You did a good job! I actually enjoy the HD version very much at my scope.
Why don't you add the possibility to import custom maps?
I could, but the format isn't very user-friendly, and it takes a lot of work to generate a map. If there is interest from multiple people, though, I can easily add the feature to the HD version.
Download a map from <a href="http://pruss.mobi/dl...rmap/">here</a>
to your PC. Then change the .lunarmap extension to .zip, and you can unzip the file and see what's inside it.
What you'll find inside it is an index.txt file, as well as lots of jpg files. The jpeg files provide map tiles at five or six different resolutions. So to generate a map, you need a high resolution moon image at a resolution that can be nicely divided up into 640x640 tiles, say 10240x10240 or 5120x5120. Then you divide it up into tiles. Rescale to half size. Repeat until you resize to a single 640x640 tile. And then add a 320x320 tile.
The tile filenames start with "lib" if the image is "librated". This means that it was projected with a modified projection that adds 7 or so degrees of the other side of the moon, so you get coverage for libration. I can give you the formula I used for the projection.
If you want straight orthographic projection, then you just don't start the tile filenames with "lib".
There are some other pieces of information you can include in the index.txt file, such as indicating that it's a map of the farside.
If after looking at all this, you're still interested, let me know. I have all sorts of messy conversion code, too.
But if the source map is public domain (like the NASA / US government ones I use), you may just want to ask me to convert it for you and make it available in the next release.