man text_length (3): Returns the length of a string in pixels. Allegro game programming library.

text_length(3) Returns the length of a string in pixels. Allegro game programming library.

SYNOPSIS

#include <allegro.h>

int text_length(const FONT *f, const char *str);

Returns the length (in pixels) of a string in the specified font. Example:

   int width = text_length(font, "I love spam");
   ...
   bmp = create_bitmap(width, height);