src/ftxfont.c

   1 /* ftxfont.c -- FreeType font driver on X (without using XFT).
   2    Copyright (C) 2006-2014 Free Software Foundation, Inc.
   3    Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011
   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
  26 #include "lisp.h"
  27 #include "dispextern.h"
  28 #include "xterm.h"
  29 #include "frame.h"
  30 #include "blockinput.h"
  31 #include "character.h"
  32 #include "charset.h"
  33 #include "fontset.h"
  34 #include "font.h"
  35
  36 /* FTX font driver.  */
  37
  38 static Lisp_Object Qftx;
  39
  40 #if defined HAVE_XFT || !defined HAVE_FREETYPE
  41 static
  42 #endif
  43 struct font_driver ftxfont_driver;
  44
  45 struct ftxfont_frame_data
  46 {
  47   /* Background and foreground colors.  */
  48   XColor colors[2];
  49   /* GCs interpolating the above colors.  gcs[0] is for a color
  50    closest to BACKGROUND, and gcs[5] is for a color closest to
  51    FOREGROUND.  */
  52   GC gcs[6];
  53   struct ftxfont_frame_data *next;
  54 };
  55
  56
  57 /* Return an array of 6 GCs for antialiasing.  */
  58
  59 static GC *
  60 ftxfont_get_gcs (struct frame *f, unsigned long foreground, unsigned long background)
  61 {
  62   XColor color;
  63   XGCValues xgcv;
  64   int i;
  65   struct ftxfont_frame_data *data = font_get_frame_data (f, &ftxfont_driver);
  66   struct ftxfont_frame_data *prev = NULL, *this = NULL, *new;
  67
  68   if (data)
  69     {
  70       for (this = data; this; prev = this, this = this->next)
  71         {
  72           if (this->colors[0].pixel < background)
  73             continue;
  74           if (this->colors[0].pixel > background)
  75             break;
  76           if (this->colors[1].pixel < foreground)
  77             continue;
  78           if (this->colors[1].pixel > foreground)
  79             break;
  80           return this->gcs;
  81         }
  82     }
  83
  84   new = malloc (sizeof *new);
  85   if (! new)
  86     return NULL;
  87   new->next = this;
  88   if (prev)
  89     {
  90       prev->next = new;
  91     }
  92   else if (font_put_frame_data (f, &ftxfont_driver, new) < 0)
  93     {
  94       free (new);
  95       return NULL;
  96     }
  97
  98   new->colors[0].pixel = background;
  99   new->colors[1].pixel = foreground;
 100
 101   block_input ();
 102   XQueryColors (FRAME_X_DISPLAY (f), FRAME_X_COLORMAP (f), new->colors, 2);
 103   for (i = 1; i < 7; i++)
 104     {
 105       /* Interpolate colors linearly.  Any better algorithm?  */
 106       color.red
 107         = (new->colors[1].red * i + new->colors[0].red * (8 - i)) / 8;
 108       color.green
 109         = (new->colors[1].green * i + new->colors[0].green * (8 - i)) / 8;
 110       color.blue
 111         = (new->colors[1].blue * i + new->colors[0].blue * (8 - i)) / 8;
 112       if (! x_alloc_nearest_color (f, FRAME_X_COLORMAP (f), &color))
 113         break;
 114       xgcv.foreground = color.pixel;
 115       new->gcs[i - 1] = XCreateGC (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f),
 116                                    GCForeground, &xgcv);
 117     }
 118   unblock_input ();
 119
 120   if (i < 7)
 121     {
 122       block_input ();
 123       for (i--; i >= 0; i--)
 124         XFreeGC (FRAME_X_DISPLAY (f), new->gcs[i]);
 125       unblock_input ();
 126       if (prev)
 127         prev->next = new->next;
 128       else if (data)
 129         font_put_frame_data (f, &ftxfont_driver, new->next);
 130       free (new);
 131       return NULL;
 132     }
 133   return new->gcs;
 134 }
 135
 136 static int
 137 ftxfont_draw_bitmap (struct frame *f, GC gc_fore, GC *gcs, struct font *font,
 138                      unsigned int code, int x, int y, XPoint *p, int size,
 139                      int *n, bool flush)
 140 {
 141   struct font_bitmap bitmap;
 142   unsigned char *b;
 143   int i, j;
 144
 145   if (ftfont_driver.get_bitmap (font, code, &bitmap, size > 0x100 ? 1 : 8) < 0)
 146     return 0;
 147   if (size > 0x100)
 148     {
 149       for (i = 0, b = bitmap.buffer; i < bitmap.rows;
 150            i++, b += bitmap.pitch)
 151         {
 152           for (j = 0; j < bitmap.width; j++)
 153             if (b[j / 8] & (1 << (7 - (j % 8))))
 154               {
 155                 p[n[0]].x = x + bitmap.left + j;
 156                 p[n[0]].y = y - bitmap.top + i;
 157                 if (++n[0] == size)
 158                   {
 159                     XDrawPoints (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f),
 160                                  gc_fore, p, size, CoordModeOrigin);
 161                     n[0] = 0;
 162                   }
 163               }
 164         }
 165       if (flush && n[0] > 0)
 166         XDrawPoints (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f),
 167                      gc_fore, p, n[0], CoordModeOrigin);
 168     }
 169   else
 170     {
 171       for (i = 0, b = bitmap.buffer; i < bitmap.rows;
 172            i++, b += bitmap.pitch)
 173         {
 174           for (j = 0; j < bitmap.width; j++)
 175             {
 176               int idx = (bitmap.bits_per_pixel == 1
 177                          ? ((b[j / 8] & (1 << (7 - (j % 8)))) ? 6 : -1)
 178                          : (b[j] >> 5) - 1);
 179
 180               if (idx >= 0)
 181                 {
 182                   XPoint *pp = p + size * idx;
 183
 184                   pp[n[idx]].x = x + bitmap.left + j;
 185                   pp[n[idx]].y = y - bitmap.top + i;
 186                   if (++(n[idx]) == size)
 187                     {
 188                       XDrawPoints (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f),
 189                                    idx == 6 ? gc_fore : gcs[idx], pp, size,
 190                                    CoordModeOrigin);
 191                       n[idx] = 0;
 192                     }
 193                 }
 194             }
 195         }
 196       if (flush)
 197         {
 198           for (i = 0; i < 6; i++)
 199             if (n[i] > 0)
 200               XDrawPoints (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f),
 201                            gcs[i], p + 0x100 * i, n[i], CoordModeOrigin);
 202           if (n[6] > 0)
 203             XDrawPoints (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f),
 204                          gc_fore, p + 0x600, n[6], CoordModeOrigin);
 205         }
 206     }
 207
 208   if (ftfont_driver.free_bitmap)
 209     ftfont_driver.free_bitmap (font, &bitmap);
 210
 211   return bitmap.advance;
 212 }
 213
 214 static void
 215 ftxfont_draw_background (struct frame *f, struct font *font, GC gc, int x, int y,
 216                          int width)
 217 {
 218   XGCValues xgcv;
 219
 220   XGetGCValues (FRAME_X_DISPLAY (f), gc,
 221                 GCForeground | GCBackground, &xgcv);
 222   XSetForeground (FRAME_X_DISPLAY (f), gc, xgcv.background);
 223   XFillRectangle (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f), gc,
 224                   x, y - FONT_BASE (font), width, FONT_HEIGHT (font));
 225   XSetForeground (FRAME_X_DISPLAY (f), gc, xgcv.foreground);
 226 }
 227
 228 static Lisp_Object
 229 ftxfont_list (struct frame *f, Lisp_Object spec)
 230 {
 231   Lisp_Object list = ftfont_driver.list (f, spec), tail;
 232
 233   for (tail = list; CONSP (tail); tail = XCDR (tail))
 234     ASET (XCAR (tail), FONT_TYPE_INDEX, Qftx);
 235   return list;
 236 }
 237
 238 static Lisp_Object
 239 ftxfont_match (struct frame *f, Lisp_Object spec)
 240 {
 241   Lisp_Object entity = ftfont_driver.match (f, spec);
 242
 243   if (VECTORP (entity))
 244     ASET (entity, FONT_TYPE_INDEX, Qftx);
 245   return entity;
 246 }
 247
 248 static Lisp_Object
 249 ftxfont_open (struct frame *f, Lisp_Object entity, int pixel_size)
 250 {
 251   Lisp_Object font_object;
 252   struct font *font;
 253
 254   font_object = ftfont_driver.open (f, entity, pixel_size);
 255   if (NILP (font_object))
 256     return Qnil;
 257   font = XFONT_OBJECT (font_object);
 258   font->driver = &ftxfont_driver;
 259   return font_object;
 260 }
 261
 262 static void
 263 ftxfont_close (struct font *font)
 264 {
 265   ftfont_driver.close (font);
 266 }
 267
 268 static int
 269 ftxfont_draw (struct glyph_string *s, int from, int to, int x, int y,
 270               bool with_background)
 271 {
 272   struct frame *f = s->f;
 273   struct face *face = s->face;
 274   struct font *font = s->font;
 275   XPoint p[0x700];
 276   int n[7];
 277   unsigned *code;
 278   int len = to - from;
 279   int i;
 280   GC *gcs;
 281   int xadvance;
 282
 283   n[0] = n[1] = n[2] = n[3] = n[4] = n[5] = n[6] = 0;
 284
 285   block_input ();
 286   if (with_background)
 287     ftxfont_draw_background (f, font, s->gc, x, y, s->width);
 288   code = alloca (sizeof (unsigned) * len);
 289   for (i = 0; i < len; i++)
 290     code[i] = ((XCHAR2B_BYTE1 (s->char2b + from + i) << 8)
 291                | XCHAR2B_BYTE2 (s->char2b + from + i));
 292
 293   if (face->gc == s->gc)
 294     {
 295       gcs = ftxfont_get_gcs (f, face->foreground, face->background);
 296     }
 297   else
 298     {
 299       XGCValues xgcv;
 300       unsigned long mask = GCForeground | GCBackground;
 301
 302       XGetGCValues (FRAME_X_DISPLAY (f), s->gc, mask, &xgcv);
 303       gcs = ftxfont_get_gcs (f, xgcv.foreground, xgcv.background);
 304     }
 305
 306   if (gcs)
 307     {
 308       if (s->num_clips)
 309         for (i = 0; i < 6; i++)
 310           XSetClipRectangles (FRAME_X_DISPLAY (f), gcs[i], 0, 0,
 311                               s->clip, s->num_clips, Unsorted);
 312
 313       for (i = 0; i < len; i++)
 314         {
 315           xadvance = ftxfont_draw_bitmap (f, s->gc, gcs, font, code[i], x, y,
 316                                           p, 0x100, n, i + 1 == len);
 317           x += (s->padding_p ? 1 : xadvance);
 318         }
 319       if (s->num_clips)
 320         for (i = 0; i < 6; i++)
 321           XSetClipMask (FRAME_X_DISPLAY (f), gcs[i], None);
 322     }
 323   else
 324     {
 325       /* We can't draw with antialiasing.
 326          s->gc should already have a proper clipping setting. */
 327       for (i = 0; i < len; i++)
 328         {
 329           xadvance = ftxfont_draw_bitmap (f, s->gc, NULL, font, code[i], x, y,
 330                                           p, 0x700, n, i + 1 == len);
 331           x += (s->padding_p ? 1 : xadvance);
 332         }
 333     }
 334
 335   unblock_input ();
 336
 337   return len;
 338 }
 339
 340 static int
 341 ftxfont_end_for_frame (struct frame *f)
 342 {
 343   struct ftxfont_frame_data *data = font_get_frame_data (f, &ftxfont_driver);
 344
 345   block_input ();
 346   while (data)
 347     {
 348       struct ftxfont_frame_data *next = data->next;
 349       int i;
 350
 351       for (i = 0; i < 6; i++)
 352         XFreeGC (FRAME_X_DISPLAY (f), data->gcs[i]);
 353       free (data);
 354       data = next;
 355     }
 356   unblock_input ();
 357   font_put_frame_data (f, &ftxfont_driver, NULL);
 358   return 0;
 359 }
 360
 361 \f
 362
 363 void
 364 syms_of_ftxfont (void)
 365 {
 366   DEFSYM (Qftx, "ftx");
 367
 368   ftxfont_driver = ftfont_driver;
 369   ftxfont_driver.type = Qftx;
 370   ftxfont_driver.list = ftxfont_list;
 371   ftxfont_driver.match = ftxfont_match;
 372   ftxfont_driver.open = ftxfont_open;
 373   ftxfont_driver.close = ftxfont_close;
 374   ftxfont_driver.draw = ftxfont_draw;
 375   ftxfont_driver.end_for_frame = ftxfont_end_for_frame;
 376   register_font_driver (&ftxfont_driver, NULL);
 377 }