Refactor the Audio buffer and span

src/sfizz/AudioBuffer.h

@@ -42,7 +42,7 @@ namespace sfz
  * @tparam MaxChannels the maximum number of channels in the buffer
  * @tparam Alignment the alignment for the buffers
  */
-template <class Type, unsigned int MaxChannels = sfz::config::numChannels, unsigned int Alignment = SIMDConfig::defaultAlignment>
+template <class Type, int MaxChannels = sfz::config::numChannels, unsigned int Alignment = SIMDConfig::defaultAlignment>
 class AudioBuffer {
 public:
     using value_type = std::remove_cv_t<Type>;
@@ -85,8 +85,13 @@ public:
     bool resize(size_type newSize)
     {
         bool returnedOK = true;
+
         for (auto i = 0; i < numChannels; ++i)
             returnedOK &= buffers[i]->resize(newSize);
+
+        if (returnedOK)
+            numFrames = newSize;
+
         return returnedOK;
     }
 
@@ -247,9 +252,34 @@ public:
         return getSample(channelIndex, frameIndex);
     }
 
+    /**
+     * @brief Remove all channels from the buffer and reset it to empty
+     *
+     */
+    void reset()
+    {
+        for (int i = 0; i < numChannels; ++i)
+            buffers[i].reset();
+        numFrames = 0;
+        numChannels = 0;
+    }
+
+    /**
+     * @brief Add a positive number of channels to the buffer
+     *
+     * @param numChannels
+     */
+    void addChannels(int numChannels)
+    {
+        ASSERT(this->numChannels + numChannels <= MaxChannels);
+        for (int i = 0; i < numChannels; ++i)
+            addChannel();
+    }
+
 private:
     using buffer_type = Buffer<Type, Alignment>;
     using buffer_ptr = std::unique_ptr<buffer_type>;
+    static_assert(MaxChannels > 0, "Need a positive number of channels");
     std::array<buffer_ptr, MaxChannels> buffers;
     int numChannels { 0 };
     size_type numFrames { 0 };

src/sfizz/AudioSpan.h

@@ -86,7 +86,7 @@ namespace sfz
  * @tparam Type the underlying buffer type
  * @tparam MaxChannels the maximum number of channels. Defaults to sfz::config::numChannels
  */
-template <class Type, unsigned int MaxChannels = sfz::config::numChannels>
+template <class Type, int MaxChannels = sfz::config::numChannels>
 class AudioSpan {
 public:
     using size_type = size_t;
@@ -106,7 +106,7 @@ public:
         : numFrames(numFrames)
         , numChannels(numChannels)
     {
-        ASSERT(static_cast<unsigned int>(numChannels) <= MaxChannels);
+        ASSERT(numChannels <= MaxChannels);
         for (auto i = 0; i < numChannels; ++i)
             this->spans[i] = spans[i] + offset;
     }
@@ -164,7 +164,7 @@ public:
      * @tparam Alignment the alignment block size for the platform
      * @param audioBuffer the source AudioBuffer.
      */
-    template <class U, unsigned int N, unsigned int Alignment, typename = std::enable_if<N <= MaxChannels>, typename = std::enable_if_t<std::is_const<U>::value, int>>
+    template <class U, int N, unsigned int Alignment, typename = std::enable_if<N <= MaxChannels>, typename = std::enable_if_t<std::is_const<U>::value, int>>
     AudioSpan(AudioBuffer<U, N, Alignment>& audioBuffer)
         : numFrames(audioBuffer.getNumFrames())
         , numChannels(audioBuffer.getNumChannels())
@@ -185,7 +185,7 @@ public:
      * @tparam Alignment the alignment block size for the platform
      * @param audioBuffer the source AudioBuffer.
      */
-    template <class U, unsigned int N, unsigned int Alignment, typename = std::enable_if<N <= MaxChannels>>
+    template <class U, int N, unsigned int Alignment, typename = std::enable_if<N <= MaxChannels>>
     AudioSpan(AudioBuffer<U, N, Alignment>& audioBuffer)
         : numFrames(audioBuffer.getNumFrames())
         , numChannels(audioBuffer.getNumChannels())
@@ -200,7 +200,7 @@ public:
      *
      * @param other the other AudioSpan
      */
-    template <class U, unsigned int N, typename = std::enable_if<N <= MaxChannels>>
+    template <class U, int N, typename = std::enable_if<N <= MaxChannels>>
     AudioSpan(const AudioSpan<U, N>& other)
         : numFrames(other.getNumFrames())
         , numChannels(other.getNumChannels())
@@ -312,7 +312,7 @@ public:
      *
      * @param other the other AudioSpan
      */
-    template <class U, unsigned int N, typename = std::enable_if<N <= MaxChannels>>
+    template <class U, int N, typename = std::enable_if<N <= MaxChannels>>
     void add(AudioSpan<U, N>& other)
     {
         static_assert(!std::is_const<Type>::value, "Can't allow mutating operations on const AudioSpans");
@@ -329,7 +329,7 @@ public:
      *
      * @param other the other AudioSpan
      */
-    template <class U, unsigned int N, typename = std::enable_if<N <= MaxChannels>>
+    template <class U, int N, typename = std::enable_if<N <= MaxChannels>>
     void copy(AudioSpan<U, N>& other)
     {
         static_assert(!std::is_const<Type>::value, "Can't allow mutating operations on const AudioSpans");
@@ -410,6 +410,7 @@ public:
     }
 
 private:
+    static_assert(MaxChannels > 0, "Need a positive number of channels");
     std::array<Type*, MaxChannels> spans;
     size_type numFrames { 0 };
     int numChannels { 0 };