/// <summary>
/// Fetch data from input buffer to OpenGL buffer
/// </summary>
/// <param name="level">level in MinMax cascade. -1 being raw data, 0..N being MinMax data</param>
/// <param name="offset">Offset in source buffer in samples</param>
/// <param name="samples">Number of samples to copy from source buffer</param>
/// <returns></returns>
private int FillBuffer(int level, long offset, int samples)
{
if (level < -1 || level > _minMax.Length)
{
throw new IndexOutOfRangeException($"Level must be in range [-1..{_minMax.Length - 1}]");
}
if (level == -1)
{
// read from file
_reader.Seek(offset, System.IO.SeekOrigin.Begin);
var read = _reader.ReadSamples(_doubleTemp, 0, samples);
for (int i = 0; i < read; i++)
{
_floatTemp[i] = (float)_doubleTemp[i];
}
_ringBuffer.ResetPointer();
_ringBuffer.AddVertices(_floatTemp, 0, (int)read);
return((int)read);
}
else
{
var c = Math.Min(samples, _minMax[level].Samples.Length - offset);
if (c < 0)
{
c = 0;
}
_minMax[level].Samples.Peek(_minMaxTemp, (int)offset, 0, (int)c);
for (int i = 0; i < 2 * c; i += 2)
{
_floatTemp[i + 0] = _minMaxTemp[i >> 1].Max;
_floatTemp[i + 1] = _minMaxTemp[i >> 1].Min;
}
_ringBuffer.ResetPointer();
_ringBuffer.AddVertices(_floatTemp, 0, 2 * (int)c);
for (int i = 0; i < c; i++)
{
_floatTemp[i] = _minMaxTemp[i].Max;
}
_ringBufferMax.ResetPointer();
_ringBufferMax.AddVertices(_floatTemp, 0, (int)c);
for (int i = 0; i < c / 2; i++)
{
_floatTemp[i] = _minMaxTemp[i].Min;
}
_ringBufferMin.ResetPointer();
_ringBufferMin.AddVertices(_floatTemp, 0, (int)c);
return(2 * (int)c);
}
}
public override void LoadState(NodeState state)
{
state.Load();
_buffer.SetTime((TimeStamp)state["time"]);
_reader.Seek((long)state["position"], SeekOrigin.Begin);
}