protected override void OnRender()

in source/SkiaSharp.Views/SkiaSharp.Views.WPF/SKElement.cs [45:89]
32 lines of code
11 McCabe index (conditional complexity)

		protected override void OnRender(DrawingContext drawingContext)
		{
			base.OnRender(drawingContext);

			if (designMode)
				return;

			if (Visibility != Visibility.Visible || PresentationSource.FromVisual(this) == null)
				return;

			var size = CreateSize(out var unscaledSize, out var scaleX, out var scaleY);
			var userVisibleSize = IgnorePixelScaling ? unscaledSize : size;

			CanvasSize = userVisibleSize;

			if (size.Width <= 0 || size.Height <= 0)
				return;

			var info = new SKImageInfo(size.Width, size.Height, SKImageInfo.PlatformColorType, SKAlphaType.Premul);

			// reset the bitmap if the size has changed
			if (bitmap == null || info.Width != bitmap.PixelWidth || info.Height != bitmap.PixelHeight)
			{
				bitmap = new WriteableBitmap(info.Width, size.Height, BitmapDpi * scaleX, BitmapDpi * scaleY, PixelFormats.Pbgra32, null);
			}

			// draw on the bitmap
			bitmap.Lock();
			using (var surface = SKSurface.Create(info, bitmap.BackBuffer, bitmap.BackBufferStride))
			{
				if (IgnorePixelScaling)
				{
					var canvas = surface.Canvas;
					canvas.Scale(scaleX, scaleY);
					canvas.Save();
				}

				OnPaintSurface(new SKPaintSurfaceEventArgs(surface, info.WithSize(userVisibleSize), info));
			}

			// draw the bitmap to the screen
			bitmap.AddDirtyRect(new Int32Rect(0, 0, info.Width, size.Height));
			bitmap.Unlock();
			drawingContext.DrawImage(bitmap, new Rect(0, 0, ActualWidth, ActualHeight));
		}