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[emacs.git] / src / composite.h
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1 /* Header for composite sequence handler.
2 Copyright (C) 1999 Electrotechnical Laboratory, JAPAN.
3 Licensed to the Free Software Foundation.
4 Copyright (C) 2001 Free Software Foundation, Inc.
6 This file is part of GNU Emacs.
8 GNU Emacs is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2, or (at your option)
11 any later version.
13 GNU Emacs is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GNU Emacs; see the file COPYING. If not, write to
20 the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
21 Boston, MA 02111-1307, USA. */
23 #ifndef EMACS_COMPOSITE_H
24 #define EMACS_COMPOSITE_H
26 /* Methods to display a sequence of components a composition. */
27 enum composition_method {
28 /* The first two are actually not methods, but used in code
29 conversion to specify the current composing status. */
30 COMPOSITION_DISABLED, /* Never handle composition data */
31 COMPOSITION_NO, /* Not processing composition data */
32 /* Compose relatively without alternate characters. */
33 COMPOSITION_RELATIVE,
34 /* Compose by specified composition rule. This is not used in Emacs
35 21 but we need it to decode files saved in the older versions of
36 Emacs. */
37 COMPOSITION_WITH_RULE,
38 /* Compose relatively with alternate characters. */
39 COMPOSITION_WITH_ALTCHARS,
40 /* Compose by specified composition rule with alternate characters. */
41 COMPOSITION_WITH_RULE_ALTCHARS
44 /* Maximum number of compoments a single composition can have. */
45 #define MAX_COMPOSITION_COMPONENTS 16
47 /* These macros access information about a composition that
48 has `composition' property PROP. PROP is:
49 ((LENGTH . COMPONENTS) . MODIFICATION-FUNC)
51 (COMPOSITION-ID . (LENGTH COMPONENTS . MODIFICATION-FUNC))
52 They don't check validity of PROP. */
54 /* Temporary variable used only in the following macros. */
55 extern Lisp_Object composition_temp;
57 /* Return 1 iff the composition is already registered. */
58 #define COMPOSITION_REGISTERD_P(prop) INTEGERP (XCAR (prop))
60 /* Return ID number of the already registered composition. */
61 #define COMPOSITION_ID(prop) XINT (XCAR (prop))
63 /* Return length of the composition. */
64 #define COMPOSITION_LENGTH(prop) \
65 (COMPOSITION_REGISTERD_P (prop) \
66 ? XINT (XCAR (XCDR (prop))) \
67 : XINT (XCAR (XCAR (prop))))
69 /* Return components of the composition. */
70 #define COMPOSITION_COMPONENTS(prop) \
71 (COMPOSITION_REGISTERD_P (prop) \
72 ? XCAR (XCDR (XCDR (prop))) \
73 : XCDR (XCAR (prop)))
75 /* Return modification function of the composition. */
76 #define COMPOSITION_MODIFICATION_FUNC(prop) \
77 (COMPOSITION_REGISTERD_P (prop) \
78 ? XCDR (XCDR (XCDR (prop))) \
79 : CONSP (prop) ? XCDR (prop) : Qnil)
81 /* Return the method of composition. */
82 #define COMPOSITION_METHOD(prop) \
83 (COMPOSITION_REGISTERD_P (prop) \
84 ? composition_table[COMPOSITION_ID (prop)]->method \
85 : (composition_temp = XCDR (XCAR (prop)), \
86 (NILP (composition_temp) \
87 ? COMPOSITION_RELATIVE \
88 : ((INTEGERP (composition_temp) || STRINGP (composition_temp)) \
89 ? COMPOSITION_WITH_ALTCHARS \
90 : COMPOSITION_WITH_RULE_ALTCHARS))))
92 /* Return 1 iff the composition is valid. It is valid if length of
93 the composition equals to (END - START). */
94 #define COMPOSITION_VALID_P(start, end, prop) \
95 (CONSP (prop) \
96 && (COMPOSITION_REGISTERD_P (prop) \
97 ? (COMPOSITION_ID (prop) >= 0 \
98 && COMPOSITION_ID (prop) <= n_compositions \
99 && CONSP (XCDR (prop))) \
100 : (composition_temp = XCAR (prop), \
101 (CONSP (composition_temp) \
102 && (composition_temp = XCDR (composition_temp), \
103 (NILP (composition_temp) \
104 || STRINGP (composition_temp) \
105 || VECTORP (composition_temp) \
106 || INTEGERP (composition_temp) \
107 || CONSP (composition_temp)))))) \
108 && (end - start) == COMPOSITION_LENGTH (prop))
110 /* Return the Nth glyph of composition specified by CMP. CMP is a
111 pointer to `struct composition'. */
112 #define COMPOSITION_GLYPH(cmp, n) \
113 XINT (XVECTOR (XVECTOR (XHASH_TABLE (composition_hash_table) \
114 ->key_and_value) \
115 ->contents[cmp->hash_index * 2]) \
116 ->contents[cmp->method == COMPOSITION_WITH_RULE_ALTCHARS \
117 ? (n) * 2 : (n)])
119 /* Return the encoded composition rule to compose the Nth glyph of
120 rule-base composition specified by CMP. CMP is a pointer to
121 `struct composition'. */
122 #define COMPOSITION_RULE(cmp, n) \
123 XINT (XVECTOR (XVECTOR (XHASH_TABLE (composition_hash_table) \
124 ->key_and_value) \
125 ->contents[cmp->hash_index * 2]) \
126 ->contents[(n) * 2 - 1])
128 /* Decode encoded composition rule RULE_CODE into GREF (global
129 reference point code) and NREF (new reference point code). Don't
130 check RULE_CODE, always set GREF and NREF to valid values. */
131 #define COMPOSITION_DECODE_RULE(rule_code, gref, nref) \
132 do { \
133 gref = (rule_code) / 12; \
134 if (gref > 12) gref = 11; \
135 nref = (rule_code) % 12; \
136 } while (0)
138 /* Return encoded composition rule for the pair of global reference
139 point GREF and new reference point NREF. If arguments are invalid,
140 return -1. */
141 #define COMPOSITION_ENCODE_RULE(gref, nref) \
142 ((unsigned) (gref) < 12 && (unsigned) (nref) < 12 \
143 ? (gref) * 12 + (nref) : -1)
145 /* Data structure that records information about a composition
146 currently used in some buffers or strings.
148 When a composition is assigned an ID number (by
149 get_composition_id), this structure is allocated for the
150 composition and linked in composition_table[ID].
152 Identical compositions appearing at different places have the same
153 ID, and thus share the same instance of this structure. */
155 struct composition {
156 /* Number of glyphs of the composition components. */
157 unsigned glyph_len;
159 /* Width, ascent, and descent pixels of the composition. */
160 short pixel_width, ascent, descent;
162 /* How many columns the overall glyphs occupy on the screen. This
163 gives an approximate value for column calculation in
164 Fcurrent_column, and etc. */
165 unsigned short width;
167 /* Method of the composition. */
168 enum composition_method method;
170 /* Index to the composition hash table. */
171 int hash_index;
173 /* For which font we have calculated the remaining members. The
174 actual type is device dependent. */
175 void *font;
177 /* Pointer to an array of x-offset and y-offset (by pixels) of
178 glyphs. This points to a sufficient memory space (sizeof (int) *
179 glyph_len * 2) that is allocated when the composition is
180 registered in composition_table. X-offset and Y-offset of Nth
181 glyph are (2N)th and (2N+1)th elements respectively. */
182 short *offsets;
185 /* Table of pointers to the structure `composition' indexed by
186 COMPOSITION-ID. */
187 extern struct composition **composition_table;
188 /* Number of the currently registered compositions. */
189 extern int n_compositions;
191 /* Mask bits for CHECK_MASK arg to update_compositions.
192 For a change in the region FROM and TO, check compositions ... */
193 #define CHECK_HEAD 1 /* adjacent to FROM */
194 #define CHECK_TAIL 2 /* adjacent to TO */
195 #define CHECK_INSIDE 4 /* between FROM and TO */
196 #define CHECK_BORDER (CHECK_HEAD | CHECK_TAIL)
197 #define CHECK_ALL (CHECK_BORDER | CHECK_INSIDE)
199 extern Lisp_Object Qcomposition;
200 extern Lisp_Object composition_hash_table;
202 extern int get_composition_id P_ ((int, int, int, Lisp_Object, Lisp_Object));
203 extern int find_composition P_ ((int, int, int *, int *, Lisp_Object *,
204 Lisp_Object));
205 extern void update_compositions P_ ((int, int, int));
206 extern void make_composition_value_copy P_ ((Lisp_Object));
207 extern void compose_region P_ ((int, int, Lisp_Object, Lisp_Object,
208 Lisp_Object));
209 extern void syms_of_composite P_ ((void));
210 extern void compose_text P_ ((int, int, Lisp_Object, Lisp_Object,
211 Lisp_Object));
212 extern void compose_chars_in_text P_ ((int, int, Lisp_Object));
214 #endif /* not EMACS_COMPOSITE_H */