fnT

fnt is a term used in computing with several related meanings centered on font data. In contemporary contexts, it most often refers to a font descriptor file used by bitmap font tools such as AngelCode BMFont. In this usage, a complete font comprises two parts: a texture atlas image that contains the glyphs and a separate descriptor file (the fnt file) that stores per-character metrics and global font information. The descriptor can be in plain text, XML, or binary form and lists each character’s coordinates on the atlas, x and y offsets, and the x advance, along with page and other metadata. Software uses the descriptor together with the atlas to render text by sampling the correct glyphs from the texture.

A older, separate meaning exists for the Windows FNT format, used in legacy environments to store bitmap font data. FNT files in that context contain the raster glyphs and basic metrics for a font used by early Windows and OS/2 systems. With the rise of scalable vector fonts, such as TrueType and OpenType, these legacy FNT fonts are largely obsolete except for compatibility with vintage software or certain embedded systems.

In practice, fnt files are common in game development and 2D graphics workflows that rely on bitmap fonts. They allow efficient rendering by enabling a single texture atlas to hold all glyphs while the descriptor provides precise positioning and spacing instructions for each character. This approach supports quick text rendering and batching in graphics pipelines and is often used in conjunction with engines or libraries that support bitmap font rendering.

See also: font, bitmap font, BMFont, TrueType, OpenType.