add export one audio file per system mode

src/engine/engine.cpp

@@ -2133,6 +2133,8 @@ bool DivEngine::isExporting() {
 #define EXPORT_BUFSIZE 2048
 
 void DivEngine::runExportThread() {
+  switch (exportMode) {
+    case DIV_EXPORT_MODE_ONE: {
       SNDFILE* sf;
       SF_INFO si;
       si.samplerate=got.rate;
@@ -2142,6 +2144,7 @@ void DivEngine::runExportThread() {
       sf=sf_open(exportPath.c_str(),SFM_WRITE,&si);
       if (sf==NULL) {
         logE("could not open file for writing!\n");
+        exporting=false;
         return;
       }
 
@@ -2183,10 +2186,92 @@ void DivEngine::runExportThread() {
           logE("error while activating audio!\n");
         }
       }
+      break;
+    }
+    case DIV_EXPORT_MODE_MANY_SYS: {
+      SNDFILE* sf[32];
+      SF_INFO si[32];
+      String fname[32];
+      for (int i=0; i<song.systemLen; i++) {
+        sf[i]=NULL;
+        si[i].samplerate=got.rate;
+        if (disCont[i].dispatch->isStereo()) {
+          si[i].channels=2;
+        } else {
+          si[i].channels=1;
+        }
+        si[i].format=SF_FORMAT_WAV|SF_FORMAT_PCM_16;
+      }
+
+      for (int i=0; i<song.systemLen; i++) {
+        fname[i]=fmt::sprintf("%s_%d.wav",exportPath,i+1);
+        sf[i]=sf_open(fname[i].c_str(),SFM_WRITE,&si[i]);
+        if (sf[i]==NULL) {
+          logE("could not open file for writing!\n");
+          for (int j=0; j<i; j++) {
+            sf_close(sf[i]);
+          }
+          return;
+        }
+      }
+
+      float* outBuf[2];
+      outBuf[0]=new float[EXPORT_BUFSIZE];
+      outBuf[1]=new float[EXPORT_BUFSIZE];
+      short* sysBuf=new short[EXPORT_BUFSIZE*2];
+
+      // take control of audio output
+      deinitAudioBackend();
+      playSub(false);
+
+      while (playing) {
+        nextBuf(NULL,outBuf,0,2,EXPORT_BUFSIZE);
+        for (int i=0; i<song.systemLen; i++) {
+          for (int j=0; j<EXPORT_BUFSIZE; j++) {
+            if (!disCont[i].dispatch->isStereo()) {
+              sysBuf[j]=disCont[i].bbOut[0][j];
+            } else {
+              sysBuf[j<<1]=disCont[i].bbOut[0][j];
+              sysBuf[1+(j<<1)]=disCont[i].bbOut[1][j];
+            }
+          }
+          if (totalProcessed>EXPORT_BUFSIZE) {
+            logE("error: total processed is bigger than export bufsize! (%d) %d>%d\n",i,totalProcessed,EXPORT_BUFSIZE);
+          }
+          if (sf_writef_short(sf[i],sysBuf,totalProcessed)!=(int)totalProcessed) {
+            logE("error: failed to write entire buffer! (%d)\n",i);
+            break;
+          }
+        }
+      }
+
+      for (int i=0; i<song.systemLen; i++) {
+        if (sf_close(sf[i])!=0) {
+          logE("could not close audio file!\n");
+        }
+      }
+      exporting=false;
+
+      if (initAudioBackend()) {
+        for (int i=0; i<song.systemLen; i++) {
+          disCont[i].setRates(got.rate);
+          disCont[i].setQuality(lowQuality);
+        }
+        if (!output->setRun(true)) {
+          logE("error while activating audio!\n");
+        }
+      }
+      break;
+    }
+    case DIV_EXPORT_MODE_MANY_CHAN: {
+      break;
+    }
+  }
 }
 
 bool DivEngine::saveAudio(const char* path, int loops, DivAudioExportModes mode) {
   exportPath=path;
+  exportMode=mode;
   exporting=true;
   stop();
   setOrder(0);