The 2560x1600 would be handled using dip (density independent pixels). While both of your tablets have the same resolution, as you have mentioned, the dpi is different, so the width/height that is reported in the application is different for the two. When defining the page size, this would be in measurements that ignores the dpi, and the page would be rendered to that, ensuring that the resulting image is the same on both devices, as all measurements are scaled to handle dpi differences.
I would be rendering a pixel image internally and scaling the pixels, so it will result in a change in appearance. This will allow it to work with the existing framework versus having to try to adjust the font size dynamically to fit the available area which is not something I want to mess with, as fonts don't scale linearly with size (something I learned the hard way as I assumed I could just adjust the font size by fractional amounts to scale text to fit a given area which didn't work).
Mike
I would be rendering a pixel image internally and scaling the pixels, so it will result in a change in appearance. This will allow it to work with the existing framework versus having to try to adjust the font size dynamically to fit the available area which is not something I want to mess with, as fonts don't scale linearly with size (something I learned the hard way as I assumed I could just adjust the font size by fractional amounts to scale text to fit a given area which didn't work).
Mike