AFM(7) UNIX Programmer's Manual AFM(7) NAME AFM - Adobe POSTSCRIPT font metrics file format DESCRIPTION AFM files are a standard interchange format for communicat- ing POSTSCRIPT font metric information to people and pro- grams. The format is ASCII encoded (for both human and machine readability), machine independent, extensible, sim- ple to parse, and simple to generate. AFM files are avail- able for all of Adobe Systems' POSTSCRIPT fonts. While somewhat verbose, the format is intended to be easily parsed, with the ability for applications to quickly skip over items that are not of interest. It should be possible to create simple line-oriented parsing programs, or tools based on _a_w_k(1) or _s_e_d(1). Each AFM file contains the information for only one font face. The file begins with global information about the font, followed by sections with character metrics. The file format is line-oriented, each line beginning with a property (key) name, followed by the values for that property. The general idea is to give key-value tuples (much like in a POSTSCRIPT font dictionary). The format is: Key [value value ...] Key names are case-sensitive. All keys beginning with a capital letter are reserved by Adobe Systems. The standard keys are detailed below, but other keys should be allowed and safely ignored by programs not recognizing them. All standard keys begin with a capital letter. User-defined non-standard entries should begin with a lower-case letter. The file begins with the line: StartFontMetrics _v_e_r_s_i_o_n The version described here is 1.0. The last line of the file is: EndFontMetrics The following global font keys are defined. Many of them are defined as in the top level or FontInfo subdictionary of a POSTSCRIPT font dictionary; their meanings are described in Appendix A of the POSTSCRIPT Language Manual. All numeric values are in the (1000 unit per em) character coor- dinate system. FontName _s_t_r_i_n_g The name of the font as presented to the POSTSCRIPT findfont operator. FullName _s_t_r_i_n_g Printed 1/10/87 12 Nov 1985 1 AFM(7) UNIX Programmer's Manual AFM(7) The ``print name'' of the font. FamilyName _s_t_r_i_n_g The font family name. Weight _s_t_r_i_n_g The weight of the font. ItalicAngle _r_e_a_l The angle (in degrees counter-clockwise from the vertical) of the dominant staffs of the font. IsFixedPitch _b_o_o_l_e_a_n Indicates monospaced (typewriter) fonts. FontBBox _l_l_x _l_l_y _u_r_x _u_r_y Four integers giving the lower left corner and the upper right corner of the font bound- ing box. _N_o_t_e: the bounding box given here is that of the flattened paths, not of the Bezier curve descriptions. UnderlinePosition _n_u_m_b_e_r The position (from the baseline) to place an underline. UnderlineThickness _n_u_m_b_e_r Thickness of an underline stroke. Version _s_t_r_i_n_g Font version identifier. Notice _s_t_r_i_n_g Font name trademark or copyright notice. Comment _s_t_r_i_n_g Comment strings may be ignored. EncodingScheme _s_t_r_i_n_g a string indicating the default encoding vec- tor for this font. The most common one is AdobeStandardEncoding. Special fonts may simply state ``FontSpecific''. In the future, other schemes may be employed. CapHeight _n_u_m_b_e_r Top of capital H. XHeight _n_u_m_b_e_r Top of lower case x. Ascender _n_u_m_b_e_r Top of lower case d. Descender _n_u_m_b_e_r Bottom of lower case p. Printed 1/10/87 12 Nov 1985 2 AFM(7) UNIX Programmer's Manual AFM(7) The individual character metrics are surrounded with the lines StartCharMetrics and EndCharMetrics and consist of a list of keys and values separated by semicolons. The char- acters are sorted (numeric ascending) by character code. Unencoded characters follow all of the encoded ones and are distinguished by having character code -1. Each character gets one line of description. Standard keys are: C _n_u_m_b_e_r decimal value of default POSTSCRIPT character code (-1 if unencoded). WX _w_i_d_t_h-_x Character width in _x (_y is 0). W _w_i_d_t_h-_x _w_i_d_t_h-_y Character width vector. N _n_a_m_e POSTSCRIPT character name. B _l_l_x _l_l_y _u_r_x _u_r_y The character bounding box. L _s_u_c_c_e_s_s_o_r _l_i_g_a_t_u_r_e A ligature sequence; The current character may join with the character named _s_u_c_c_e_s_s_o_r to form the character named _l_i_g_a_t_u_r_e. Note that characters may have more than one such entry. Most western language fonts have WX entries rather than W ones. Note that keys are one letter for brevity. Here too, the set is extensible, with unknown entries ignored. (This leaves room for addition of new information, for example.) A future revision of this format will have a specification for kerning information. FILES /usr/misc/lib/ps/*.afm AFM files in the TRANSCRIPT distribution. SEE ALSO awk(1), sed(1). AUTHOR Adobe Systems Incorporated NOTES POSTSCRIPT and TRANSCRIPT are trademarks of Adobe Systems Incorporated. Printed 1/10/87 12 Nov 1985 3