GUI: make playing needles in sample editor work

currently only for YM2612 but I will implement more soon

src/engine/dispatch.h

@@ -293,6 +293,18 @@ struct DivDelayedWrite {
     write(a,v) {}
 };
 
+struct DivSamplePos {
+  int sample, pos, freq;
+  DivSamplePos(int s, int p, int f):
+    sample(s),
+    pos(p),
+    freq(f) {}
+  DivSamplePos():
+    sample(-1),
+    pos(0),
+    freq(0) {}
+};
+
 struct DivDispatchOscBuffer {
   bool follow;
   unsigned int rate;
@@ -371,18 +383,29 @@ class DivDispatch {
 
     /**
      * get the state of a channel.
+     * @param chan the channel.
      * @return a pointer, or NULL.
      */
     virtual void* getChanState(int chan);
 
     /**
-     * get the DivMacroInt of a chanmel.
+     * get the DivMacroInt of a channel.
+     * @param chan the channel.
      * @return a pointer, or NULL.
      */
     virtual DivMacroInt* getChanMacroInt(int chan);
 
+    /**
+     * get currently playing sample (and its position).
+     * @param chan the channel.
+     * @return a DivSamplePos. if sample is -1 then nothing is playing or the
+     * channel doesn't play samples.
+     */
+    virtual DivSamplePos getSamplePos(int chan);
+
     /**
      * get an oscilloscope buffer for a channel.
+     * @param chan the channel.
      * @return a pointer to a DivDispatchOscBuffer, or NULL if not supported.
      */
     virtual DivDispatchOscBuffer* getOscBuffer(int chan);

src/engine/engine.cpp

@@ -2119,6 +2119,11 @@ DivMacroInt* DivEngine::getMacroInt(int chan) {
   return disCont[dispatchOfChan[chan]].dispatch->getChanMacroInt(dispatchChanOfChan[chan]);
 }
 
+DivSamplePos DivEngine::getSamplePos(int chan) {
+  if (chan<0 || chan>=chans) return DivSamplePos();
+  return disCont[dispatchOfChan[chan]].dispatch->getSamplePos(dispatchChanOfChan[chan]);
+}
+
 DivDispatchOscBuffer* DivEngine::getOscBuffer(int chan) {
   if (chan<0 || chan>=chans) return NULL;
   return disCont[dispatchOfChan[chan]].dispatch->getOscBuffer(dispatchChanOfChan[chan]);

src/engine/engine.h

@@ -914,6 +914,9 @@ class DivEngine {
     // get macro interpreter
     DivMacroInt* getMacroInt(int chan);
 
+    // get sample position
+    DivSamplePos getSamplePos(int chan);
+
     // get osc buffer
     DivDispatchOscBuffer* getOscBuffer(int chan);
 

src/engine/platform/abstract.cpp

@@ -37,6 +37,10 @@ DivMacroInt* DivDispatch::getChanMacroInt(int chan) {
   return NULL;
 }
 
+DivSamplePos DivDispatch::getSamplePos(int chan) {
+  return DivSamplePos();
+}
+
 DivDispatchOscBuffer* DivDispatch::getOscBuffer(int chan) {
   return NULL;
 }

src/engine/platform/genesis.cpp

@@ -1209,6 +1209,16 @@ DivMacroInt* DivPlatformGenesis::getChanMacroInt(int ch) {
   return &chan[ch].std;
 }
 
+DivSamplePos DivPlatformGenesis::getSamplePos(int ch) {
+  if (ch<5) return DivSamplePos();
+  if (ch>5 && !softPCM) return DivSamplePos();
+  return DivSamplePos(
+    chan[ch].dacSample,
+    chan[ch].dacPos,
+    chan[ch].dacRate
+  );
+}
+
 DivDispatchOscBuffer* DivPlatformGenesis::getOscBuffer(int ch) {
   return oscBuf[ch];
 }

src/engine/platform/genesis.h

@@ -105,6 +105,7 @@ class DivPlatformGenesis: public DivPlatformOPN {
     int dispatch(DivCommand c);
     void* getChanState(int chan);
     DivMacroInt* getChanMacroInt(int ch);
+    DivSamplePos getSamplePos(int ch);
     DivDispatchOscBuffer* getOscBuffer(int chan);
     unsigned char* getRegisterPool();
     int getRegisterPoolSize();

src/gui/sampleEdit.cpp

@@ -1407,6 +1407,46 @@ void FurnaceGUI::drawSampleEdit() {
           dl->AddLine(p1,p2,ImGui::GetColorU32(posColor));
         }
 
+        if (e->isRunning()) {
+          for (int i=0; i<e->getTotalChannelCount(); i++) {
+            DivSamplePos chanPos=e->getSamplePos(i);
+            if (chanPos.sample!=curSample) continue;
+
+            int start=sampleSelStart;
+            int end=sampleSelEnd;
+            if (start>end) {
+              start^=end;
+              end^=start;
+              start^=end;
+            }
+            ImDrawList* dl=ImGui::GetWindowDrawList();
+            ImVec2 p1=rectMin;
+            p1.x+=(chanPos.pos-samplePos)/sampleZoom;     
+            ImVec4 posColor=uiColors[GUI_COLOR_SAMPLE_NEEDLE_PLAYING];
+            ImVec4 posTrail1=posColor;
+            ImVec4 posTrail2=posColor;
+            posTrail1.w*=0.5f;
+            posTrail2.w=0.0f;
+            float trailDistance=((float)chanPos.freq/100.0f)/sampleZoom;
+
+            if (p1.x<rectMin.x) p1.x=rectMin.x;
+            if (p1.x>rectMax.x) p1.x=rectMax.x;
+
+            ImVec2 p2=p1;
+            p2.y=rectMax.y;
+
+            dl->AddRectFilledMultiColor(
+              ImVec2(p1.x-trailDistance,p1.y),
+              p2,
+              ImGui::GetColorU32(posTrail2),
+              ImGui::GetColorU32(posTrail1),
+              ImGui::GetColorU32(posTrail1),
+              ImGui::GetColorU32(posTrail2)
+            );
+            dl->AddLine(p1,p2,ImGui::GetColorU32(posColor));
+          }
+        }
+
         if (drawSelection) {
           int start=sampleSelStart;
           int end=sampleSelEnd;