Line Density Symbolism for Higher-Density Torus Cores

I'm relieved because line density is being used in symbolism to indicate areas of higher-density, so we don't have to painstakingly account for every line doing something significant.

Image A's is a portal and the upper half is in higher-density. Image B would look more familiar as a top-center portal if it were a red circle. The rest of the images are showing the high-density core inside a torus.