A conversion tool for Truetype Fonts to bitmap C header files for any character and for use with monochrome LCD or OLED displays
The software renders arbitrary TTF Fonts of character to a monochrome array of bytes, and stores these arrays in a C header file. This file can be used for any C microcontroller Code so that the characters can be displayed on monochrome OLED or LCD Display. A png picture with the rendered characters is also stored within the library.
The header file contains one byte array per selected character, with currently a variable type "const char bitmap_32[]", so that it compiles for Microchip AVR microcontrollers. The variable name is always bitmap_XX, where XX is the decimal ASCII value of that character. The variable type can be changed in the source code, so that header files for different MCU architectures can be generated.
The byte array is followed by an address pointer, so that the characters can be addressed easily.
The byte array is ordered the following:
- Each byte contains 8 bits for one column with 8 pixel-rows.
- For a character height of 24, three bytes (three byte-rows) are required for a full column
- The first W bytes describe the first byte-row, the second W bytes describe the second byte-row, etc.
The script offers a command line interface with somehow self-describing arguments. On the command line, the search path and the folder name can be chosen. Default search path is the Windows Font directory under C:\Windows\Fonts.
usage: ttf2bmh.py [-h] [-l] [-f TTF_FOLDER] [-o OUTPUT_FOLDER] [-c CHARACTER_FILENAME] [-C CHARACTERS] [--ascii]
[--font FONT] [-s {8,24,32,40,48,56,64,all}] [--variable_width] [--progmem] [-p] [--square]
optional arguments:
-h, --help show this help message and exit
-l, --license show license terms
-f TTF_FOLDER, --ttf_folder TTF_FOLDER
Folder where ttf files are stored (Defaults to C:\Windows\Fonts\ on Windows,
/usr/share/fonts on Linux)
-o OUTPUT_FOLDER, --output_folder OUTPUT_FOLDER
Folder where bitmapheader output files will be stored. A subfolder for each Font will be
created under the directory (Defaults to ./bmhfonts)
-c CHARACTER_FILENAME, --character_filename CHARACTER_FILENAME
filename for characters to be processed
-C CHARACTERS, --characters CHARACTERS
String of characters to be processed (if no character_filename passed in)
--ascii Convert for all ascii characters (overrides -c and -C)
--font FONT Define Font Name to be processed. Name should include modifier like Bold or Italic. If none
is given, all fonts in folder will be processed.
-s {8,24,32,40,48,56,64,all}, --fontsize {8,24,32,40,48,56,64,all}
Fontsize (Fontheight) in pixels. Default: 32
--variable_width Variable width of characters.
--progmem C Variable declaration adds PROGMEM to character arrays. Useful to store the characters in
porgram memory for AVR Microcontrollers with limited Flash or EEprom
-p, --print_ascii Print each character as ASCII Art on commandline, for debugging
--square Make the font square instead of height by (height * 0.75)
The program can also be run directly on Linux systems by doing ./ttf2bmh.py
Conversion of all digits including colon from Font "Courier New", pixel size 32 with variable width.
$ python ./ttf2bmh.py -s 32 -c ../characters_digits.txt --progmem --font "Courier New" --variable_width
Converting characters: "0123456789:"
Courier New_32.h written
TTF2BMH Finished
Example to convert all fonts in specific folder:
python ./ttf2bmh.py -s 32 -c ../characters_digits.txt --progmem -f ../ttf_fonts/liberation-fonts-ttf/ --variable_width
Example to convert all system fonts for all ascii values at a size of 32 to a folder bmh_fonts in the current directory
python ./ttf2bmh.py --ascii
Further examples can be found within the ipython notebook RUN within the src folder. The scripts have been used to create the fonts of my BMH_fonts repository https://github.com/jdmorise/BMH-fonts.
- Python 3
- PIL
- fontTools
- argparse
The latest version is not tested on MCU device level yet.