add some basic playback code!

here it begins

src/engine/dispatch.h

@@ -13,6 +13,15 @@ enum DivDispatchCmds {
 
 struct DivCommand {
   DivDispatchCmds cmd;
+  unsigned char chan, value;
+  DivCommand(DivDispatchCmds c, unsigned char ch, unsigned char val):
+    cmd(c),
+    chan(ch),
+    value(val) {}
+  DivCommand(DivDispatchCmds c, unsigned char ch):
+    cmd(c),
+    chan(ch),
+    value(0) {}
 };
 
 struct DivDelayedCommand {
@@ -33,6 +42,7 @@ class DivDispatch {
     int rate;
     virtual void acquire(short& l, short& r);
     virtual int dispatch(DivCommand c);
+    virtual void tick();
 
     /**
      * initialize this DivDispatch.
@@ -43,4 +53,4 @@ class DivDispatch {
      */
     virtual int init(DivEngine* parent, int channels, int sugRate);
 };
-#endif
+#endif

src/engine/engine.h

@@ -22,6 +22,7 @@ class DivEngine {
   bool playing;
   bool speedAB;
   int ticks, cycles, curRow, curOrder;
+  int changeOrd, changePos;
   std::vector<DivChannelState> chan;
 
   blip_buffer_t* bb[2];
@@ -53,7 +54,9 @@ class DivEngine {
       cycles(0),
       curRow(-1),
       curOrder(0),
+      changeOrd(-1),
+      changePos(0),
       temp{0,0},
       prevSample{0,0} {}
 };
-#endif
+#endif

src/engine/platform/abstract.cpp

@@ -5,10 +5,13 @@ void DivDispatch::acquire(short& l, short& r) {
   r=0;
 }
 
+void DivDispatch::tick() {
+}
+
 int DivDispatch::dispatch(DivCommand c) {
   return 1;
 }
 
 int DivDispatch::init(DivEngine* p, int channels, int sugRate) {
   return 0;
-}
+}

src/engine/platform/dummy.cpp

@@ -1,16 +1,42 @@
 #include "dummy.h"
+#include <math.h>
 
 void DivPlatformDummy::acquire(short& l, short& r) {
   l=0;
-  r=0;
+  for (unsigned char i=0; i<chans; i++) {
+    if (chan[i].active) {
+      l+=((chan[i].pos>=0x8000)?chan[i].vol:-chan[i].vol)<<5;
+      chan[i].pos+=chan[i].freq;
+    }
+  }
+  r=l;
+}
+
+void DivPlatformDummy::tick() {
+  for (unsigned char i=0; i<chans; i++) {
+    chan[i].vol=chan[i].vol-(chan[i].vol>>3);
+  }
 }
 
 int DivPlatformDummy::dispatch(DivCommand c) {
+  switch (c.cmd) {
+    case DIV_CMD_NOTE_ON:
+      chan[c.chan].vol=0x7f;
+      chan[c.chan].freq=16.4f*pow(2.0f,((float)c.value/12.0f));
+      chan[c.chan].active=true;
+      break;
+    case DIV_CMD_NOTE_OFF:
+      chan[c.chan].active=false;
+      break;
+    default:
+      break;
+  }
   return 1;
 }
 
 int DivPlatformDummy::init(DivEngine* p, int channels, int sugRate) {
   parent=p;
-  rate=sugRate;
+  rate=65536;
+  chans=channels;
   return channels;
-}
+}

src/engine/platform/dummy.h

@@ -3,8 +3,18 @@
 // the dummy platform outputs square waves, interprets STD instruments and plays samples.
 // used when a DivDispatch for a system is not found.
 class DivPlatformDummy: public DivDispatch {
+  struct Channel {
+    unsigned short freq;
+    unsigned short pos;
+    bool active;
+    unsigned char vol;
+    Channel(): freq(0), pos(0), active(false), vol(0) {}
+  };
+  Channel chan[17];
+  unsigned char chans;
   public:
     void acquire(short& l, short& r);
     int dispatch(DivCommand c);
+    void tick();
     int init(DivEngine* parent, int channels, int sugRate);
-};
+};

src/engine/playback.cpp

@@ -30,6 +30,14 @@ void DivEngine::nextRow() {
   if (++curRow>=song.patLen) {
     nextOrder();
   }
+  if (changeOrd>=0) {
+    curRow=changePos;
+    curOrder=changeOrd;
+    if (curOrder>=song.ordersLen) {
+      curOrder=0;
+    }
+    changeOrd=-1;
+  }
   strcpy(pb1,"");
   strcpy(pb3,"");
   for (int i=0; i<chans; i++) {
@@ -68,6 +76,39 @@ void DivEngine::nextRow() {
     }
   }
   printf("| %.2x:%s | \x1b[1;33m%3d%s\x1b[m\n",curOrder,pb1,curRow,pb3);
+
+  for (int i=0; i<chans; i++) {
+    DivPattern* pat=song.pat[i]->data[curOrder];
+    // note
+    if (pat->data[curRow][0]==100) {
+      dispatch->dispatch(DivCommand(DIV_CMD_NOTE_OFF,i));
+    } else if (pat->data[curRow][1]!=0) {
+      dispatch->dispatch(DivCommand(DIV_CMD_NOTE_ON,i,pat->data[curRow][0]+pat->data[curRow][1]*12));
+    }
+
+    // effects
+    for (int j=0; j<song.pat[i]->effectRows; j++) {
+      unsigned char effect=pat->data[curRow][4+(j<<1)];
+      unsigned char effectVal=pat->data[curRow][5+(j<<1)];
+
+      switch (effect) {
+        case 0x09: // speed 1
+          song.speed1=effectVal;
+          break;
+        case 0x0f: // speed 2
+          song.speed2=effectVal;
+          break;
+        case 0x0b: // change order
+          changeOrd=effectVal;
+          changePos=0;
+          break;
+        case 0x0d: // next order
+          changeOrd=curOrder+1;
+          changePos=effectVal;
+          break;
+      }
+    }
+  }
 }
 
 void DivEngine::nextTick() {
@@ -81,14 +122,15 @@ void DivEngine::nextTick() {
     }
   }
   if (--ticks<=0) {
+    nextRow();
     if (speedAB) {
       ticks=song.speed2*(song.timeBase+1);
     } else {
       ticks=song.speed1*(song.timeBase+1);
     }
     speedAB=!speedAB;
-    nextRow();
   }
+  dispatch->tick();
 }
 
 void DivEngine::nextBuf(float** in, float** out, int inChans, int outChans, unsigned int size) {
@@ -115,4 +157,4 @@ void DivEngine::nextBuf(float** in, float** out, int inChans, int outChans, unsi
     out[0][i]=(float)bbOut[0][i]/32768.0;
     out[1][i]=(float)bbOut[1][i]/32768.0;
   }
-}
+}