[Zubersoft]

So, looking at this from a different angle, how is the zooming/panning sluggishness impacting your ability to use the app? Is it making it difficult to position the page accurately when you zoom all the way in and that is creating frustration? Or do you just generally want the zooming to be smoother? As it stands, I switched the rendering code so that it only draws what is actually visible on the screen when you zoom in. So even if the page is blown up to 6000x4000 pixels, for example, it's only actually drawing the 3240x2160 area of the page that is visible on the screen. I'm assuming you already tried going to Settings->Display Settings and changing the "Image Quality" setting to "Low", correct? that will render the image with less precision which helps draw it faster. If that doesn't help, and you want to test out a few things, we could try dropping the image quality even further to the lowest supported in Win2D (which does look pretty bad in my opinion) to see if that runs any better on your device. I also just noticed that I'm not honoring the "Image Quality" setting correctly if the "Draw highlights behind content" setting is enabled in the annotations editor. If you currently have that enabled, can you try turning that off to see if it helps at all with the sluggishness?

Thanks,
Mike