private bool SetBrightnessAndContrast(Contrast contrast, Brightness brightness)
{
lock (brightLock)
{
lock (contrastLock)
{
if (!this.Contrast.Equals(contrast) || !this.Brightness.Equals(brightness))
{
this.Contrast.SetTo(contrast);
this.Brightness.SetTo(brightness);
return(true);
}
return(false);
}
}
}
/// <summary>
/// Pushes the work of recalculating the image for
/// a new contrast and brightness to a background
/// thread with Task.Run(() => {});
/// Only fires the event changed handler if the
/// brightness and contrast calculated are still
/// valid upon completion.
/// </summary>
/// <param name="contrast"></param>
/// <param name="brightness"></param>
public void AdjustImage(Contrast contrast, Brightness brightness)
{
if (!this.SetBrightnessAndContrast(contrast, brightness))
{
return;
}
var adjust = Task.Run(() =>
{
if (contrast.IsDefault && brightness.IsDefault)
{
this.CurrentBytes = this.OriginalBytes;
this.ImageUpdated?.Invoke(this, EventArgs.Empty);
return;
}
var temp = new byte[this.OriginalBytes.Length];
var pixel = new byte[4];
using (Stream source = this.OriginalBytes.AsBuffer().AsStream())
{
using (Stream dest = temp.AsBuffer().AsStream())
{
while (source.Read(pixel, 0, 4) > 0)
{
pixel = CalculatePixel(pixel, brightness.Value, contrast.Value);
dest.Write(pixel, 0, 4);
}
}
}
lock (brightLock)
{
lock (contrastLock)
{
if (this.Brightness.Equals(brightness) && this.Contrast.Equals(contrast))
{
this.CurrentBytes = temp;
this.ImageUpdated?.Invoke(this, EventArgs.Empty);
}
}
}
});
}
