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, or (at your option)
  12 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; see the file COPYING.  If not, write to
  21 the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  22 Boston, MA 02110-1301, USA.  */
  23
  24 #include <config.h>
  25 #include <stdio.h>
  26 #include <X11/Xlib.h>
  27 #include <X11/Xft/Xft.h>
  28
  29 #include "lisp.h"
  30 #include "dispextern.h"
  31 #include "xterm.h"
  32 #include "frame.h"
  33 #include "blockinput.h"
  34 #include "character.h"
  35 #include "charset.h"
  36 #include "fontset.h"
  37 #include "font.h"
  38 #include "ftfont.h"
  39
  40 /* Xft font driver.  */
  41
  42 static Lisp_Object Qxft;
  43
  44 /* The actual structure for Xft font that can be casted to struct
  45    font.  */
  46
  47 struct xftfont_info
  48 {
  49   struct font font;
  50   Display *display;
  51   int screen;
  52   XftFont *xftfont;
  53 #ifdef HAVE_LIBOTF
  54   int maybe_otf;          /* Flag to tell if this may be OTF or not.  */
  55   OTF *otf;
  56 #endif  /* HAVE_LIBOTF */
  57 };
  58
  59 /* Structure pointed by (struct face *)->extra  */
  60
  61 struct xftface_info
  62 {
  63   XftColor xft_fg;              /* color for face->foreground */
  64   XftColor xft_bg;              /* color for face->background */
  65 };
  66
  67 static void xftfont_get_colors P_ ((FRAME_PTR, struct face *, GC gc,
  68                                     struct xftface_info *,
  69                                     XftColor *fg, XftColor *bg));
  70
  71
  72 /* Setup foreground and background colors of GC into FG and BG.  If
  73    XFTFACE_INFO is not NULL, reuse the colors in it if possible.  BG
  74    may be NULL.  */
  75
  76 static void
  77 xftfont_get_colors (f, face, gc, xftface_info, fg, bg)
  78      FRAME_PTR f;
  79      struct face *face;
  80      GC gc;
  81      struct xftface_info *xftface_info;
  82      XftColor *fg, *bg;
  83 {
  84   if (xftface_info && face->gc == gc)
  85     {
  86       *fg = xftface_info->xft_fg;
  87       if (bg)
  88         *bg = xftface_info->xft_bg;
  89     }
  90   else
  91     {
  92       XGCValues xgcv;
  93       int fg_done = 0, bg_done = 0;
  94
  95       BLOCK_INPUT;
  96       XGetGCValues (FRAME_X_DISPLAY (f), gc,
  97                     GCForeground | GCBackground, &xgcv);
  98       if (xftface_info)
  99         {
 100           if (xgcv.foreground == face->foreground)
 101             *fg = xftface_info->xft_fg, fg_done = 1;
 102           else if (xgcv.foreground == face->background)
 103             *fg = xftface_info->xft_bg, fg_done = 1;
 104           if (! bg)
 105             bg_done = 1;
 106           else if (xgcv.background == face->background)
 107             *bg = xftface_info->xft_bg, bg_done = 1;
 108           else if (xgcv.background == face->foreground)
 109             *bg = xftface_info->xft_fg, bg_done = 1;
 110         }
 111
 112       if (fg_done + bg_done < 2)
 113         {
 114           XColor colors[2];
 115
 116           colors[0].pixel = fg->pixel = xgcv.foreground;
 117           if (bg)
 118             colors[1].pixel = bg->pixel = xgcv.background;
 119           XQueryColors (FRAME_X_DISPLAY (f), FRAME_X_COLORMAP (f), colors,
 120                         bg ? 2 : 1);
 121           fg->color.alpha = 0xFFFF;
 122           fg->color.red = colors[0].red;
 123           fg->color.green = colors[0].green;
 124           fg->color.blue = colors[0].blue;
 125           if (bg)
 126             {
 127               bg->color.alpha = 0xFFFF;
 128               bg->color.red = colors[1].red;
 129               bg->color.green = colors[1].green;
 130               bg->color.blue = colors[1].blue;
 131             }
 132         }
 133       UNBLOCK_INPUT;
 134     }
 135 }
 136
 137
 138 static Lisp_Object xftfont_list P_ ((Lisp_Object, Lisp_Object));
 139 static Lisp_Object xftfont_match P_ ((Lisp_Object, Lisp_Object));
 140 static Lisp_Object xftfont_open P_ ((FRAME_PTR, Lisp_Object, int));
 141 static void xftfont_close P_ ((FRAME_PTR, struct font *));
 142 static int xftfont_prepare_face P_ ((FRAME_PTR, struct face *));
 143 static void xftfont_done_face P_ ((FRAME_PTR, struct face *));
 144 static unsigned xftfont_encode_char P_ ((struct font *, int));
 145 static int xftfont_text_extents P_ ((struct font *, unsigned *, int,
 146                                      struct font_metrics *));
 147 static int xftfont_draw P_ ((struct glyph_string *, int, int, int, int, int));
 148
 149 static int xftfont_anchor_point P_ ((struct font *, unsigned, int,
 150                                      int *, int *));
 151 static int xftfont_end_for_frame P_ ((FRAME_PTR f));
 152
 153 struct font_driver xftfont_driver;
 154
 155 static Lisp_Object
 156 xftfont_list (frame, spec)
 157      Lisp_Object frame;
 158      Lisp_Object spec;
 159 {
 160   Lisp_Object list = ftfont_driver.list (frame, spec), tail;
 161   int i;
 162
 163   for (tail = list; CONSP (tail); tail = XCDR (tail))
 164     ASET (XCAR (tail), FONT_TYPE_INDEX, Qxft);
 165   return list;
 166 }
 167
 168 static Lisp_Object
 169 xftfont_match (frame, spec)
 170      Lisp_Object frame;
 171      Lisp_Object spec;
 172 {
 173   Lisp_Object entity = ftfont_driver.match (frame, spec);
 174
 175   if (! NILP (entity))
 176     ASET (entity, FONT_TYPE_INDEX, Qxft);
 177   return entity;
 178 }
 179
 180 extern Lisp_Object ftfont_font_format P_ ((FcPattern *));
 181
 182 static FcChar8 ascii_printable[95];
 183
 184 static Lisp_Object
 185 xftfont_open (f, entity, pixel_size)
 186      FRAME_PTR f;
 187      Lisp_Object entity;
 188      int pixel_size;
 189 {
 190   Display_Info *dpyinfo = FRAME_X_DISPLAY_INFO (f);
 191   Display *display = FRAME_X_DISPLAY (f);
 192   Lisp_Object val, font_object;
 193   FcPattern *pattern, *pat = NULL;
 194   FcChar8 *file;
 195   struct xftfont_info *xftfont_info = NULL;
 196   XFontStruct *xfont = NULL;
 197   struct font *font;
 198   double size = 0;
 199   XftFont *xftfont = NULL;
 200   int spacing;
 201   char name[256];
 202   int len, i;
 203   XGlyphInfo extents;
 204   FT_Face ft_face;
 205
 206   val = assq_no_quit (QCfont_entity, AREF (entity, FONT_EXTRA_INDEX));
 207   if (! CONSP (val)
 208       || XTYPE (XCDR (val)) != Lisp_Misc
 209       || XMISCTYPE (XCDR (val)) != Lisp_Misc_Save_Value)
 210     return Qnil;
 211   pattern = XSAVE_VALUE (XCDR (val))->pointer;
 212   if (FcPatternGetString (pattern, FC_FILE, 0, &file) != FcResultMatch)
 213     return Qnil;
 214
 215   size = XINT (AREF (entity, FONT_SIZE_INDEX));
 216   if (size == 0)
 217     size = pixel_size;
 218
 219   pat = FcPatternCreate ();
 220   FcPatternAddString (pat, FC_FILE, file);
 221   FcPatternAddDouble (pat, FC_PIXEL_SIZE, pixel_size);
 222   /*FcPatternAddBool (pat, FC_ANTIALIAS, FcTrue);*/
 223   val = AREF (entity, FONT_FAMILY_INDEX);
 224   if (! NILP (val))
 225     FcPatternAddString (pat, FC_FAMILY, (FcChar8 *) SDATA (SYMBOL_NAME (val)));
 226   FcConfigSubstitute (NULL, pat, FcMatchPattern);
 227
 228   BLOCK_INPUT;
 229   XftDefaultSubstitute (display, FRAME_X_SCREEN_NUMBER (f), pat);
 230   xftfont = XftFontOpenPattern (display, pat);
 231   UNBLOCK_INPUT;
 232   if (! xftfont)
 233     return Qnil;
 234   /* We should not destroy PAT here because it is kept in XFTFONT and
 235      destroyed automatically when XFTFONT is closed.  */
 236   font_object = font_make_object (VECSIZE (struct xftfont_info));
 237   ASET (font_object, FONT_TYPE_INDEX, Qxft);
 238   for (i = 1; i < FONT_ENTITY_MAX; i++)
 239     ASET (font_object, i, AREF (entity, i));
 240   ASET (font_object, FONT_SIZE_INDEX, make_number (size));
 241   len = font_unparse_xlfd (entity, size, name, 256);
 242   if (len > 0)
 243     ASET (font_object, FONT_NAME_INDEX, make_unibyte_string (name, len));
 244   len = font_unparse_fcname (entity, size, name, 256);
 245   if (len > 0)
 246     ASET (font_object, FONT_FULLNAME_INDEX, make_unibyte_string (name, len));
 247   else
 248     ASET (font_object, FONT_FULLNAME_INDEX,
 249           AREF (font_object, FONT_NAME_INDEX));
 250   ASET (font_object, FONT_FILE_INDEX,
 251         make_unibyte_string ((char *) file, strlen ((char *) file)));
 252   ASET (font_object, FONT_FORMAT_INDEX, ftfont_font_format (pattern));
 253   font = XFONT_OBJECT (font_object);
 254   font->pixel_size = pixel_size;
 255   font->driver = &xftfont_driver;
 256   font->encoding_charset = font->repertory_charset = -1;
 257
 258   xftfont_info = (struct xftfont_info *) font;
 259   xftfont_info->display = display;
 260   xftfont_info->screen = FRAME_X_SCREEN_NUMBER (f);
 261   xftfont_info->xftfont = xftfont;
 262   font->pixel_size = size;
 263   font->driver = &xftfont_driver;
 264   if (FcPatternGetInteger (xftfont->pattern, FC_SPACING, 0, &spacing)
 265       != FcResultMatch)
 266     spacing = FC_PROPORTIONAL;
 267   if (! ascii_printable[0])
 268     {
 269       int i;
 270       for (i = 0; i < 95; i++)
 271         ascii_printable[i] = ' ' + i;
 272     }
 273   BLOCK_INPUT;
 274   if (spacing != FC_PROPORTIONAL)
 275     {
 276       font->min_width = font->average_width = font->space_width
 277         = xftfont->max_advance_width;
 278       XftTextExtents8 (display, xftfont, ascii_printable + 1, 94, &extents);
 279     }
 280   else
 281     {
 282       XftTextExtents8 (display, xftfont, ascii_printable, 1, &extents);
 283       font->space_width = extents.xOff;
 284       if (font->space_width <= 0)
 285         /* dirty workaround */
 286         font->space_width = pixel_size;
 287       XftTextExtents8 (display, xftfont, ascii_printable + 1, 94, &extents);
 288       font->average_width = (font->space_width + extents.xOff) / 95;
 289     }
 290   UNBLOCK_INPUT;
 291
 292   font->ascent = xftfont->ascent;
 293   if (font->ascent < extents.y)
 294     font->ascent = extents.y;
 295   font->descent = xftfont->descent;
 296   if (font->descent < extents.height - extents.y)
 297     font->descent = extents.height - extents.y;
 298   font->height = font->ascent + font->descent;
 299
 300   ft_face = XftLockFace (xftfont);
 301   if (XINT (AREF (entity, FONT_SIZE_INDEX)) == 0)
 302     {
 303       int upEM = ft_face->units_per_EM;
 304
 305       font->underline_position = -ft_face->underline_position * size / upEM;
 306       font->underline_thickness = -ft_face->underline_thickness * size / upEM;
 307     }
 308   else
 309     {
 310       font->underline_position = -1;
 311       font->underline_thickness = 0;
 312     }
 313 #ifdef HAVE_LIBOTF
 314   xftfont_info->maybe_otf = ft_face->face_flags & FT_FACE_FLAG_SFNT;
 315   xftfont_info->otf = NULL;
 316 #endif  /* HAVE_LIBOTF */
 317   XftUnlockFace (xftfont);
 318
 319   /* Unfortunately Xft doesn't provide a way to get minimum char
 320      width.  So, we use space_width instead.  */
 321   font->min_width = font->space_width;
 322
 323   font->baseline_offset = 0;
 324   font->relative_compose = 0;
 325   font->default_ascent = 0;
 326   font->vertical_centering = 0;
 327
 328   return font_object;
 329 }
 330
 331 static void
 332 xftfont_close (f, font)
 333      FRAME_PTR f;
 334      struct font *font;
 335 {
 336   struct xftfont_info *xftfont_info = (struct xftfont_info *) font;
 337
 338 #ifdef HAVE_LIBOTF
 339   if (xftfont_info->otf)
 340     OTF_close (xftfont_info->otf);
 341 #endif
 342   BLOCK_INPUT;
 343   XftFontClose (xftfont_info->display, xftfont_info->xftfont);
 344   UNBLOCK_INPUT;
 345 }
 346
 347 static int
 348 xftfont_prepare_face (f, face)
 349      FRAME_PTR f;
 350      struct face *face;
 351 {
 352   struct xftface_info *xftface_info;
 353
 354 #if 0
 355   /* This doesn't work if face->ascii_face doesn't use an Xft font. */
 356   if (face != face->ascii_face)
 357     {
 358       face->extra = face->ascii_face->extra;
 359       return 0;
 360     }
 361 #endif
 362
 363   xftface_info = malloc (sizeof (struct xftface_info));
 364   if (! xftface_info)
 365     return -1;
 366   xftfont_get_colors (f, face, face->gc, NULL,
 367                       &xftface_info->xft_fg, &xftface_info->xft_bg);
 368   face->extra = xftface_info;
 369   return 0;
 370 }
 371
 372 static void
 373 xftfont_done_face (f, face)
 374      FRAME_PTR f;
 375      struct face *face;
 376 {
 377   struct xftface_info *xftface_info;
 378
 379 #if 0
 380   /* This doesn't work if face->ascii_face doesn't use an Xft font. */
 381   if (face != face->ascii_face
 382       || ! face->extra)
 383     return;
 384 #endif
 385
 386   xftface_info = (struct xftface_info *) face->extra;
 387   if (xftface_info)
 388     {
 389       free (xftface_info);
 390       face->extra = NULL;
 391     }
 392 }
 393
 394 static unsigned
 395 xftfont_encode_char (font, c)
 396      struct font *font;
 397      int c;
 398 {
 399   struct xftfont_info *xftfont_info = (struct xftfont_info *) font;
 400   unsigned code = XftCharIndex (xftfont_info->display, xftfont_info->xftfont,
 401                                 (FcChar32) c);
 402
 403   return (code ? code : FONT_INVALID_CODE);
 404 }
 405
 406 static int
 407 xftfont_text_extents (font, code, nglyphs, metrics)
 408      struct font *font;
 409      unsigned *code;
 410      int nglyphs;
 411      struct font_metrics *metrics;
 412 {
 413   struct xftfont_info *xftfont_info = (struct xftfont_info *) font;
 414   XGlyphInfo extents;
 415
 416   BLOCK_INPUT;
 417   XftGlyphExtents (xftfont_info->display, xftfont_info->xftfont, code, nglyphs,
 418                    &extents);
 419   UNBLOCK_INPUT;
 420   if (metrics)
 421     {
 422       metrics->lbearing = - extents.x;
 423       metrics->rbearing = - extents.x + extents.width;
 424       metrics->width = extents.xOff;
 425       metrics->ascent = extents.y;
 426       metrics->descent = extents.height - extents.y;
 427     }
 428   return extents.xOff;
 429 }
 430
 431 static XftDraw *
 432 xftfont_get_xft_draw (f)
 433      FRAME_PTR f;
 434 {
 435   XftDraw *xft_draw = font_get_frame_data (f, &xftfont_driver);;
 436
 437   if (! xft_draw)
 438     {
 439       BLOCK_INPUT;
 440       xft_draw= XftDrawCreate (FRAME_X_DISPLAY (f),
 441                                FRAME_X_WINDOW (f),
 442                                FRAME_X_VISUAL (f),
 443                                FRAME_X_COLORMAP (f));
 444       UNBLOCK_INPUT;
 445       if (! xft_draw)
 446         abort ();
 447       font_put_frame_data (f, &xftfont_driver, xft_draw);
 448     }
 449   return xft_draw;
 450 }
 451
 452 static int
 453 xftfont_draw (s, from, to, x, y, with_background)
 454      struct glyph_string *s;
 455      int from, to, x, y, with_background;
 456 {
 457   FRAME_PTR f = s->f;
 458   struct face *face = s->face;
 459   struct xftfont_info *xftfont_info = (struct xftfont_info *) s->font;
 460   struct xftface_info *xftface_info = NULL;
 461   XftDraw *xft_draw = xftfont_get_xft_draw (f);
 462   FT_UInt *code;
 463   XftColor fg, bg;
 464   XRectangle r;
 465   int len = to - from;
 466   int i;
 467
 468   if (s->font == face->font)
 469     xftface_info = (struct xftface_info *) face->extra;
 470   xftfont_get_colors (f, face, s->gc, xftface_info,
 471                       &fg, with_background ? &bg : NULL);
 472   BLOCK_INPUT;
 473   if (s->num_clips > 0)
 474     XftDrawSetClipRectangles (xft_draw, 0, 0, s->clip, s->num_clips);
 475   else
 476     XftDrawSetClip (xft_draw, NULL);
 477
 478   if (with_background)
 479     XftDrawRect (xft_draw, &bg,
 480                  x, y - face->font->ascent, s->width, face->font->height);
 481   code = alloca (sizeof (FT_UInt) * len);
 482   for (i = 0; i < len; i++)
 483     code[i] = ((XCHAR2B_BYTE1 (s->char2b + from + i) << 8)
 484                | XCHAR2B_BYTE2 (s->char2b + from + i));
 485
 486   if (s->padding_p)
 487     for (i = 0; i < len; i++)
 488       XftDrawGlyphs (xft_draw, &fg, xftfont_info->xftfont,
 489                      x + i, y, code + i, 1);
 490   else
 491     XftDrawGlyphs (xft_draw, &fg, xftfont_info->xftfont,
 492                    x, y, code, len);
 493   UNBLOCK_INPUT;
 494
 495   return len;
 496 }
 497
 498 static int
 499 xftfont_anchor_point (font, code, index, x, y)
 500      struct font *font;
 501      unsigned code;
 502      int index;
 503      int *x, *y;
 504 {
 505   struct xftfont_info *xftfont_info = (struct xftfont_info *) font;
 506   FT_Face ft_face = XftLockFace (xftfont_info->xftfont);
 507   int result;
 508
 509   if (FT_Load_Glyph (ft_face, code, FT_LOAD_DEFAULT) != 0)
 510     result = -1;
 511   else if (ft_face->glyph->format != FT_GLYPH_FORMAT_OUTLINE)
 512     result = -1;
 513   else if (index >= ft_face->glyph->outline.n_points)
 514     result = -1;
 515   else
 516     {
 517       *x = ft_face->glyph->outline.points[index].x;
 518       *y = ft_face->glyph->outline.points[index].y;
 519     }
 520   XftUnlockFace (xftfont_info->xftfont);
 521   return result;
 522 }
 523
 524 static int
 525 xftfont_end_for_frame (f)
 526      FRAME_PTR f;
 527 {
 528   XftDraw *xft_draw = font_get_frame_data (f, &xftfont_driver);
 529
 530   if (xft_draw)
 531     {
 532       BLOCK_INPUT;
 533       XftDrawDestroy (xft_draw);
 534       UNBLOCK_INPUT;
 535       font_put_frame_data (f, &xftfont_driver, NULL);
 536     }
 537   return 0;
 538 }
 539
 540 #ifdef HAVE_LIBOTF
 541 #ifdef HAVE_M17N_FLT
 542 static Lisp_Object
 543 xftfont_shape (lgstring)
 544      Lisp_Object lgstring;
 545 {
 546   struct font *font;
 547   struct xftfont_info *xftfont_info;
 548   Lisp_Object result;
 549   FT_Face ft_face;
 550
 551   CHECK_FONT_GET_OBJECT (LGSTRING_FONT (lgstring), font);
 552   xftfont_info = (struct xftfont_info *) font;
 553   if (! xftfont_info->maybe_otf)
 554     return Qnil;
 555   ft_face = XftLockFace (xftfont_info->xftfont);
 556   if (! xftfont_info->otf)
 557     {
 558       OTF *otf = OTF_open_ft_face (ft_face);
 559
 560       if (! otf || OTF_get_table (otf, "head") < 0)
 561         {
 562           if (otf)
 563             OTF_close (otf);
 564           xftfont_info->maybe_otf = 0;
 565           XftUnlockFace (xftfont_info->xftfont);
 566           return Qnil;
 567         }
 568       xftfont_info->otf = otf;
 569     }
 570
 571   result = ftfont_shape_by_flt (lgstring, font, ft_face, xftfont_info->otf);
 572   XftUnlockFace (xftfont_info->xftfont);
 573   return result;
 574 }
 575 #endif  /* HAVE_M17N_FLT */
 576 #endif  /* HAVE_LIBOTF */
 577
 578 void
 579 syms_of_xftfont ()
 580 {
 581   DEFSYM (Qxft, "xft");
 582
 583   xftfont_driver = ftfont_driver;
 584   xftfont_driver.type = Qxft;
 585   xftfont_driver.get_cache = xfont_driver.get_cache;
 586   xftfont_driver.list = xftfont_list;
 587   xftfont_driver.match = xftfont_match;
 588   xftfont_driver.open = xftfont_open;
 589   xftfont_driver.close = xftfont_close;
 590   xftfont_driver.prepare_face = xftfont_prepare_face;
 591   xftfont_driver.done_face = xftfont_done_face;
 592   xftfont_driver.encode_char = xftfont_encode_char;
 593   xftfont_driver.text_extents = xftfont_text_extents;
 594   xftfont_driver.draw = xftfont_draw;
 595   xftfont_driver.anchor_point = xftfont_anchor_point;
 596   xftfont_driver.end_for_frame = xftfont_end_for_frame;
 597 #ifdef HAVE_LIBOTF
 598 #ifdef HAVE_M17N_FLT
 599   xftfont_driver.shape = xftfont_shape;
 600 #endif  /* HAVE_M17N_FLT */
 601 #endif  /* HAVE_LIBOTF */
 602
 603   register_font_driver (&xftfont_driver, NULL);
 604 }
 605
 606 /* arch-tag: 64ec61bf-7c8e-4fe6-b953-c6a85d5e1605
 607    (do not change this comment) */