gfngfn / otfed

An OpenType font format encoder & decoder written in OCaml

otfed: OpenType Font Format Encoder & Decoder

Table of Contents

• How to install
• Usage of an example CLI otfedcli
• Development status
• How to develop this library
• Remarks

How to install

Under the condition that opam (a package manager for OCaml, Coq, etc.) is installed, invoke the following commands:

$ cd <your-workspace>
$ git clone https://github.com/gfngfn/otfed
$ cd otfed
$ opam pin add otfed .

Probably the last command above will ask you whether to install otfed. Then answer y.

If not, invoking the following command will do:

$ opam install otfed

Usage of an example CLI otfedcli

$ dune exec otfedcli <path/to/font-file> <command> ... <command>

<command> ::=
  | tables                             # Prints all the tags of tables contained in the font.
  | cmap                               # Prints all the Unicode-aware `cmap` subtables.
  | cmap_word "<arbitrary-utf8-text>"  # Consults `cmap` subtables for each character in the given text.
  | head                               # Prints the contents of `head` table.
  | hhea                               # Prints the contents of `hhea` table.
  | vhea                               # Prints the contents of `vhea` table.
  | maxp                               # Prints the contents of `maxp` table.
  | hmtx <glyph-id>                    # Consults the `hmtx` table by the glyph of ID <glyph-id>.
  | vmtx <glyph-id>                    # Consults the `vmtx` table by the glyph of ID <glyph-id>.
  | glyf <glyph-id> <output-svg-file>  # Outputs the glyph of ID <glyph-id> that has TrueType outlines.
  | cff <glyph-id> <output-svg-file>   # Outputs the glyph of ID <glyph-id> that has CFF outlines.
  | cff_lex <glyph-id>                 # Prints the tokenized CharString of the glyph of ID <glyph-id>.
  | cff_top                            # Prints the Top DICT in the `CFF␣` table.
  | charset <glyph-id>                 # Prints the name of the glyph by consulting the charset in `CFF␣`.
  | gsub <script> <langsys> <feature>  # Prints the contents of `GSUB` subtables.
  | gpos <script> <langsys> <feature>  # Prints the contents of `GPOS` subtables.
  | subset <glyph-ids> <output-ttf>    # Makes a subset font by using given glyph IDs.

<glyph-ids> ::= (comma-separated glyph IDs where no space is allowed around commas)

Example usage

Consults cmap subtables by Unicode code points:

$ dune exec otfedcli input/ipaexm.ttf cmap_word "田中太郎"
* subtable (platform: 0, encoding: 3)
  - U+7530 --> 2900
  - U+4E2D --> 2746
  - U+592A --> 2614
  - U+90CE --> 3830
* subtable (platform: 3, encoding: 1)
  - U+7530 --> 2900
  - U+4E2D --> 2746
  - U+592A --> 2614
  - U+90CE --> 3830
* subtable (platform: 3, encoding: 10)
  - U+7530 --> 2900
  - U+4E2D --> 2746
  - U+592A --> 2614
  - U+90CE --> 3830

Prints all of the Unicode-aware cmap subtables in IPAex Mincho (please be careful of large outputs on stdout):

$ dune exec otfedcli input/ipaexm.ttf cmap
(omitted)

Outputs the glyph of ID 1000 in IPAex Mincho as an SVG file:

$ dune exec otfedcli input/ipaexm.ttf glyf 1000 output/ipaexm1000.svg
(omitted)

Outputs the glyph of ID 50 in Computer Modern Typewriter Italic as an SVG file:

$ dune exec otfedcli input/cmunit.otf cff 50 output/cmunit1000.svg
(omitted)

Outputs the subset of Junicode which contains .notdef, “Q”, and “f” only:

$ dune exec otfedcli input/Junicode.ttf subset 0,113,302 output/Junicode-subset.ttf

Development status

• Support:
  • V = supported
  • - = not supported yet
• Test:
  • V = having automated tests
  • - = not supported
  • o = no automated test has been given, but seems to be working fine for many inputs
  • x = not well-tested

Tables			Encoding operations		Decoding operations
			Supported	Tested	Supported	Tested
Required	cmap	Format 0	-	-	-	-
		Format 2	-	-	-	-
		Format 4	-	-	V	V
		Format 6	-	-	-	-
		Format 8	-	-	-	-
		Format 10	-	-	-	-
		Format 12	V	V	V	V
		Format 13	-	-	V	V
		Format 14	V	V	V	V
	head		V	V	V	V
	hhea		V	V	V	V
	hmtx		V	V	V	V
	maxp		V	V	V	V
	name		V	V	V	V
	OS/2	ver. 0	V	o	V	o
		ver. 1	V	o	V	o
		ver. 2	V	V	V	V
		ver. 3, 4, & 5	V	o	V	o
	post		V	V	V	V
TTF	cvt␣		-	-	-	-
	fpgm		-	-	-	-
	glyf		V	V	V	V
	loca	short	V	V	V	o
		long	V	o	V	V
	prep		-	-	-	-
	gasp		-	-	-	-
CFF	CFF␣		V	o	V	V
	CFF2		-	-	-	-
	VORG		-	-	-	-
SVG	SVG␣		-	-	-	-
Optional	DSIG		-	-	-	-
	kern	Format 0	-	-	V	V
		other	-	-	-	-
	vhea	ver. 1.0	V	V	V	V
		ver. 1.1	V	x	V	x
	vmtx		V	V	V	V
Advanced	BASE		-	-	-	-
	GDEF		-	-	-	-
	GPOS	LookupType 1	-	-	V	o
		LookupType 2	-	-	V	o
		LookupType 3	-	-	V	x
		LookupType 4	-	-	V	o
		LookupType 5	-	-	V	o
		LookupType 6	-	-	V	o
		LookupType 7	-	-	-	-
		LookupType 8	-	-	-	-
		LookupType 9	-	-	V	o
	GSUB	LookupType 1	-	-	V	o
		LookupType 2	-	-	V	o
		LookupType 3	-	-	-	-
		LookupType 4	-	-	V	o
		LookupType 5	-	-	-	-
		LookupType 6	-	-	-	-
		LookupType 7	-	-	-	-
		LookupType 8	-	-	-	-
	JSTF		-	-	-	-
	MATH		-	-	V	V

How to develop this library

Assumes that Dune (≥2.7) is installed.

How to build

$ dune build

How to run tests

$ dune test

Remarks

Origin

This library has been developed with the intension of reformulating otfm.

See also:

• an extended version of otfm for SATySFi
• SATySFi

Data used in unit tests

Some unit tests use data extracted from the following fonts:

• IPAex明朝 (IPAex Mincho): ipaexm.ttf
  • See the license here
• Latin Modern: lmroman10-regular.otf and lmmono10-regular.otf
  • See the license here
• Latin Modern Math
  • See the license here
• Junicode
  • See the license here
• DejaVu Sans: DejaVuSans-ExtraLight.ttf
  • See the license here