src/composite.h

   1 /* Header for composite sequence handler.
   2    Copyright (C) 2001, 2002, 2003, 2004, 2005,
   3                  2006 Free Software Foundation, Inc.
   4    Copyright (C) 1997
   5      National Institute of Advanced Industrial Science and Technology (AIST)
   6      Registration Number H14PRO021
   7    Copyright (C) 2003
   8      National Institute of Advanced Industrial Science and Technology (AIST)
   9      Registration Number H13PRO009
  10
  11 This file is part of GNU Emacs.
  12
  13 GNU Emacs is free software; you can redistribute it and/or modify
  14 it under the terms of the GNU General Public License as published by
  15 the Free Software Foundation; either version 2, or (at your option)
  16 any later version.
  17
  18 GNU Emacs is distributed in the hope that it will be useful,
  19 but WITHOUT ANY WARRANTY; without even the implied warranty of
  20 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21 GNU General Public License for more details.
  22
  23 You should have received a copy of the GNU General Public License
  24 along with GNU Emacs; see the file COPYING.  If not, write to
  25 the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  26 Boston, MA 02110-1301, USA.  */
  27
  28 #ifndef EMACS_COMPOSITE_H
  29 #define EMACS_COMPOSITE_H
  30
  31 /* Methods to display a sequence of components a composition.  */
  32 enum composition_method {
  33   /* Compose relatively without alternate characters.  */
  34   COMPOSITION_RELATIVE,
  35   /* Compose by specified composition rules.  This is not used in
  36      Emacs 21 but we need it to decode files saved in the older
  37      versions of Emacs.  */
  38   COMPOSITION_WITH_RULE,
  39   /* Compose relatively with alternate characters.  */
  40   COMPOSITION_WITH_ALTCHARS,
  41   /* Compose by specified composition rules with alternate characters.  */
  42   COMPOSITION_WITH_RULE_ALTCHARS,
  43   /* This is not a method.  */
  44   COMPOSITION_NO
  45 };
  46
  47 /* Maximum number of compoments a single composition can have.  */
  48 #define MAX_COMPOSITION_COMPONENTS 16
  49
  50 /* These macros access information about a composition that
  51    has `composition' property PROP.  PROP is:
  52         ((LENGTH . COMPONENTS) . MODIFICATION-FUNC)
  53    or
  54         (COMPOSITION-ID . (LENGTH COMPONENTS . MODIFICATION-FUNC))
  55    They don't check validity of PROP.  */
  56
  57 /* Temporary variable used only in the following macros.  */
  58 extern Lisp_Object composition_temp;
  59
  60 /* Return 1 iff the composition is already registered.  */
  61 #define COMPOSITION_REGISTERD_P(prop) INTEGERP (XCAR (prop))
  62
  63 /* Return ID number of the already registered composition.  */
  64 #define COMPOSITION_ID(prop) XINT (XCAR (prop))
  65
  66 /* Return length of the composition.  */
  67 #define COMPOSITION_LENGTH(prop)        \
  68   (COMPOSITION_REGISTERD_P (prop)       \
  69    ? XINT (XCAR (XCDR (prop)))          \
  70    : XINT (XCAR (XCAR (prop))))
  71
  72 /* Return components of the composition.  */
  73 #define COMPOSITION_COMPONENTS(prop)    \
  74   (COMPOSITION_REGISTERD_P (prop)       \
  75    ? XCAR (XCDR (XCDR (prop)))          \
  76    : XCDR (XCAR (prop)))
  77
  78 /* Return modification function of the composition.  */
  79 #define COMPOSITION_MODIFICATION_FUNC(prop)     \
  80   (COMPOSITION_REGISTERD_P (prop)               \
  81    ? XCDR (XCDR (XCDR (prop)))                  \
  82    : CONSP (prop) ? XCDR (prop) : Qnil)
  83
  84 /* Return the method of composition.  */
  85 #define COMPOSITION_METHOD(prop)                                        \
  86   (COMPOSITION_REGISTERD_P (prop)                                       \
  87    ? composition_table[COMPOSITION_ID (prop)]->method                   \
  88    : (composition_temp = XCDR (XCAR (prop)),                            \
  89       (NILP (composition_temp)                                          \
  90        ? COMPOSITION_RELATIVE                                           \
  91        : ((INTEGERP (composition_temp) || STRINGP (composition_temp))   \
  92           ? COMPOSITION_WITH_ALTCHARS                                   \
  93           : COMPOSITION_WITH_RULE_ALTCHARS))))
  94
  95 /* Return 1 iff the composition is valid.  It is valid if length of
  96    the composition equals to (END - START).  */
  97 #define COMPOSITION_VALID_P(start, end, prop)                   \
  98   (CONSP (prop)                                                 \
  99    && (COMPOSITION_REGISTERD_P (prop)                           \
 100        ? (COMPOSITION_ID (prop) >= 0                            \
 101           && COMPOSITION_ID (prop) <= n_compositions            \
 102           && CONSP (XCDR (prop)))                               \
 103        : (composition_temp = XCAR (prop),                       \
 104           (CONSP (composition_temp)                             \
 105            && (composition_temp = XCDR (composition_temp),      \
 106                (NILP (composition_temp)                         \
 107                 || STRINGP (composition_temp)                   \
 108                 || VECTORP (composition_temp)                   \
 109                 || INTEGERP (composition_temp)                  \
 110                 || CONSP (composition_temp))))))                \
 111    && (end - start) == COMPOSITION_LENGTH (prop))
 112
 113 /* Return the Nth glyph of composition specified by CMP.  CMP is a
 114    pointer to `struct composition'. */
 115 #define COMPOSITION_GLYPH(cmp, n)                                       \
 116   XINT (XVECTOR (XVECTOR (XHASH_TABLE (composition_hash_table)          \
 117                           ->key_and_value)                              \
 118                  ->contents[cmp->hash_index * 2])                       \
 119         ->contents[cmp->method == COMPOSITION_WITH_RULE_ALTCHARS        \
 120                   ? (n) * 2 : (n)])
 121
 122 /* Return the encoded composition rule to compose the Nth glyph of
 123    rule-base composition specified by CMP.  CMP is a pointer to
 124    `struct composition'. */
 125 #define COMPOSITION_RULE(cmp, n)                                \
 126   XINT (XVECTOR (XVECTOR (XHASH_TABLE (composition_hash_table)  \
 127                           ->key_and_value)                      \
 128                  ->contents[cmp->hash_index * 2])               \
 129         ->contents[(n) * 2 - 1])
 130
 131 /* Decode encoded composition rule RULE_CODE into GREF (global
 132    reference point code), NREF (new reference point code), XOFF
 133    (horizontal offset) YOFF (vertical offset).  Don't check RULE_CODE,
 134    always set GREF and NREF to valid values.  By side effect,
 135    RULE_CODE is modified.  */
 136
 137 #define COMPOSITION_DECODE_RULE(rule_code, gref, nref, xoff, yoff)      \
 138   do {                                                                  \
 139     xoff = (rule_code) >> 16;                                           \
 140     yoff = ((rule_code) >> 8) & 0xFF;                                   \
 141     rule_code &= 0xFF;                                                  \
 142     gref = (rule_code) / 12;                                            \
 143     if (gref > 12) gref = 11;                                           \
 144     nref = (rule_code) % 12;                                            \
 145   } while (0)
 146
 147 /* Return encoded composition rule for the pair of global reference
 148    point GREF and new reference point NREF.  If arguments are invalid,
 149    return -1. */
 150 #define COMPOSITION_ENCODE_RULE(gref, nref)             \
 151   ((unsigned) (gref) < 12 && (unsigned) (nref) < 12     \
 152    ? (gref) * 12 + (nref) : -1)
 153
 154 /* Data structure that records information about a composition
 155    currently used in some buffers or strings.
 156
 157    When a composition is assigned an ID number (by
 158    get_composition_id), this structure is allocated for the
 159    composition and linked in composition_table[ID].
 160
 161    Identical compositions appearing at different places have the same
 162    ID, and thus share the same instance of this structure.  */
 163
 164 struct composition {
 165   /* Number of glyphs of the composition components.  */
 166   unsigned glyph_len;
 167
 168   /* Width, ascent, and descent pixels of the composition.  */
 169   short pixel_width, ascent, descent;
 170
 171   short lbearing, rbearing;
 172
 173   /* How many columns the overall glyphs occupy on the screen.  This
 174      gives an approximate value for column calculation in
 175      Fcurrent_column, and etc.  */
 176   unsigned short width;
 177
 178   /* Method of the composition.  */
 179   enum composition_method method;
 180
 181   /* Index to the composition hash table.  */
 182   int hash_index;
 183
 184   /* For which font we have calculated the remaining members.  The
 185      actual type is device dependent.  */
 186   void *font;
 187
 188   /* Pointer to an array of x-offset and y-offset (by pixels) of
 189      glyphs.  This points to a sufficient memory space (sizeof (int) *
 190      glyph_len * 2) that is allocated when the composition is
 191      registered in composition_table.  X-offset and Y-offset of Nth
 192      glyph are (2N)th and (2N+1)th elements respectively.  */
 193   short *offsets;
 194 };
 195
 196 /* Table of pointers to the structure `composition' indexed by
 197    COMPOSITION-ID.  */
 198 extern struct composition **composition_table;
 199 /* Number of the currently registered compositions.  */
 200 extern int n_compositions;
 201
 202 /* Mask bits for CHECK_MASK arg to update_compositions.
 203    For a change in the region FROM and TO, check compositions ... */
 204 #define CHECK_HEAD      1       /* adjacent to FROM */
 205 #define CHECK_TAIL      2       /* adjacent to TO */
 206 #define CHECK_INSIDE    4       /* between FROM and TO */
 207 #define CHECK_BORDER    (CHECK_HEAD | CHECK_TAIL)
 208 #define CHECK_ALL       (CHECK_BORDER | CHECK_INSIDE)
 209
 210 extern Lisp_Object Qcomposition;
 211 extern Lisp_Object composition_hash_table;
 212 extern Lisp_Object Qauto_composed;
 213 extern Lisp_Object Vauto_composition_function;
 214 extern Lisp_Object Qauto_composition_function;
 215
 216 extern int get_composition_id P_ ((int, int, int, Lisp_Object, Lisp_Object));
 217 extern int find_composition P_ ((int, int, EMACS_INT *, EMACS_INT *, Lisp_Object *,
 218                                  Lisp_Object));
 219 extern void update_compositions P_ ((EMACS_INT, EMACS_INT, int));
 220 extern void make_composition_value_copy P_ ((Lisp_Object));
 221 extern void compose_region P_ ((int, int, Lisp_Object, Lisp_Object,
 222                                 Lisp_Object));
 223 extern void syms_of_composite P_ ((void));
 224 extern void compose_text P_ ((int, int, Lisp_Object, Lisp_Object,
 225                               Lisp_Object));
 226
 227 #endif /* not EMACS_COMPOSITE_H */
 228
 229 /* arch-tag: 59524d89-c645-47bd-b5e6-65e861690118
 230    (do not change this comment) */