private Bitmap DrawSpectrum(int smapleOffset, int sampleLength, Rectangle clip)
{
if (_waveFile == null)
{
return null;
}
if (clip.Width == 0 || clip.Height == 0)
{
return null;
}
Bitmap spectrum = new Bitmap(clip.Width, clip.Height);
using (UnsafeBitmap unsafeMap = new UnsafeBitmap(spectrum))
{
Graphics graphics = Graphics.FromImage(unsafeMap.Bitmap);
graphics.FillRectangle(Brushes.WhiteSmoke, graphics.VisibleClipBounds);
int windowCount = (sampleLength - Fft.WindowSize) / Fft.WindowIncrement;
int windowOffset = smapleOffset / Fft.WindowIncrement;
int windowEndIndex = windowOffset + windowCount;
unsafeMap.LockBitmap();
float stepX = (float)clip.Width / windowCount;
float stepY = (float)clip.Height / Fft.FftWidth;
float offsetX = stepX / 2;
for (int windowIndex = windowOffset; windowIndex < windowEndIndex; windowIndex++)
{
float[] data = _waveFile.Spectrum[windowIndex];
if (data == null)
{
System.Diagnostics.Debug.Assert(false);
continue;
}
int length = data.Length;
float x = (windowIndex - windowOffset) * stepX;
for (int j = 0; j < length; ++j)
{
float value = data[j];
float y = ((length - j) * stepY) - 1;
int i = (int)(value / 18);
i = (i > 256) ? 255 : i;
byte color = (byte)(128 - (i / 2));
for (float rx = -stepX / 2; rx < stepX / 2; rx++)
{
for (float ry = -stepY / 2; ry < stepY / 2; ry++)
{
int px = (int)(x + rx + offsetX);
int py = (int)(y + ry);
double distance = Math.Sqrt((rx * rx) + (ry * ry));
byte alpha = (distance > 256) ? (byte)255 : (byte)distance;
if (px >= 0 && px < clip.Width
&& py >= 0 && py < clip.Height)
{
unsafeMap.SetAt((int)px, (int)py, (byte)i, color, 0, alpha);
}
}
}
unsafeMap.SetAt((int)(x + offsetX), (int)y, (byte)i, (byte)(128 - (i / 2)), 0, 0);
}
}
unsafeMap.UnlockBitmap();
spectrum = unsafeMap.Detach();
}
return spectrum;
}
private Bitmap DrawWaveform(int sampleOffset, int sampleLength, Rectangle clip)
{
ArbgPixel waveColor = new ArbgPixel(255, 0, 255, 0);
if (_waveFile == null)
{
return null;
}
if (clip.Width == 0 || clip.Height == 0)
{
return null;
}
Bitmap waveform = new Bitmap(clip.Width, clip.Height);
using (UnsafeBitmap unsafeMap = new UnsafeBitmap(waveform))
{
Graphics graphics = Graphics.FromImage(unsafeMap.Bitmap);
graphics.FillRectangle(Brushes.WhiteSmoke, graphics.VisibleClipBounds);
unsafeMap.LockBitmap();
float stepY = (float)clip.Height / 2 / short.MaxValue;
float stepX = (float)clip.Width / sampleLength;
//// #region Draw middle line
int middleY = (int)clip.Height / 2;
for (int x = 0; x < clip.Width; x++)
{
unsafeMap.SetAt(x, middleY, 0, 255, 0, 0);
}
//// #endregion
short[] data = _waveFile.DataIn16Bits;
int sampleEndIndex = sampleOffset + sampleLength;
Point prevPoint = new Point(0, middleY);
Point currPoint = new Point(0, middleY);
int prevY = int.MinValue;
for (int sampleIndex = sampleOffset; sampleIndex < sampleEndIndex; sampleIndex++)
{
currPoint.X = (int)(((sampleIndex - sampleOffset) * stepX) + 0.5);
currPoint.Y = middleY - (int)((data[sampleIndex] * stepY) + 0.5);
unsafeMap.SetAt((int)currPoint.X, (int)currPoint.Y, waveColor);
if (currPoint.X != prevPoint.X)
{
// connect two points in line
float tag = (float)(currPoint.Y - prevPoint.Y) / (currPoint.X - prevPoint.X);
for (int interX = prevPoint.X; interX < currPoint.X; interX++)
{
int interY = (int)(((interX - prevPoint.X) * tag) + 0.5) + prevPoint.Y;
if (prevY != interY && prevY != int.MinValue)
{
int insertDirect = Math.Sign(interY - prevY);
int insertLength = Math.Abs(interY - prevY);
for (int insertY = 1; insertY < insertLength; insertY++)
{
unsafeMap.SetAt(interX, prevY + (insertY * insertDirect), waveColor);
}
}
unsafeMap.SetAt(interX, interY, waveColor);
prevY = interY;
}
}
else
{
if (prevPoint.Y != currPoint.Y)
{
int insertDirect = Math.Sign(currPoint.Y - prevPoint.Y);
int insertLength = Math.Abs(currPoint.Y - prevPoint.Y);
for (int insertY = 1; insertY < insertLength; insertY++)
{
unsafeMap.SetAt(prevPoint.X, prevPoint.Y + (insertY * insertDirect),
waveColor);
}
}
}
prevPoint = currPoint;
}
unsafeMap.UnlockBitmap();
waveform = unsafeMap.Detach();
}
return waveform;
}