void Canvas_Draw(CanvasControl sender, CanvasDrawEventArgs args)
{
if (photo.SourceBitmap == null)
{
return;
}
var drawingSession = args.DrawingSession;
drawingSession.Units = CanvasUnits.Pixels;
drawingSession.Blend = CanvasBlend.Copy;
// Draw the main photo image.
ICanvasImage image;
if (editingRegion != null)
{
image = cachedImage.Get() ?? cachedImage.Cache(photo, photo.GetImage());
}
else
{
image = photo.GetImage();
}
drawingSession.DrawImage(image);
// Highlight the current region (if any).
lastDrawnZoomFactor = null;
foreach (var edit in photo.Edits)
{
if (edit.DisplayRegionMask(drawingSession, scrollView.ZoomFactor, editingRegion != null))
{
lastDrawnZoomFactor = scrollView.ZoomFactor;
}
}
// Display any in-progress region edits.
if (editingRegion != null)
{
editingRegion.DisplayRegionEditInProgress(drawingSession, regionPoints, scrollView.ZoomFactor);
}
}
public ICanvasImage GetRegionMask()
{
// Do we already have a cached version of this mask?
ICanvasImage mask = cachedRegionMask.Get(regionFeather, regionDilate);
if (mask == null)
{
mask = regionMask;
// Expand or contract the selection?
if (regionDilate != 0)
{
mask = new MorphologyEffect
{
Source = new BorderEffect {
Source = mask
},
Mode = (regionDilate > 0) ? MorphologyEffectMode.Dilate : MorphologyEffectMode.Erode,
Height = Math.Abs(regionDilate),
Width = Math.Abs(regionDilate)
};
}
// Feather the selection?
if (regionFeather > 0)
{
mask = new GaussianBlurEffect
{
Source = mask,
BlurAmount = regionFeather,
BorderMode = EffectBorderMode.Hard
};
}
// If this mask was expensive to compute, cache it now.
if (mask != regionMask)
{
mask = cachedRegionMask.Cache(Parent, mask, regionFeather, regionDilate);
}
}
return(mask);
}