src/xftfont.c

   1 /* xftfont.c -- XFT font driver.
   2    Copyright (C) 2006 Free Software Foundation, Inc.
   3    Copyright (C) 2006
   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 2, 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
  39 /* Xft font driver.  */
  40
  41 static Lisp_Object Qxft;
  42
  43 /* The actual structure for Xft font that can be casted to struct
  44    font.  */
  45
  46 struct xftfont_info
  47 {
  48   struct font font;
  49   Display *display;
  50   int screen;
  51   XftFont *xftfont;
  52   FT_Face ft_face;
  53 };
  54
  55 /* Structure pointed by (struct face *)->extra  */
  56 struct xftface_info
  57 {
  58   XftColor xft_fg;
  59   XftColor xft_bg;
  60   XftDraw *xft_draw;
  61 };
  62
  63 static void xftfont_get_colors P_ ((FRAME_PTR, struct face *, GC gc,
  64                                     struct xftface_info *,
  65                                     XftColor *fg, XftColor *bg));
  66 static Font xftfont_default_fid P_ ((FRAME_PTR));
  67
  68
  69 /* Setup colors pointed by FG and BG for GC.  If XFTFACE_INFO is not
  70    NULL, reuse the colors in it if possible.  BG may be NULL.  */
  71 static void
  72 xftfont_get_colors (f, face, gc, xftface_info, fg, bg)
  73      FRAME_PTR f;
  74      struct face *face;
  75      GC gc;
  76      struct xftface_info *xftface_info;
  77      XftColor *fg, *bg;
  78 {
  79   if (xftface_info && face->gc == gc)
  80     {
  81       *fg = xftface_info->xft_fg;
  82       if (bg)
  83         *bg = xftface_info->xft_bg;
  84     }
  85   else
  86     {
  87       XGCValues xgcv;
  88       int fg_done = 0, bg_done = 0;
  89
  90       BLOCK_INPUT;
  91       XGetGCValues (FRAME_X_DISPLAY (f), gc,
  92                     GCForeground | GCBackground, &xgcv);
  93       if (xftface_info)
  94         {
  95           if (xgcv.foreground == face->foreground)
  96             *fg = xftface_info->xft_fg, fg_done = 1;
  97           else if (xgcv.foreground == face->background)
  98             *fg = xftface_info->xft_bg, fg_done = 1;
  99           if (! bg)
 100             bg_done = 1;
 101           else if (xgcv.background == face->background)
 102             *bg = xftface_info->xft_bg, bg_done = 1;
 103           else if (xgcv.background == face->foreground)
 104             *bg = xftface_info->xft_fg, bg_done = 1;
 105         }
 106
 107       if (fg_done + bg_done < 2)
 108         {
 109           XColor colors[2];
 110
 111           colors[0].pixel = fg->pixel = xgcv.foreground;
 112           if (bg)
 113             colors[1].pixel = bg->pixel = xgcv.background;
 114           XQueryColors (FRAME_X_DISPLAY (f), FRAME_X_COLORMAP (f), colors,
 115                         bg ? 2 : 1);
 116           fg->color.alpha = 0xFFFF;
 117           fg->color.red = colors[0].red;
 118           fg->color.green = colors[0].green;
 119           fg->color.blue = colors[0].blue;
 120           if (bg)
 121             {
 122               bg->color.alpha = 0xFFFF;
 123               bg->color.red = colors[1].red;
 124               bg->color.green = colors[1].green;
 125               bg->color.blue = colors[1].blue;
 126             }
 127         }
 128       UNBLOCK_INPUT;
 129     }
 130 }
 131
 132 /* Return the default Font ID on frame F.  */
 133
 134 static Font
 135 xftfont_default_fid (f)
 136      FRAME_PTR f;
 137 {
 138   static int fid_known;
 139   static Font fid;
 140
 141   if (! fid_known)
 142     {
 143       fid = XLoadFont (FRAME_X_DISPLAY (f), "fixed");
 144       if (! fid)
 145         {
 146           fid = XLoadFont (FRAME_X_DISPLAY (f), "*");
 147           if (! fid)
 148             abort ();
 149         }
 150       fid_known = 1;
 151     }
 152   return fid;
 153 }
 154
 155
 156 static Lisp_Object xftfont_list P_ ((Lisp_Object, Lisp_Object));
 157 static struct font *xftfont_open P_ ((FRAME_PTR, Lisp_Object, int));
 158 static void xftfont_close P_ ((FRAME_PTR, struct font *));
 159 static int xftfont_prepare_face P_ ((FRAME_PTR, struct face *));
 160 static void xftfont_done_face P_ ((FRAME_PTR, struct face *));
 161 static unsigned xftfont_encode_char P_ ((struct font *, int));
 162 static int xftfont_text_extents P_ ((struct font *, unsigned *, int,
 163                                      struct font_metrics *));
 164 static int xftfont_draw P_ ((struct glyph_string *, int, int, int, int, int));
 165
 166 static int xftfont_anchor_point P_ ((struct font *, unsigned, int,
 167                                      int *, int *));
 168
 169 struct font_driver xftfont_driver;
 170
 171 static Lisp_Object
 172 xftfont_list (frame, spec)
 173      Lisp_Object frame;
 174      Lisp_Object spec;
 175 {
 176   Lisp_Object val = ftfont_driver.list (frame, spec);
 177
 178   if (! NILP (val))
 179     {
 180       int i;
 181
 182       for (i = 0; i < ASIZE (val); i++)
 183         ASET (AREF (val, i), FONT_TYPE_INDEX, Qxft);
 184     }
 185   return val;
 186 }
 187
 188 static FcChar8 ascii_printable[95];
 189
 190 static struct font *
 191 xftfont_open (f, entity, pixel_size)
 192      FRAME_PTR f;
 193      Lisp_Object entity;
 194      int pixel_size;
 195 {
 196   Display_Info *dpyinfo = FRAME_X_DISPLAY_INFO (f);
 197   Display *display = FRAME_X_DISPLAY (f);
 198   Lisp_Object val;
 199   FcPattern *pattern, *pat = NULL;
 200   FcChar8 *file;
 201   struct xftfont_info *xftfont_info = NULL;
 202   XFontStruct *xfont = NULL;
 203   struct font *font;
 204   double size = 0;
 205   XftFont *xftfont = NULL;
 206   int spacing;
 207   char *name;
 208   int len;
 209
 210   val = AREF (entity, FONT_EXTRA_INDEX);
 211   if (XTYPE (val) != Lisp_Misc
 212       || XMISCTYPE (val) != Lisp_Misc_Save_Value)
 213     return NULL;
 214   pattern = XSAVE_VALUE (val)->pointer;
 215   if (FcPatternGetString (pattern, FC_FILE, 0, &file) != FcResultMatch)
 216     return NULL;
 217
 218   size = XINT (AREF (entity, FONT_SIZE_INDEX));
 219   if (size == 0)
 220     size = pixel_size;
 221
 222   pat = FcPatternCreate ();
 223   FcPatternAddString (pat, FC_FILE, file);
 224   FcPatternAddDouble (pat, FC_PIXEL_SIZE, pixel_size);
 225   FcPatternAddBool (pat, FC_ANTIALIAS, FcTrue);
 226
 227   BLOCK_INPUT;
 228   xftfont = XftFontOpenPattern (display, pat);
 229   /* We should not destroy PAT here because it is kept in XFTFONT and
 230      destroyed automatically when XFTFONT is closed.  */
 231   if (! xftfont)
 232     goto err;
 233
 234   xftfont_info = malloc (sizeof (struct xftfont_info));
 235   if (! xftfont_info)
 236     goto err;
 237   xfont = malloc (sizeof (XFontStruct));
 238   if (! xfont)
 239     goto err;
 240   xftfont_info->display = display;
 241   xftfont_info->screen = FRAME_X_SCREEN_NUMBER (f);
 242   xftfont_info->xftfont = xftfont;
 243   xftfont_info->ft_face = XftLockFace (xftfont);
 244
 245   font = (struct font *) xftfont_info;
 246   font->entity = entity;
 247   font->pixel_size = size;
 248   font->driver = &xftfont_driver;
 249   len = 64;
 250   name = malloc (len);
 251   while (name && font_unparse_fcname (entity, pixel_size, name, len) < 0)
 252     {
 253       char *new = realloc (name, len += 32);
 254
 255       if (! new)
 256         free (name);
 257       name = new;
 258     }
 259   if (! name)
 260     goto err;
 261   font->font.full_name = font->font.name = name;
 262   font->file_name = (char *) file;
 263   font->font.size = xftfont->max_advance_width;
 264   font->ascent = xftfont->ascent;
 265   font->descent = xftfont->descent;
 266   font->font.height = xftfont->ascent + xftfont->descent;
 267
 268   if (FcPatternGetInteger (xftfont->pattern, FC_SPACING, 0, &spacing)
 269       != FcResultMatch)
 270     spacing = FC_PROPORTIONAL;
 271   if (spacing != FC_PROPORTIONAL)
 272     font->font.average_width = font->font.space_width
 273       = xftfont->max_advance_width;
 274   else
 275     {
 276       XGlyphInfo extents;
 277
 278       if (! ascii_printable[0])
 279         {
 280           int i;
 281           for (i = 0; i < 95; i++)
 282             ascii_printable[i] = ' ' + i;
 283         }
 284       XftTextExtents8 (display, xftfont, ascii_printable, 1, &extents);
 285       font->font.space_width = extents.xOff;
 286       if (font->font.space_width <= 0)
 287         /* dirty workaround */
 288         font->font.space_width = pixel_size;
 289       XftTextExtents8 (display, xftfont, ascii_printable + 1, 94, &extents);
 290       font->font.average_width = (font->font.space_width + extents.xOff) / 95;
 291     }
 292   UNBLOCK_INPUT;
 293
 294   /* Unfortunately Xft doesn't provide a way to get minimum char
 295      width.  So, we use space_width instead.  */
 296   font->min_width = font->font.space_width;
 297
 298   font->font.baseline_offset = 0;
 299   font->font.relative_compose = 0;
 300   font->font.default_ascent = 0;
 301   font->font.vertical_centering = 0;
 302
 303   /* Setup pseudo XFontStruct */
 304   xfont->fid = xftfont_default_fid (f);
 305   xfont->ascent = xftfont->ascent;
 306   xfont->descent = xftfont->descent;
 307   xfont->max_bounds.descent = xftfont->descent;
 308   xfont->max_bounds.width = xftfont->max_advance_width;
 309   xfont->min_bounds.width = font->font.space_width;
 310   font->font.font = xfont;
 311
 312   dpyinfo->n_fonts++;
 313
 314   /* Set global flag fonts_changed_p to non-zero if the font loaded
 315      has a character with a smaller width than any other character
 316      before, or if the font loaded has a smaller height than any other
 317      font loaded before.  If this happens, it will make a glyph matrix
 318      reallocation necessary.  */
 319   if (dpyinfo->n_fonts == 1)
 320     {
 321       dpyinfo->smallest_font_height = font->font.height;
 322       dpyinfo->smallest_char_width = font->min_width;
 323       fonts_changed_p = 1;
 324     }
 325   else
 326     {
 327       if (dpyinfo->smallest_font_height > font->font.height)
 328         dpyinfo->smallest_font_height = font->font.height,
 329           fonts_changed_p |= 1;
 330       if (dpyinfo->smallest_char_width > font->min_width)
 331         dpyinfo->smallest_char_width = font->min_width,
 332           fonts_changed_p |= 1;
 333     }
 334
 335   return font;
 336
 337  err:
 338   if (xftfont) XftFontClose (display, xftfont);
 339   UNBLOCK_INPUT;
 340   if (xftfont_info) free (xftfont_info);
 341   if (xfont) free (xfont);
 342   return NULL;
 343 }
 344
 345 static void
 346 xftfont_close (f, font)
 347      FRAME_PTR f;
 348      struct font *font;
 349 {
 350   struct xftfont_info *xftfont_info = (struct xftfont_info *) font;
 351
 352   XftUnlockFace (xftfont_info->xftfont);
 353   XftFontClose (xftfont_info->display, xftfont_info->xftfont);
 354   if (font->font.name)
 355     free (font->font.name);
 356   free (font);
 357   FRAME_X_DISPLAY_INFO (f)->n_fonts--;
 358 }
 359
 360 static int
 361 xftfont_prepare_face (f, face)
 362      FRAME_PTR f;
 363      struct face *face;
 364 {
 365   struct xftface_info *xftface_info = malloc (sizeof (struct xftface_info));
 366
 367   if (! xftface_info)
 368     return -1;
 369
 370   BLOCK_INPUT;
 371   xftface_info->xft_draw = XftDrawCreate (FRAME_X_DISPLAY (f),
 372                                           FRAME_X_WINDOW (f),
 373                                           FRAME_X_VISUAL (f),
 374                                           FRAME_X_COLORMAP (f));
 375   xftfont_get_colors (f, face, face->gc, NULL,
 376                       &xftface_info->xft_fg, &xftface_info->xft_bg);
 377   UNBLOCK_INPUT;
 378
 379   face->extra = xftface_info;
 380   return 0;
 381 }
 382
 383 static void
 384 xftfont_done_face (f, face)
 385      FRAME_PTR f;
 386      struct face *face;
 387 {
 388   struct xftface_info *xftface_info = (struct xftface_info *) face->extra;
 389
 390   if (xftface_info)
 391     {
 392       BLOCK_INPUT;
 393       XftDrawDestroy (xftface_info->xft_draw);
 394       UNBLOCK_INPUT;
 395       free (xftface_info);
 396       face->extra = NULL;
 397     }
 398 }
 399
 400 static unsigned
 401 xftfont_encode_char (font, c)
 402      struct font *font;
 403      int c;
 404 {
 405   struct xftfont_info *xftfont_info = (struct xftfont_info *) font;
 406   unsigned code = XftCharIndex (xftfont_info->display, xftfont_info->xftfont,
 407                                 (FcChar32) c);
 408
 409   return (code ? code : 0xFFFFFFFF);
 410 }
 411
 412 static int
 413 xftfont_text_extents (font, code, nglyphs, metrics)
 414      struct font *font;
 415      unsigned *code;
 416      int nglyphs;
 417      struct font_metrics *metrics;
 418 {
 419   struct xftfont_info *xftfont_info = (struct xftfont_info *) font;
 420   XGlyphInfo extents;
 421
 422   BLOCK_INPUT;
 423   XftGlyphExtents (xftfont_info->display, xftfont_info->xftfont, code, nglyphs,
 424                    &extents);
 425   UNBLOCK_INPUT;
 426   if (metrics)
 427     {
 428       metrics->lbearing = - extents.x;
 429       metrics->rbearing = - extents.x + extents.width;
 430       metrics->width = extents.xOff;
 431       metrics->ascent = extents.y;
 432       metrics->descent = extents.y - extents.height;
 433     }
 434   return extents.xOff;
 435 }
 436
 437 static int
 438 xftfont_draw (s, from, to, x, y, with_background)
 439      struct glyph_string *s;
 440      int from, to, x, y, with_background;
 441 {
 442   FRAME_PTR f = s->f;
 443   struct face *face = s->face;
 444   struct xftfont_info *xftfont_info = (struct xftfont_info *) face->font_info;
 445   struct xftface_info *xftface_info = (struct xftface_info *) face->extra;
 446   FT_UInt *code;
 447   XftColor fg, bg;
 448   XRectangle r;
 449   int len = to - from;
 450   int i;
 451
 452   xftfont_get_colors (f, face, s->gc, xftface_info,
 453                       &fg, with_background ? &bg : NULL);
 454   BLOCK_INPUT;
 455   if (s->clip_width)
 456     {
 457       r.x = s->clip_x, r.width = s->clip_width;
 458       r.y = s->clip_y, r.height = s->clip_height;
 459       XftDrawSetClipRectangles (xftface_info->xft_draw, 0, 0, &r, 1);
 460     }
 461   if (with_background)
 462     {
 463       struct font *font = (struct font *) face->font_info;
 464
 465       XftDrawRect (xftface_info->xft_draw, &bg,
 466                    x, y - face->font->ascent, s->width, font->font.height);
 467     }
 468   code = alloca (sizeof (FT_UInt) * len);
 469   for (i = 0; i < len; i++)
 470     code[i] = ((XCHAR2B_BYTE1 (s->char2b + from + i) << 8)
 471                | XCHAR2B_BYTE2 (s->char2b + from + i));
 472
 473   XftDrawGlyphs (xftface_info->xft_draw, &fg, xftfont_info->xftfont,
 474                  x, y, code, len);
 475   if (s->clip_width)
 476     XftDrawSetClip (xftface_info->xft_draw, NULL);
 477   UNBLOCK_INPUT;
 478
 479   return len;
 480 }
 481
 482 static int
 483 xftfont_anchor_point (font, code, index, x, y)
 484      struct font *font;
 485      unsigned code;
 486      int index;
 487      int *x, *y;
 488 {
 489   struct xftfont_info *xftfont_info = (struct xftfont_info *) font;
 490   FT_Face ft_face = xftfont_info->ft_face;
 491
 492   if (FT_Load_Glyph (ft_face, code, FT_LOAD_DEFAULT) != 0)
 493     return -1;
 494   if (ft_face->glyph->format != FT_GLYPH_FORMAT_OUTLINE)
 495     return -1;
 496   if (index >= ft_face->glyph->outline.n_points)
 497     return -1;
 498   *x = ft_face->glyph->outline.points[index].x;
 499   *y = ft_face->glyph->outline.points[index].y;
 500   return 0;
 501 }
 502
 503
 504 void
 505 syms_of_xftfont ()
 506 {
 507   DEFSYM (Qxft, "xft");
 508
 509   xftfont_driver = ftfont_driver;
 510   xftfont_driver.type = Qxft;
 511   xftfont_driver.get_cache = xfont_driver.get_cache;
 512   xftfont_driver.list = xftfont_list;
 513   xftfont_driver.open = xftfont_open;
 514   xftfont_driver.close = xftfont_close;
 515   xftfont_driver.prepare_face = xftfont_prepare_face;
 516   xftfont_driver.done_face = xftfont_done_face;
 517   xftfont_driver.encode_char = xftfont_encode_char;
 518   xftfont_driver.text_extents = xftfont_text_extents;
 519   xftfont_driver.draw = xftfont_draw;
 520   xftfont_driver.anchor_point = xftfont_anchor_point;
 521
 522   register_font_driver (&xftfont_driver, NULL);
 523 }
 524
 525 /* arch-tag: 64ec61bf-7c8e-4fe6-b953-c6a85d5e1605
 526    (do not change this comment) */