fix certain issues with TimeMicros

src/engine/playback.cpp

@@ -2136,9 +2136,8 @@ bool DivEngine::nextTick(bool noAccum, bool inhibitLowLat) {
       // advance tempo accumulator (for virtual tempo) unless we are step playing and waiting for the next step (stepPlay==2)
       // then advance tick counter and then call nextRow()
       if (stepPlay!=1) {
-        // fast-forward the accumulator if we are "skipping" (seeking to a position)
-        // otherwise increase accumulator by virtual tempo numerator
-        tempoAccum+=(skipping && virtualTempoN<virtualTempoD)?virtualTempoD:virtualTempoN;
+        // increase accumulator by virtual tempo numerator
+        tempoAccum+=virtualTempoN;
         // while accumulator is higher than virtual tempo denominator
         while (tempoAccum>=virtualTempoD) {
           // wrap the accumulator back

src/timeutils.h

@@ -55,7 +55,7 @@ struct TimeMicros {
   }
 
   // operators
-  inline TimeMicros& operator+(TimeMicros& other) {
+  inline TimeMicros& operator+=(TimeMicros& other) {
     seconds+=other.seconds;
     micros+=other.micros;
     while (micros>=1000000) {
@@ -64,11 +64,11 @@ struct TimeMicros {
     }
     return *this;
   }
-  inline TimeMicros& operator+(int other) {
+  inline TimeMicros& operator+=(int other) {
     seconds+=other;
     return *this;
   }
-  inline TimeMicros& operator-(TimeMicros& other) {
+  inline TimeMicros& operator-=(TimeMicros& other) {
     seconds-=other.seconds;
     micros-=other.micros;
     while (micros<0) {
@@ -77,7 +77,7 @@ struct TimeMicros {
     }
     return *this;
   }
-  inline TimeMicros& operator-(int other) {
+  inline TimeMicros& operator-=(int other) {
     seconds-=other;
     return *this;
   }
@@ -124,4 +124,16 @@ struct TimeMicros {
     seconds(0), micros(0) {}
 };
 
+inline TimeMicros operator+(TimeMicros& t1, TimeMicros t2) {
+  TimeMicros result=t1;
+  result+=t2;
+  return result;
+}
+
+inline TimeMicros operator-(TimeMicros& t1, TimeMicros t2) {
+  TimeMicros result=t1;
+  result-=t2;
+  return result;
+}
+
 #endif