These files describes glyphs, contained on images 
at data/images/engine/fonts/ 
(or any subdirectory)

Each file describes separate font.
When extended fonts put in addon, names should be prefixed, like 
addonname-foo.stf to be added to font foo.stf

(supertux-font
  ; height of font and glyph on images
  (glyph-height $h)    
  
  ; default width of glyph on images and width of fixed-font
  (glyph-width $w)   

  ; text in this font is written from right-to-left (optional)
  (rtl #t)

  ; one or more surfaces, containing glyph images
  (surface              
 
    ; may override default width
    (glyph-width $w)    

    ; may prevent to form variable-width glyphs from this surface
    (monospace #t)      

    ; filename containing glyph images,
    ; related to data/images/engine/fonts/
    ; any dimentions, RGBS pixel format
    (glyphs $filename)   
    
    ; filename containing shadow images, 
    ; should fit glyph image
    (shadows $filename)  

    ; charset definition
    ; each string represent separate row of glyphs on image
    ; spaces may be put to skip glyph (not drawn)
    (chars 
      $strings)
  )
)