+ /* Minimum glyph width (in pixels). */
+ int min_width;
+
+ /* Ascent and descent of the font (in pixels). */
+ int ascent, descent;
+
+ /* Vertical pixel width of the underline. If is zero if that
+ information is not in the font. */
+ int underline_thickness;
+
+ /* Vertical pixel position (relative to the baseline) of the
+ underline. If it is positive, it is below the baseline. It is
+ negative if that information is not in the font. */
+ int underline_position;
+
+ /* 1 if `vertical-centering-font-regexp' matches this font name.
+ In this case, we render characters at vartical center positions
+ of lines. */
+ int vertical_centering;
+
+ /* Encoding type of the font. The value is one of
+ 0, 1, 2, or 3:
+ 0: code points 0x20..0x7F or 0x2020..0x7F7F are used
+ 1: code points 0xA0..0xFF or 0xA0A0..0xFFFF are used
+ 2: code points 0x20A0..0x7FFF are used
+ 3: code points 0xA020..0xFF7F are used
+ If the member `font_encoder' is not NULL, this member is ignored. */
+ unsigned char encoding_type;
+
+ /* The baseline position of a font is normally `ascent' value of the
+ font. However, there exists many fonts which don't set `ascent'
+ an appropriate value to be used as baseline position. This is
+ typical in such ASCII fonts which are designed to be used with
+ Chinese, Japanese, Korean characters. When we use mixture of
+ such fonts and normal fonts (having correct `ascent' value), a
+ display line gets very ugly. Since we have no way to fix it
+ automatically, it is users responsibility to supply well designed
+ fonts or correct `ascent' value of fonts. But, the latter
+ requires heavy work (modifying all bitmap data in BDF files).
+ So, Emacs accepts a private font property
+ `_MULE_BASELINE_OFFSET'. If a font has this property, we
+ calculate the baseline position by subtracting the value from
+ `ascent'. In other words, the value indicates how many bits
+ higher we should draw a character of the font than normal ASCII
+ text for a better looking.
+
+ We also have to consider the fact that the concept of `baseline'
+ differs among scripts to which each character belongs. For
+ instance, baseline should be at the bottom most position of all
+ glyphs for Chinese, Japanese, and Korean. But, many of existing
+ fonts for those characters doesn't have correct `ascent' values
+ because they are designed to be used with ASCII fonts. To
+ display characters of different language on the same line, the
+ best way will be to arrange them in the middle of the line. So,
+ in such a case, again, we utilize the font property
+ `_MULE_BASELINE_OFFSET'. If the value is larger than `ascent' we
+ calculate baseline so that a character is arranged in the middle
+ of a line. */
+ int baseline_offset;
+
+ /* Non zero means a character should be composed at a position
+ relative to the height (or depth) of previous glyphs in the
+ following cases:
+ (1) The bottom of the character is higher than this value. In
+ this case, the character is drawn above the previous glyphs.
+ (2) The top of the character is lower than 0 (i.e. baseline
+ height). In this case, the character is drawn beneath the
+ previous glyphs.
+
+ This value is taken from a private font property
+ `_MULE_RELATIVE_COMPOSE' which is introduced by Emacs. */
+ int relative_compose;
+
+ /* Non zero means an ascent value to be used for a character
+ registered in char-table `use-default-ascent'. */
+ int default_ascent;
+
+ /* CCL program to calculate code points of the font. */
+ struct ccl_program *font_encoder;
+
+ /* Font-driver for the font. */
+ struct font_driver *driver;