Initial community commit

Src/nu/GaplessRingBuffer.cpp

@@ -0,0 +1,64 @@
+#include "GaplessRingBuffer.h"
+#include <bfc/platform/types.h>
+#include <bfc/error.h>
+#include <algorithm>
+
+GaplessRingBuffer::GaplessRingBuffer()
+{
+	pregapBytes = 0;
+	frameBytes = 0;
+	postgapBytes = 0;
+	currentPregapBytes = 0;
+}
+
+GaplessRingBuffer::~GaplessRingBuffer()
+{
+}
+
+int GaplessRingBuffer::Initialize(size_t samples, size_t bps, size_t channels, size_t pregap, size_t postgap)
+{
+	this->frameBytes = channels * bps / 8;
+	this->currentPregapBytes = this->pregapBytes = pregap * frameBytes;
+	this->postgapBytes = postgap * frameBytes;
+
+	ring_buffer.reserve(samples * frameBytes + pregapBytes);
+	return NErr_Success;
+}
+
+bool GaplessRingBuffer::Empty() const
+{
+	return (ring_buffer.size() <= pregapBytes);
+}
+
+size_t GaplessRingBuffer::Read(void *destination, size_t destination_bytes)
+{
+	// make sure we've filled enough of the buffer to satisfy the postgap
+	if (Empty()) {
+		return 0;
+	}
+
+	// don't read into postgap area
+	size_t remaining = ring_buffer.size() - postgapBytes;
+	destination_bytes = min(remaining, destination_bytes);
+
+	return ring_buffer.read(destination, destination_bytes);
+}
+
+size_t GaplessRingBuffer::Write(const void *input, size_t input_bytes)
+{
+	// cut pregap if necessary
+	if (currentPregapBytes) {
+		size_t cut = min(input_bytes, currentPregapBytes);
+		currentPregapBytes -= cut;
+		input_bytes -= cut;
+		input = (const uint8_t *)input + cut;
+	}
+
+	return ring_buffer.write(input, input_bytes);
+}
+
+void GaplessRingBuffer::Reset()
+{
+	currentPregapBytes = pregapBytes;
+	ring_buffer.clear();
+}