Load Adafruit GFX bitmap fonts on desktop for pixel-level design
As explained here and here the font format in the GFX-library is GFXglyph, you can use the free tool from the second link adafonteditor v1.0.3 on the desktop.EDITOk so its actually decompile the gfx header file to something on the desktop. Take a look at the Adafruit GFX Font Customiser Source can be used as basis for own projects or compiled to the designated OS.