public async Task LoadFileAsync(string fileName)
{
try { audioFile = new BufferedAudioFile(fileName); }
catch (Exception e)
{
System.Windows.MessageBox.Show("Could not load music file: " + Path.GetFileName(fileName) + Environment.NewLine + Environment.NewLine + e.Message, "Problem opening file",
System.Windows.MessageBoxButton.OK, System.Windows.MessageBoxImage.Warning);
return;
}
MusicFileName = fileName;
// TODO progress inidicator for file loading
audioFile.LoadIntoMemoryAsync(null).Forget();
audioPlayback.Init(audioFile.CreateStream(infinite: true));
// Initialize our user-facing value from the playback device (which apparently gets its value from Windows).
MusicVolume = LoudnessHelper.VolumeFromLoudness(audioPlayback.Volume);
CurrentWaveform = null;
await RenderWaveformAsync(false);
Notify(nameof(MusicDuration));
}
public PlaybackViewModel(SequencerViewModel sequencer)
{
this.sequencer = sequencer;
this.timelineModel = sequencer.GetModel();
cursorUpdateTimer = new System.Windows.Threading.DispatcherTimer()
{
Interval = CURSOR_UPDATE_INTERVAL
};
cursorUpdateTimer.Tick += (_, __) => UpdateCursorPosition();
ForwardPropertyEvents(nameof(MusicVolume), this, () => audioPlayback.Volume = LoudnessHelper.LoudnessFromVolume(MusicVolume));
ForwardPropertyEvents(nameof(sequencer.CurrentViewLeftPositionTime), sequencer, InvalidateWaveform);
// Note: Because CurrentViewLeftPositionTime depends on TimePixelScale and is always changed together with the right position,
// it is enough to only depend on this one to reduce callback duplication.
//ForwardPropertyEvents(nameof(sequencer.TimePixelScale), sequencer, InvalidateWaveform);
//ForwardPropertyEvents(nameof(sequencer.CurrentViewRightPositionTime), sequencer, InvalidateWaveform);
ForwardPropertyEvents(nameof(sequencer.CursorPosition), sequencer, OnCursorPositionChanged);
audioPlayback.PlaybackStopped += OnPlaybackStopped;
audioPlayback.Init(EmptySampleProvider.Singleton);
}
private void RenderPolygon(DrawingContext drawingContext)
{
var fillBrush = Brushes.LawnGreen;
var borderPen = new Pen(Brushes.DarkGreen, 1.0);
if (WaveformDisplayMode == WaveformDisplayMode.Linear)
{
sampleTransformerFunc = (x => x);
}
else if (WaveformDisplayMode == WaveformDisplayMode.Logarithmic)
{
sampleTransformerFunc = (x => Math.Sign(x) * LoudnessHelper.VolumeFromLoudness(Math.Abs(x)));
}
else
{
throw new InvalidOperationException("display mode not supported: " + WaveformDisplayMode);
}
var maximums = Waveform.Maximums;
var minimums = Waveform.Minimums;
if (maximums.Length == 0)
{
return;
}
// px/sample = px/sec * sec/sample
double xScale = TimeScale * Waveform.TimePerSample;
double offsetPx = Waveform.TimeOffset * TimeScale;
double rightmostPx = offsetPx + maximums.Length * xScale;
StreamGeometry geometry = new StreamGeometry();
using (var ctx = geometry.Open())
{
ctx.BeginFigure(new Point(offsetPx, SampleToYPosition(maximums[0])), isFilled: true, isClosed: true);
for (int i = 1; i < maximums.Length; i++)
{
ctx.LineTo(new Point(offsetPx + i * xScale, SampleToYPosition(maximums[i])), true, false);
}
ctx.LineTo(new Point(rightmostPx, SampleToYPosition(maximums[maximums.Length - 1])), true, false);
ctx.LineTo(new Point(rightmostPx, SampleToYPosition(minimums[minimums.Length - 1])), true, false);
for (int i = minimums.Length - 1; i >= 0; i--)
{
ctx.LineTo(new Point(offsetPx + i * xScale, SampleToYPosition(minimums[i])), true, false);
}
}
geometry.Freeze();
drawingContext.DrawGeometry(fillBrush, borderPen, geometry);
// Alternative rendering method that draws rectangles/lines directly onto the drawingContext.
//for (int i=0; i<maximums.Length; i++)
//{
// double y = SampleToYPosition(maximums[i]);
// double h = SampleToYPosition(minimums[i]) - y;
// if (h > halfHeight * 0.1 || i == 0)
// {
// drawingContext.DrawRectangle(fillBrush, null, new Rect(
// offsetPx + i * xScale, y,
// xScale, h));
// } else
// {
// double prevMid = (SampleToYPosition(maximums[i - 1]) + SampleToYPosition(minimums[i - 1])) / 2;
// drawingContext.DrawLine(new Pen(fillBrush, 3),
// new Point(offsetPx + (i-1) * xScale, prevMid),
// new Point(offsetPx + i * xScale, y + h/2));
// }
//}
}
