pyokagan / easy-sdf-font Goto Github PK

A single-file small embeddable single-stroke font for use with existing signed distance field (SDF) text rendering engines.

Only supports the 95 ASCII printable characters (space to tilde).

I needed a small embeddable font for use as a debug/fallback font for SDF text rendering.

Truetype outline fonts were ruled out because SDF generation is very expensive for them (around 5-9x slower compared to single-stroke fonts, the pause becomes noticeable to the user with Javascript which runs around 3x slower compared to C).

SDF font atlas generation for single-stroke fonts, on the other hand, is very cheap since the formula for the distance to a straight line is very simple.

On my system with -O2, easy-sdf-font.h takes around 3ms for SDF generation, whereas a truetype outline font (with stb_truetype) takes around 21ms.

Two implementations are provided: easy_sdf_font.h (for C) and easy_sdf_font.js (for Javascript).

See the header comments of those files or demo.c/demo.html for information of how to use them.

Public domain.