Stuart.EditGroup.DisplayRegionEditInProgress C# (CSharp) Method

        public void DisplayRegionEditInProgress(CanvasDrawingSession drawingSession, List<Vector2> points, float zoomFactor)
        {
            if (RegionSelectionMode == SelectionMode.MagicWand)
            {
                // Display a magic wand selection.
                var mask = GetMagicWandMask(points, zoomFactor);
                var border = GetSelectionBorder(mask, zoomFactor);

                drawingSession.Blend = CanvasBlend.Add;
                drawingSession.DrawImage(mask, Vector2.Zero, SourceBitmap.Bounds, 0.25f);

                drawingSession.Blend = CanvasBlend.SourceOver;
                drawingSession.DrawImage(border);
            }
            else
            {
                // Display a geometric shape selection.
                var geometry = GetSelectionGeometry(drawingSession, points);

                drawingSession.Blend = CanvasBlend.Add;
                drawingSession.FillGeometry(geometry, Color.FromArgb(0x20, 0xFF, 0xFF, 0xFF));

                drawingSession.Blend = CanvasBlend.SourceOver;
                drawingSession.DrawGeometry(geometry, Colors.Magenta, 1f / zoomFactor);
            }
        }

        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);
            }
        }