GUI: prepare for oscilloscope improvements

src/engine/engine.h

@@ -298,6 +298,7 @@ class DivEngine {
     bool keyHit[DIV_MAX_CHANS];
     float* oscBuf[2];
     float oscSize;
+    int oscReadPos, oscWritePos;
 
     void runExportThread();
     void nextBuf(float** in, float** out, int inChans, int outChans, unsigned int size);
@@ -772,6 +773,8 @@ class DivEngine {
       totalProcessed(0),
       oscBuf{NULL,NULL},
       oscSize(1),
+      oscReadPos(0),
+      oscWritePos(0),
       adpcmAMem(NULL),
       adpcmAMemLen(0),
       adpcmBMem(NULL),

src/engine/playback.cpp

@@ -1896,8 +1896,11 @@ void DivEngine::nextBuf(float** in, float** out, int inChans, int outChans, unsi
     while (metroPos>=1) metroPos--;
   }
 
-  memcpy(oscBuf[0],out[0],size*sizeof(float));
+  for (unsigned int i=0; i<size; i++) {
-  memcpy(oscBuf[1],out[1],size*sizeof(float));
+    oscBuf[0][oscWritePos]=out[0][i];
+    oscBuf[1][oscWritePos]=out[1][i];
+    if (++oscWritePos>=32768) oscWritePos=0;
+  }
   oscSize=size;
 
   if (forceMono) {

src/gui/gui.cpp

@@ -2600,6 +2600,9 @@ bool FurnaceGUI::loop() {
     drawInsList();
     drawInsEdit();
     drawMixer();
+
+    readOsc();
+
     drawOsc();
     drawVolMeter();
     drawSettings();
@@ -3428,7 +3431,8 @@ FurnaceGUI::FurnaceGUI():
   openSampleResampleOpt(false),
   openSampleAmplifyOpt(false),
   openSampleSilenceOpt(false),
-  openSampleFilterOpt(false) {
+  openSampleFilterOpt(false),
+  oscTotal(0) {
   // value keys
   valueKeys[SDLK_0]=0;
   valueKeys[SDLK_1]=1;
@@ -3469,4 +3473,5 @@ FurnaceGUI::FurnaceGUI():
   memset(patChanX,0,sizeof(float)*(DIV_MAX_CHANS+1));
   memset(patChanSlideY,0,sizeof(float)*(DIV_MAX_CHANS+1));
   memset(lastIns,-1,sizeof(int)*DIV_MAX_CHANS);
+  memset(oscValues,0,sizeof(float)*512);
 }

src/gui/gui.h

@@ -976,6 +976,10 @@ class FurnaceGUI {
   size_t sampleClipboardLen;
   bool openSampleResizeOpt, openSampleResampleOpt, openSampleAmplifyOpt, openSampleSilenceOpt, openSampleFilterOpt;
 
+  // oscilloscope
+  int oscTotal;
+  float oscValues[512];
+
   // visualizer
   float keyHit[DIV_MAX_CHANS];
   int lastIns[DIV_MAX_CHANS];
@@ -996,6 +1000,8 @@ class FurnaceGUI {
   void updateWindowTitle();
   void prepareLayout();
 
+  void readOsc();
+
   float calcBPM(int s1, int s2, float hz);
 
   void patternRow(int i, bool isPlaying, float lineHeight, int chans, int ord, const DivPattern** patCache);

src/gui/osc.cpp

@@ -18,6 +18,50 @@
  */
 
 #include "gui.h"
+#include <math.h>
+
+void FurnaceGUI::readOsc() {
+  int writePos=e->oscWritePos;
+  int readPos=e->oscReadPos;
+  int avail=0;
+  int total=0;
+  if (writePos>=readPos) {
+    avail=writePos-readPos;
+  } else {
+    avail=writePos-readPos+32768;
+  }
+  if (oscTotal==0) {
+    oscTotal=ImGui::GetIO().DeltaTime*e->getAudioDescGot().rate;
+  } else {
+    oscTotal=(oscTotal+(int)round(ImGui::GetIO().DeltaTime*e->getAudioDescGot().rate))>>1;
+  }
+  int bias=avail-oscTotal-e->getAudioDescGot().bufsize;
+  if (bias<0) bias=0;
+  total=oscTotal+(bias>>6);
+  if (total>avail) total=avail;
+  //printf("total: %d. avail: %d bias: %d\n",total,avail,bias);
+  for (int i=0; i<512; i++) {
+    int pos=(readPos+(i*total/512))&0x7fff;
+    oscValues[i]=(e->oscBuf[0][pos]+e->oscBuf[1][pos])*0.5f;
+  }
+
+  float peakDecay=0.05f*60.0f*ImGui::GetIO().DeltaTime;
+  for (int i=0; i<2; i++) {
+    peak[i]*=1.0-peakDecay;
+    if (peak[i]<0.0001) peak[i]=0.0;
+    float newPeak=peak[i];
+    for (int j=0; j<total; j++) {
+      int pos=(readPos+j)&0x7fff;
+      if (fabs(e->oscBuf[i][pos])>newPeak) {
+        newPeak=fabs(e->oscBuf[i][pos]);
+      }
+    }
+    peak[i]+=(newPeak-peak[i])*0.9;
+  }
+
+  readPos=(readPos+total)&0x7fff;
+  e->oscReadPos=readPos;
+}
 
 void FurnaceGUI::drawOsc() {
   if (nextWindow==GUI_WINDOW_OSCILLOSCOPE) {
@@ -31,14 +75,9 @@ void FurnaceGUI::drawOsc() {
   ImGui::PushStyleVar(ImGuiStyleVar_ItemSpacing,ImVec2(0,0));
   ImGui::PushStyleVar(ImGuiStyleVar_ItemInnerSpacing,ImVec2(0,0));
   if (ImGui::Begin("Oscilloscope",&oscOpen)) {
-    float values[512];
-    for (int i=0; i<512; i++) {
-      int pos=i*e->oscSize/512;
-      values[i]=(e->oscBuf[0][pos]+e->oscBuf[1][pos])*0.5f;
-    }
     //ImGui::SetCursorPos(ImVec2(0,0));
     ImGui::BeginDisabled();
-    ImGui::PlotLines("##SingleOsc",values,512,0,NULL,-1.0f,1.0f,ImGui::GetContentRegionAvail());
+    ImGui::PlotLines("##SingleOsc",oscValues,512,0,NULL,-1.0f,1.0f,ImGui::GetContentRegionAvail());
     ImGui::EndDisabled();
   }
   ImGui::PopStyleVar(3);

src/gui/volMeter.cpp

@@ -49,17 +49,9 @@ void FurnaceGUI::drawVolMeter() {
     ImGuiStyle& style=ImGui::GetStyle();
     ImGui::ItemSize(ImVec2(4.0f,4.0f),style.FramePadding.y);
     ImU32 lowColor=ImGui::GetColorU32(uiColors[GUI_COLOR_VOLMETER_LOW]);
-    float peakDecay=0.05f*60.0f*ImGui::GetIO().DeltaTime;
     if (ImGui::ItemAdd(rect,ImGui::GetID("volMeter"))) {
       ImGui::RenderFrame(rect.Min,rect.Max,ImGui::GetColorU32(ImGuiCol_FrameBg),true,style.FrameRounding);
       for (int i=0; i<2; i++) {
-        peak[i]*=1.0-peakDecay;
-        if (peak[i]<0.0001) peak[i]=0.0;
-        for (int j=0; j<e->oscSize; j++) {
-          if (fabs(e->oscBuf[i][j])>peak[i]) {
-            peak[i]=fabs(e->oscBuf[i][j]);
-          }
-        }
         float logPeak=(20*log10(peak[i])/36.0);
         if (logPeak==NAN) logPeak=0.0;
         if (logPeak<-1.0) logPeak=-1.0;