You can't really "generate" a high-DPI segment. The display either has a sufficient pixel density or it doesn't. Foveated rendering let's you cheat the details

You can't really "generate" a high-DPI segment. The display either has a sufficient pixel density or it doesn't. Foveated rendering let's you cheat the details you render outside the focal point, but since your eyes can move to any portion of the display, the entire display needs to have a high-enough DPI that, once your eye moves to focus on that section, the content rendered in that location will be sharp.