These BMP files are converted to byte tables for use in the FT2 code. They are then unpacked on runtime by routines in ft2_bmp.c. If you plan to modify the graphics, you need to also update the table length number in ft2_gfxdata.h for the corresponding graphics! If you want to add more graphics, it's a bit more complicated. You need to add the entry to the bmp struct list in ft2_bmp.h, then add a new line to loadBMPs() and freeBMPs() in ft2_bmp.c. Changing/adding graphics is not simple because stuff is quite hardcoded, so Good Luck :-). Please read LICENSE.txt (in this directory) if you plan on using these in another project... Note: The BMPs *must* be RLE compressed, at 4-bit or 8-bit only! It's important that you don't change the palette colors in any of these BMPs (except ft2AboutLogo.bmp which is converted to true-color internally). Doing so will mess up the "pixel color -> FT2 palette number" conversion when unpacking the graphics on runtime.