TIA: acquireDirect()

# TIA Benchmark

twin.fur

acquire(): 11.324s
acquireDirect(): 1.267s

Balmeranda.fur

acquire(): 11.923s
acquireDirect(): 1.093s

# MMC5 (Goofy Asses per second)

unoptimized: 9.22/s
optimized: 108.96/s

src/engine/platform/sound/tia/Audio.cpp

@@ -34,6 +34,14 @@ namespace {
 
 namespace TIA {
 
+static const int phaseCounters[5]={
+  9,
+  28,
+  44,
+  68,
+  79
+};
+
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 Audio::Audio()
 {
@@ -46,7 +54,8 @@ Audio::Audio()
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 void Audio::reset(bool st)
 {
-  myCounter = 0;
+  myCounter = 9;
+  myPhase = 0;
   mySampleIndex = 0;
   stereo = st;
 
@@ -61,23 +70,32 @@ void Audio::reset(bool st)
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void Audio::tick()
+// steps: (228 total)
+// 0 - wait
+// 1 - 9: phase0
+// 2 - 37: phase1
+// 3 - 81: phase0
+// 4 - 149: phase1
+// 5 - 228: go back to step 0
+void Audio::tick(int len)
 {
-  switch (myCounter) {
+  myCounter-=len;
-    case 9:
+  while (myCounter<=0) {
-    case 81:
+    switch (myPhase) {
+      case 0:
+      case 2:
         myChannel0.phase0();
         myChannel1.phase0();
-
         break;
 
-    case 37:
+      case 1:
-    case 149:
+      case 3:
         phase1();
         break;
     }
-
+    if (++myPhase>4) myPhase=0;
-  if (++myCounter == 228) myCounter = 0;
+    myCounter+=phaseCounters[myPhase];
+  }
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

src/engine/platform/sound/tia/Audio.h

@@ -29,7 +29,7 @@ namespace TIA {
 
       void reset(bool stereo);
 
-      void tick();
+      void tick(int len);
 
       void write(unsigned char addr, unsigned char val);
 
@@ -44,9 +44,11 @@ namespace TIA {
       void phase1();
       void addSample(unsigned char sample0, unsigned char sample1);
 
-    private:
+    public:
-      unsigned char myCounter{0};
+      int myCounter;
+      unsigned char myPhase;
 
+    private:
       AudioChannel myChannel0;
       AudioChannel myChannel1;
 

src/engine/platform/tia.cpp

@@ -38,15 +38,32 @@ const char** DivPlatformTIA::getRegisterSheet() {
   return regCheatSheetTIA;
 }
 
-void DivPlatformTIA::acquire(short** buf, size_t len) {
+void DivPlatformTIA::acquireDirect(blip_buffer_t** bb, size_t len) {
+  thread_local int out[2];
   for (int i=0; i<2; i++) {
     oscBuf[i]->begin(len);
   }
 
   for (size_t h=0; h<len; h++) {
+    int advance=len-h;
+
+    if (tia.myCounter<advance) advance=tia.myCounter;
+    if (softwarePitch) {
+      if (tuneCounter>=228) {
+        if (456-tuneCounter<advance) {
+          advance=456-tuneCounter;
+        }
+      } else {
+        if (228-tuneCounter<advance) {
+          advance=228-tuneCounter;
+        }
+      }
+    }
+    if (advance<1) advance=1;
+
     if (softwarePitch) {
       int i=-1;
-      tuneCounter++;
+      tuneCounter+=advance;
       if (tuneCounter==228) {
         i=0;
       }
@@ -68,14 +85,26 @@ void DivPlatformTIA::acquire(short** buf, size_t len) {
         }
       }
     }
-    tia.tick();
+    tia.tick(advance);
+
+    h+=advance-1;
+
     if (mixingType==2) {
-      buf[0][h]=tia.myCurrentSample[0];
+      out[0]=tia.myCurrentSample[0];
-      buf[1][h]=tia.myCurrentSample[1];
+      out[1]=tia.myCurrentSample[1];
     } else if (mixingType==1) {
-      buf[0][h]=(tia.myCurrentSample[0]+tia.myCurrentSample[1])>>1;
+      out[0]=(tia.myCurrentSample[0]+tia.myCurrentSample[1])>>1;
     } else {
-      buf[0][h]=tia.myCurrentSample[0];
+      out[0]=tia.myCurrentSample[0];
+    }
+
+    if (out[0]!=prevSample[0]) {
+      blip_add_delta(bb[0],h,out[0]-prevSample[0]);
+      prevSample[0]=out[0];
+    }
+    if (mixingType==2) {
+      blip_add_delta(bb[1],h,out[1]-prevSample[1]);
+      prevSample[1]=out[1];
     }
     if (++chanOscCounter>=114) {
       chanOscCounter=0;
@@ -428,6 +457,8 @@ int DivPlatformTIA::getRegisterPoolSize() {
 
 void DivPlatformTIA::reset() {
   tuneCounter=0;
+  prevSample[0]=0;
+  prevSample[1]=0;
   tia.reset(mixingType);
   memset(regPool,0,16);
   for (int i=0; i<2; i++) {
@@ -449,6 +480,10 @@ bool DivPlatformTIA::keyOffAffectsArp(int ch) {
   return true;
 }
 
+bool DivPlatformTIA::hasAcquireDirect() {
+  return true;
+}
+
 bool DivPlatformTIA::getLegacyAlwaysSetVolume() {
   return false;
 }

src/engine/platform/tia.h

@@ -47,6 +47,7 @@ class DivPlatformTIA: public DivDispatch {
     TIA::Audio tia;
     unsigned char regPool[16];
     int tuneCounter;
+    int prevSample[2];
     friend void putDispatchChip(void*,int);
     friend void putDispatchChan(void*,int,int);
 
@@ -54,7 +55,7 @@ class DivPlatformTIA: public DivDispatch {
     int dealWithFreqNew(int shape, int bp);
   
   public:
-    void acquire(short** buf, size_t len);
+    void acquireDirect(blip_buffer_t** bb, size_t len);
     int dispatch(DivCommand c);
     void* getChanState(int chan);
     DivMacroInt* getChanMacroInt(int ch);
@@ -69,6 +70,7 @@ class DivPlatformTIA: public DivDispatch {
     float getPostAmp();
     int getOutputCount();
     bool keyOffAffectsArp(int ch);
+    bool hasAcquireDirect();
     bool getLegacyAlwaysSetVolume();
     void notifyInsDeletion(void* ins);
     void poke(unsigned int addr, unsigned short val);