Loading the textures files into the ModelConverterX tool is something that has given me quite some challenges already. I have used different libraries for it already and all of them gave me some trouble. At the moment I am using the library by Martin Wright and although this one can read all the files I want, it is not a very fast library. So this makes the loading of models relatively slow.
That is why I decided to have a look at how the different texture formats exactly work and see if I could create my own texture file loaders. At the moment I have been studying the BMP and DDS formats. Creating a loader for those formats was not so hard, so at the moment I can read these formats. This should allow loading most of the texture formats used by Flight Simulator.
Only the R8 format is still on my todo list, as this is still used by older API macros that the tool should be able to convert. Maybe it is a good idea then to convert the textures to the DDS format when exporting to FSX MDL files.
I still have to test my new loaders with some more models, to see if there are not some “exotic” variants in use that I can not yet read at the moment. But all together it has been quite interesting to study those formats and gave me a lot of useful background information on how they work.