basics: Change sampleFrame to use std::array (#5536)

... in order to make standard containers be able to store it. Required for
#5532 (#4899) and the recording PR.

This includes:

* removing the `LocklessRingBuffer<sampleFrame>` specialization
* passing samplerame in `StereoDelay::tick` as a reference

Additional cleanups:

* removing already unused typedef `sampleFrameA`
* add some `const_cast` to make code more readable

include/LocklessRingBuffer.h

@@ -28,27 +28,32 @@
 #include <QMutex>
 #include <QWaitCondition>
 
-#include "lmms_basics.h"
-#include "lmms_export.h"
 #include "../src/3rdparty/ringbuffer/include/ringbuffer/ringbuffer.h"
 
 
-//! A convenience layer for a realtime-safe and thread-safe multi-reader ring buffer library.
+//! A convenience layer for a realtime-safe and thread-safe multi-reader ringbuffer
 template <class T>
-class LocklessRingBufferBase
+class LocklessRingBuffer
 {
 	template<class _T>
 	friend class LocklessRingBufferReader;
 public:
-	LocklessRingBufferBase(std::size_t sz) : m_buffer(sz)
+	LocklessRingBuffer(std::size_t sz) : m_buffer(sz)
 	{
 		m_buffer.touch();	// reserve storage space before realtime operation starts
 	}
-	~LocklessRingBufferBase() {};
+	~LocklessRingBuffer() {};
 
 	std::size_t capacity() const {return m_buffer.maximum_eventual_write_space();}
 	std::size_t free() const {return m_buffer.write_space();}
 	void wakeAll() {m_notifier.wakeAll();}
+	std::size_t write(const sampleFrame *src, std::size_t cnt, bool notify = false)
+	{
+		std::size_t written = LocklessRingBuffer<T>::m_buffer.write(src, cnt);
+		// Let all waiting readers know new data are available.
+		if (notify) {LocklessRingBuffer<T>::m_notifier.wakeAll();}
+		return written;
+	}
 
 protected:
 	ringbuffer_t<T> m_buffer;
@@ -56,59 +61,6 @@ protected:
 };
 
 
-// The SampleFrameCopier is required because sampleFrame is just a two-element
-// array and therefore does not have a copy constructor needed by std::copy.
-class SampleFrameCopier
-{
-	const sampleFrame* m_src;
-public:
-	SampleFrameCopier(const sampleFrame* src) : m_src(src) {}
-	void operator()(std::size_t src_offset, std::size_t count, sampleFrame* dest)
-	{
-		for (std::size_t i = src_offset; i < src_offset + count; i++, dest++)
-		{
-			(*dest)[0] = m_src[i][0];
-			(*dest)[1] = m_src[i][1];
-		}
-	}
-};
-
-
-//! Standard ring buffer template for data types with copy constructor.
-template <class T>
-class LocklessRingBuffer : public LocklessRingBufferBase<T>
-{
-public:
-	LocklessRingBuffer(std::size_t sz) : LocklessRingBufferBase<T>(sz) {};
-
-	std::size_t write(const sampleFrame *src, std::size_t cnt, bool notify = false)
-	{
-		std::size_t written = LocklessRingBufferBase<T>::m_buffer.write(src, cnt);
-		// Let all waiting readers know new data are available.
-		if (notify) {LocklessRingBufferBase<T>::m_notifier.wakeAll();}
-		return written;
-	}
-};
-
-
-//! Specialized ring buffer template with write function modified to support sampleFrame.
-template <>
-class LocklessRingBuffer<sampleFrame> : public LocklessRingBufferBase<sampleFrame>
-{
-public:
-	LocklessRingBuffer(std::size_t sz) : LocklessRingBufferBase<sampleFrame>(sz) {};
-
-	std::size_t write(const sampleFrame *src, std::size_t cnt, bool notify = false)
-	{
-		SampleFrameCopier copier(src);
-		std::size_t written = LocklessRingBufferBase<sampleFrame>::m_buffer.write_func<SampleFrameCopier>(copier, cnt);
-		// Let all waiting readers know new data are available.
-		if (notify) {LocklessRingBufferBase<sampleFrame>::m_notifier.wakeAll();}
-		return written;
-	}
-};
-
-
 //! Wrapper for lockless ringbuffer reader
 template <class T>
 class LocklessRingBufferReader : public ringbuffer_reader_t<T>

include/lmms_basics.h

@@ -32,6 +32,7 @@
 
 #ifdef LMMS_HAVE_STDINT_H
 #include <cstdint>
+#include <array>
 #endif
 
 
@@ -127,12 +128,9 @@ const ch_cnt_t SURROUND_CHANNELS =
 
 
 
-typedef sample_t sampleFrame[DEFAULT_CHANNELS];
-typedef sample_t surroundSampleFrame[SURROUND_CHANNELS];
+using         sampleFrame = std::array<sample_t,  DEFAULT_CHANNELS>;
+using surroundSampleFrame = std::array<sample_t, SURROUND_CHANNELS>;
 #define ALIGN_SIZE 16
-#if __GNUC__
-typedef sample_t sampleFrameA[DEFAULT_CHANNELS] __attribute__((__aligned__(ALIGN_SIZE)));
-#endif
 
 
 #define STRINGIFY(s) STR(s)

plugins/Delay/StereoDelay.cpp

@@ -55,7 +55,7 @@ StereoDelay::~StereoDelay()
 
 
 
-void StereoDelay::tick( sampleFrame frame )
+void StereoDelay::tick( sampleFrame& frame )
 {
 	m_writeIndex = ( m_writeIndex + 1 ) % ( int )m_maxLength;
 	int readIndex = m_writeIndex - m_length;

plugins/Delay/StereoDelay.h

@@ -45,7 +45,7 @@ public:
 		m_feedback = feedback;
 	}
 
-	void tick( sampleFrame frame );
+	void tick( sampleFrame& frame );
 	void setSampleRate( int sampleRate );
 
 private:

src/core/Effect.cpp

@@ -203,8 +203,8 @@ void Effect::resample( int _i, const sampleFrame * _src_buf,
 	}
 	m_srcData[_i].input_frames = _frames;
 	m_srcData[_i].output_frames = Engine::mixer()->framesPerPeriod();
-	m_srcData[_i].data_in = (float *) _src_buf[0];
-	m_srcData[_i].data_out = _dst_buf[0];
+	m_srcData[_i].data_in = const_cast<float*>(_src_buf[0].data());
+	m_srcData[_i].data_out = _dst_buf[0].data ();
 	m_srcData[_i].src_ratio = (double) _dst_sr / _src_sr;
 	m_srcData[_i].end_of_input = 0;
 	int error;

src/core/SampleBuffer.cpp

@@ -693,8 +693,8 @@ bool SampleBuffer::play( sampleFrame * _ab, handleState * _state,
 		// Generate output
 		src_data.data_in =
 			getSampleFragment( play_frame, fragment_size, _loopmode, &tmp, &is_backwards,
-			loopStartFrame, loopEndFrame, endFrame )[0];
-		src_data.data_out = _ab[0];
+			loopStartFrame, loopEndFrame, endFrame )->data ();
+		src_data.data_out = _ab->data ();
 		src_data.input_frames = fragment_size;
 		src_data.output_frames = _frames;
 		src_data.src_ratio = 1.0 / freq_factor;
@@ -1196,8 +1196,8 @@ SampleBuffer * SampleBuffer::resample( const sample_rate_t _src_sr,
 	{
 		SRC_DATA src_data;
 		src_data.end_of_input = 1;
-		src_data.data_in = data[0];
-		src_data.data_out = dst_buf[0];
+		src_data.data_in = data->data ();
+		src_data.data_out = dst_buf->data ();
 		src_data.input_frames = frames;
 		src_data.output_frames = dst_frames;
 		src_data.src_ratio = (double) _dst_sr / _src_sr;

src/core/audio/AudioDevice.cpp

@@ -194,8 +194,8 @@ fpp_t AudioDevice::resample( const surroundSampleFrame * _src,
 	}
 	m_srcData.input_frames = _frames;
 	m_srcData.output_frames = _frames;
-	m_srcData.data_in = (float *) _src[0];
-	m_srcData.data_out = _dst[0];
+	m_srcData.data_in = const_cast<float*>(_src[0].data());
+	m_srcData.data_out = _dst[0].data ();
 	m_srcData.src_ratio = (double) _dst_sr / _src_sr;
 	m_srcData.end_of_input = 0;
 	int error;