this use of getSourcePosition is wrong (sourcePosition is not increased if e.g. the voice is a generator for example)

To avoid this I removed the API which has really no purpose

src/sfizz/Synth.cpp

@@ -1018,7 +1018,7 @@ void sfz::Synth::checkNotePolyphony(const Region* region, int delay, const Trigg
                 }
                 break;
             case SfzSelfMask::dontMask:
-                if (!selfMaskCandidate || selfMaskCandidate->getSourcePosition() < voice->getSourcePosition())
+                if (!selfMaskCandidate || selfMaskCandidate->getAge() < voice->getAge())
                     selfMaskCandidate = voice;
                 break;
             }

src/sfizz/Voice.cpp

@@ -856,11 +856,6 @@ bool sfz::Voice::releasedOrFree() const noexcept
     return state != State::playing || egAmplitude.isReleased();
 }
 
-uint32_t sfz::Voice::getSourcePosition() const noexcept
-{
-    return sourcePosition;
-}
-
 void sfz::Voice::setMaxFiltersPerVoice(size_t numFilters)
 {
     if (numFilters == filters.size())

src/sfizz/Voice.h

@@ -248,12 +248,6 @@ public:
      * @return float
      */
     float getAveragePower() const noexcept;
-    /**
-     * @brief Get the position of the voice in the source, in samples
-     *
-     * @return uint32_t
-     */
-    uint32_t getSourcePosition() const noexcept;
     /**
      * Returns the region that is currently playing. May be null if the voice is not active!
      *