GUI: add a preliminary oscilloscope

src/engine/engine.cpp

@@ -4857,6 +4857,7 @@ bool DivEngine::initAudioBackend() {
     output=NULL;
     return false;
   }
+
   return true;
 }
 
@@ -4931,6 +4932,9 @@ bool DivEngine::init() {
     isMuted[i]=0;
   }
 
+  oscBuf[0]=new float[32768];
+  oscBuf[1]=new float[32768];
+
   initDispatch();
   reset();
   active=true;
@@ -4948,5 +4952,7 @@ bool DivEngine::quit() {
   logI("saving config.\n");
   saveConf();
   active=false;
+  delete[] oscBuf[0];
+  delete[] oscBuf[1];
   return true;
 }

src/engine/engine.h

@@ -206,6 +206,8 @@ class DivEngine {
     DivSystem sysOfChan[DIV_MAX_CHANS];
     int dispatchOfChan[DIV_MAX_CHANS];
     int dispatchChanOfChan[DIV_MAX_CHANS];
+    float* oscBuf[2];
+    float oscSize;
 
     void runExportThread();
     void nextBuf(float** in, float** out, int inChans, int outChans, unsigned int size);
@@ -549,6 +551,8 @@ class DivEngine {
       metroAmp(0.0f),
       totalProcessed(0),
       jediTable(NULL),
+      oscBuf{NULL,NULL},
+      oscSize(1),
       adpcmMem(NULL),
       adpcmMemLen(0) {}
 };

src/engine/playback.cpp

@@ -1138,5 +1138,10 @@ void DivEngine::nextBuf(float** in, float** out, int inChans, int outChans, unsi
     metroPos+=metroFreq;
     while (metroPos>=1) metroPos--;
   }
+
+  // TODO: improve
+  memcpy(oscBuf[0],out[0],size*sizeof(float));
+  memcpy(oscBuf[1],out[1],size*sizeof(float));
+  oscSize=size;
   isBusy.unlock();
 }

src/gui/gui.cpp

@@ -1977,6 +1977,25 @@ void FurnaceGUI::drawMixer() {
   ImGui::End();
 }
 
+void FurnaceGUI::drawOsc() {
+  if (!oscOpen) return;
+  ImGui::SetNextWindowSizeConstraints(ImVec2(64.0f*dpiScale,32.0f*dpiScale),ImVec2(scrW*dpiScale,scrH*dpiScale));
+  if (ImGui::Begin("Oscilloscope",&oscOpen)) {
+    ImGui::PushStyleVar(ImGuiStyleVar_WindowPadding,ImVec2(0,0));
+    ImGui::PushStyleVar(ImGuiStyleVar_FramePadding,ImVec2(0,0));
+    ImGui::PushStyleVar(ImGuiStyleVar_ItemSpacing,ImVec2(0,0));
+    ImGui::PushStyleVar(ImGuiStyleVar_ItemInnerSpacing,ImVec2(0,0));
+    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::PlotLines("##SingleOsc",values,512,0,NULL,-1.0f,1.0f,ImGui::GetContentRegionAvail());
+    ImGui::PopStyleVar(4);
+  }
+  ImGui::End();
+}
+
 void FurnaceGUI::drawPattern() {
   if (!patternOpen) return;
   if (e->isPlaying() && followPattern) cursor.y=oldRow;
@@ -4571,6 +4590,7 @@ bool FurnaceGUI::loop() {
       if (ImGui::MenuItem("orders")) ordersOpen=!ordersOpen;
       if (ImGui::MenuItem("pattern")) patternOpen=!patternOpen;
       if (ImGui::MenuItem("mixer")) mixerOpen=!mixerOpen;
+      if (ImGui::MenuItem("oscilloscope")) oscOpen=!oscOpen;
       ImGui::EndMenu();
     }
     if (ImGui::BeginMenu("help")) {
@@ -4607,6 +4627,7 @@ bool FurnaceGUI::loop() {
     drawSampleList();
     drawSampleEdit();
     drawMixer();
+    drawOsc();
     drawPattern();
     drawSettings();
     drawDebug();
@@ -5209,6 +5230,7 @@ FurnaceGUI::FurnaceGUI():
   settingsOpen(false),
   mixerOpen(false),
   debugOpen(false),
+  oscOpen(true),
   selecting(false),
   curNibble(false),
   orderNibble(false),

src/gui/gui.h

@@ -236,7 +236,7 @@ class FurnaceGUI {
   int loopOrder, loopRow, loopEnd;
   bool editControlsOpen, ordersOpen, insListOpen, songInfoOpen, patternOpen, insEditOpen;
   bool waveListOpen, waveEditOpen, sampleListOpen, sampleEditOpen, aboutOpen, settingsOpen;
-  bool mixerOpen, debugOpen;
+  bool mixerOpen, debugOpen, oscOpen;
   SelectionPoint selStart, selEnd, cursor;
   bool selecting, curNibble, orderNibble, extraChannelButtons, followOrders, followPattern, changeAllOrders;
   FurnaceGUIWindows curWindow;
@@ -315,6 +315,7 @@ class FurnaceGUI {
   void drawSampleList();
   void drawSampleEdit();
   void drawMixer();
+  void drawOsc();
   void drawAbout();
   void drawSettings();
   void drawDebug();