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   int i;
 160
 161   for (tail = list; CONSP (tail); tail = XCDR (tail))
 162     ASET (XCAR (tail), FONT_TYPE_INDEX, Qxft);
 163   return list;
 164 }
 165
 166 static Lisp_Object
 167 xftfont_match (frame, spec)
 168      Lisp_Object frame;
 169      Lisp_Object spec;
 170 {
 171   Lisp_Object entity = ftfont_driver.match (frame, spec);
 172
 173   if (! NILP (entity))
 174     ASET (entity, FONT_TYPE_INDEX, Qxft);
 175   return entity;
 176 }
 177
 178 extern Lisp_Object ftfont_font_format P_ ((FcPattern *));
 179
 180 static FcChar8 ascii_printable[95];
 181
 182 static Lisp_Object
 183 xftfont_open (f, entity, pixel_size)
 184      FRAME_PTR f;
 185      Lisp_Object entity;
 186      int pixel_size;
 187 {
 188   Display_Info *dpyinfo = FRAME_X_DISPLAY_INFO (f);
 189   Display *display = FRAME_X_DISPLAY (f);
 190   Lisp_Object val, font_object;
 191   FcPattern *pattern, *pat = NULL;
 192   FcChar8 *file;
 193   struct xftfont_info *xftfont_info = NULL;
 194   XFontStruct *xfont = NULL;
 195   struct font *font;
 196   double size = 0;
 197   XftFont *xftfont = NULL;
 198   int spacing;
 199   char name[256];
 200   int len, i;
 201   XGlyphInfo extents;
 202   FT_Face ft_face;
 203
 204   val = assq_no_quit (QCfont_entity, AREF (entity, FONT_EXTRA_INDEX));
 205   if (! CONSP (val)
 206       || XTYPE (XCDR (val)) != Lisp_Misc
 207       || XMISCTYPE (XCDR (val)) != Lisp_Misc_Save_Value)
 208     return Qnil;
 209   pattern = XSAVE_VALUE (XCDR (val))->pointer;
 210   if (FcPatternGetString (pattern, FC_FILE, 0, &file) != FcResultMatch)
 211     return Qnil;
 212
 213   size = XINT (AREF (entity, FONT_SIZE_INDEX));
 214   if (size == 0)
 215     size = pixel_size;
 216
 217   pat = FcPatternCreate ();
 218   FcPatternAddString (pat, FC_FILE, file);
 219   FcPatternAddDouble (pat, FC_PIXEL_SIZE, pixel_size);
 220   /*FcPatternAddBool (pat, FC_ANTIALIAS, FcTrue);*/
 221   val = AREF (entity, FONT_FAMILY_INDEX);
 222   if (! NILP (val))
 223     FcPatternAddString (pat, FC_FAMILY, (FcChar8 *) SDATA (SYMBOL_NAME (val)));
 224   FcConfigSubstitute (NULL, pat, FcMatchPattern);
 225
 226   BLOCK_INPUT;
 227   XftDefaultSubstitute (display, FRAME_X_SCREEN_NUMBER (f), pat);
 228   xftfont = XftFontOpenPattern (display, pat);
 229   UNBLOCK_INPUT;
 230   if (! xftfont)
 231     return Qnil;
 232   /* We should not destroy PAT here because it is kept in XFTFONT and
 233      destroyed automatically when XFTFONT is closed.  */
 234   font_object = font_make_object (VECSIZE (struct xftfont_info));
 235   ASET (font_object, FONT_TYPE_INDEX, Qxft);
 236   for (i = 1; i < FONT_ENTITY_MAX; i++)
 237     ASET (font_object, i, AREF (entity, i));
 238   ASET (font_object, FONT_SIZE_INDEX, make_number (size));
 239   len = font_unparse_xlfd (entity, size, name, 256);
 240   if (len > 0)
 241     ASET (font_object, FONT_NAME_INDEX, make_unibyte_string (name, len));
 242   len = font_unparse_fcname (entity, size, name, 256);
 243   if (len > 0)
 244     ASET (font_object, FONT_FULLNAME_INDEX, make_unibyte_string (name, len));
 245   else
 246     ASET (font_object, FONT_FULLNAME_INDEX,
 247           AREF (font_object, FONT_NAME_INDEX));
 248   ASET (font_object, FONT_FILE_INDEX,
 249         make_unibyte_string ((char *) file, strlen ((char *) file)));
 250   ASET (font_object, FONT_FORMAT_INDEX, ftfont_font_format (pattern));
 251   font = XFONT_OBJECT (font_object);
 252   font->pixel_size = pixel_size;
 253   font->driver = &xftfont_driver;
 254   font->encoding_charset = font->repertory_charset = -1;
 255
 256   xftfont_info = (struct xftfont_info *) font;
 257   xftfont_info->display = display;
 258   xftfont_info->screen = FRAME_X_SCREEN_NUMBER (f);
 259   xftfont_info->xftfont = xftfont;
 260   font->pixel_size = size;
 261   font->driver = &xftfont_driver;
 262   if (FcPatternGetInteger (xftfont->pattern, FC_SPACING, 0, &spacing)
 263       != FcResultMatch)
 264     spacing = FC_PROPORTIONAL;
 265   if (! ascii_printable[0])
 266     {
 267       int i;
 268       for (i = 0; i < 95; i++)
 269         ascii_printable[i] = ' ' + i;
 270     }
 271   BLOCK_INPUT;
 272   if (spacing != FC_PROPORTIONAL)
 273     {
 274       font->min_width = font->average_width = font->space_width
 275         = xftfont->max_advance_width;
 276       XftTextExtents8 (display, xftfont, ascii_printable + 1, 94, &extents);
 277     }
 278   else
 279     {
 280       XftTextExtents8 (display, xftfont, ascii_printable, 1, &extents);
 281       font->space_width = extents.xOff;
 282       if (font->space_width <= 0)
 283         /* dirty workaround */
 284         font->space_width = pixel_size;
 285       XftTextExtents8 (display, xftfont, ascii_printable + 1, 94, &extents);
 286       font->average_width = (font->space_width + extents.xOff) / 95;
 287     }
 288   UNBLOCK_INPUT;
 289
 290   font->ascent = xftfont->ascent;
 291   if (font->ascent < extents.y)
 292     font->ascent = extents.y;
 293   font->descent = xftfont->descent;
 294   if (font->descent < extents.height - extents.y)
 295     font->descent = extents.height - extents.y;
 296   font->height = font->ascent + font->descent;
 297
 298   ft_face = XftLockFace (xftfont);
 299   if (XINT (AREF (entity, FONT_SIZE_INDEX)) == 0)
 300     {
 301       int upEM = ft_face->units_per_EM;
 302
 303       font->underline_position = -ft_face->underline_position * size / upEM;
 304       font->underline_thickness = -ft_face->underline_thickness * size / upEM;
 305     }
 306   else
 307     {
 308       font->underline_position = -1;
 309       font->underline_thickness = 0;
 310     }
 311 #ifdef HAVE_LIBOTF
 312   xftfont_info->maybe_otf = ft_face->face_flags & FT_FACE_FLAG_SFNT;
 313   xftfont_info->otf = NULL;
 314 #endif  /* HAVE_LIBOTF */
 315   XftUnlockFace (xftfont);
 316
 317   /* Unfortunately Xft doesn't provide a way to get minimum char
 318      width.  So, we use space_width instead.  */
 319   font->min_width = font->space_width;
 320
 321   font->baseline_offset = 0;
 322   font->relative_compose = 0;
 323   font->default_ascent = 0;
 324   font->vertical_centering = 0;
 325
 326   return font_object;
 327 }
 328
 329 static void
 330 xftfont_close (f, font)
 331      FRAME_PTR f;
 332      struct font *font;
 333 {
 334   struct xftfont_info *xftfont_info = (struct xftfont_info *) font;
 335
 336 #ifdef HAVE_LIBOTF
 337   if (xftfont_info->otf)
 338     OTF_close (xftfont_info->otf);
 339 #endif
 340   BLOCK_INPUT;
 341   XftFontClose (xftfont_info->display, xftfont_info->xftfont);
 342   UNBLOCK_INPUT;
 343 }
 344
 345 static int
 346 xftfont_prepare_face (f, face)
 347      FRAME_PTR f;
 348      struct face *face;
 349 {
 350   struct xftface_info *xftface_info;
 351
 352 #if 0
 353   /* This doesn't work if face->ascii_face doesn't use an Xft font. */
 354   if (face != face->ascii_face)
 355     {
 356       face->extra = face->ascii_face->extra;
 357       return 0;
 358     }
 359 #endif
 360
 361   xftface_info = malloc (sizeof (struct xftface_info));
 362   if (! xftface_info)
 363     return -1;
 364   xftfont_get_colors (f, face, face->gc, NULL,
 365                       &xftface_info->xft_fg, &xftface_info->xft_bg);
 366   face->extra = xftface_info;
 367   return 0;
 368 }
 369
 370 static void
 371 xftfont_done_face (f, face)
 372      FRAME_PTR f;
 373      struct face *face;
 374 {
 375   struct xftface_info *xftface_info;
 376
 377 #if 0
 378   /* This doesn't work if face->ascii_face doesn't use an Xft font. */
 379   if (face != face->ascii_face
 380       || ! face->extra)
 381     return;
 382 #endif
 383
 384   xftface_info = (struct xftface_info *) face->extra;
 385   if (xftface_info)
 386     {
 387       free (xftface_info);
 388       face->extra = NULL;
 389     }
 390 }
 391
 392 static unsigned
 393 xftfont_encode_char (font, c)
 394      struct font *font;
 395      int c;
 396 {
 397   struct xftfont_info *xftfont_info = (struct xftfont_info *) font;
 398   unsigned code = XftCharIndex (xftfont_info->display, xftfont_info->xftfont,
 399                                 (FcChar32) c);
 400
 401   return (code ? code : FONT_INVALID_CODE);
 402 }
 403
 404 static int
 405 xftfont_text_extents (font, code, nglyphs, metrics)
 406      struct font *font;
 407      unsigned *code;
 408      int nglyphs;
 409      struct font_metrics *metrics;
 410 {
 411   struct xftfont_info *xftfont_info = (struct xftfont_info *) font;
 412   XGlyphInfo extents;
 413
 414   BLOCK_INPUT;
 415   XftGlyphExtents (xftfont_info->display, xftfont_info->xftfont, code, nglyphs,
 416                    &extents);
 417   UNBLOCK_INPUT;
 418   if (metrics)
 419     {
 420       metrics->lbearing = - extents.x;
 421       metrics->rbearing = - extents.x + extents.width;
 422       metrics->width = extents.xOff;
 423       metrics->ascent = extents.y;
 424       metrics->descent = extents.height - extents.y;
 425     }
 426   return extents.xOff;
 427 }
 428
 429 static XftDraw *
 430 xftfont_get_xft_draw (f)
 431      FRAME_PTR f;
 432 {
 433   XftDraw *xft_draw = font_get_frame_data (f, &xftfont_driver);;
 434
 435   if (! xft_draw)
 436     {
 437       BLOCK_INPUT;
 438       xft_draw= XftDrawCreate (FRAME_X_DISPLAY (f),
 439                                FRAME_X_WINDOW (f),
 440                                FRAME_X_VISUAL (f),
 441                                FRAME_X_COLORMAP (f));
 442       UNBLOCK_INPUT;
 443       if (! xft_draw)
 444         abort ();
 445       font_put_frame_data (f, &xftfont_driver, xft_draw);
 446     }
 447   return xft_draw;
 448 }
 449
 450 static int
 451 xftfont_draw (s, from, to, x, y, with_background)
 452      struct glyph_string *s;
 453      int from, to, x, y, with_background;
 454 {
 455   FRAME_PTR f = s->f;
 456   struct face *face = s->face;
 457   struct xftfont_info *xftfont_info = (struct xftfont_info *) s->font;
 458   struct xftface_info *xftface_info = NULL;
 459   XftDraw *xft_draw = xftfont_get_xft_draw (f);
 460   FT_UInt *code;
 461   XftColor fg, bg;
 462   XRectangle r;
 463   int len = to - from;
 464   int i;
 465
 466   if (s->font == face->font)
 467     xftface_info = (struct xftface_info *) face->extra;
 468   xftfont_get_colors (f, face, s->gc, xftface_info,
 469                       &fg, with_background ? &bg : NULL);
 470   BLOCK_INPUT;
 471   if (s->num_clips > 0)
 472     XftDrawSetClipRectangles (xft_draw, 0, 0, s->clip, s->num_clips);
 473   else
 474     XftDrawSetClip (xft_draw, NULL);
 475
 476   if (with_background)
 477     XftDrawRect (xft_draw, &bg,
 478                  x, y - face->font->ascent, s->width, face->font->height);
 479   code = alloca (sizeof (FT_UInt) * len);
 480   for (i = 0; i < len; i++)
 481     code[i] = ((XCHAR2B_BYTE1 (s->char2b + from + i) << 8)
 482                | XCHAR2B_BYTE2 (s->char2b + from + i));
 483
 484   if (s->padding_p)
 485     for (i = 0; i < len; i++)
 486       XftDrawGlyphs (xft_draw, &fg, xftfont_info->xftfont,
 487                      x + i, y, code + i, 1);
 488   else
 489     XftDrawGlyphs (xft_draw, &fg, xftfont_info->xftfont,
 490                    x, y, code, len);
 491   UNBLOCK_INPUT;
 492
 493   return len;
 494 }
 495
 496 static int
 497 xftfont_anchor_point (font, code, index, x, y)
 498      struct font *font;
 499      unsigned code;
 500      int index;
 501      int *x, *y;
 502 {
 503   struct xftfont_info *xftfont_info = (struct xftfont_info *) font;
 504   FT_Face ft_face = XftLockFace (xftfont_info->xftfont);
 505   int result;
 506
 507   if (FT_Load_Glyph (ft_face, code, FT_LOAD_DEFAULT) != 0)
 508     result = -1;
 509   else if (ft_face->glyph->format != FT_GLYPH_FORMAT_OUTLINE)
 510     result = -1;
 511   else if (index >= ft_face->glyph->outline.n_points)
 512     result = -1;
 513   else
 514     {
 515       *x = ft_face->glyph->outline.points[index].x;
 516       *y = ft_face->glyph->outline.points[index].y;
 517     }
 518   XftUnlockFace (xftfont_info->xftfont);
 519   return result;
 520 }
 521
 522 static int
 523 xftfont_end_for_frame (f)
 524      FRAME_PTR f;
 525 {
 526   XftDraw *xft_draw = font_get_frame_data (f, &xftfont_driver);
 527
 528   if (xft_draw)
 529     {
 530       BLOCK_INPUT;
 531       XftDrawDestroy (xft_draw);
 532       UNBLOCK_INPUT;
 533       font_put_frame_data (f, &xftfont_driver, NULL);
 534     }
 535   return 0;
 536 }
 537
 538 #ifdef HAVE_LIBOTF
 539 #ifdef HAVE_M17N_FLT
 540 static Lisp_Object
 541 xftfont_shape (lgstring)
 542      Lisp_Object lgstring;
 543 {
 544   struct font *font;
 545   struct xftfont_info *xftfont_info;
 546   Lisp_Object result;
 547   FT_Face ft_face;
 548
 549   CHECK_FONT_GET_OBJECT (LGSTRING_FONT (lgstring), font);
 550   xftfont_info = (struct xftfont_info *) font;
 551   if (! xftfont_info->maybe_otf)
 552     return Qnil;
 553   ft_face = XftLockFace (xftfont_info->xftfont);
 554   if (! xftfont_info->otf)
 555     {
 556       OTF *otf = OTF_open_ft_face (ft_face);
 557
 558       if (! otf || OTF_get_table (otf, "head") < 0)
 559         {
 560           if (otf)
 561             OTF_close (otf);
 562           xftfont_info->maybe_otf = 0;
 563           XftUnlockFace (xftfont_info->xftfont);
 564           return Qnil;
 565         }
 566       xftfont_info->otf = otf;
 567     }
 568
 569   result = ftfont_shape_by_flt (lgstring, font, ft_face, xftfont_info->otf);
 570   XftUnlockFace (xftfont_info->xftfont);
 571   return result;
 572 }
 573 #endif  /* HAVE_M17N_FLT */
 574 #endif  /* HAVE_LIBOTF */
 575
 576 void
 577 syms_of_xftfont ()
 578 {
 579   DEFSYM (Qxft, "xft");
 580
 581   xftfont_driver = ftfont_driver;
 582   xftfont_driver.type = Qxft;
 583   xftfont_driver.get_cache = xfont_driver.get_cache;
 584   xftfont_driver.list = xftfont_list;
 585   xftfont_driver.match = xftfont_match;
 586   xftfont_driver.open = xftfont_open;
 587   xftfont_driver.close = xftfont_close;
 588   xftfont_driver.prepare_face = xftfont_prepare_face;
 589   xftfont_driver.done_face = xftfont_done_face;
 590   xftfont_driver.encode_char = xftfont_encode_char;
 591   xftfont_driver.text_extents = xftfont_text_extents;
 592   xftfont_driver.draw = xftfont_draw;
 593   xftfont_driver.anchor_point = xftfont_anchor_point;
 594   xftfont_driver.end_for_frame = xftfont_end_for_frame;
 595 #ifdef HAVE_LIBOTF
 596 #ifdef HAVE_M17N_FLT
 597   xftfont_driver.shape = xftfont_shape;
 598 #endif  /* HAVE_M17N_FLT */
 599 #endif  /* HAVE_LIBOTF */
 600
 601   register_font_driver (&xftfont_driver, NULL);
 602 }
 603
 604 /* arch-tag: 64ec61bf-7c8e-4fe6-b953-c6a85d5e1605
 605    (do not change this comment) */