This article (17 pages) was written to accompany an Overleaf help item. It explores the meaning of underfull or overfull boxes and examines the calculation of badness using an \hbox with finite and infinite glues. We have tried to provide a range of examples to demonstrate various aspects of TeX engines’ box-construction behaviour and the underfull or overfull “diagnostic messages” issued by TeX engines during the box-creation process.
PDF accessibility requirements stipulate that word breaks must be represented explicitly in the PDF. However, TeX engines do not use space characters to separate words: they use interword glue. This project shows how you can use LuaTeX to replace interword glue with space characters and kerns without affecting the visual appearance of typeset text.
To understand the difference this makes for users of accessibility software, listen to this sound recording made using Adobe Reader DC's Read Out Loud feature. It records the two lines of text in this project being read out loud, before and after converting glue to spaces.
This is a plain TeX file compiled using LuaTeX. It is for experimental use only and not intended to be a full, production-quality solution. Primarily, it is designed to assist with understanding technical issues related to accessible PDFs. The Lua code in this project is based on the earlier Overleaf article Boxes and Glue: A Brief, but Visual, Introduction Using LuaTeX.
This project uses its own simple and very minimal OpenType font loader derived from this code: http://wiki.luatex.org/index.php/Use_a_TrueType_font.
J'ai essayé de reproduire sous LaTeX la mise en page d'un extrait du manuel de français Colibris à destination des 5e. On voit que LaTeX permet en particulier d'afficher des notes de bas de page directement en dessous d'un texte.