game boy progress, part 1

noise and wave channels don't play correctly yet

src/engine/engine.cpp

@@ -188,6 +188,11 @@ bool DivEngine::load(void* f, size_t slen) {
   try {
     DivSong ds;
 
+    ds.nullWave.len=32;
+    for (int i=0; i<32; i++) {
+      ds.nullWave.data[i]=15;
+    }
+
     if (!reader.seek(16,SEEK_SET)) {
       logE("premature end of file!");
       return false;
@@ -645,6 +650,11 @@ DivInstrument* DivEngine::getIns(int index) {
   return song.ins[index];
 }
 
+DivWavetable* DivEngine::getWave(int index) {
+  if (index<0 || index>=song.waveLen) return &song.nullWave;
+  return song.wave[index];
+}
+
 void DivEngine::play() {
   
 }

src/engine/engine.h

@@ -74,6 +74,7 @@ class DivEngine {
     DivSong song;
     void nextBuf(float** in, float** out, int inChans, int outChans, unsigned int size);
     DivInstrument* getIns(int index);
+    DivWavetable* getWave(int index);
     // load a .dmf.
     bool load(void* f, size_t length);
     // save as .dmf.

src/engine/platform/gb.cpp

@@ -13,6 +13,22 @@ void DivPlatformGB::acquire(int& l, int& r) {
   r=gb->apu_output.final_sample.right<<3;
 }
 
+void DivPlatformGB::updateWave() {
+  printf("updating wave\n");
+  for (int i=0; i<16; i++) {
+    DivWavetable* wt=parent->getWave(chan[2].wave);
+    unsigned char next=((wt->data[i*2]&15)<<4)|(wt->data[1+i*2]&15);
+    rWrite(0x30+i,next);
+  }
+}
+
+static unsigned char gbVolMap[16]={
+  0x00, 0x60, 0x60, 0x60,
+  0x60, 0x60, 0x40, 0x40,
+  0x40, 0x40, 0x40, 0x40,
+  0x20, 0x20, 0x20, 0x20
+};
+
 void DivPlatformGB::tick() {
   for (int i=0; i<4; i++) {
     chan[i].std.next();
@@ -26,20 +42,38 @@ void DivPlatformGB::tick() {
     }
     if (chan[i].std.hadDuty) {
       chan[i].duty=chan[i].std.duty;
-      rWrite(16+i*5+1,(chan[i].duty&3)<<6);
+      if (i!=2) {
+        rWrite(16+i*5+1,(chan[i].duty&3)<<6);
+      }
     }
-    if (chan[i].freqChanged) {
+    if (chan[i].std.hadWave) {
+      chan[i].wave=chan[i].std.wave;
+      if (i==2) updateWave();
+    }
+    if (chan[i].freqChanged || chan[i].keyOn || chan[i].keyOff) {
       chan[i].freq=(chan[i].baseFreq*(ONE_SEMITONE-chan[i].pitch))/ONE_SEMITONE;
       if (chan[i].note>0x5d) chan[i].freq=0x01;
-      if (i==0 || i==1) {
-        if (chan[i].keyOn) {
-          DivInstrument* ins=parent->getIns(chan[i].ins);
-          rWrite(16+i*5+2,((chan[i].vol*ins->gb.envVol)&0xf0)|(ins->gb.envLen&7)|((ins->gb.envDir&1)<<3));
+      if (chan[i].keyOn) {
+        DivInstrument* ins=parent->getIns(chan[i].ins);
+        if (i==2) { // wave
+          rWrite(16+i*5,0x80);
+          rWrite(16+i*5+2,gbVolMap[chan[i].vol]);
+        } else {
+          rWrite(16+i*5,0x00);
+          rWrite(16+i*5+2,((chan[i].vol<<4))|(ins->gb.envLen&7)|((ins->gb.envDir&1)<<3));
         }
-        rWrite(16+i*5+3,(2048-chan[i].freq)&0xff);
-        rWrite(16+i*5+4,(((2048-chan[i].freq)>>8)&7)|(chan[i].keyOn?0x80:0x00));
-        if (chan[i].keyOn) chan[i].keyOn=false;
       }
+      if (chan[i].keyOff) {
+        if (i==2) {
+          rWrite(16+i*5+2,0);
+        } else {
+          rWrite(16+i*5+2,8);
+        }
+      }
+      rWrite(16+i*5+3,(2048-chan[i].freq)&0xff);
+      rWrite(16+i*5+4,(((2048-chan[i].freq)>>8)&7)|((chan[i].keyOn||chan[i].keyOff)?0x80:0x00));
+      if (chan[i].keyOn) chan[i].keyOn=false;
+      if (chan[i].keyOff) chan[i].keyOff=false;
       chan[i].freqChanged=false;
     }
   }
@@ -60,6 +94,7 @@ int DivPlatformGB::dispatch(DivCommand c) {
       chan[c.chan].note=c.value;
       chan[c.chan].active=true;
       chan[c.chan].keyOn=true;
+      if (c.chan==2) updateWave();
       chan[c.chan].std.init(parent->getIns(chan[c.chan].ins));
       break;
     case DIV_CMD_NOTE_OFF:
@@ -69,10 +104,16 @@ int DivPlatformGB::dispatch(DivCommand c) {
       break;
     case DIV_CMD_INSTRUMENT:
       chan[c.chan].ins=c.value;
+      if (c.chan!=2) {
+        chan[c.chan].vol=parent->getIns(chan[c.chan].ins)->gb.envVol;
+      }
       break;
     case DIV_CMD_VOLUME:
       if (chan[c.chan].vol!=c.value) {
         chan[c.chan].vol=c.value;
+        if (c.chan==2) {
+          rWrite(16+c.chan*5+2,gbVolMap[chan[c.chan].vol]);
+        }
       }
       break;
     case DIV_CMD_GET_VOLUME:

src/engine/platform/gb.h

@@ -34,6 +34,7 @@ class DivPlatformGB: public DivDispatch {
   short pendingWrites[64];
 
   GB_gameboy_t* gb;
+  void updateWave();
   public:
     void acquire(int& l, int& r);
     int dispatch(DivCommand c);

src/engine/platform/sound/gb/apu.c

@@ -266,6 +266,7 @@ static void render(GB_gameboy_t *gb)
     }
     
     
+    /*
     if (gb->apu_output.interference_volume) {
         signed interference_bias = interference(gb);
         int16_t interference_sample = (interference_bias - gb->apu_output.interference_highpass);
@@ -275,7 +276,8 @@ static void render(GB_gameboy_t *gb)
         
         filtered_output.left = MAX(MIN(filtered_output.left + interference_bias, 0x7FFF), -0x8000);
         filtered_output.right = MAX(MIN(filtered_output.right + interference_bias, 0x7FFF), -0x8000);
-    }
+    }*/
+
     gb->apu_output.final_sample=filtered_output;
 }
 

src/engine/song.h

@@ -96,4 +96,5 @@ struct DivSong {
   std::vector<DivSample*> sample;
 
   DivInstrument nullIns;
+  DivWavetable nullWave;
 };