convfont converts Windows .FNT files into a form usable by FontLibC.

Usage:

convfont -o <output format> -f <font FNT> [-metrics] [-f <font FNT 2> [-metrics]] <output file name>

The fontpack output format supports packing multiple fonts. To specify multiple fonts, use -f <font> repeatedly for reach input font.

Font properties are metadata associated with each font that assist in layout and font selection.

All font properties default to zero if left unspecified.

Adding additional blank space between lines of text helps improve readability. FontLibC can add such blank space automatically based on metadata in the font or programmer request. Specifying blank space does not change the byte size of the font, only its layout.

-a specifies recommended additional blank space above each line of text.

-b specifies recommended additional blank space below.

-i is for italic space adjust, a feature allowing the left side of a glyph to partially overlap the right of the previous glyph.

-w specifies the weight of the font. This is purely used for font selection and has no direct effect on how the font is displayed. You may directly specify a numeric value, optionally using the prefix 0x for hexadecimal; see fontlibc.h for standard values. Alternatively, the following names may be used: thin, "extra light", extralight (synonym for previous), light, semilight, normal, semibold, bold, "extra bold", extrabold (synonym for previous), black.

-s specifies the style of the font. This is purely used for font selection and has no direct effect on how the font is displayed. You may directly specify a numeric value, optionally using the prefix 0x for hexadecimal; see fontlibc.h for standard values. Alternatively, the following names may be used: sans-serif, sansserif (synonym for previous), serif, upright, oblique, italic, monospaced, fixed (synonym for previous), proportional.

If -s is specified more than once for the same font, the values are ORed together. For example, you can specify a font as both italic and serif font by doing -s serif -s italic.

-c, -x, and -l specify these values. They count lines from the top of the glyph going down. Client layout code can use these values to align text from different font families.

convfont supports several different output formats, allowing you to select a format suitable for your needs.

The carray output format allows embedding a font directly into a C program. For example, if you specify an output file named myfont.inc you can use it in your program like so:

unsigned char my_font_data[] = {
    #include "myfont.inc"
}
fontlib_font_t my_font* = (fontlib_font_t *)my_font_data;
. . .
fontlib_SetFont(my_font, 0);

asmarray is like carray except for use in assembly programs.

binary produces a binary blob you can post-process for whatever other purpose you might need.

A fontpack consists of multiple fonts, typically composing a single typeface. Font packs allow multiple programs to use the same font data, saving space on-calculator. Since font packs can be archived, they also free up user RAM.

You can bundle multiple sizes of a font together. When your calculator program runs, you can use a routine like fontlib_GetFontByStyle() to get the font you want from your font pack.

A fontpack binary needs to be packaged into an appvar before it can be used on-calculator:

convhex -a -v myfont.bin myfont.8xv

Because font packs are intended to represent a single typeface and allowing users to select a font is an anticipated use case, font packs may also contain metadata describing them. Metadata strings should be terse, as they consume limited memory on-calculator.

The version field is a string, not a number. It is not intended to support automatic version control.

Note that the United States does not allow copyrighting bitmapped fonts, though many other jurisdictions do.