a fix

src/engine/workPool.cpp

@@ -0,0 +1,20 @@
+/**
+ * Furnace Tracker - multi-system chiptune tracker
+ * Copyright (C) 2021-2023 tildearrow and contributors
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+ #include "workPool.h"

src/engine/workPool.h

@@ -0,0 +1,66 @@
+/**
+ * Furnace Tracker - multi-system chiptune tracker
+ * Copyright (C) 2021-2023 tildearrow and contributors
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef _WORKPOOL_H
+#define _WORKPOOL_H
+
+#include <thread>
+#include <mutex>
+#include <functional>
+#include <condition_variable>
+
+struct DivWorkThread {
+  std::mutex lock;
+  std::thread* thread;
+  std::condition_variable notify;
+  bool busy, terminate;
+
+  void run();
+  DivWorkThread():
+    busy(false) {}
+};
+
+/**
+ * this class provides an implementation of a "thread pool" for executing tasks in parallel.
+ * it is highly recommended to use `new` when allocating a DivWorkPool.
+ */
+class DivWorkPool {
+  DivWorkThread* workThreads;
+  public:
+    /**
+     * push a new job to this work pool.
+     * if all work threads are busy, this will block until one is free.
+     */
+    bool push();
+    
+    /**
+     * check whether this work pool is busy.
+     */
+    bool busy();
+
+    /**
+     * wait for all work threads to finish.
+     */
+    bool wait();
+
+    DivWorkPool(unsigned int threads=0);
+    ~DivWorkPool();
+};
+
+#endif

src/gui/chanOsc.cpp

@@ -500,14 +500,20 @@ void FurnaceGUI::drawChanOsc() {
                   fft->outBuf[1][1]=0;
                   fftw_execute(fft->planI);
 
+                  // window
+                  for (int j=0; j<(FURNACE_FFT_SIZE>>1); j++) {
+                    fft->corrBuf[j]*=1.0-((double)j/(double)(FURNACE_FFT_SIZE<<1));
+                  }
+
                   // find size of period
                   double waveLen=FURNACE_FFT_SIZE-1;
                   double waveLenCandL=DBL_MAX;
                   double waveLenCandH=DBL_MIN;
                   int waveLenBottom=0;
+                  int waveLenTop=0;
 
                   // find lowest point
-                  for (int j=(FURNACE_FFT_SIZE>>1); j>2; j--) {
+                  for (int j=(FURNACE_FFT_SIZE>>2); j>2; j--) {
                     if (fft->corrBuf[j]<waveLenCandL) {
                       waveLenCandL=fft->corrBuf[j];
                       waveLenBottom=j;
@@ -515,27 +521,28 @@ void FurnaceGUI::drawChanOsc() {
                   }
                   
                   // find highest point
-                  for (int j=(FURNACE_FFT_SIZE>>1); j>waveLenBottom; j--) {
+                  for (int j=(FURNACE_FFT_SIZE>>1)-1; j>waveLenBottom; j--) {
                     if (fft->corrBuf[j]>waveLenCandH) {
                       waveLenCandH=fft->corrBuf[j];
                       waveLen=j;
                     }
                   }
+                  waveLenTop=waveLen;
 
                   // did we find the period size?
                   if (waveLen<(FURNACE_FFT_SIZE-32)) {
-                    waveLen*=(double)displaySize*2.0/(double)FURNACE_FFT_SIZE;
-
                     // we got pitch
-                    chanOscPitch[ch]=1.0-pow(waveLen/(double)(FURNACE_FFT_SIZE>>1),2.0);
+                    chanOscPitch[ch]=pow(1.0-(waveLen/(double)(FURNACE_FFT_SIZE>>1)),4.0);
+                    
+                    waveLen*=(double)displaySize*2.0/(double)FURNACE_FFT_SIZE;
 
                     // DFT of one period (x_1)
                     double dft[2];
                     dft[0]=0.0;
                     dft[1]=0.0;
-                    for (int j=0; j<waveLen; j++) {
-                      double one=((double)buf->data[(unsigned short)(needlePos-((int)waveLen)+j)&0xffff]/32768.0);
-                      double two=(double)j*(-2.0*M_PI)/waveLen;
+                    for (int j=needlePos-1-(displaySize>>1)-(int)waveLen, k=0; k<waveLen; j++, k++) {
+                      double one=((double)buf->data[j&0xffff]/32768.0);
+                      double two=(double)k*(-2.0*M_PI)/waveLen;
                       dft[0]+=one*cos(two);
                       dft[1]+=one*sin(two);
                     }
@@ -545,26 +552,66 @@ void FurnaceGUI::drawChanOsc() {
 
                     if (chanOscWaveCorr) {
                       needlePos-=phase*waveLen;
-                      needlePos-=(2*waveLen-fmod(displaySize,waveLen*2))*0.5;
+                       //needlePos-=(2*waveLen-fmod(displaySize,waveLen*2))*0.5;
                     }
                   }
+
+                  // FFT debug code!
+                  if (debugFFT) {
+                    double maxavg=0.0;
+                    for (unsigned short j=0; j<(FURNACE_FFT_SIZE>>1); j++) {
+                      if (fabs(fft->corrBuf[j]>maxavg)) {
+                        maxavg=fabs(fft->corrBuf[j]);
+                      }
+                    }
+                    if (maxavg>0.0000001) maxavg=0.5/maxavg;
+
+                    for (unsigned short j=0; j<precision; j++) {
+                      float x=(float)j/(float)precision;
+                      float y=fft->corrBuf[(j*FURNACE_FFT_SIZE)/precision]*maxavg;
+                      if (j>=precision/2) {
+                        y=fft->inBuf[((j-(precision/2))*FURNACE_FFT_SIZE*2)/(precision)];
+                      }
+
+                      waveform[j]=ImLerp(inRect.Min,inRect.Max,ImVec2(x,0.5f-y));
+                    }
+                    String cPhase=fmt::sprintf("\n%.1f (b: %d t: %d)",waveLen,waveLenBottom,waveLenTop);
+                    dl->AddText(inRect.Min,0xffffffff,cPhase.c_str());
+
+                    dl->AddLine(
+                      ImLerp(inRect.Min,inRect.Max,ImVec2((double)waveLenBottom/(double)FURNACE_FFT_SIZE,0.0)),
+                      ImLerp(inRect.Min,inRect.Max,ImVec2((double)waveLenBottom/(double)FURNACE_FFT_SIZE,1.0)),
+                      0xffffff00
+                    );
+                    dl->AddLine(
+                      ImLerp(inRect.Min,inRect.Max,ImVec2((double)waveLenTop/(double)FURNACE_FFT_SIZE,0.0)),
+                      ImLerp(inRect.Min,inRect.Max,ImVec2((double)waveLenTop/(double)FURNACE_FFT_SIZE,1.0)),
+                      0xff00ff00
+                    );
+                  }
+                } else {
+                  if (debugFFT) {
+                    dl->AddText(inRect.Min,0xffffffff,"\nquiet");
+                  }
                 }
 
-                needlePos-=displaySize;
-                for (unsigned short j=0; j<precision; j++) {
-                  float y=(float)buf->data[(unsigned short)(needlePos+(j*displaySize/precision))]/32768.0f;
-                  if (minLevel>y) minLevel=y;
-                  if (maxLevel<y) maxLevel=y;
-                }
-                dcOff=(minLevel+maxLevel)*0.5f;
-                for (unsigned short j=0; j<precision; j++) {
-                  float x=(float)j/(float)precision;
-                  float y=(float)buf->data[(unsigned short)(needlePos+(j*displaySize/precision))]/32768.0f;
-                  y-=dcOff;
-                  if (y<-0.5f) y=-0.5f;
-                  if (y>0.5f) y=0.5f;
-                  y*=chanOscAmplify;
-                  waveform[j]=ImLerp(inRect.Min,inRect.Max,ImVec2(x,0.5f-y));
+                if (!debugFFT || !loudEnough) {
+                  needlePos-=displaySize;
+                  for (unsigned short j=0; j<precision; j++) {
+                    float y=(float)buf->data[(unsigned short)(needlePos+(j*displaySize/precision))]/32768.0f;
+                    if (minLevel>y) minLevel=y;
+                    if (maxLevel<y) maxLevel=y;
+                  }
+                  dcOff=(minLevel+maxLevel)*0.5f;
+                  for (unsigned short j=0; j<precision; j++) {
+                    float x=(float)j/(float)precision;
+                    float y=(float)buf->data[(unsigned short)(needlePos+(j*displaySize/precision))]/32768.0f;
+                    y-=dcOff;
+                    if (y<-0.5f) y=-0.5f;
+                    if (y>0.5f) y=0.5f;
+                    y*=chanOscAmplify;
+                    waveform[j]=ImLerp(inRect.Min,inRect.Max,ImVec2(x,0.5f-y));
+                  }
                 }
               }
               ImU32 color=ImGui::GetColorU32(chanOscColor);
@@ -693,9 +740,6 @@ void FurnaceGUI::drawChanOsc() {
         if (ImGui::IsItemClicked(ImGuiMouseButton_Right)) {
           chanOscOptions=!chanOscOptions;
         }
-        if (ImGui::IsItemClicked(ImGuiMouseButton_Left)) {
-          debugFFT=!debugFFT;
-        }
       }
       ImGui::PopStyleVar();
     }

src/gui/debugWindow.cpp

@@ -212,6 +212,7 @@ void FurnaceGUI::drawDebug() {
     }
     if (ImGui::TreeNode("Oscilloscope Debug")) {
       int c=0;
+      ImGui::Checkbox("FFT debug view",&debugFFT);
       for (int i=0; i<e->song.systemLen; i++) {
         DivSystem system=e->song.system[i];
         if (e->getChannelCount(system)>0) {