GUI: improve note input timing

during playback, it rounds to nearest cell now
this greatly enhances the recording experience

to-do: test on higher latencies and see if we have to compensate somehow...

src/engine/engine.cpp

@@ -2393,6 +2393,15 @@ void DivEngine::getPlayPos(int& order, int& row) {
   playPosLock.unlock();
 }
 
+void DivEngine::getPlayPosTick(int& order, int& row, int& tick, int& speed) {
+  playPosLock.lock();
+  order=prevOrder;
+  row=prevRow;
+  tick=ticks;
+  speed=nextSpeed;
+  playPosLock.unlock();
+}
+
 int DivEngine::getElapsedBars() {
   return elapsedBars;
 }

src/engine/engine.h

@@ -965,6 +965,7 @@ class DivEngine {
 
     // synchronous get order/row
     void getPlayPos(int& order, int& row);
+    void getPlayPosTick(int& order, int& row, int& tick, int& speed);
 
     // get beat/bar
     int getElapsedBars();

src/gui/gui.cpp

@@ -1257,10 +1257,23 @@ void FurnaceGUI::noteInput(int num, int key, int vol) {
   int ch=cursor.xCoarse;
   int ord=curOrder;
   int y=cursor.y;
+  int tick=0;
+  int speed=0;
 
   if (e->isPlaying()) {
-    e->getPlayPos(ord,y);
+    e->getPlayPosTick(ord,y,tick,speed);
+    if (tick<=(speed/2)) { // round
+      // TODO: detect 0Dxx/0Bxx?
+      if (++y>=e->curSubSong->patLen) {
+        y=0;
+        if (++ord>=e->curSubSong->ordersLen) {
+          ord=0;
         }
+      }
+    }
+  }
+
+  logV("chan %d, %d:%d %d/%d",ch,ord,y,tick,speed);
 
   DivPattern* pat=e->curPat[ch].getPattern(e->curOrders->ord[ch][ord],true);
   bool removeIns=false;