DOKK / manpages / debian 12 / freetype2-demos / ttdebug.1.en
TTDEBUG(1) General Commands Manual TTDEBUG(1)

ttdebug - a TrueType bytecode debugger

ttdebug [options] index size font

ttdebug is an interactive TrueType bytecode debugger working in a terminal. Its spartanic interface faintly resembles debuggers like gdb.

For the specified font, a glyph with the given index and size is loaded, making it possible to trace the bytecode execution step by step.

This program is part of the FreeType demos package.

Use TrueType interpreter version ver. Available versions are depending on compilation options of FreeType; call ttdebug without an argument to get the actual list.
To access member font face_index (default zero) in TTCs.
Specify the design coordinates for each variation axis at start-up.
Show version.
May 2022 FreeType 2.12.1