enum glUnitsType

typedef enum {
	GL_UNITS_POINT, /* encoded as "pt" */
	GL_UNITS_INCH,  /* encoded as "in" */
	GL_UNITS_MM,    /* encoded as "mm" */
	GL_UNITS_CM,    /* encoded as "cm" */
	GL_UNITS_PICA,  /* encoded as "pc" */

	GL_UNITS_FIRST = GL_UNITS_POINT,
	GL_UNITS_LAST  = GL_UNITS_PICA,
} glUnitsType;

Enumerations for the units of length supported by libglabels. Internally all lengths are in points. Externally libglabels supports points ("pt"), inches ("in"), millimeters ("mm"), centimeters ("cm"), and picas ("pc"). These units are identical to the absolute length units supported in the CSS2 Specification (Section 4.3.2).