I've got a library, which I inherited, which presents a zoomable representation of the Earth. It's a Mercator projection and is constructed from triangles, the properties of which are stored in binary files.

The surface is built up, for any given view port, by drawing these triangles in an overlapping fashion to produce the image. The definition of each triangle is the lat/long of the vertices.

It looks OK at low values of zoom but looks progressively more ragged as the user zooms in. The view ports are primarily referenced though a rectangle of lat/long co-ordinates.

I'd like to replace it with a better quality approach. The problem is, I don't know where to begin researching the options as I am not familiar either with the projections needed nor the graphics techniques used to render them.

For example, I imagine that I could acquire high resolution images, say Mercator projections although I'm open to anything, break them into tiles and somehow wrap them onto a graphical representation of a sphere.

I'm not asking for "how do I", more where should I begin to understand what might be involved and the techniques I will need to learn.

I am most grateful for any "Earth rendering 101" pointers folks might have.