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1 | /* Header for fontset handler. |
2 | Ver.1.0 | |
3 | ||
4 | Copyright (C) 1995 Free Software Foundation, Inc. | |
5 | Copyright (C) 1995 Electrotechnical Laboratory, JAPAN. | |
6 | ||
7 | This program is free software; you can redistribute it and/or modify | |
8 | it under the terms of the GNU General Public License as published by | |
9 | the Free Software Foundation; either version 2, or (at your option) | |
10 | any later version. | |
11 | ||
12 | This program is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with this program; if not, write to the Free Software | |
19 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ | |
20 | ||
21 | #ifndef _FONTSET_H | |
22 | #define _FONTSET_H | |
23 | ||
24 | /* | |
25 | ||
26 | #define GENERIC_FONT_PTR void | |
27 | ||
28 | /* This data type is used for the font_table field of window system | |
29 | depending data area (e.g. struct x_display_info on X window). */ | |
30 | ||
31 | struct font_info | |
32 | { | |
33 | /* Pointer to window system dependent font structure. On X window, | |
34 | this value should be coerced to (XFontStruct *). */ | |
35 | void *font; | |
36 | ||
37 | /* Index number of the font. */ | |
38 | int font_idx; | |
39 | ||
40 | /* Name to be used to find the font. */ | |
41 | char *name; | |
42 | ||
43 | /* Full name of the font given by a window system. */ | |
44 | char *full_name; | |
45 | ||
46 | /* Charset of characters displayed by the font. */ | |
47 | int charset; | |
48 | ||
49 | /* Maximum bound width over all existing characters of the font. On | |
50 | X window, this is same as (font->max_bounds.width) */ | |
51 | int size; | |
52 | ||
53 | /* Height of the font. On X window, this is same as (font->ascent | |
54 | + font->descent). */ | |
55 | int height; | |
56 | ||
57 | /* Encodings of the font indexed by CHARSET. The value an integer | |
58 | 0, 1, 2, or 3: | |
59 | 0: code points 0x20..0x7F or 0x2020..0x7F7F are used | |
60 | 1: code points 0xA0..0xFF or 0xA0A0..0xFFFF are used | |
61 | 2: code points 0x20A0..0x7FFF are used | |
62 | 3: code points 0xA020..0xFF7F are used | |
63 | For instance, ASCII and Latin-1 characters may use the same font | |
64 | but different code points (ASCII uses 0x20..0x7F and Latin-1 uses | |
65 | 0xA0..0xFF). | |
66 | ||
67 | If the value can't be decided from information of the font, we | |
68 | consult `font-encoding-alist' to get of the corresponding charset | |
69 | whose default value is defined in lisp/fontset.el. Since there's | |
70 | no charset whose id is 1, we use encoding[1] to store the | |
71 | encoding information decided by the font itself. */ | |
72 | char encoding[MAX_CHARSET]; | |
73 | ||
74 | /* The baseline position of a font is normally `ascent' value of the | |
75 | font. However, there exists many fonts which don't set `ascent' | |
76 | an appropriate value to be used as baseline position. This is | |
77 | typical in such ASCII fonts which are designed to be used with | |
78 | Chinese, Japanese, Korean characters. When we use mixture of | |
79 | such fonts and normal fonts (having correct `ascent' value), a | |
80 | display line gets very ugly. Since we have no way to fix it | |
81 | automatically, it is users responsibility to supply well designed | |
82 | fonts or correct `ascent' value of fonts. But, the latter | |
83 | requires heavy work (modifying all bitmap data in BDF files). | |
84 | So, Emacs accepts a private font property | |
85 | `_MULE_BASELINE_OFFSET'. If a font has this property, we | |
86 | calculate the baseline position by subtracting the value from | |
87 | `ascent'. In other words, the value indicates how many bits | |
88 | higher we should draw a character of the font than normal ASCII | |
89 | text for a better looking. | |
90 | ||
91 | We also have to consider the fact that the concept of `baseline' | |
92 | differs among languages to which each character belongs. For | |
93 | instance, baseline should be at the bottom most position of all | |
94 | glyphs for Chinese, Japanese, and Korean. But, many of existing | |
95 | fonts for those characters doesn't have correct `ascent' values | |
96 | because they are designed to be used with ASCII fonts. To | |
97 | display characters of different language on the same line, the | |
98 | best way will be to arrange them in the middle of the line. So, | |
99 | in such a case, again, we utilize the font property | |
100 | `_MULE_BASELINE_OFFSET'. If the value is larger than `ascent' we | |
101 | calculate baseline so that a character is arranged in the middle | |
102 | of a line. */ | |
103 | ||
104 | int baseline_offset; | |
105 | ||
106 | /* Non zero means a character should be composed at a position | |
107 | relative to the height (or depth) of previous glyphs in the | |
108 | following cases: | |
109 | (1) The bottom of the character is higher than this value. In | |
110 | this case, the character is drawn above the previous glyphs. | |
111 | (2) The top of the character is lower than 0 (i.e. baseline | |
112 | height). In this case, the character is drawn beneath the | |
113 | previous glyphs. | |
114 | ||
115 | This value is take from a private font property | |
116 | `_MULE_RELATIVE_COMPOSE' which is introduced by Emacs. */ | |
117 | int relative_compose; | |
118 | ||
119 | /* CCL program to calculate code points of the font. */ | |
120 | struct ccl_program *font_encoder; | |
121 | }; | |
122 | ||
123 | #define FONT_NOT_OPENED -1 | |
124 | #define FONT_NOT_FOUND -2 | |
125 | ||
126 | struct fontset_info | |
127 | { | |
128 | /* Name of the fontset. */ | |
129 | char *name; | |
130 | ||
131 | /* Size of the fontset. This is the same as the size of ASCII font | |
132 | of this fontset. */ | |
133 | int size; | |
134 | ||
135 | /* Height of the tallest font in the fontset. */ | |
136 | int height; | |
137 | ||
138 | /* Table of font name for each character set. */ | |
139 | char *fontname[MAX_CHARSET]; | |
140 | ||
141 | /* Table of index numbers of fonts indexed by charset. If a font is | |
142 | not yet loaded, the value is -1 (FONT_NOT_OPENED). If font | |
143 | loading is failed, the value is -2 (FONT_NOT_FOUND). */ | |
144 | int font_indexes[MAX_CHARSET]; | |
145 | }; | |
146 | ||
147 | /* This data type is used for the fontset_data field of struct frame. */ | |
148 | ||
149 | struct fontset_data | |
150 | { | |
151 | /* A table of pointers to all the fontsets. */ | |
152 | struct fontset_info **fontset_table; | |
153 | ||
154 | /* The current capacity of fontset_table. */ | |
155 | int fontset_table_size; | |
156 | ||
157 | /* The number of fontsets actually stored in fontset_table. | |
158 | fontset_table[n] is used and valid iff 0 <= n < n_fontsets. | |
159 | 0 <= n_fontsets <= fontset_table_size. */ | |
160 | int n_fontsets; | |
161 | }; | |
162 | ||
163 | /* The following six are window system dependent functions. | |
164 | Initialization routine of each window system should set appropriate | |
165 | functions to these variables. For instance, in case of X window, | |
166 | x_term_init does this. */ | |
167 | ||
168 | /* Return a pointer to struct font_info of font FONT_IDX of frame F. */ | |
169 | extern struct font_info *(*get_font_info_func) (/* FRAME_PTR f; | |
170 | int font_idx */); | |
171 | ||
172 | /* Return a list of font names which matches PATTERN. See the document of | |
173 | `x-list-fonts' for more detail. */ | |
174 | extern Lisp_Object (*list_fonts_func) (/* Lisp_Object pattern, face, frame, | |
175 | width */); | |
176 | ||
177 | /* Load a font named NAME for frame F and return a pointer to the | |
178 | information of the loaded font. If loading is failed, return -1. */ | |
179 | extern struct font_info *(*load_font_func) (/* FRAME_PTR f; char *name */); | |
180 | ||
181 | /* Return a pointer to struct font_info of a font named NAME for frame F. | |
182 | If no such font is loaded, return NULL. */ | |
183 | extern struct font_info *(*query_font_func) (/* FRAME_PTR f; char *name */); | |
184 | ||
185 | /* Additional function for setting fontset or changing fontset | |
186 | contents of frame F. This function may change the coordinate of | |
187 | the frame. */ | |
188 | extern void (*set_frame_fontset_func) (/* FRAME_PTR f; Lisp_Object arg, oldval */); | |
189 | ||
190 | /* Check if any window system is used now. */ | |
191 | extern void (*check_window_system_func) (); | |
192 | ||
193 | extern struct fontset_data *alloc_fontset_data (); | |
194 | extern void free_fontset_data (); | |
195 | extern struct font_info *fs_load_font (); | |
196 | extern Lisp_Object list_fontsets (); | |
197 | extern Lisp_Object Vglobal_fontset_alist; | |
198 | ||
199 | extern Lisp_Object Qfontset; | |
200 | ||
201 | #endif /* _FONTSET_H */ |