FontForge

Overview

This document explains how to use Fontforge to generate a MicroEJ Font.

Requirements

This how-to has been tested on

• MicroEJ Studio or SDK 5.1
• Python (3.8.0) with Pillow module (6.2.1)
• FontForge (FontForge-2019-08-01 64-bit) - if you have a 64-bit OS, install a 64-bit font forge
• Windows 10

Usage

Install the dependencies

1. Download and Install Python and Pillow: how to
2. Download and install FontForge: website
3. Add ffpython, available in [Fontforge installation directory]/bin, to the system path

Usage

Generate the images

Use a command line to execute fontConverter:

python fontConverter fontFilePath sizeInPixel [startRange endRange [bpp [algorithm]]
                fontFilePath: the path to the font file
                sizeInPixel: the size in pixel to use for the output (c.f. algorithm)
                startRange: (default = 0x21) hexadecimal value of the first unicode character to export
                endRange: (default = 0x24F)  hexadecimal value of the last unicode character last character to export, it is recommanded to export a wide range
                bpp: (default = 8) the bpp to use for the export
                algorithm: (default = 0) the algorithm to use :
                        0: bodyHeight => The sizeInPixel define the height of `Xg` (the generated image height will be the biggest height required to print all the character in range)
                        1: capitalHeight => The sizeInPixel define the size of a capital `X` (the generated image height will be the biggest height required to print all the character in range)
                        2: emHeight => The sizeInPixel define the size of an em (the generated image height will be the biggest height required to print all the character in range)
                        3: bestFit => The sizeInPixel define the size of the final output (the size of the font used will be the biggest possible to fit all the characters within the sizeInPixel)

The output should looks like:

Generating images
Mapping em font size to 14px
Resizing images to 15px
Generating EJF
EJF file can be found at [PATH]\NotoSerif-Regular_capitalHeight_10px.ejf

Algorithm

• bodyHeight will use the height of Xg (the generated image height will be the biggest height required to print all the character in range). In case of increase of the characters range, the size of the printed characters will be the same, but the size of the EJF file may be different.
• capitalHeight will use the height of a capital X (the generated image height will be the biggest height required to print all the character in range). In case of increase of the characters range, the size of the printed characters will be the same, but the size of the EJF file may be different.
• emHeight will use the height of an em (the generated image height will be the biggest height required to print all the character in range). In case of increase of the characters range, the size of the printed characters will be the same, but the size of the EJF file may be different.
• bestFit will use the height of the final output (the size of the font used will be the biggest possible to fit all the characters within the sizeInPixel). In case of increase of the characters range, the size of the printed characters may vary, but the size of the EJF file will stay the same.

Import the images into an EJF

In MicroEJ SDK:

1. Import the MicroEJ font
2. Adapt the base line to Map your font's base line

Troubleshooting

DLL load failed

When using a 64-bit Windows and a 32-bit version of FontForge, the script fails to load some DLL. Using a 64-bit version should fix the use. Font forge 64-bit portable