src/xftfont.c

   1 /* xftfont.c -- XFT font driver.
   2    Copyright (C) 2006, 2007, 2008 Free Software Foundation, Inc.
   3    Copyright (C) 2006, 2007, 2008
   4      National Institute of Advanced Industrial Science and Technology (AIST)
   5      Registration Number H13PRO009
   6
   7 This file is part of GNU Emacs.
   8
   9 GNU Emacs is free software: you can redistribute it and/or modify
  10 it under the terms of the GNU General Public License as published by
  11 the Free Software Foundation, either version 3 of the License, or
  12 (at your option) any later version.
  13
  14 GNU Emacs is distributed in the hope that it will be useful,
  15 but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 GNU General Public License for more details.
  18
  19 You should have received a copy of the GNU General Public License
  20 along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
  21
  22 #include <config.h>
  23 #include <stdio.h>
  24 #include <X11/Xlib.h>
  25 #include <X11/Xft/Xft.h>
  26
  27 #include "lisp.h"
  28 #include "dispextern.h"
  29 #include "xterm.h"
  30 #include "frame.h"
  31 #include "blockinput.h"
  32 #include "character.h"
  33 #include "charset.h"
  34 #include "fontset.h"
  35 #include "font.h"
  36 #include "ftfont.h"
  37
  38 /* Xft font driver.  */
  39
  40 static Lisp_Object Qxft;
  41
  42 /* The actual structure for Xft font that can be casted to struct
  43    font.  */
  44
  45 struct xftfont_info
  46 {
  47   struct font font;
  48   Display *display;
  49   int screen;
  50   XftFont *xftfont;
  51 #ifdef HAVE_LIBOTF
  52   int maybe_otf;          /* Flag to tell if this may be OTF or not.  */
  53   OTF *otf;
  54 #endif  /* HAVE_LIBOTF */
  55 };
  56
  57 /* Structure pointed by (struct face *)->extra  */
  58
  59 struct xftface_info
  60 {
  61   XftColor xft_fg;              /* color for face->foreground */
  62   XftColor xft_bg;              /* color for face->background */
  63 };
  64
  65 static void xftfont_get_colors P_ ((FRAME_PTR, struct face *, GC gc,
  66                                     struct xftface_info *,
  67                                     XftColor *fg, XftColor *bg));
  68
  69
  70 /* Setup foreground and background colors of GC into FG and BG.  If
  71    XFTFACE_INFO is not NULL, reuse the colors in it if possible.  BG
  72    may be NULL.  */
  73
  74 static void
  75 xftfont_get_colors (f, face, gc, xftface_info, fg, bg)
  76      FRAME_PTR f;
  77      struct face *face;
  78      GC gc;
  79      struct xftface_info *xftface_info;
  80      XftColor *fg, *bg;
  81 {
  82   if (xftface_info && face->gc == gc)
  83     {
  84       *fg = xftface_info->xft_fg;
  85       if (bg)
  86         *bg = xftface_info->xft_bg;
  87     }
  88   else
  89     {
  90       XGCValues xgcv;
  91       int fg_done = 0, bg_done = 0;
  92
  93       BLOCK_INPUT;
  94       XGetGCValues (FRAME_X_DISPLAY (f), gc,
  95                     GCForeground | GCBackground, &xgcv);
  96       if (xftface_info)
  97         {
  98           if (xgcv.foreground == face->foreground)
  99             *fg = xftface_info->xft_fg, fg_done = 1;
 100           else if (xgcv.foreground == face->background)
 101             *fg = xftface_info->xft_bg, fg_done = 1;
 102           if (! bg)
 103             bg_done = 1;
 104           else if (xgcv.background == face->background)
 105             *bg = xftface_info->xft_bg, bg_done = 1;
 106           else if (xgcv.background == face->foreground)
 107             *bg = xftface_info->xft_fg, bg_done = 1;
 108         }
 109
 110       if (fg_done + bg_done < 2)
 111         {
 112           XColor colors[2];
 113
 114           colors[0].pixel = fg->pixel = xgcv.foreground;
 115           if (bg)
 116             colors[1].pixel = bg->pixel = xgcv.background;
 117           XQueryColors (FRAME_X_DISPLAY (f), FRAME_X_COLORMAP (f), colors,
 118                         bg ? 2 : 1);
 119           fg->color.alpha = 0xFFFF;
 120           fg->color.red = colors[0].red;
 121           fg->color.green = colors[0].green;
 122           fg->color.blue = colors[0].blue;
 123           if (bg)
 124             {
 125               bg->color.alpha = 0xFFFF;
 126               bg->color.red = colors[1].red;
 127               bg->color.green = colors[1].green;
 128               bg->color.blue = colors[1].blue;
 129             }
 130         }
 131       UNBLOCK_INPUT;
 132     }
 133 }
 134
 135
 136 static Lisp_Object xftfont_list P_ ((Lisp_Object, Lisp_Object));
 137 static Lisp_Object xftfont_match P_ ((Lisp_Object, Lisp_Object));
 138 static Lisp_Object xftfont_open P_ ((FRAME_PTR, Lisp_Object, int));
 139 static void xftfont_close P_ ((FRAME_PTR, struct font *));
 140 static int xftfont_prepare_face P_ ((FRAME_PTR, struct face *));
 141 static void xftfont_done_face P_ ((FRAME_PTR, struct face *));
 142 static unsigned xftfont_encode_char P_ ((struct font *, int));
 143 static int xftfont_text_extents P_ ((struct font *, unsigned *, int,
 144                                      struct font_metrics *));
 145 static int xftfont_draw P_ ((struct glyph_string *, int, int, int, int, int));
 146
 147 static int xftfont_anchor_point P_ ((struct font *, unsigned, int,
 148                                      int *, int *));
 149 static int xftfont_end_for_frame P_ ((FRAME_PTR f));
 150
 151 struct font_driver xftfont_driver;
 152
 153 static Lisp_Object
 154 xftfont_list (frame, spec)
 155      Lisp_Object frame;
 156      Lisp_Object spec;
 157 {
 158   Lisp_Object list = ftfont_driver.list (frame, spec), tail;
 159
 160   for (tail = list; CONSP (tail); tail = XCDR (tail))
 161     ASET (XCAR (tail), FONT_TYPE_INDEX, Qxft);
 162   return list;
 163 }
 164
 165 static Lisp_Object
 166 xftfont_match (frame, spec)
 167      Lisp_Object frame;
 168      Lisp_Object spec;
 169 {
 170   Lisp_Object entity = ftfont_driver.match (frame, spec);
 171
 172   if (! NILP (entity))
 173     ASET (entity, FONT_TYPE_INDEX, Qxft);
 174   return entity;
 175 }
 176
 177 extern Lisp_Object ftfont_font_format P_ ((FcPattern *));
 178
 179 static FcChar8 ascii_printable[95];
 180
 181 static Lisp_Object
 182 xftfont_open (f, entity, pixel_size)
 183      FRAME_PTR f;
 184      Lisp_Object entity;
 185      int pixel_size;
 186 {
 187   Display *display = FRAME_X_DISPLAY (f);
 188   Lisp_Object val, filename, font_object;
 189   FcPattern *pat = NULL;
 190   struct xftfont_info *xftfont_info = NULL;
 191   struct font *font;
 192   double size = 0;
 193   XftFont *xftfont = NULL;
 194   int spacing;
 195   char name[256];
 196   int len, i;
 197   XGlyphInfo extents;
 198   FT_Face ft_face;
 199
 200   val = assq_no_quit (QCfont_entity, AREF (entity, FONT_EXTRA_INDEX));
 201   if (! CONSP (val))
 202     return Qnil;
 203   val = XCDR (val);
 204   filename = XCAR (val);
 205   size = XINT (AREF (entity, FONT_SIZE_INDEX));
 206   if (size == 0)
 207     size = pixel_size;
 208   pat = FcPatternCreate ();
 209   FcPatternAddString (pat, FC_FILE, (FcChar8 *) SDATA (filename));
 210   FcPatternAddDouble (pat, FC_PIXEL_SIZE, pixel_size);
 211   /*FcPatternAddBool (pat, FC_ANTIALIAS, FcTrue);*/
 212   val = AREF (entity, FONT_FAMILY_INDEX);
 213   if (! NILP (val))
 214     FcPatternAddString (pat, FC_FAMILY, (FcChar8 *) SDATA (SYMBOL_NAME (val)));
 215   FcConfigSubstitute (NULL, pat, FcMatchPattern);
 216
 217   BLOCK_INPUT;
 218   XftDefaultSubstitute (display, FRAME_X_SCREEN_NUMBER (f), pat);
 219   xftfont = XftFontOpenPattern (display, pat);
 220   UNBLOCK_INPUT;
 221   if (! xftfont)
 222     return Qnil;
 223   /* We should not destroy PAT here because it is kept in XFTFONT and
 224      destroyed automatically when XFTFONT is closed.  */
 225   font_object = font_make_object (VECSIZE (struct xftfont_info));
 226   ASET (font_object, FONT_TYPE_INDEX, Qxft);
 227   for (i = 1; i < FONT_ENTITY_MAX; i++)
 228     ASET (font_object, i, AREF (entity, i));
 229   ASET (font_object, FONT_SIZE_INDEX, make_number (size));
 230   len = font_unparse_xlfd (entity, size, name, 256);
 231   if (len > 0)
 232     ASET (font_object, FONT_NAME_INDEX, make_unibyte_string (name, len));
 233   len = font_unparse_fcname (entity, size, name, 256);
 234   if (len > 0)
 235     ASET (font_object, FONT_FULLNAME_INDEX, make_unibyte_string (name, len));
 236   else
 237     ASET (font_object, FONT_FULLNAME_INDEX,
 238           AREF (font_object, FONT_NAME_INDEX));
 239   ASET (font_object, FONT_FILE_INDEX, filename);
 240   ASET (font_object, FONT_FORMAT_INDEX,
 241         ftfont_font_format (xftfont->pattern));
 242   font = XFONT_OBJECT (font_object);
 243   font->pixel_size = pixel_size;
 244   font->driver = &xftfont_driver;
 245   font->encoding_charset = font->repertory_charset = -1;
 246
 247   xftfont_info = (struct xftfont_info *) font;
 248   xftfont_info->display = display;
 249   xftfont_info->screen = FRAME_X_SCREEN_NUMBER (f);
 250   xftfont_info->xftfont = xftfont;
 251   font->pixel_size = size;
 252   font->driver = &xftfont_driver;
 253   if (INTEGERP (AREF (entity, FONT_SPACING_INDEX)))
 254     spacing = XINT (AREF (entity, FONT_SPACING_INDEX));
 255   else
 256     spacing = FC_PROPORTIONAL;
 257   if (! ascii_printable[0])
 258     {
 259       int i;
 260       for (i = 0; i < 95; i++)
 261         ascii_printable[i] = ' ' + i;
 262     }
 263   BLOCK_INPUT;
 264   if (spacing != FC_PROPORTIONAL)
 265     {
 266       font->min_width = font->average_width = font->space_width
 267         = xftfont->max_advance_width;
 268       XftTextExtents8 (display, xftfont, ascii_printable + 1, 94, &extents);
 269     }
 270   else
 271     {
 272       XftTextExtents8 (display, xftfont, ascii_printable, 1, &extents);
 273       font->space_width = extents.xOff;
 274       if (font->space_width <= 0)
 275         /* dirty workaround */
 276         font->space_width = pixel_size;
 277       XftTextExtents8 (display, xftfont, ascii_printable + 1, 94, &extents);
 278       font->average_width = (font->space_width + extents.xOff) / 95;
 279     }
 280   UNBLOCK_INPUT;
 281
 282   font->ascent = xftfont->ascent;
 283   if (font->ascent < extents.y)
 284     font->ascent = extents.y;
 285   font->descent = xftfont->descent;
 286   if (font->descent < extents.height - extents.y)
 287     font->descent = extents.height - extents.y;
 288   font->height = font->ascent + font->descent;
 289
 290   ft_face = XftLockFace (xftfont);
 291   if (XINT (AREF (entity, FONT_SIZE_INDEX)) == 0)
 292     {
 293       int upEM = ft_face->units_per_EM;
 294
 295       font->underline_position = -ft_face->underline_position * size / upEM;
 296       font->underline_thickness = -ft_face->underline_thickness * size / upEM;
 297       if (font->underline_thickness > 2)
 298         font->underline_position -= font->underline_thickness / 2;
 299     }
 300   else
 301     {
 302       font->underline_position = -1;
 303       font->underline_thickness = 0;
 304     }
 305 #ifdef HAVE_LIBOTF
 306   xftfont_info->maybe_otf = ft_face->face_flags & FT_FACE_FLAG_SFNT;
 307   xftfont_info->otf = NULL;
 308 #endif  /* HAVE_LIBOTF */
 309   XftUnlockFace (xftfont);
 310
 311   /* Unfortunately Xft doesn't provide a way to get minimum char
 312      width.  So, we use space_width instead.  */
 313   font->min_width = font->space_width;
 314
 315   font->baseline_offset = 0;
 316   font->relative_compose = 0;
 317   font->default_ascent = 0;
 318   font->vertical_centering = 0;
 319
 320   return font_object;
 321 }
 322
 323 static void
 324 xftfont_close (f, font)
 325      FRAME_PTR f;
 326      struct font *font;
 327 {
 328   struct xftfont_info *xftfont_info = (struct xftfont_info *) font;
 329
 330 #ifdef HAVE_LIBOTF
 331   if (xftfont_info->otf)
 332     OTF_close (xftfont_info->otf);
 333 #endif
 334   BLOCK_INPUT;
 335   XftFontClose (xftfont_info->display, xftfont_info->xftfont);
 336   UNBLOCK_INPUT;
 337 }
 338
 339 static int
 340 xftfont_prepare_face (f, face)
 341      FRAME_PTR f;
 342      struct face *face;
 343 {
 344   struct xftface_info *xftface_info;
 345
 346 #if 0
 347   /* This doesn't work if face->ascii_face doesn't use an Xft font. */
 348   if (face != face->ascii_face)
 349     {
 350       face->extra = face->ascii_face->extra;
 351       return 0;
 352     }
 353 #endif
 354
 355   xftface_info = malloc (sizeof (struct xftface_info));
 356   if (! xftface_info)
 357     return -1;
 358   xftfont_get_colors (f, face, face->gc, NULL,
 359                       &xftface_info->xft_fg, &xftface_info->xft_bg);
 360   face->extra = xftface_info;
 361   return 0;
 362 }
 363
 364 static void
 365 xftfont_done_face (f, face)
 366      FRAME_PTR f;
 367      struct face *face;
 368 {
 369   struct xftface_info *xftface_info;
 370
 371 #if 0
 372   /* This doesn't work if face->ascii_face doesn't use an Xft font. */
 373   if (face != face->ascii_face
 374       || ! face->extra)
 375     return;
 376 #endif
 377
 378   xftface_info = (struct xftface_info *) face->extra;
 379   if (xftface_info)
 380     {
 381       free (xftface_info);
 382       face->extra = NULL;
 383     }
 384 }
 385
 386 static unsigned
 387 xftfont_encode_char (font, c)
 388      struct font *font;
 389      int c;
 390 {
 391   struct xftfont_info *xftfont_info = (struct xftfont_info *) font;
 392   unsigned code = XftCharIndex (xftfont_info->display, xftfont_info->xftfont,
 393                                 (FcChar32) c);
 394
 395   return (code ? code : FONT_INVALID_CODE);
 396 }
 397
 398 static int
 399 xftfont_text_extents (font, code, nglyphs, metrics)
 400      struct font *font;
 401      unsigned *code;
 402      int nglyphs;
 403      struct font_metrics *metrics;
 404 {
 405   struct xftfont_info *xftfont_info = (struct xftfont_info *) font;
 406   XGlyphInfo extents;
 407
 408   BLOCK_INPUT;
 409   XftGlyphExtents (xftfont_info->display, xftfont_info->xftfont, code, nglyphs,
 410                    &extents);
 411   UNBLOCK_INPUT;
 412   if (metrics)
 413     {
 414       metrics->lbearing = - extents.x;
 415       metrics->rbearing = - extents.x + extents.width;
 416       metrics->width = extents.xOff;
 417       metrics->ascent = extents.y;
 418       metrics->descent = extents.height - extents.y;
 419     }
 420   return extents.xOff;
 421 }
 422
 423 static XftDraw *
 424 xftfont_get_xft_draw (f)
 425      FRAME_PTR f;
 426 {
 427   XftDraw *xft_draw = font_get_frame_data (f, &xftfont_driver);;
 428
 429   if (! xft_draw)
 430     {
 431       BLOCK_INPUT;
 432       xft_draw= XftDrawCreate (FRAME_X_DISPLAY (f),
 433                                FRAME_X_WINDOW (f),
 434                                FRAME_X_VISUAL (f),
 435                                FRAME_X_COLORMAP (f));
 436       UNBLOCK_INPUT;
 437       if (! xft_draw)
 438         abort ();
 439       font_put_frame_data (f, &xftfont_driver, xft_draw);
 440     }
 441   return xft_draw;
 442 }
 443
 444 static int
 445 xftfont_draw (s, from, to, x, y, with_background)
 446      struct glyph_string *s;
 447      int from, to, x, y, with_background;
 448 {
 449   FRAME_PTR f = s->f;
 450   struct face *face = s->face;
 451   struct xftfont_info *xftfont_info = (struct xftfont_info *) s->font;
 452   struct xftface_info *xftface_info = NULL;
 453   XftDraw *xft_draw = xftfont_get_xft_draw (f);
 454   FT_UInt *code;
 455   XftColor fg, bg;
 456   int len = to - from;
 457   int i;
 458
 459   if (s->font == face->font)
 460     xftface_info = (struct xftface_info *) face->extra;
 461   xftfont_get_colors (f, face, s->gc, xftface_info,
 462                       &fg, with_background ? &bg : NULL);
 463   BLOCK_INPUT;
 464   if (s->num_clips > 0)
 465     XftDrawSetClipRectangles (xft_draw, 0, 0, s->clip, s->num_clips);
 466   else
 467     XftDrawSetClip (xft_draw, NULL);
 468
 469   if (with_background)
 470     XftDrawRect (xft_draw, &bg,
 471                  x, y - face->font->ascent, s->width, face->font->height);
 472   code = alloca (sizeof (FT_UInt) * len);
 473   for (i = 0; i < len; i++)
 474     code[i] = ((XCHAR2B_BYTE1 (s->char2b + from + i) << 8)
 475                | XCHAR2B_BYTE2 (s->char2b + from + i));
 476
 477   if (s->padding_p)
 478     for (i = 0; i < len; i++)
 479       XftDrawGlyphs (xft_draw, &fg, xftfont_info->xftfont,
 480                      x + i, y, code + i, 1);
 481   else
 482     XftDrawGlyphs (xft_draw, &fg, xftfont_info->xftfont,
 483                    x, y, code, len);
 484   UNBLOCK_INPUT;
 485
 486   return len;
 487 }
 488
 489 static int
 490 xftfont_anchor_point (font, code, index, x, y)
 491      struct font *font;
 492      unsigned code;
 493      int index;
 494      int *x, *y;
 495 {
 496   struct xftfont_info *xftfont_info = (struct xftfont_info *) font;
 497   FT_Face ft_face = XftLockFace (xftfont_info->xftfont);
 498   int result;
 499
 500   if (FT_Load_Glyph (ft_face, code, FT_LOAD_DEFAULT) != 0)
 501     result = -1;
 502   else if (ft_face->glyph->format != FT_GLYPH_FORMAT_OUTLINE)
 503     result = -1;
 504   else if (index >= ft_face->glyph->outline.n_points)
 505     result = -1;
 506   else
 507     {
 508       *x = ft_face->glyph->outline.points[index].x;
 509       *y = ft_face->glyph->outline.points[index].y;
 510     }
 511   XftUnlockFace (xftfont_info->xftfont);
 512   return result;
 513 }
 514
 515 static int
 516 xftfont_end_for_frame (f)
 517      FRAME_PTR f;
 518 {
 519   XftDraw *xft_draw = font_get_frame_data (f, &xftfont_driver);
 520
 521   if (xft_draw)
 522     {
 523       BLOCK_INPUT;
 524       XftDrawDestroy (xft_draw);
 525       UNBLOCK_INPUT;
 526       font_put_frame_data (f, &xftfont_driver, NULL);
 527     }
 528   return 0;
 529 }
 530
 531 #ifdef HAVE_LIBOTF
 532 #ifdef HAVE_M17N_FLT
 533 static Lisp_Object
 534 xftfont_shape (lgstring)
 535      Lisp_Object lgstring;
 536 {
 537   struct font *font;
 538   struct xftfont_info *xftfont_info;
 539   Lisp_Object result;
 540   FT_Face ft_face;
 541
 542   CHECK_FONT_GET_OBJECT (LGSTRING_FONT (lgstring), font);
 543   xftfont_info = (struct xftfont_info *) font;
 544   if (! xftfont_info->maybe_otf)
 545     return Qnil;
 546   ft_face = XftLockFace (xftfont_info->xftfont);
 547   if (! xftfont_info->otf)
 548     {
 549       OTF *otf = OTF_open_ft_face (ft_face);
 550
 551       if (! otf || OTF_get_table (otf, "head") < 0)
 552         {
 553           if (otf)
 554             OTF_close (otf);
 555           xftfont_info->maybe_otf = 0;
 556           XftUnlockFace (xftfont_info->xftfont);
 557           return Qnil;
 558         }
 559       xftfont_info->otf = otf;
 560     }
 561
 562   result = ftfont_shape_by_flt (lgstring, font, ft_face, xftfont_info->otf);
 563   XftUnlockFace (xftfont_info->xftfont);
 564   return result;
 565 }
 566 #endif  /* HAVE_M17N_FLT */
 567 #endif  /* HAVE_LIBOTF */
 568
 569 void
 570 syms_of_xftfont ()
 571 {
 572   DEFSYM (Qxft, "xft");
 573
 574   xftfont_driver = ftfont_driver;
 575   xftfont_driver.type = Qxft;
 576   xftfont_driver.get_cache = xfont_driver.get_cache;
 577   xftfont_driver.list = xftfont_list;
 578   xftfont_driver.match = xftfont_match;
 579   xftfont_driver.open = xftfont_open;
 580   xftfont_driver.close = xftfont_close;
 581   xftfont_driver.prepare_face = xftfont_prepare_face;
 582   xftfont_driver.done_face = xftfont_done_face;
 583   xftfont_driver.encode_char = xftfont_encode_char;
 584   xftfont_driver.text_extents = xftfont_text_extents;
 585   xftfont_driver.draw = xftfont_draw;
 586   xftfont_driver.anchor_point = xftfont_anchor_point;
 587   xftfont_driver.end_for_frame = xftfont_end_for_frame;
 588 #ifdef HAVE_LIBOTF
 589 #ifdef HAVE_M17N_FLT
 590   xftfont_driver.shape = xftfont_shape;
 591 #endif  /* HAVE_M17N_FLT */
 592 #endif  /* HAVE_LIBOTF */
 593
 594   register_font_driver (&xftfont_driver, NULL);
 595 }
 596
 597 /* arch-tag: 64ec61bf-7c8e-4fe6-b953-c6a85d5e1605
 598    (do not change this comment) */