private void Visualizer_Draw(AudioVisualizer.IVisualizer sender, AudioVisualizer.VisualizerDrawEventArgs args)
{
var drawingSession = (CanvasDrawingSession)args.DrawingSession;
var spectrum = args.Data != null?args.Data.Spectrum.TransformLinearFrequency(20) : _emptySpectrum;
_previousSpectrum = spectrum.ApplyRiseAndFall(_previousSpectrum, _rmsRiseTime, _rmsFallTime, _frameDuration);
_previousPeakSpectrum = spectrum.ApplyRiseAndFall(_previousPeakSpectrum, _peakRiseTime, _peakFallTime, _frameDuration);
// This is temp hack. once visualizer passes in dimensions won't be necessary
float w = 0f, h = 0f;
lock (_sizeLock)
{
w = _visualizerWidth;
h = _visualizerHeight;
}
// There are bugs in ConverToLogAmplitude. It is returning 0 if max is not 0 and min negative.
// The heightScale is a workaround for this
var s = _previousSpectrum.ConvertToLogAmplitude(-50, 0);
var p = _previousPeakSpectrum.ConvertToLogAmplitude(-50, 0);
DrawSpectrumSpline(p[0], drawingSession, Vector2.Zero, w, h, -0.02f, Color.FromArgb(0xff, 0x38, 0x38, 0x38));
DrawSpectrumSpline(p[1], drawingSession, Vector2.Zero, w, h, -0.02f, Color.FromArgb(0xff, 0x38, 0x38, 0x38), true);
DrawSpectrumSpline(s[0], drawingSession, Vector2.Zero, w, h, -0.02f, Color.FromArgb(0xff, 0x30, 0x30, 0x30));
DrawSpectrumSpline(s[1], drawingSession, Vector2.Zero, w, h, -0.02f, Color.FromArgb(0xff, 0x30, 0x30, 0x30), true);
}
private void Visualizer_Draw(AudioVisualizer.IVisualizer sender, AudioVisualizer.VisualizerDrawEventArgs args)
{
var drawingSession = (CanvasDrawingSession)args.DrawingSession;
var spectrum = args.Data != null?args.Data.Spectrum.LogarithmicTransform(20, 27, 5500) : _emptySpectrum;
_previousSpectrum = spectrum.ApplyRiseAndFall(_previousSpectrum, _rmsRiseTime, _rmsFallTime, _frameDuration);
_previousPeakSpectrum = spectrum.ApplyRiseAndFall(_previousPeakSpectrum, _peakRiseTime, _peakFallTime, _frameDuration);
float w = (float)args.ViewExtent.Width;
float h = (float)args.ViewExtent.Height;
// There are bugs in ConverToLogAmplitude. It is returning 0 if max is not 0 and min negative.
// The heightScale is a workaround for this
var s = _previousSpectrum.ConvertToDecibels(-50, 0);
var p = _previousPeakSpectrum.ConvertToDecibels(-50, 0);
DrawSpectrumSpline(p[0], drawingSession, Vector2.Zero, w, h, -0.02f, Color.FromArgb(0xff, 0x38, 0x38, 0x38));
DrawSpectrumSpline(p[1], drawingSession, Vector2.Zero, w, h, -0.02f, Color.FromArgb(0xff, 0x38, 0x38, 0x38), true);
DrawSpectrumSpline(s[0], drawingSession, Vector2.Zero, w, h, -0.02f, Color.FromArgb(0xff, 0x30, 0x30, 0x30));
DrawSpectrumSpline(s[1], drawingSession, Vector2.Zero, w, h, -0.02f, Color.FromArgb(0xff, 0x30, 0x30, 0x30), true);
}
private void spectrum_Draw(object sender, AudioVisualizer.VisualizerDrawEventArgs args)
{
var drawingSession = (CanvasDrawingSession)args.DrawingSession;
Thickness margin = new Thickness(40, 10, 20, 10);
// Calculate spectum metrics
Vector2 barSize = new Vector2((float)(args.ViewExtent.Width - margin.Left - margin.Right) / spectrumBarCount,
(float)(args.ViewExtent.Height / 2 - margin.Top * 2 - margin.Bottom * 2)); // Top and bottom margins apply twice (as there are two spectrum displays)
Color gridlineColor = Colors.Black;
Color textColor = Colors.Blue;
// Draw bounding rectangles for spectrum
Rect boundingRectTop = new Rect(margin.Left, margin.Top, args.ViewExtent.Width - margin.Right - margin.Left, barSize.Y);
Rect boundingRectBottom = new Rect(margin.Left, margin.Top * 2 + margin.Bottom + barSize.Y, args.ViewExtent.Width - margin.Right - margin.Left, barSize.Y);
// Get the data if data exists and source is in play state, else use empty
var spectrumData = args.Data != null &&
spectrum.Source?.PlaybackState == SourcePlaybackState.Playing ?
args.Data.Spectrum.LogarithmicTransform(spectrumBarCount, 20f, 20000f) :
_emptySpectrum;
_previousSpectrum = spectrumData.ApplyRiseAndFall(_previousSpectrum, _rmsRiseTime, _rmsFallTime, _frameDuration);
_previousPeakSpectrum = spectrumData.ApplyRiseAndFall(_previousPeakSpectrum, _peakRiseTime, _peakFallTime, _frameDuration);
var logSpectrum = _previousSpectrum.ConvertToDecibels(-50, 0);
var logPeakSpectrum = _previousPeakSpectrum.ConvertToDecibels(-50, 0);
// Draw spectrum bars
for (int index = 0; index < spectrumBarCount; index++)
{
float barX = (float)margin.Left + index * barSize.X;
float spectrumBarHeight1 = barSize.Y * (1.0f - logSpectrum[0][index] / -50.0f);
float spectrumBarHeight2 = barSize.Y * (1.0f - logSpectrum[1][index] / -50.0f);
drawingSession.FillRectangle(barX, (float)boundingRectTop.Bottom - spectrumBarHeight1, barSize.X, spectrumBarHeight1, Colors.DarkCyan);
drawingSession.FillRectangle(barX, (float)boundingRectBottom.Bottom - spectrumBarHeight2, barSize.X, spectrumBarHeight2, Colors.DarkCyan);
}
// Spectrum points to draw a slow decay line
Vector2 prevPointLeft = new Vector2(), prevPointRight = new Vector2();
for (int index = 0; index < spectrumBarCount; index++)
{
float X = (float)margin.Left + index * barSize.X + barSize.X / 2;
Vector2 leftPoint = new Vector2(X, (float)boundingRectTop.Bottom - barSize.Y * (1.0f - logPeakSpectrum[0][index] / -50.0f));
Vector2 rightPoint = new Vector2(X, (float)boundingRectBottom.Bottom - barSize.Y * (1.0f - logPeakSpectrum[1][index] / -50.0f));
if (index != 0)
{
drawingSession.DrawLine(prevPointLeft, leftPoint, Colors.Red, 3);
drawingSession.DrawLine(prevPointRight, rightPoint, Colors.Red, 3);
}
prevPointLeft = leftPoint;
prevPointRight = rightPoint;
}
// Draw grid for 1k step from 0 - 20kHz
float fStepWidth = (float)boundingRectTop.Width / 20;
float freq = 20.0f;
float fStep = (float)Math.Pow(1000.0, 1.0 / 20.0);
for (int f = 0; f < 20; f++, freq *= fStep)
{
float X = f * fStepWidth + (float)margin.Left;
if (f != 0)
{
drawingSession.DrawLine(X, (float)boundingRectTop.Top, X, (float)boundingRectTop.Bottom, gridlineColor);
drawingSession.DrawLine(X, (float)boundingRectBottom.Top, X, (float)boundingRectBottom.Bottom, gridlineColor);
}
string freqText = freq < 100.0f ? $"{freq:F0}" :
freq < 1000.0f ? $"{10 * Math.Round(freq / 10):F0}" :
freq < 10000.0f ? $"{freq / 1e3:F1}k" : $"{freq / 1e3:F0}k";
drawingSession.DrawText(freqText, X + fStepWidth / 2, (float)boundingRectTop.Bottom + 10, textColor, _spectrumTextFormat);
drawingSession.DrawText(freqText, X + fStepWidth / 2, (float)boundingRectBottom.Bottom + 10, textColor, _spectrumTextFormat);
}
drawingSession.DrawRectangle(boundingRectTop, gridlineColor);
drawingSession.DrawRectangle(boundingRectBottom, gridlineColor);
// Draw db based volume grid for spectrum -40 to 0db, every 10db
for (int i = -50; i <= 0; i += 10)
{
float topY = (float)boundingRectTop.Top - (float)i * (float)boundingRectTop.Height / 50.0f;
float bottomY = (float)boundingRectBottom.Bottom + (float)i * (float)boundingRectBottom.Height / 50.0f;
drawingSession.DrawLine((float)boundingRectTop.Left, topY, (float)boundingRectTop.Right, topY, gridlineColor);
drawingSession.DrawLine((float)boundingRectTop.Left, bottomY, (float)boundingRectTop.Right, bottomY, gridlineColor);
drawingSession.DrawText($"{i}dB", (float)boundingRectTop.Left - (float)margin.Left / 2, topY, textColor, _spectrumTextFormat);
drawingSession.DrawText($"{i}dB", (float)boundingRectTop.Left - (float)margin.Left / 2, bottomY, textColor, _spectrumTextFormat);
}
}