code.delx.au - gnu-emacs/blob - src/composite.h

   1 /* Header for composite sequence handler.
   2    Copyright (C) 2001, 2002, 2003, 2004, 2005,
   3                  2006, 2007, 2008 Free Software Foundation, Inc.
   4    Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
   5      National Institute of Advanced Industrial Science and Technology (AIST)
   6      Registration Number H14PRO021
   7    Copyright (C) 2003, 2006
   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 3, 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 of 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   /* Compose by specified lispy glyph-string.  */
  44   COMPOSITION_WITH_GLYPH_STRING,
  45   /* This is not a method.  */
  46   COMPOSITION_NO
  47 };
  48
  49 /* Maximum number of compoments a single composition can have.  */
  50 #define MAX_COMPOSITION_COMPONENTS 16
  51
  52 /* These macros access information about a composition that
  53    has `composition' property PROP.  PROP is:
  54         ((LENGTH . COMPONENTS) . MODIFICATION-FUNC)
  55    or
  56         (COMPOSITION-ID . (LENGTH COMPONENTS . MODIFICATION-FUNC))
  57    They don't check validity of PROP.  */
  58
  59 /* Temporary variable used only in the following macros.  */
  60 extern Lisp_Object composition_temp;
  61
  62 /* Return 1 if the composition is already registered.  */
  63 #define COMPOSITION_REGISTERD_P(prop) INTEGERP (XCAR (prop))
  64
  65 /* Return ID number of the already registered composition.  */
  66 #define COMPOSITION_ID(prop) XINT (XCAR (prop))
  67
  68 /* Return length of the composition.  */
  69 #define COMPOSITION_LENGTH(prop)        \
  70   (COMPOSITION_REGISTERD_P (prop)       \
  71    ? XINT (XCAR (XCDR (prop)))          \
  72    : XINT (XCAR (XCAR (prop))))
  73
  74 /* Return components of the composition.  */
  75 #define COMPOSITION_COMPONENTS(prop)    \
  76   (COMPOSITION_REGISTERD_P (prop)       \
  77    ? XCAR (XCDR (XCDR (prop)))          \
  78    : XCDR (XCAR (prop)))
  79
  80 /* Return modification function of the composition.  */
  81 #define COMPOSITION_MODIFICATION_FUNC(prop)     \
  82   (COMPOSITION_REGISTERD_P (prop)               \
  83    ? XCDR (XCDR (XCDR (prop)))                  \
  84    : CONSP (prop) ? XCDR (prop) : Qnil)
  85
  86 /* Return the method of composition.  */
  87 #define COMPOSITION_METHOD(prop)                                        \
  88   (COMPOSITION_REGISTERD_P (prop)                                       \
  89    ? composition_table[COMPOSITION_ID (prop)]->method                   \
  90    : (composition_temp = XCDR (XCAR (prop)),                            \
  91       (NILP (composition_temp)                                          \
  92        ? COMPOSITION_RELATIVE                                           \
  93        : (INTEGERP (composition_temp) || STRINGP (composition_temp))    \
  94        ? COMPOSITION_WITH_ALTCHARS                                      \
  95        : (VECTORP (composition_temp)                                    \
  96           && ASIZE (composition_temp) >= 2                              \
  97           && VECTORP (AREF (composition_temp, 0)))                      \
  98        ? COMPOSITION_WITH_GLYPH_STRING                                  \
  99        : COMPOSITION_WITH_RULE_ALTCHARS)))
 100
 101 /* Return 1 if the composition is valid.  It is valid if length of
 102    the composition equals to (END - START).  */
 103 #define COMPOSITION_VALID_P(start, end, prop)                   \
 104   (CONSP (prop)                                                 \
 105    && (COMPOSITION_REGISTERD_P (prop)                           \
 106        ? (COMPOSITION_ID (prop) >= 0                            \
 107           && COMPOSITION_ID (prop) <= n_compositions            \
 108           && CONSP (XCDR (prop)))                               \
 109        : (composition_temp = XCAR (prop),                       \
 110           (CONSP (composition_temp)                             \
 111            && (composition_temp = XCDR (composition_temp),      \
 112                (NILP (composition_temp)                         \
 113                 || STRINGP (composition_temp)                   \
 114                 || VECTORP (composition_temp)                   \
 115                 || INTEGERP (composition_temp)                  \
 116                 || CONSP (composition_temp))))))                \
 117    && (end - start) == COMPOSITION_LENGTH (prop))
 118
 119 /* Return the Nth glyph of composition specified by CMP.  CMP is a
 120    pointer to `struct composition'. */
 121 #define COMPOSITION_GLYPH(cmp, n)                                       \
 122   XINT (XVECTOR (XVECTOR (XHASH_TABLE (composition_hash_table)          \
 123                           ->key_and_value)                              \
 124                  ->contents[cmp->hash_index * 2])                       \
 125         ->contents[cmp->method == COMPOSITION_WITH_RULE_ALTCHARS        \
 126                   ? (n) * 2 : (n)])
 127
 128 /* Return the encoded composition rule to compose the Nth glyph of
 129    rule-base composition specified by CMP.  CMP is a pointer to
 130    `struct composition'. */
 131 #define COMPOSITION_RULE(cmp, n)                                \
 132   XINT (XVECTOR (XVECTOR (XHASH_TABLE (composition_hash_table)  \
 133                           ->key_and_value)                      \
 134                  ->contents[cmp->hash_index * 2])               \
 135         ->contents[(n) * 2 - 1])
 136
 137 /* Decode encoded composition rule RULE_CODE into GREF (global
 138    reference point code), NREF (new reference point code), XOFF
 139    (horizontal offset) YOFF (vertical offset).  Don't check RULE_CODE,
 140    always set GREF and NREF to valid values.  By side effect,
 141    RULE_CODE is modified.  */
 142
 143 #define COMPOSITION_DECODE_RULE(rule_code, gref, nref, xoff, yoff)      \
 144   do {                                                                  \
 145     xoff = (rule_code) >> 16;                                           \
 146     yoff = ((rule_code) >> 8) & 0xFF;                                   \
 147     rule_code &= 0xFF;                                                  \
 148     gref = (rule_code) / 12;                                            \
 149     if (gref > 12) gref = 11;                                           \
 150     nref = (rule_code) % 12;                                            \
 151   } while (0)
 152
 153 /* Return encoded composition rule for the pair of global reference
 154    point GREF and new reference point NREF.  If arguments are invalid,
 155    return -1. */
 156 #define COMPOSITION_ENCODE_RULE(gref, nref)             \
 157   ((unsigned) (gref) < 12 && (unsigned) (nref) < 12     \
 158    ? (gref) * 12 + (nref) : -1)
 159
 160 /* Data structure that records information about a composition
 161    currently used in some buffers or strings.
 162
 163    When a composition is assigned an ID number (by
 164    get_composition_id), this structure is allocated for the
 165    composition and linked in composition_table[ID].
 166
 167    Identical compositions appearing at different places have the same
 168    ID, and thus share the same instance of this structure.  */
 169
 170 struct composition {
 171   /* Number of glyphs of the composition components.  */
 172   unsigned glyph_len;
 173
 174   /* Width, ascent, and descent pixels of the composition.  */
 175   short pixel_width, ascent, descent;
 176
 177   short lbearing, rbearing;
 178
 179   /* How many columns the overall glyphs occupy on the screen.  This
 180      gives an approximate value for column calculation in
 181      Fcurrent_column, and etc.  */
 182   unsigned short width;
 183
 184   /* Method of the composition.  */
 185   enum composition_method method;
 186
 187   /* Index to the composition hash table.  */
 188   int hash_index;
 189
 190   /* For which font we have calculated the remaining members.  The
 191      actual type is device dependent.  */
 192   void *font;
 193
 194   /* Pointer to an array of x-offset and y-offset (by pixels) of
 195      glyphs.  This points to a sufficient memory space (sizeof (int) *
 196      glyph_len * 2) that is allocated when the composition is
 197      registered in composition_table.  X-offset and Y-offset of Nth
 198      glyph are (2N)th and (2N+1)th elements respectively.  */
 199   short *offsets;
 200 };
 201
 202 /* Table of pointers to the structure `composition' indexed by
 203    COMPOSITION-ID.  */
 204 extern struct composition **composition_table;
 205 /* Number of the currently registered compositions.  */
 206 extern int n_compositions;
 207
 208 /* Mask bits for CHECK_MASK arg to update_compositions.
 209    For a change in the region FROM and TO, check compositions ... */
 210 #define CHECK_HEAD      1       /* adjacent to FROM */
 211 #define CHECK_TAIL      2       /* adjacent to TO */
 212 #define CHECK_INSIDE    4       /* between FROM and TO */
 213 #define CHECK_BORDER    (CHECK_HEAD | CHECK_TAIL)
 214 #define CHECK_ALL       (CHECK_BORDER | CHECK_INSIDE)
 215
 216 extern Lisp_Object Qcomposition;
 217 extern Lisp_Object composition_hash_table;
 218 extern Lisp_Object Qauto_composed;
 219 extern Lisp_Object Vauto_composition_function;
 220 extern Lisp_Object Qauto_composition_function;
 221
 222 extern int get_composition_id P_ ((int, int, int, Lisp_Object, Lisp_Object));
 223 extern int find_composition P_ ((int, int, EMACS_INT *, EMACS_INT *, Lisp_Object *,
 224                                  Lisp_Object));
 225 extern void update_compositions P_ ((EMACS_INT, EMACS_INT, int));
 226 extern void make_composition_value_copy P_ ((Lisp_Object));
 227 extern void compose_region P_ ((int, int, Lisp_Object, Lisp_Object,
 228                                 Lisp_Object));
 229 extern void syms_of_composite P_ ((void));
 230 extern void compose_text P_ ((int, int, Lisp_Object, Lisp_Object,
 231                               Lisp_Object));
 232
 233 #endif /* not EMACS_COMPOSITE_H */
 234
 235 /* arch-tag: 59524d89-c645-47bd-b5e6-65e861690118
 236    (do not change this comment) */