.amd.com/v/u/en-US/xapp052 for 30 bits: 30, 6, 4, 1
       pcm(false),
       wavetable(-1),
       dacPeriod(0),
       dacRate(0),
       dacOut(0),
       dacPos(0),
-      dacSample(-1) {} //https://docs.amd.com/v/u/en-US/xapp052 for 30 bits: 30, 6, 4, 1
+      dacSample(-1),
+      phaseInv(0),
+      feedback(0) {}
   };
   Channel chan[SID3_NUM_CHANNELS];
   DivDispatchOscBuffer* oscBuf[SID3_NUM_CHANNELS];

src/engine/platform/sound/sid3.c

@@ -3061,6 +3061,11 @@ void sid3_clock(SID3* sid3)
             ch->noise_accumulator += ch->phase_mod_source == SID3_NUM_CHANNELS - 1 ? ((uint64_t)sid3->wave_channel_output << 18) : ((uint64_t)sid3->channel_output[ch->phase_mod_source] << 18);
         }
 
+        if(ch->feedback)
+        {
+            ch->accumulator += (ch->prev_output + ch->prev_output2) * ch->feedback;
+        }
+
         ch->accumulator &= SID3_ACC_MASK;
 
         if((prev_noise_acc & ((uint32_t)1 << (SID3_ACC_BITS - 6))) != (ch->noise_accumulator & ((uint32_t)1 << (SID3_ACC_BITS - 6))))
@@ -3098,10 +3103,16 @@ void sid3_clock(SID3* sid3)
             output = ch->output_before_filter;
         }
         
+        if(ch->feedback)
+        {
+            ch->prev_output2 = ch->prev_output;
+            ch->prev_output = output + 0xffff;
+        }
+
         if(!sid3->muted[i])
         {
-            sid3->output_l += output * ch->panning_left / 0x8f0;
+            sid3->output_l += output * ch->panning_left / 0x8f0 * ((ch->phase_inv & SID3_INV_SIGNAL_LEFT) ? -1 : 1);
-            sid3->output_r += output * ch->panning_right / 0x8f0;
+            sid3->output_r += output * ch->panning_right / 0x8f0 * ((ch->phase_inv & SID3_INV_SIGNAL_RIGHT) ? -1 : 1);
         }
 
         sid3->channel_output[i] = output;
@@ -3189,8 +3200,8 @@ void sid3_clock(SID3* sid3)
 
     if(!sid3->muted[SID3_NUM_CHANNELS - 1])
     {
-        sid3->output_l += output * ch->panning_left / 0x8f0;
+        sid3->output_l += output * ch->panning_left / 0x8f0 * ((ch->phase_inv & SID3_INV_SIGNAL_LEFT) ? -1 : 1);
-        sid3->output_r += output * ch->panning_right / 0x8f0;
+        sid3->output_r += output * ch->panning_right / 0x8f0 * ((ch->phase_inv & SID3_INV_SIGNAL_RIGHT) ? -1 : 1);
     }
 
     sid3->wave_channel_output = output;
@@ -3726,6 +3737,26 @@ void sid3_write(SID3* sid3, uint16_t address, uint8_t data)
             }
             break;
         }
+        case SID3_REGISTER_PHASE_INVERSION:
+        {
+            if(channel != SID3_NUM_CHANNELS - 1)
+            {
+                sid3->chan[channel].phase_inv = data;
+            }
+            else
+            {
+                sid3->wave_chan.phase_inv = data;
+            }
+            break;
+        }
+        case SID3_REGISTER_FEEDBACK:
+        {
+            if(channel != SID3_NUM_CHANNELS - 1)
+            {
+                sid3->chan[channel].feedback = (uint32_t)data * (uint32_t)data;
+            }
+            break;
+        }
         default: break;
     }
 }

src/engine/platform/sound/sid3.h

@@ -42,6 +42,12 @@ enum Flags
     SID3_CHAN_1_BIT_NOISE = 128,
 };
 
+enum PhaseInversion
+{
+    SID3_INV_SIGNAL_RIGHT = 1,
+    SID3_INV_SIGNAL_LEFT = 2,
+};
+
 enum Waveforms
 {
     SID3_WAVE_TRIANGLE = 1,
@@ -127,6 +133,10 @@ enum Registers
 
     SID3_REGISTER_STREAMED_SAMPLE_HIGH = SID3_REGISTER_AFTER_FILT_1ST_REG + 10,
     SID3_REGISTER_STREAMED_SAMPLE_LOW = SID3_REGISTER_AFTER_FILT_1ST_REG + 11,
+
+    SID3_REGISTER_PHASE_INVERSION = SID3_REGISTER_AFTER_FILT_1ST_REG + 12,
+
+    SID3_REGISTER_FEEDBACK = SID3_REGISTER_AFTER_FILT_1ST_REG + 13,
 };
 
 typedef struct
@@ -200,9 +210,13 @@ typedef struct
     uint8_t clock_filter;
 
     uint8_t panning_left, panning_right;
-    bool invert_left, invert_right; //invert channel signal
 
     int32_t output_before_filter;
+
+    uint8_t phase_inv;
+    uint32_t feedback;
+
+    int32_t prev_output, prev_output2;
 } sid3_channel;
 
 typedef struct
@@ -229,9 +243,10 @@ typedef struct
     uint8_t clock_filter;
 
     uint8_t panning_left, panning_right;
-    bool invert_left, invert_right; //invert channel signal
 
     int32_t output_before_filter;
+
+    uint8_t phase_inv;
 } sid3_wavetable_chan;
 
 typedef struct

src/gui/insEdit.cpp

@@ -5915,6 +5915,24 @@ void FurnaceGUI::drawInsSID3(DivInstrument* ins)
         ImGui::SetTooltip(_("Forces waveform macro to control wavetable index."));
       }
 
+      bool invLeft=ins->sid3.phaseInv & SID3_INV_SIGNAL_LEFT;
+      if (ImGui::Checkbox(_("Inv. left"),&invLeft)) { PARAMETER
+        ins->sid3.phaseInv^=SID3_INV_SIGNAL_LEFT;
+      }
+      if (ImGui::IsItemHovered())
+      {
+        ImGui::SetTooltip(_("Invert left channel signal"));
+      }
+      ImGui::SameLine();
+      bool invRight=ins->sid3.phaseInv & SID3_INV_SIGNAL_RIGHT;
+      if (ImGui::Checkbox(_("Inv. right"),&invRight)) { PARAMETER
+        ins->sid3.phaseInv^=SID3_INV_SIGNAL_RIGHT;
+      }
+      if (ImGui::IsItemHovered())
+      {
+        ImGui::SetTooltip(_("Invert right channel signal"));
+      }
+
       ImGui::TableNextColumn();
 
       CENTER_TEXT(_("Special wave preview"));
@@ -5975,6 +5993,7 @@ void FurnaceGUI::drawInsSID3(DivInstrument* ins)
     strncpy(buffer,macroSID3WaveMixMode(0,(float)ins->sid2.mixMode,NULL).c_str(),40);
     P(CWSliderScalar(_("Wave Mix Mode"),ImGuiDataType_U8,&ins->sid2.mixMode,&_ZERO,&_FOUR,buffer));
     P(CWSliderScalar(_("Duty"),ImGuiDataType_U16,&ins->c64.duty,&_ZERO,&_SIXTY_FIVE_THOUSAND_FIVE_HUNDRED_THIRTY_FIVE)); rightClickable
+    P(CWSliderScalar(_("Feedback"),ImGuiDataType_U8,&ins->sid3.feedback,&_ZERO,&_TWO_HUNDRED_FIFTY_FIVE));
     bool resetDuty=ins->c64.resetDuty;
     if (ImGui::Checkbox(_("Reset duty on new note"),&resetDuty)) 
     { PARAMETER
@@ -6261,6 +6280,8 @@ void FurnaceGUI::drawInsSID3(DivInstrument* ins)
     macroList.push_back(FurnaceGUIMacroDesc(_("Panning (left)"),&ins->std.panLMacro,0,255,160,uiColors[GUI_COLOR_MACRO_OTHER],false,NULL));
     macroList.push_back(FurnaceGUIMacroDesc(_("Panning (right)"),&ins->std.panRMacro,0,255,160,uiColors[GUI_COLOR_MACRO_OTHER]));
 
+    macroList.push_back(FurnaceGUIMacroDesc(_("Channel inversion"),&ins->std.opMacros[2].arMacro,0,2,32,uiColors[GUI_COLOR_MACRO_OTHER],false,NULL,NULL,true,minModModeBits));
+
     macroList.push_back(FurnaceGUIMacroDesc(_("Key On/Off"),&ins->std.opMacros[0].amMacro,0,1,32,uiColors[GUI_COLOR_MACRO_OTHER],false,NULL,NULL,true));
 
     macroList.push_back(FurnaceGUIMacroDesc(_("Special"),&ins->std.ex1Macro,0,3,48,uiColors[GUI_COLOR_MACRO_OTHER],false,NULL,NULL,true,sid3ControlBits));
@@ -6269,6 +6290,11 @@ void FurnaceGUI::drawInsSID3(DivInstrument* ins)
     macroList.push_back(FurnaceGUIMacroDesc(_("Hard Sync Source"),&ins->std.amsMacro,0,SID3_NUM_CHANNELS - 1,64,uiColors[GUI_COLOR_MACRO_OTHER],false,NULL,macroSID3SourceChan));
     macroList.push_back(FurnaceGUIMacroDesc(_("Phase Mod Source"),&ins->std.fbMacro,0,SID3_NUM_CHANNELS - 1,64,uiColors[GUI_COLOR_MACRO_OTHER],false,NULL,macroSID3SourceChan));
     
+    if(!ins->sid3.doWavetable)
+    {
+      macroList.push_back(FurnaceGUIMacroDesc(_("Feedback"),&ins->std.opMacros[3].arMacro,0,255,160,uiColors[GUI_COLOR_MACRO_OTHER]));
+    }
+
     macroList.push_back(FurnaceGUIMacroDesc(_("Phase Reset"),&ins->std.phaseResetMacro,0,1,32,uiColors[GUI_COLOR_MACRO_OTHER],false,NULL,NULL,true));
 
     if(!ins->sid3.doWavetable)