added a spinlock on the scope

src/synth/ScopeBuffer.cpp

@@ -14,6 +14,9 @@ void ScopeBuffer::push(float sample) {
 // TODO: needs a mutex to prevent flickering
 // outputs value from the scope buffer, called by the scope widget
 void ScopeBuffer::read(std::vector<float>& out) const {
+
+    while(!spinLock_) { int x = 1 + 1; }
+
     size_t w = writeIndex_.load(std::memory_order_relaxed);
     for (size_t i = 0; i < out.size(); i++) {
         size_t idx = (w + trigger_ + i * wavelength_ / out.size()) % buffer_.size();

src/synth/ScopeBuffer.h

@@ -21,6 +21,7 @@ public:
     void setWavelength(int32_t wavelength) { wavelength_ = wavelength; }
     int32_t trigger() { return trigger_; }
     int32_t wavelength() { return wavelength_; }
+    void spinlock(bool lock) { spinLock_ = lock; };
 
     // NOTE: there are limits to the wavelengths that the scope can show cleanly due to the size of the audio buffer
     // at a buffer size of 256 at 44100hz the min visible steady frequency is ~172hz
@@ -33,4 +34,6 @@ private:
     int32_t trigger_ = 0; // units in array indices
     int32_t wavelength_ = 400;
 
+    bool spinLock_ = false;
+
 };

src/synth/Synth.cpp

@@ -92,6 +92,9 @@ void Synth::process(float* out, uint32_t nFrames, uint32_t sampleRate) {
         }
     }
 
+    // lock the scope from the buffer
+    scope_->spinlock(true);
+
     for (uint32_t i = 0; i < nFrames; i++) {
 
         // updates internal buffered parameters for smoothing
@@ -133,4 +136,7 @@ void Synth::process(float* out, uint32_t nFrames, uint32_t sampleRate) {
         }
     }
 
+    // unlock the scope from the buffer
+    scope_->spinlock(false);
+
 }

src/synth/Voice.h

@@ -63,6 +63,7 @@ private:
     // filters
     Filter filter1_;
     Filter filter2_;
+    // TODO: I think the filter's state being uninitialized is what's causing popping when a voice starts for the first time
 
     // paramstore pointer
     SmoothedParam* params_;

src/ui/widgets/Scope/Scope.cpp

@@ -24,7 +24,7 @@ void Scope::setScopeBuffer(ScopeBuffer* buffer) {
 }
 
 void Scope::paintEvent(QPaintEvent*) {
-    if (!buffer_) return;
+    if(!buffer_) return;
 
     int32_t wavelength = buffer_->wavelength();
     int32_t trigger = buffer_->trigger();

src/ui/widgets/Scope/Scope.h

@@ -32,4 +32,5 @@ private:
     ScopeBuffer* buffer_ = nullptr;
     std::vector<float> samples_;
     QTimer timer_;
+    
 };