dtk_load_font man page
dtk_load_font — Load an font
dtk_hfont dtk_load_font(const char *fontname);
void dtk_destroy_font(dtk_hfont font);
dtk_load_font() loads the font specified by fontname argument. This should be the path of a file whose file format can be any of the file format supported by the freetype library (TrueType and Type 1 among many others) or a font description pattern understood by fontconfig (like "Times new roman:bold"). dtk_load_font() will first interpret fontname as a font filename and then, if this fail interpret as a font pattern and load the closest font available on the system.
Upon creation, the font data is then tracked by an internal resource manager so that the next call using the same fontname argument will return the same font handle, thus sparing the resources of the system.
There is no need for a valid window to create successfully a font, i.e. font loading is completely decoupled from the creation of others resources and can even be created in one thread to be used in another one.
dtk_destroy_font() frees the resource referenced by font. If the font is used several times, i.e. several call to dtk_load_font() with the same file path, it decreases the number of uses by one.
Calling dtk_destroy_texture() on each created font is currently not mandatory since all font remaining fonts are destroyed when the last window is closed. However, if no window can be closed (for example, no window has been created), dtk_destroy_font() should be called on each created font to avoid any memory leak.
In case of success, the dtk_load_font() returns the handle to the loaded font. In case of failure, NULL is returned.
dtk_destroy_texture() does not return any value.
dtk_load_font() and dtk_destroy_texture() are thread-safe.
dtk_create_string(3) fc-list(1) FcPatternFormat(3)
dtk_destroy_font(3) is an alias of dtk_load_font(3).