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;
 200   FcChar8 *file;
 201   XFontStruct *xfont;
 202   struct xftfont_info *xftfont_info;
 203   struct font *font;
 204   double size = 0;
 205   XftFont *xftfont;
 206   int spacing;
 207
 208   val = AREF (entity, FONT_EXTRA_INDEX);
 209   if (XTYPE (val) != Lisp_Misc
 210       || XMISCTYPE (val) != Lisp_Misc_Save_Value)
 211     return NULL;
 212   pattern = XSAVE_VALUE (val)->pointer;
 213   if (FcPatternGetString (pattern, FC_FILE, 0, &file) != FcResultMatch)
 214     return NULL;
 215
 216   size = XINT (AREF (entity, FONT_SIZE_INDEX));
 217   if (size == 0)
 218     size = pixel_size;
 219   pat = FcPatternCreate ();
 220   FcPatternAddString (pat, FC_FILE, file);
 221   FcPatternAddDouble (pat, FC_PIXEL_SIZE, pixel_size);
 222   FcPatternAddBool (pat, FC_ANTIALIAS, FcTrue);
 223   xftfont = XftFontOpenPattern (display, pat);
 224   /* We should not destroy PAT here because it is kept in XFTFONT and
 225      destroyed automatically when XFTFONT is closed.  */
 226   if (! xftfont)
 227     return NULL;
 228
 229   xftfont_info = malloc (sizeof (struct xftfont_info));
 230   if (! xftfont_info)
 231     {
 232       XftFontClose (display, xftfont);
 233       return NULL;
 234     }
 235   xfont = malloc (sizeof (XFontStruct));
 236   if (! xftfont_info)
 237     {
 238       XftFontClose (display, xftfont);
 239       free (xftfont_info);
 240       return NULL;
 241     }
 242   xftfont_info->display = display;
 243   xftfont_info->screen = FRAME_X_SCREEN_NUMBER (f);
 244   xftfont_info->xftfont = xftfont;
 245   xftfont_info->ft_face = XftLockFace (xftfont);
 246
 247   font = (struct font *) xftfont_info;
 248   font->entity = entity;
 249   font->pixel_size = size;
 250   font->driver = &xftfont_driver;
 251   font->font.name = font->font.full_name = NULL;
 252   font->file_name = (char *) file;
 253   font->font.size = xftfont->max_advance_width;
 254   font->ascent = xftfont->ascent;
 255   font->descent = xftfont->descent;
 256   font->font.height = xftfont->ascent + xftfont->descent;
 257
 258   if (FcPatternGetInteger (xftfont->pattern, FC_SPACING, 0, &spacing)
 259       != FcResultMatch)
 260     spacing = FC_PROPORTIONAL;
 261   if (spacing != FC_PROPORTIONAL)
 262     font->font.average_width = font->font.space_width
 263       = xftfont->max_advance_width;
 264   else
 265     {
 266       XGlyphInfo extents;
 267
 268       if (! ascii_printable[0])
 269         {
 270           int i;
 271           for (i = 0; i < 95; i++)
 272             ascii_printable[i] = ' ' + i;
 273         }
 274       XftTextExtents8 (display, xftfont, ascii_printable, 1, &extents);
 275       font->font.space_width = extents.xOff;
 276       if (font->font.space_width <= 0)
 277         /* dirty workaround */
 278         font->font.space_width = pixel_size;
 279       XftTextExtents8 (display, xftfont, ascii_printable + 1, 94, &extents);
 280       font->font.average_width = (font->font.space_width + extents.xOff) / 95;
 281     }
 282
 283   /* Unfortunately Xft doesn't provide a way to get minimum char
 284      width.  So, we use space_width instead.  */
 285   font->min_width = font->font.space_width;
 286
 287   font->font.baseline_offset = 0;
 288   font->font.relative_compose = 0;
 289   font->font.default_ascent = 0;
 290   font->font.vertical_centering = 0;
 291
 292   /* Setup pseudo XFontStruct */
 293   xfont->fid = xftfont_default_fid (f);
 294   xfont->ascent = xftfont->ascent;
 295   xfont->descent = xftfont->descent;
 296   xfont->max_bounds.descent = xftfont->descent;
 297   xfont->max_bounds.width = xftfont->max_advance_width;
 298   xfont->min_bounds.width = font->font.space_width;
 299   font->font.font = xfont;
 300
 301   dpyinfo->n_fonts++;
 302
 303   /* Set global flag fonts_changed_p to non-zero if the font loaded
 304      has a character with a smaller width than any other character
 305      before, or if the font loaded has a smaller height than any other
 306      font loaded before.  If this happens, it will make a glyph matrix
 307      reallocation necessary.  */
 308   if (dpyinfo->n_fonts == 1)
 309     {
 310       dpyinfo->smallest_font_height = font->font.height;
 311       dpyinfo->smallest_char_width = font->min_width;
 312       fonts_changed_p = 1;
 313     }
 314   else
 315     {
 316       if (dpyinfo->smallest_font_height > font->font.height)
 317         dpyinfo->smallest_font_height = font->font.height,
 318           fonts_changed_p |= 1;
 319       if (dpyinfo->smallest_char_width > font->min_width)
 320         dpyinfo->smallest_char_width = font->min_width,
 321           fonts_changed_p |= 1;
 322     }
 323
 324   return font;
 325 }
 326
 327 static void
 328 xftfont_close (f, font)
 329      FRAME_PTR f;
 330      struct font *font;
 331 {
 332   struct xftfont_info *xftfont_info = (struct xftfont_info *) font;
 333
 334   XftUnlockFace (xftfont_info->xftfont);
 335   XftFontClose (xftfont_info->display, xftfont_info->xftfont);
 336   free (font);
 337   FRAME_X_DISPLAY_INFO (f)->n_fonts--;
 338 }
 339
 340 static int
 341 xftfont_prepare_face (f, face)
 342      FRAME_PTR f;
 343      struct face *face;
 344 {
 345   struct xftface_info *xftface_info = malloc (sizeof (struct xftface_info));
 346
 347   if (! xftface_info)
 348     return -1;
 349
 350   BLOCK_INPUT;
 351   xftface_info->xft_draw = XftDrawCreate (FRAME_X_DISPLAY (f),
 352                                           FRAME_X_WINDOW (f),
 353                                           FRAME_X_VISUAL (f),
 354                                           FRAME_X_COLORMAP (f));
 355   xftfont_get_colors (f, face, face->gc, NULL,
 356                       &xftface_info->xft_fg, &xftface_info->xft_bg);
 357   UNBLOCK_INPUT;
 358
 359   face->extra = xftface_info;
 360   return 0;
 361 }
 362
 363 static void
 364 xftfont_done_face (f, face)
 365      FRAME_PTR f;
 366      struct face *face;
 367 {
 368   struct xftface_info *xftface_info = (struct xftface_info *) face->extra;
 369
 370   if (xftface_info)
 371     {
 372       BLOCK_INPUT;
 373       XftDrawDestroy (xftface_info->xft_draw);
 374       UNBLOCK_INPUT;
 375       free (xftface_info);
 376       face->extra = NULL;
 377     }
 378 }
 379
 380 static unsigned
 381 xftfont_encode_char (font, c)
 382      struct font *font;
 383      int c;
 384 {
 385   struct xftfont_info *xftfont_info = (struct xftfont_info *) font;
 386   unsigned code = XftCharIndex (xftfont_info->display, xftfont_info->xftfont,
 387                                 (FcChar32) c);
 388
 389   return (code ? code : 0xFFFFFFFF);
 390 }
 391
 392 static int
 393 xftfont_text_extents (font, code, nglyphs, metrics)
 394      struct font *font;
 395      unsigned *code;
 396      int nglyphs;
 397      struct font_metrics *metrics;
 398 {
 399   struct xftfont_info *xftfont_info = (struct xftfont_info *) font;
 400   XGlyphInfo extents;
 401
 402   BLOCK_INPUT;
 403   XftGlyphExtents (xftfont_info->display, xftfont_info->xftfont, code, nglyphs,
 404                    &extents);
 405   UNBLOCK_INPUT;
 406   if (metrics)
 407     {
 408       metrics->lbearing = - extents.x;
 409       metrics->rbearing = - extents.x + extents.width;
 410       metrics->width = extents.xOff;
 411       metrics->ascent = extents.y;
 412       metrics->descent = extents.y - extents.height;
 413     }
 414   return extents.xOff;
 415 }
 416
 417 static int
 418 xftfont_draw (s, from, to, x, y, with_background)
 419      struct glyph_string *s;
 420      int from, to, x, y, with_background;
 421 {
 422   FRAME_PTR f = s->f;
 423   struct face *face = s->face;
 424   struct xftfont_info *xftfont_info = (struct xftfont_info *) face->font_info;
 425   struct xftface_info *xftface_info = (struct xftface_info *) face->extra;
 426   FT_UInt *code;
 427   XftColor fg, bg;
 428   XRectangle r;
 429   int len = to - from;
 430   int i;
 431
 432   xftfont_get_colors (f, face, s->gc, xftface_info,
 433                       &fg, with_background ? &bg : NULL);
 434   BLOCK_INPUT;
 435   if (s->clip_width)
 436     {
 437       r.x = s->clip_x, r.width = s->clip_width;
 438       r.y = s->clip_y, r.height = s->clip_height;
 439       XftDrawSetClipRectangles (xftface_info->xft_draw, 0, 0, &r, 1);
 440     }
 441   if (with_background)
 442     {
 443       struct font *font = (struct font *) face->font_info;
 444
 445       XftDrawRect (xftface_info->xft_draw, &bg,
 446                    x, y - face->font->ascent, s->width, font->font.height);
 447     }
 448   code = alloca (sizeof (FT_UInt) * len);
 449   for (i = 0; i < len; i++)
 450     code[i] = ((XCHAR2B_BYTE1 (s->char2b + from + i) << 8)
 451                | XCHAR2B_BYTE2 (s->char2b + from + i));
 452
 453   XftDrawGlyphs (xftface_info->xft_draw, &fg, xftfont_info->xftfont,
 454                  x, y, code, len);
 455   if (s->clip_width)
 456     XftDrawSetClip (xftface_info->xft_draw, NULL);
 457   UNBLOCK_INPUT;
 458
 459   return len;
 460 }
 461
 462 static int
 463 xftfont_anchor_point (font, code, index, x, y)
 464      struct font *font;
 465      unsigned code;
 466      int index;
 467      int *x, *y;
 468 {
 469   struct xftfont_info *xftfont_info = (struct xftfont_info *) font;
 470   FT_Face ft_face = xftfont_info->ft_face;
 471
 472   if (FT_Load_Glyph (ft_face, code, FT_LOAD_DEFAULT) != 0)
 473     return -1;
 474   if (ft_face->glyph->format != FT_GLYPH_FORMAT_OUTLINE)
 475     return -1;
 476   if (index >= ft_face->glyph->outline.n_points)
 477     return -1;
 478   *x = ft_face->glyph->outline.points[index].x;
 479   *y = ft_face->glyph->outline.points[index].y;
 480   return 0;
 481 }
 482
 483
 484 void
 485 syms_of_xftfont ()
 486 {
 487   DEFSYM (Qxft, "xft");
 488
 489   xftfont_driver = ftfont_driver;
 490   xftfont_driver.type = Qxft;
 491   xftfont_driver.get_cache = xfont_driver.get_cache;
 492   xftfont_driver.list = xftfont_list;
 493   xftfont_driver.open = xftfont_open;
 494   xftfont_driver.close = xftfont_close;
 495   xftfont_driver.prepare_face = xftfont_prepare_face;
 496   xftfont_driver.done_face = xftfont_done_face;
 497   xftfont_driver.encode_char = xftfont_encode_char;
 498   xftfont_driver.text_extents = xftfont_text_extents;
 499   xftfont_driver.draw = xftfont_draw;
 500   xftfont_driver.anchor_point = xftfont_anchor_point;
 501
 502   register_font_driver (&xftfont_driver, NULL);
 503 }
 504
 505 /* arch-tag: 64ec61bf-7c8e-4fe6-b953-c6a85d5e1605
 506    (do not change this comment) */