Pinta.ImageManipulation.Effects.InkSketchEffect.RenderLine C# (CSharp) Method

		protected unsafe override void RenderLine (ISurface src, ISurface dest, Rectangle roi)
		{
			// Glow backgound 
			glow_effect.Render (src, dest, roi);

			// Create black outlines by finding the edges of objects 
			for (int y = roi.Top; y <= roi.Bottom; ++y) {
				int top = y - radius;
				int bottom = y + radius + 1;

				if (top < 0) {
					top = 0;
				}

				if (bottom > dest.Height) {
					bottom = dest.Height;
				}

				ColorBgra* srcPtr = src.GetPointAddress (roi.X, y);
				ColorBgra* dstPtr = dest.GetPointAddress (roi.X, y);

				for (int x = roi.Left; x <= roi.Right; ++x) {
					int left = x - radius;
					int right = x + radius + 1;

					if (left < 0) {
						left = 0;
					}

					if (right > dest.Width) {
						right = dest.Width;
					}

					int r = 0;
					int g = 0;
					int b = 0;

					for (int v = top; v < bottom; v++) {
						ColorBgra* pRow = src.GetRowAddress (v);
						int j = v - y + radius;

						for (int u = left; u < right; u++) {
							int i1 = u - x + radius;
							int w = conv[j][i1];

							ColorBgra* pRef = pRow + u;

							r += pRef->R * w;
							g += pRef->G * w;
							b += pRef->B * w;
						}
					}

					ColorBgra topLayer = ColorBgra.FromBgr (
						Utility.ClampToByte (b),
						Utility.ClampToByte (g),
						Utility.ClampToByte (r));

					// Desaturate 
					topLayer = this.desaturate_op.Apply (topLayer);

					// Adjust Brightness and Contrast 
					if (topLayer.R > (ink_outline * 255 / 100)) {
						topLayer = ColorBgra.FromBgra (255, 255, 255, topLayer.A);
					} else {
						topLayer = ColorBgra.FromBgra (0, 0, 0, topLayer.A);
					}

					// Change Blend Mode to Darken 
					ColorBgra myPixel = this.darken_op.Apply (topLayer, *dstPtr);
					*dstPtr = myPixel;

					++srcPtr;
					++dstPtr;
				}
			}
		}
		#endregion