Emitter: Use std::array where applicable

Makes the data more strongly-typed and prevents implicit array->pointer
decay

include/amuse/BooBackend.hpp

@@ -1,5 +1,6 @@
 #pragma once
 
+#include <array>
 #include <cstddef>
 #include <cstdint>
 #include <list>
@@ -39,7 +40,7 @@ public:
   void resetSampleRate(double sampleRate) override;
 
   void resetChannelLevels() override;
-  void setChannelLevels(IBackendSubmix* submix, const float coefs[8], bool slew) override;
+  void setChannelLevels(IBackendSubmix* submix, const std::array<float, 8>& coefs, bool slew) override;
   void setPitchRatio(double ratio, bool slew) override;
   void start() override;
   void stop() override;

include/amuse/Emitter.hpp

@@ -1,5 +1,6 @@
 #pragma once
 
+#include <array>
 #include <cfloat>
 #include <cmath>
 
@@ -10,9 +11,9 @@
 namespace amuse {
 class Listener;
 
-using Vector3f = float[3];
+using Vector3f = std::array<float, 3>;
 
-inline float Dot(const Vector3f& a, const Vector3f& b) { return a[0] * b[0] + a[1] * b[1] + a[2] * b[2]; }
+constexpr float Dot(const Vector3f& a, const Vector3f& b) { return a[0] * b[0] + a[1] * b[1] + a[2] * b[2]; }
 
 inline float Length(const Vector3f& a) {
   if (std::fabs(a[0]) <= FLT_EPSILON && std::fabs(a[1]) <= FLT_EPSILON && std::fabs(a[2]) <= FLT_EPSILON)
@@ -20,14 +21,14 @@ inline float Length(const Vector3f& a) {
   return std::sqrt(Dot(a, a));
 }
 
-inline float Normalize(Vector3f& out) {
-  float dist = Length(out);
-  if (dist == 0.f)
-    return 0.f;
-  out[0] /= dist;
-  out[1] /= dist;
-  out[2] /= dist;
-  return dist;
+inline Vector3f Normalize(const Vector3f& in) {
+  const float dist = Length(in);
+
+  if (dist == 0.f) {
+    return {};
+  }
+
+  return {in[0] / dist, in[1] / dist, in[2] / dist};
 }
 
 /** Voice wrapper with positional-3D level control */

include/amuse/IBackendVoice.hpp

@@ -1,5 +1,7 @@
 #pragma once
 
+#include <array>
+
 namespace amuse {
 class IBackendSubmix;
 
@@ -34,7 +36,7 @@ public:
   virtual void resetChannelLevels() = 0;
 
   /** Set channel-gains for audio source (AudioChannel enum for array index) */
-  virtual void setChannelLevels(IBackendSubmix* submix, const float coefs[8], bool slew) = 0;
+  virtual void setChannelLevels(IBackendSubmix* submix, const std::array<float, 8>& coefs, bool slew) = 0;
 
   /** Called by client to dynamically adjust the pitch of voices with dynamic pitch enabled */
   virtual void setPitchRatio(double ratio, bool slew) = 0;

include/amuse/Voice.hpp

@@ -1,5 +1,6 @@
 #pragma once
 
+#include <array>
 #include <cstdint>
 #include <cstdlib>
 #include <list>
@@ -146,7 +147,7 @@ class Voice : public Entity {
   float m_tremoloScale = 0.f;    /**< minimum volume factor produced via LFO */
   float m_tremoloModScale = 0.f; /**< minimum volume factor produced via LFO, scaled via mod wheel */
 
-  float m_lfoPeriods[2] = {};               /**< time-periods for LFO1 and LFO2 */
+  std::array<float, 2> m_lfoPeriods{};      /**< time-periods for LFO1 and LFO2 */
   std::unique_ptr<int8_t[]> m_ctrlValsSelf; /**< Self-owned MIDI Controller values */
   int8_t* m_extCtrlVals = nullptr;          /**< MIDI Controller values (external storage) */
 
@@ -186,10 +187,10 @@ class Voice : public Entity {
   ObjToken<Voice> _startChildMacro(ObjectId macroId, int macroStep, double ticksPerSec, uint8_t midiKey,
                                    uint8_t midiVel, uint8_t midiMod, bool pushPc = false);
 
-  void _panLaw(float coefsOut[8], float frontPan, float backPan, float totalSpan) const;
+  std::array<float, 8> _panLaw(float frontPan, float backPan, float totalSpan) const;
   void _setPan(float pan);
   void _setSurroundPan(float span);
-  void _setChannelCoefs(const float coefs[8]);
+  void _setChannelCoefs(const std::array<float, 8>& coefs);
   void _setPitchWheel(float pitchWheel);
   void _notifyCtrlChange(uint8_t ctrl, int8_t val);
 
@@ -261,7 +262,7 @@ public:
   void setSurroundPan(float span);
 
   /** Set current voice channel coefficients immediately */
-  void setChannelCoefs(const float coefs[8]);
+  void setChannelCoefs(const std::array<float, 8>& coefs);
 
   /** Start volume envelope to specified level */
   void startEnvelope(double dur, float vol, const Curve* envCurve);

lib/BooBackend.cpp

@@ -36,9 +36,9 @@ void BooBackendVoice::resetSampleRate(double sampleRate) { m_booVoice->resetSamp
 
 void BooBackendVoice::resetChannelLevels() { m_booVoice->resetChannelLevels(); }
 
-void BooBackendVoice::setChannelLevels(IBackendSubmix* submix, const float coefs[8], bool slew) {
-  BooBackendSubmix& smx = *reinterpret_cast<BooBackendSubmix*>(submix);
-  m_booVoice->setMonoChannelLevels(smx.m_booSubmix.get(), coefs, slew);
+void BooBackendVoice::setChannelLevels(IBackendSubmix* submix, const std::array<float, 8>& coefs, bool slew) {
+  auto& smx = *static_cast<BooBackendSubmix*>(submix);
+  m_booVoice->setMonoChannelLevels(smx.m_booSubmix.get(), coefs.data(), slew);
 }
 
 void BooBackendVoice::setPitchRatio(double ratio, bool slew) { m_booVoice->setPitchRatio(ratio, slew); }

lib/Emitter.cpp

@@ -5,14 +5,11 @@
 #include "amuse/Voice.hpp"
 
 namespace amuse {
-
-static void Delta(Vector3f& out, const Vector3f& a, const Vector3f& b) {
-  out[0] = a[0] - b[0];
-  out[1] = a[1] - b[1];
-  out[2] = a[2] - b[2];
+static constexpr Vector3f Delta(const Vector3f& a, const Vector3f& b) {
+  return {a[0] - b[0], a[1] - b[1], a[2] - b[2]};
 }
 
-Emitter::~Emitter() {}
+Emitter::~Emitter() = default;
 
 Emitter::Emitter(Engine& engine, const AudioGroup& group, ObjToken<Voice> vox, float maxDist, float minVol,
                  float falloff, bool doppler)
@@ -54,12 +51,11 @@ void Emitter::_update() {
       return;
   }
 
-  float coefs[8] = {};
+  std::array<float, 8> coefs{};
   double avgDopplerRatio = 0.0;
 
   for (auto& listener : m_engine.m_activeListeners) {
-    Vector3f listenerToEmitter;
-    Delta(listenerToEmitter, m_pos, listener->m_pos);
+    const Vector3f listenerToEmitter = Delta(m_pos, listener->m_pos);
     const float dist = Length(listenerToEmitter);
     const float panDist = Dot(listenerToEmitter, listener->m_right);
     const float frontPan = std::clamp(panDist / listener->m_frontDiff, -1.f, 1.f);
@@ -74,27 +70,25 @@ void Emitter::_update() {
     att = m_attCache.getVolume(att, false);
     if (att > FLT_EPSILON) {
       /* Apply pan law */
-      float thisCoefs[8] = {};
-      m_vox->_panLaw(thisCoefs, frontPan, backPan, span);
+      const std::array<float, 8> thisCoefs = m_vox->_panLaw(frontPan, backPan, span);
 
       /* Take maximum coefficient across listeners */
-      for (int i = 0; i < 8; ++i)
+      for (size_t i = 0; i < coefs.size(); ++i) {
         coefs[i] = std::max(coefs[i], thisCoefs[i] * att * listener->m_volume);
+      }
     }
 
     /* Calculate doppler */
     if (m_doppler) {
       /* Positive values indicate emitter and listener closing in */
-      Vector3f dirDelta;
-      Delta(dirDelta, m_dir, listener->m_dir);
-      Vector3f posDelta;
-      Delta(posDelta, listener->m_pos, m_pos);
-      Normalize(posDelta);
-      float deltaSpeed = Dot(dirDelta, posDelta);
-      if (listener->m_soundSpeed != 0.f)
+      const Vector3f dirDelta = Delta(m_dir, listener->m_dir);
+      const Vector3f posDelta = Normalize(Delta(listener->m_pos, m_pos));
+      const float deltaSpeed = Dot(dirDelta, posDelta);
+      if (listener->m_soundSpeed != 0.f) {
         avgDopplerRatio += 1.0 + deltaSpeed / listener->m_soundSpeed;
-      else
+      } else {
         avgDopplerRatio += 1.0;
+      }
     }
   }
 
@@ -110,7 +104,7 @@ void Emitter::_update() {
 }
 
 void Emitter::setVectors(const float* pos, const float* dir) {
-  for (int i = 0; i < 3; ++i) {
+  for (size_t i = 0; i < m_pos.size(); ++i) {
     m_pos[i] = pos[i];
     m_dir[i] = dir[i];
   }

lib/Engine.cpp

@@ -1,5 +1,7 @@
 #include "amuse/Engine.hpp"
 
+#include <array>
+
 #include "amuse/AudioGroup.hpp"
 #include "amuse/AudioGroupData.hpp"
 #include "amuse/Common.hpp"
@@ -11,7 +13,7 @@
 
 namespace amuse {
 
-static const float FullLevels[8] = {1.f, 1.f, 1.f, 1.f, 1.f, 1.f, 1.f, 1.f};
+constexpr std::array<float, 8> FullLevels{1.f, 1.f, 1.f, 1.f, 1.f, 1.f, 1.f, 1.f};
 
 Engine::~Engine() {
   m_backend.setCallbackInterface(nullptr);

lib/Listener.cpp

@@ -2,10 +2,12 @@
 
 namespace amuse {
 
-static void Cross(Vector3f& out, const Vector3f& a, const Vector3f& b) {
-  out[0] = a[1] * b[2] - a[2] * b[1];
-  out[1] = a[2] * b[0] - a[0] * b[2];
-  out[2] = a[0] * b[1] - a[1] * b[0];
+static constexpr Vector3f Cross(const Vector3f& a, const Vector3f& b) {
+  return {
+      a[1] * b[2] - a[2] * b[1],
+      a[2] * b[0] - a[0] * b[2],
+      a[0] * b[1] - a[1] * b[0],
+  };
 }
 
 void Listener::setVectors(const float* pos, const float* dir, const float* heading, const float* up) {
@@ -16,11 +18,9 @@ void Listener::setVectors(const float* pos, const float* dir, const float* headi
     m_up[i] = up[i];
   }
 
-  Normalize(m_heading);
-  Normalize(m_up);
-  Cross(m_right, m_heading, m_up);
-  Normalize(m_right);
-
+  m_heading = Normalize(m_heading);
+  m_up = Normalize(m_up);
+  m_right = Normalize(Cross(m_heading, m_up));
   m_dirty = true;
 }
 

lib/Voice.cpp

@@ -155,10 +155,11 @@ ObjToken<Voice> Voice::_findVoice(int vid, ObjToken<Voice> thisPtr) {
 }
 
 std::unique_ptr<int8_t[]>& Voice::_ensureCtrlVals() {
-  if (m_ctrlValsSelf)
+  if (m_ctrlValsSelf) {
     return m_ctrlValsSelf;
-  m_ctrlValsSelf.reset(new int8_t[128]);
-  memset(m_ctrlValsSelf.get(), 0, 128);
+  }
+
+  m_ctrlValsSelf = std::make_unique<int8_t[]>(128);
   return m_ctrlValsSelf;
 }
 
@@ -902,7 +903,9 @@ void Voice::setVolume(float vol) {
     vox->setVolume(vol);
 }
 
-void Voice::_panLaw(float coefs[8], float frontPan, float backPan, float totalSpan) const {
+std::array<float, 8> Voice::_panLaw(float frontPan, float backPan, float totalSpan) const {
+  std::array<float, 8> coefs{};
+
   /* -3dB panning law for various channel configs */
   switch (m_engine.m_channelSet) {
   case AudioChannelSet::Stereo:
@@ -1010,6 +1013,8 @@ void Voice::_panLaw(float coefs[8], float frontPan, float backPan, float totalSp
 
     break;
   }
+
+  return coefs;
 }
 
 void Voice::_setPan(float pan) {
@@ -1020,8 +1025,7 @@ void Voice::_setPan(float pan) {
   m_curPan = std::clamp(pan, -1.f, 1.f);
   const float totalPan = std::clamp(m_curPan, -1.f, 1.f);
   const float totalSpan = std::clamp(m_curSpan, -1.f, 1.f);
-  float coefs[8] = {};
-  _panLaw(coefs, totalPan, totalPan, totalSpan);
+  const auto coefs = _panLaw(totalPan, totalPan, totalSpan);
   _setChannelCoefs(coefs);
 }
 
@@ -1048,13 +1052,13 @@ void Voice::setSurroundPan(float span) {
     vox->setSurroundPan(span);
 }
 
-void Voice::_setChannelCoefs(const float coefs[8]) {
+void Voice::_setChannelCoefs(const std::array<float, 8>& coefs) {
   m_backendVoice->setChannelLevels(m_studio->getMaster().m_backendSubmix.get(), coefs, true);
   m_backendVoice->setChannelLevels(m_studio->getAuxA().m_backendSubmix.get(), coefs, true);
   m_backendVoice->setChannelLevels(m_studio->getAuxB().m_backendSubmix.get(), coefs, true);
 }
 
-void Voice::setChannelCoefs(const float coefs[8]) {
+void Voice::setChannelCoefs(const std::array<float, 8>& coefs) {
   if (m_destroyed)
     return;