src/composite.h

   1 /* Header for composite sequence handler.
   2    Copyright (C) 2001-2016 Free Software Foundation, Inc.
   3    Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
   4      National Institute of Advanced Industrial Science and Technology (AIST)
   5      Registration Number H14PRO021
   6    Copyright (C) 2003, 2006
   7      National Institute of Advanced Industrial Science and Technology (AIST)
   8      Registration Number H13PRO009
   9
  10 This file is part of GNU Emacs.
  11
  12 GNU Emacs is free software: you can redistribute it and/or modify
  13 it under the terms of the GNU General Public License as published by
  14 the Free Software Foundation, either version 3 of the License, or (at
  15 your option) any later version.
  16
  17 GNU Emacs is distributed in the hope that it will be useful,
  18 but WITHOUT ANY WARRANTY; without even the implied warranty of
  19 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20 GNU General Public License for more details.
  21
  22 You should have received a copy of the GNU General Public License
  23 along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
  24
  25 #ifndef EMACS_COMPOSITE_H
  26 #define EMACS_COMPOSITE_H
  27
  28 #include "font.h"
  29
  30 INLINE_HEADER_BEGIN
  31
  32 /* Methods to display a sequence of components of a composition.  */
  33 enum composition_method {
  34   /* Compose relatively without alternate characters.  */
  35   COMPOSITION_RELATIVE,
  36   /* Compose by specified composition rules.  This is not used in
  37      Emacs 21 but we need it to decode files saved in the older
  38      versions of Emacs.  */
  39   COMPOSITION_WITH_RULE,
  40   /* Compose relatively with alternate characters.  */
  41   COMPOSITION_WITH_ALTCHARS,
  42   /* Compose by specified composition rules with alternate characters.  */
  43   COMPOSITION_WITH_RULE_ALTCHARS,
  44   /* This is not a method.  */
  45   COMPOSITION_NO
  46 };
  47
  48 /* Maximum number of components a single composition can have.  */
  49 #define MAX_COMPOSITION_COMPONENTS 16
  50
  51 /* These operations access information about a composition that
  52    has `composition' property PROP.  PROP is:
  53         ((LENGTH . COMPONENTS) . MODIFICATION-FUNC)
  54    or
  55         (COMPOSITION-ID . (LENGTH COMPONENTS . MODIFICATION-FUNC))
  56    They don't check validity of PROP.  */
  57
  58 /* Return true if PROP is already registered.  */
  59 INLINE bool
  60 composition_registered_p (Lisp_Object prop)
  61 {
  62   return INTEGERP (XCAR (prop));
  63 }
  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_registered_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_registered_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_registered_p (prop)              \
  83    ? XCDR (XCDR (XCDR (prop)))                  \
  84    : CONSP (prop) ? XCDR (prop) : Qnil)
  85
  86 /* Return the Nth glyph of composition specified by CMP.  CMP is a
  87    pointer to `struct composition'.  */
  88 #define COMPOSITION_GLYPH(cmp, n)                                       \
  89   XINT (XVECTOR (XVECTOR (XHASH_TABLE (composition_hash_table)          \
  90                           ->key_and_value)                              \
  91                  ->contents[cmp->hash_index * 2])                       \
  92         ->contents[cmp->method == COMPOSITION_WITH_RULE_ALTCHARS        \
  93                   ? (n) * 2 : (n)])
  94
  95 /* Return the encoded composition rule to compose the Nth glyph of
  96    rule-base composition specified by CMP.  CMP is a pointer to
  97    `struct composition'. */
  98 #define COMPOSITION_RULE(cmp, n)                                \
  99   XINT (XVECTOR (XVECTOR (XHASH_TABLE (composition_hash_table)  \
 100                           ->key_and_value)                      \
 101                  ->contents[cmp->hash_index * 2])               \
 102         ->contents[(n) * 2 - 1])
 103
 104 /* Decode encoded composition rule RULE_CODE into GREF (global
 105    reference point code), NREF (new ref. point code).  Don't check RULE_CODE;
 106    always set GREF and NREF to valid values.  By side effect,
 107    RULE_CODE is modified.  */
 108
 109 #define COMPOSITION_DECODE_REFS(rule_code, gref, nref)                  \
 110   do {                                                                  \
 111     rule_code &= 0xFF;                                                  \
 112     gref = (rule_code) / 12;                                            \
 113     if (gref > 12) gref = 11;                                           \
 114     nref = (rule_code) % 12;                                            \
 115   } while (false)
 116
 117 /* Like COMPOSITION_DECODE_REFS (RULE_CODE, GREF, NREF), but also
 118    decode RULE_CODE into XOFF and YOFF (vertical offset).  */
 119
 120 #define COMPOSITION_DECODE_RULE(rule_code, gref, nref, xoff, yoff)      \
 121   do {                                                                  \
 122     xoff = (rule_code) >> 16;                                           \
 123     yoff = ((rule_code) >> 8) & 0xFF;                                   \
 124     COMPOSITION_DECODE_REFS (rule_code, gref, nref);                    \
 125   } while (false)
 126
 127 /* Nonzero if the global reference point GREF and new reference point NREF are
 128    valid.  */
 129 #define COMPOSITION_ENCODE_RULE_VALID(gref, nref)       \
 130   (UNSIGNED_CMP (gref, <, 12) && UNSIGNED_CMP (nref, <, 12))
 131
 132 /* Return encoded composition rule for the pair of global reference
 133    point GREF and new reference point NREF.  Arguments must be valid.  */
 134 #define COMPOSITION_ENCODE_RULE(gref, nref)             \
 135   ((gref) * 12 + (nref))
 136
 137 /* Data structure that records information about a composition
 138    currently used in some buffers or strings.
 139
 140    When a composition is assigned an ID number (by
 141    get_composition_id), this structure is allocated for the
 142    composition and linked in composition_table[ID].
 143
 144    Identical compositions appearing at different places have the same
 145    ID, and thus share the same instance of this structure.  */
 146
 147 struct composition {
 148   /* Number of glyphs of the composition components.  */
 149   int glyph_len;
 150
 151   /* Width, ascent, and descent pixels of the composition.  */
 152   short pixel_width, ascent, descent;
 153
 154   short lbearing, rbearing;
 155
 156   /* How many columns the overall glyphs occupy on the screen.  This
 157      gives an approximate value for column calculation in
 158      Fcurrent_column, and etc.  */
 159   int width;
 160
 161   /* Method of the composition.  */
 162   enum composition_method method;
 163
 164   /* Index to the composition hash table.  */
 165   ptrdiff_t hash_index;
 166
 167   /* For which font we have calculated the remaining members.  The
 168      actual type is device dependent.  */
 169   void *font;
 170
 171   /* Pointer to an array of x-offset and y-offset (by pixels) of
 172      glyphs.  This points to a sufficient memory space (sizeof (short) *
 173      glyph_len * 2) that is allocated when the composition is
 174      registered in composition_table.  X-offset and Y-offset of Nth
 175      glyph are (2N)th and (2N+1)th elements respectively.  */
 176   short *offsets;
 177 };
 178
 179 /* Table of pointers to the structure `composition' indexed by
 180    COMPOSITION-ID.  */
 181 extern struct composition **composition_table;
 182 /* Number of the currently registered compositions.  */
 183 extern ptrdiff_t n_compositions;
 184
 185 /* Mask bits for CHECK_MASK arg to update_compositions.
 186    For a change in the region FROM and TO, check compositions ... */
 187 #define CHECK_HEAD      1       /* adjacent to FROM */
 188 #define CHECK_TAIL      2       /* adjacent to TO */
 189 #define CHECK_INSIDE    4       /* between FROM and TO */
 190 #define CHECK_BORDER    (CHECK_HEAD | CHECK_TAIL)
 191 #define CHECK_ALL       (CHECK_BORDER | CHECK_INSIDE)
 192
 193 extern Lisp_Object composition_hash_table;
 194 extern ptrdiff_t get_composition_id (ptrdiff_t, ptrdiff_t, ptrdiff_t,
 195                                      Lisp_Object, Lisp_Object);
 196 extern bool find_composition (ptrdiff_t, ptrdiff_t, ptrdiff_t *, ptrdiff_t *,
 197                               Lisp_Object *, Lisp_Object);
 198 extern void update_compositions (ptrdiff_t, ptrdiff_t, int);
 199 extern void make_composition_value_copy (Lisp_Object);
 200 extern void syms_of_composite (void);
 201 extern void compose_text (ptrdiff_t, ptrdiff_t, Lisp_Object, Lisp_Object,
 202                           Lisp_Object);
 203
 204 /* Return the method of a composition with property PROP.  */
 205
 206 INLINE enum composition_method
 207 composition_method (Lisp_Object prop)
 208 {
 209   if (composition_registered_p (prop))
 210     return composition_table[COMPOSITION_ID (prop)]->method;
 211   else
 212     {
 213       Lisp_Object temp = XCDR (XCAR (prop));
 214       return (NILP (temp)
 215               ? COMPOSITION_RELATIVE
 216               : INTEGERP (temp) || STRINGP (temp)
 217               ? COMPOSITION_WITH_ALTCHARS
 218               : COMPOSITION_WITH_RULE_ALTCHARS);
 219     }
 220 }
 221
 222 /* Given offsets START and END, return true if PROP is a valid composition
 223    property with length END - START.  */
 224
 225 INLINE bool
 226 composition_valid_p (ptrdiff_t start, ptrdiff_t end, Lisp_Object prop)
 227 {
 228   return (CONSP (prop)
 229           && (composition_registered_p (prop)
 230               ? (COMPOSITION_ID (prop) >= 0
 231                  && COMPOSITION_ID (prop) <= n_compositions
 232                  && CONSP (XCDR (prop)))
 233               : (CONSP (XCAR (prop))
 234                   && (NILP (XCDR (XCAR (prop)))
 235                       || STRINGP (XCDR (XCAR (prop)))
 236                       || VECTORP (XCDR (XCAR (prop)))
 237                       || INTEGERP (XCDR (XCAR (prop)))
 238                       || CONSP (XCDR (XCAR (prop))))))
 239           && COMPOSITION_LENGTH (prop) == end - start);
 240 }
 241
 242 /* Macros for lispy glyph-string.  This is completely different from
 243    struct glyph_string.  */
 244
 245 #define LGSTRING_HEADER(lgs) AREF (lgs, 0)
 246 #define LGSTRING_SET_HEADER(lgs, header) ASET (lgs, 0, header)
 247
 248 #define LGSTRING_FONT(lgs) AREF (LGSTRING_HEADER (lgs), 0)
 249 #define LGSTRING_CHAR(lgs, i) AREF (LGSTRING_HEADER (lgs), (i) + 1)
 250 #define LGSTRING_CHAR_LEN(lgs) (ASIZE (LGSTRING_HEADER (lgs)) - 1)
 251
 252 #define LGSTRING_SET_FONT(lgs, val) ASET (LGSTRING_HEADER (lgs), 0, (val))
 253 #define LGSTRING_SET_CHAR(lgs, i, c) ASET (LGSTRING_HEADER (lgs), (i) + 1, (c))
 254
 255 #define LGSTRING_ID(lgs) AREF (lgs, 1)
 256 #define LGSTRING_SET_ID(lgs, id) ASET (lgs, 1, id)
 257
 258 #define LGSTRING_GLYPH_LEN(lgs) (ASIZE ((lgs)) - 2)
 259 #define LGSTRING_GLYPH(lgs, idx) AREF ((lgs), (idx) + 2)
 260 #define LGSTRING_SET_GLYPH(lgs, idx, val) ASET ((lgs), (idx) + 2, (val))
 261 INLINE Lisp_Object *
 262 lgstring_glyph_addr (Lisp_Object lgs, ptrdiff_t idx)
 263 {
 264   return aref_addr (lgs, idx + 2);
 265 }
 266
 267 /* Vector size of Lispy glyph.  */
 268 enum lglyph_indices
 269   {
 270     LGLYPH_IX_FROM, LGLYPH_IX_TO,  LGLYPH_IX_CHAR, LGLYPH_IX_CODE,
 271     LGLYPH_IX_WIDTH, LGLYPH_IX_LBEARING, LGLYPH_IX_RBEARING,
 272     LGLYPH_IX_ASCENT, LGLYPH_IX_DESCENT, LGLYPH_IX_ADJUSTMENT,
 273     /* Not an index.  */
 274     LGLYPH_SIZE
 275   };
 276
 277 #define LGLYPH_NEW() Fmake_vector (make_number (LGLYPH_SIZE), Qnil)
 278 #define LGLYPH_FROM(g) XINT (AREF ((g), LGLYPH_IX_FROM))
 279 #define LGLYPH_TO(g) XINT (AREF ((g), LGLYPH_IX_TO))
 280 #define LGLYPH_CHAR(g) XINT (AREF ((g), LGLYPH_IX_CHAR))
 281 #define LGLYPH_CODE(g)                                          \
 282   (NILP (AREF ((g), LGLYPH_IX_CODE))                            \
 283    ? FONT_INVALID_CODE                                          \
 284    : cons_to_unsigned (AREF (g, LGLYPH_IX_CODE), TYPE_MAXIMUM (unsigned)))
 285 #define LGLYPH_WIDTH(g) XINT (AREF ((g), LGLYPH_IX_WIDTH))
 286 #define LGLYPH_LBEARING(g) XINT (AREF ((g), LGLYPH_IX_LBEARING))
 287 #define LGLYPH_RBEARING(g) XINT (AREF ((g), LGLYPH_IX_RBEARING))
 288 #define LGLYPH_ASCENT(g) XINT (AREF ((g), LGLYPH_IX_ASCENT))
 289 #define LGLYPH_DESCENT(g) XINT (AREF ((g), LGLYPH_IX_DESCENT))
 290 #define LGLYPH_ADJUSTMENT(g) AREF ((g), LGLYPH_IX_ADJUSTMENT)
 291 #define LGLYPH_SET_FROM(g, val) ASET ((g), LGLYPH_IX_FROM, make_number (val))
 292 #define LGLYPH_SET_TO(g, val) ASET ((g), LGLYPH_IX_TO, make_number (val))
 293 #define LGLYPH_SET_CHAR(g, val) ASET ((g), LGLYPH_IX_CHAR, make_number (val))
 294 /* Callers must assure that VAL is not negative!  */
 295 #define LGLYPH_SET_CODE(g, val)                                         \
 296   ASET (g, LGLYPH_IX_CODE,                                              \
 297         val == FONT_INVALID_CODE ? Qnil : INTEGER_TO_CONS (val))
 298
 299 #define LGLYPH_SET_WIDTH(g, val) ASET ((g), LGLYPH_IX_WIDTH, make_number (val))
 300 #define LGLYPH_SET_LBEARING(g, val) ASET ((g), LGLYPH_IX_LBEARING, make_number (val))
 301 #define LGLYPH_SET_RBEARING(g, val) ASET ((g), LGLYPH_IX_RBEARING, make_number (val))
 302 #define LGLYPH_SET_ASCENT(g, val) ASET ((g), LGLYPH_IX_ASCENT, make_number (val))
 303 #define LGLYPH_SET_DESCENT(g, val) ASET ((g), LGLYPH_IX_DESCENT, make_number (val))
 304 #define LGLYPH_SET_ADJUSTMENT(g, val) ASET ((g), LGLYPH_IX_ADJUSTMENT, (val))
 305
 306 #define LGLYPH_XOFF(g) (VECTORP (LGLYPH_ADJUSTMENT (g)) \
 307                         ? XINT (AREF (LGLYPH_ADJUSTMENT (g), 0)) : 0)
 308 #define LGLYPH_YOFF(g) (VECTORP (LGLYPH_ADJUSTMENT (g)) \
 309                         ? XINT (AREF (LGLYPH_ADJUSTMENT (g), 1)) : 0)
 310 #define LGLYPH_WADJUST(g) (VECTORP (LGLYPH_ADJUSTMENT (g)) \
 311                            ? XINT (AREF (LGLYPH_ADJUSTMENT (g), 2)) : 0)
 312
 313 extern Lisp_Object composition_gstring_put_cache (Lisp_Object, ptrdiff_t);
 314 extern Lisp_Object composition_gstring_from_id (ptrdiff_t);
 315 extern bool composition_gstring_p (Lisp_Object);
 316 extern int composition_gstring_width (Lisp_Object, ptrdiff_t, ptrdiff_t,
 317                                       struct font_metrics *);
 318
 319 extern void composition_compute_stop_pos (struct composition_it *,
 320                                           ptrdiff_t, ptrdiff_t, ptrdiff_t,
 321                                           Lisp_Object);
 322 extern bool composition_reseat_it (struct composition_it *, ptrdiff_t,
 323                                    ptrdiff_t, ptrdiff_t, struct window *,
 324                                    struct face *, Lisp_Object);
 325 extern int composition_update_it (struct composition_it *,
 326                                   ptrdiff_t, ptrdiff_t, Lisp_Object);
 327
 328 extern ptrdiff_t composition_adjust_point (ptrdiff_t, ptrdiff_t);
 329
 330 INLINE_HEADER_END
 331
 332 #endif /* not EMACS_COMPOSITE_H */