src/ftxfont.c

   1 /* ftxfont.c -- FreeType font driver on X (without using XFT).
   2    Copyright (C) 2006-2015 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 struct font_driver ftxfont_driver;
  39
  40 struct ftxfont_frame_data
  41 {
  42   /* Background and foreground colors.  */
  43   XColor colors[2];
  44   /* GCs interpolating the above colors.  gcs[0] is for a color
  45    closest to BACKGROUND, and gcs[5] is for a color closest to
  46    FOREGROUND.  */
  47   GC gcs[6];
  48   struct ftxfont_frame_data *next;
  49 };
  50
  51
  52 /* Return an array of 6 GCs for antialiasing.  */
  53
  54 static GC *
  55 ftxfont_get_gcs (struct frame *f, unsigned long foreground, unsigned long background)
  56 {
  57   XColor color;
  58   XGCValues xgcv;
  59   int i;
  60   struct ftxfont_frame_data *data = font_get_frame_data (f, Qftx);
  61   struct ftxfont_frame_data *prev = NULL, *this = NULL, *new;
  62
  63   if (data)
  64     {
  65       for (this = data; this; prev = this, this = this->next)
  66         {
  67           if (this->colors[0].pixel < background)
  68             continue;
  69           if (this->colors[0].pixel > background)
  70             break;
  71           if (this->colors[1].pixel < foreground)
  72             continue;
  73           if (this->colors[1].pixel > foreground)
  74             break;
  75           return this->gcs;
  76         }
  77     }
  78
  79   new = xmalloc (sizeof *new);
  80   new->next = this;
  81   if (prev)
  82       prev->next = new;
  83   font_put_frame_data (f, Qftx, new);
  84
  85   new->colors[0].pixel = background;
  86   new->colors[1].pixel = foreground;
  87
  88   block_input ();
  89   XQueryColors (FRAME_X_DISPLAY (f), FRAME_X_COLORMAP (f), new->colors, 2);
  90   for (i = 1; i < 7; i++)
  91     {
  92       /* Interpolate colors linearly.  Any better algorithm?  */
  93       color.red
  94         = (new->colors[1].red * i + new->colors[0].red * (8 - i)) / 8;
  95       color.green
  96         = (new->colors[1].green * i + new->colors[0].green * (8 - i)) / 8;
  97       color.blue
  98         = (new->colors[1].blue * i + new->colors[0].blue * (8 - i)) / 8;
  99       if (! x_alloc_nearest_color (f, FRAME_X_COLORMAP (f), &color))
 100         break;
 101       xgcv.foreground = color.pixel;
 102       new->gcs[i - 1] = XCreateGC (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f),
 103                                    GCForeground, &xgcv);
 104     }
 105   unblock_input ();
 106
 107   if (i < 7)
 108     {
 109       block_input ();
 110       for (i--; i >= 0; i--)
 111         XFreeGC (FRAME_X_DISPLAY (f), new->gcs[i]);
 112       unblock_input ();
 113       if (prev)
 114         prev->next = new->next;
 115       else if (data)
 116         font_put_frame_data (f, Qftx, new->next);
 117       xfree (new);
 118       return NULL;
 119     }
 120   return new->gcs;
 121 }
 122
 123 static int
 124 ftxfont_draw_bitmap (struct frame *f, GC gc_fore, GC *gcs, struct font *font,
 125                      unsigned int code, int x, int y, XPoint *p, int size,
 126                      int *n, bool flush)
 127 {
 128   struct font_bitmap bitmap;
 129   unsigned char *b;
 130   int i, j;
 131
 132   if (ftfont_driver.get_bitmap (font, code, &bitmap, size > 0x100 ? 1 : 8) < 0)
 133     return 0;
 134   if (size > 0x100)
 135     {
 136       for (i = 0, b = bitmap.buffer; i < bitmap.rows;
 137            i++, b += bitmap.pitch)
 138         {
 139           for (j = 0; j < bitmap.width; j++)
 140             if (b[j / 8] & (1 << (7 - (j % 8))))
 141               {
 142                 p[n[0]].x = x + bitmap.left + j;
 143                 p[n[0]].y = y - bitmap.top + i;
 144                 if (++n[0] == size)
 145                   {
 146                     XDrawPoints (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f),
 147                                  gc_fore, p, size, CoordModeOrigin);
 148                     n[0] = 0;
 149                   }
 150               }
 151         }
 152       if (flush && n[0] > 0)
 153         XDrawPoints (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f),
 154                      gc_fore, p, n[0], CoordModeOrigin);
 155     }
 156   else
 157     {
 158       for (i = 0, b = bitmap.buffer; i < bitmap.rows;
 159            i++, b += bitmap.pitch)
 160         {
 161           for (j = 0; j < bitmap.width; j++)
 162             {
 163               int idx = (bitmap.bits_per_pixel == 1
 164                          ? ((b[j / 8] & (1 << (7 - (j % 8)))) ? 6 : -1)
 165                          : (b[j] >> 5) - 1);
 166
 167               if (idx >= 0)
 168                 {
 169                   XPoint *pp = p + size * idx;
 170
 171                   pp[n[idx]].x = x + bitmap.left + j;
 172                   pp[n[idx]].y = y - bitmap.top + i;
 173                   if (++(n[idx]) == size)
 174                     {
 175                       XDrawPoints (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f),
 176                                    idx == 6 ? gc_fore : gcs[idx], pp, size,
 177                                    CoordModeOrigin);
 178                       n[idx] = 0;
 179                     }
 180                 }
 181             }
 182         }
 183       if (flush)
 184         {
 185           for (i = 0; i < 6; i++)
 186             if (n[i] > 0)
 187               XDrawPoints (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f),
 188                            gcs[i], p + 0x100 * i, n[i], CoordModeOrigin);
 189           if (n[6] > 0)
 190             XDrawPoints (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f),
 191                          gc_fore, p + 0x600, n[6], CoordModeOrigin);
 192         }
 193     }
 194
 195   if (ftfont_driver.free_bitmap)
 196     ftfont_driver.free_bitmap (font, &bitmap);
 197
 198   return bitmap.advance;
 199 }
 200
 201 static void
 202 ftxfont_draw_background (struct frame *f, struct font *font, GC gc, int x, int y,
 203                          int width)
 204 {
 205   XGCValues xgcv;
 206
 207   XGetGCValues (FRAME_X_DISPLAY (f), gc,
 208                 GCForeground | GCBackground, &xgcv);
 209   XSetForeground (FRAME_X_DISPLAY (f), gc, xgcv.background);
 210   XFillRectangle (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f), gc,
 211                   x, y - FONT_BASE (font), width, FONT_HEIGHT (font));
 212   XSetForeground (FRAME_X_DISPLAY (f), gc, xgcv.foreground);
 213 }
 214
 215 static Lisp_Object
 216 ftxfont_list (struct frame *f, Lisp_Object spec)
 217 {
 218   Lisp_Object list = ftfont_driver.list (f, spec), tail;
 219
 220   for (tail = list; CONSP (tail); tail = XCDR (tail))
 221     ASET (XCAR (tail), FONT_TYPE_INDEX, Qftx);
 222   return list;
 223 }
 224
 225 static Lisp_Object
 226 ftxfont_match (struct frame *f, Lisp_Object spec)
 227 {
 228   Lisp_Object entity = ftfont_driver.match (f, spec);
 229
 230   if (VECTORP (entity))
 231     ASET (entity, FONT_TYPE_INDEX, Qftx);
 232   return entity;
 233 }
 234
 235 static Lisp_Object
 236 ftxfont_open (struct frame *f, Lisp_Object entity, int pixel_size)
 237 {
 238   Lisp_Object font_object;
 239   struct font *font;
 240
 241   font_object = ftfont_driver.open (f, entity, pixel_size);
 242   if (NILP (font_object))
 243     return Qnil;
 244   font = XFONT_OBJECT (font_object);
 245   font->driver = &ftxfont_driver;
 246   return font_object;
 247 }
 248
 249 static void
 250 ftxfont_close (struct font *font)
 251 {
 252   ftfont_driver.close (font);
 253 }
 254
 255 static int
 256 ftxfont_draw (struct glyph_string *s, int from, int to, int x, int y,
 257               bool with_background)
 258 {
 259   struct frame *f = s->f;
 260   struct face *face = s->face;
 261   struct font *font = s->font;
 262   XPoint p[0x700];
 263   int n[7];
 264   unsigned *code;
 265   int len = to - from;
 266   int i;
 267   GC *gcs;
 268   int xadvance;
 269
 270   n[0] = n[1] = n[2] = n[3] = n[4] = n[5] = n[6] = 0;
 271
 272   USE_SAFE_ALLOCA;
 273   SAFE_NALLOCA (code, 1, len);
 274   block_input ();
 275   if (with_background)
 276     ftxfont_draw_background (f, font, s->gc, x, y, s->width);
 277   for (i = 0; i < len; i++)
 278     code[i] = ((XCHAR2B_BYTE1 (s->char2b + from + i) << 8)
 279                | XCHAR2B_BYTE2 (s->char2b + from + i));
 280
 281   if (face->gc == s->gc)
 282     {
 283       gcs = ftxfont_get_gcs (f, face->foreground, face->background);
 284     }
 285   else
 286     {
 287       XGCValues xgcv;
 288       unsigned long mask = GCForeground | GCBackground;
 289
 290       XGetGCValues (FRAME_X_DISPLAY (f), s->gc, mask, &xgcv);
 291       gcs = ftxfont_get_gcs (f, xgcv.foreground, xgcv.background);
 292     }
 293
 294   if (gcs)
 295     {
 296       if (s->num_clips)
 297         for (i = 0; i < 6; i++)
 298           XSetClipRectangles (FRAME_X_DISPLAY (f), gcs[i], 0, 0,
 299                               s->clip, s->num_clips, Unsorted);
 300
 301       for (i = 0; i < len; i++)
 302         {
 303           xadvance = ftxfont_draw_bitmap (f, s->gc, gcs, font, code[i], x, y,
 304                                           p, 0x100, n, i + 1 == len);
 305           x += (s->padding_p ? 1 : xadvance);
 306         }
 307       if (s->num_clips)
 308         for (i = 0; i < 6; i++)
 309           XSetClipMask (FRAME_X_DISPLAY (f), gcs[i], None);
 310     }
 311   else
 312     {
 313       /* We can't draw with antialiasing.
 314          s->gc should already have a proper clipping setting. */
 315       for (i = 0; i < len; i++)
 316         {
 317           xadvance = ftxfont_draw_bitmap (f, s->gc, NULL, font, code[i], x, y,
 318                                           p, 0x700, n, i + 1 == len);
 319           x += (s->padding_p ? 1 : xadvance);
 320         }
 321     }
 322
 323   unblock_input ();
 324   SAFE_FREE ();
 325
 326   return len;
 327 }
 328
 329 static int
 330 ftxfont_end_for_frame (struct frame *f)
 331 {
 332   struct ftxfont_frame_data *data = font_get_frame_data (f, Qftx);
 333
 334   block_input ();
 335   while (data)
 336     {
 337       struct ftxfont_frame_data *next = data->next;
 338       int i;
 339
 340       for (i = 0; i < 6; i++)
 341         XFreeGC (FRAME_X_DISPLAY (f), data->gcs[i]);
 342       xfree (data);
 343       data = next;
 344     }
 345   unblock_input ();
 346   font_put_frame_data (f, Qftx, NULL);
 347   return 0;
 348 }
 349
 350 \f
 351
 352 void
 353 syms_of_ftxfont (void)
 354 {
 355   DEFSYM (Qftx, "ftx");
 356
 357   ftxfont_driver = ftfont_driver;
 358   ftxfont_driver.type = Qftx;
 359   ftxfont_driver.list = ftxfont_list;
 360   ftxfont_driver.match = ftxfont_match;
 361   ftxfont_driver.open = ftxfont_open;
 362   ftxfont_driver.close = ftxfont_close;
 363   ftxfont_driver.draw = ftxfont_draw;
 364   ftxfont_driver.end_for_frame = ftxfont_end_for_frame;
 365   register_font_driver (&ftxfont_driver, NULL);
 366 }