src/ftxfont.c

   1 /* ftxfont.c -- FreeType font driver on X (without using XFT).
   2    Copyright (C) 2006-2018 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 (at
  12 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 <https://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 "xterm.h"
  28 #include "frame.h"
  29 #include "blockinput.h"
  30 #include "font.h"
  31
  32 /* FTX font driver.  */
  33
  34 struct ftxfont_frame_data
  35 {
  36   /* Background and foreground colors.  */
  37   XColor colors[2];
  38   /* GCs interpolating the above colors.  gcs[0] is for a color
  39    closest to BACKGROUND, and gcs[5] is for a color closest to
  40    FOREGROUND.  */
  41   GC gcs[6];
  42   struct ftxfont_frame_data *next;
  43 };
  44
  45
  46 /* Return an array of 6 GCs for antialiasing.  */
  47
  48 static GC *
  49 ftxfont_get_gcs (struct frame *f, unsigned long foreground, unsigned long background)
  50 {
  51   XColor color;
  52   XGCValues xgcv;
  53   int i;
  54   struct ftxfont_frame_data *data = font_get_frame_data (f, Qftx);
  55   struct ftxfont_frame_data *prev = NULL, *this = NULL, *new;
  56
  57   if (data)
  58     {
  59       for (this = data; this; prev = this, this = this->next)
  60         {
  61           if (this->colors[0].pixel < background)
  62             continue;
  63           if (this->colors[0].pixel > background)
  64             break;
  65           if (this->colors[1].pixel < foreground)
  66             continue;
  67           if (this->colors[1].pixel > foreground)
  68             break;
  69           return this->gcs;
  70         }
  71     }
  72
  73   new = xmalloc (sizeof *new);
  74   new->next = this;
  75   if (prev)
  76       prev->next = new;
  77   font_put_frame_data (f, Qftx, new);
  78
  79   new->colors[0].pixel = background;
  80   new->colors[1].pixel = foreground;
  81
  82   block_input ();
  83   XQueryColors (FRAME_X_DISPLAY (f), FRAME_X_COLORMAP (f), new->colors, 2);
  84   for (i = 1; i < 7; i++)
  85     {
  86       /* Interpolate colors linearly.  Any better algorithm?  */
  87       color.red
  88         = (new->colors[1].red * i + new->colors[0].red * (8 - i)) / 8;
  89       color.green
  90         = (new->colors[1].green * i + new->colors[0].green * (8 - i)) / 8;
  91       color.blue
  92         = (new->colors[1].blue * i + new->colors[0].blue * (8 - i)) / 8;
  93       if (! x_alloc_nearest_color (f, FRAME_X_COLORMAP (f), &color))
  94         break;
  95       xgcv.foreground = color.pixel;
  96       new->gcs[i - 1] = XCreateGC (FRAME_X_DISPLAY (f), FRAME_X_DRAWABLE (f),
  97                                    GCForeground, &xgcv);
  98     }
  99   unblock_input ();
 100
 101   if (i < 7)
 102     {
 103       block_input ();
 104       for (i--; i >= 0; i--)
 105         XFreeGC (FRAME_X_DISPLAY (f), new->gcs[i]);
 106       unblock_input ();
 107       if (prev)
 108         prev->next = new->next;
 109       else if (data)
 110         font_put_frame_data (f, Qftx, new->next);
 111       xfree (new);
 112       return NULL;
 113     }
 114   return new->gcs;
 115 }
 116
 117 static int
 118 ftxfont_draw_bitmap (struct frame *f, GC gc_fore, GC *gcs, struct font *font,
 119                      unsigned int code, int x, int y, XPoint *p, int size,
 120                      int *n, bool flush)
 121 {
 122   struct font_bitmap bitmap;
 123   unsigned char *b;
 124   int i, j;
 125
 126   if (ftfont_get_bitmap (font, code, &bitmap, size > 0x100 ? 1 : 8) < 0)
 127     return 0;
 128   if (size > 0x100)
 129     {
 130       for (i = 0, b = bitmap.buffer; i < bitmap.rows;
 131            i++, b += bitmap.pitch)
 132         {
 133           for (j = 0; j < bitmap.width; j++)
 134             if (b[j / 8] & (1 << (7 - (j % 8))))
 135               {
 136                 p[n[0]].x = x + bitmap.left + j;
 137                 p[n[0]].y = y - bitmap.top + i;
 138                 if (++n[0] == size)
 139                   {
 140                     XDrawPoints (FRAME_X_DISPLAY (f), FRAME_X_DRAWABLE (f),
 141                                  gc_fore, p, size, CoordModeOrigin);
 142                     n[0] = 0;
 143                   }
 144               }
 145         }
 146       if (flush && n[0] > 0)
 147         XDrawPoints (FRAME_X_DISPLAY (f), FRAME_X_DRAWABLE (f),
 148                      gc_fore, p, n[0], CoordModeOrigin);
 149     }
 150   else
 151     {
 152       for (i = 0, b = bitmap.buffer; i < bitmap.rows;
 153            i++, b += bitmap.pitch)
 154         {
 155           for (j = 0; j < bitmap.width; j++)
 156             {
 157               int idx = (bitmap.bits_per_pixel == 1
 158                          ? ((b[j / 8] & (1 << (7 - (j % 8)))) ? 6 : -1)
 159                          : (b[j] >> 5) - 1);
 160
 161               if (idx >= 0)
 162                 {
 163                   XPoint *pp = p + size * idx;
 164
 165                   pp[n[idx]].x = x + bitmap.left + j;
 166                   pp[n[idx]].y = y - bitmap.top + i;
 167                   if (++(n[idx]) == size)
 168                     {
 169                       XDrawPoints (FRAME_X_DISPLAY (f), FRAME_X_DRAWABLE (f),
 170                                    idx == 6 ? gc_fore : gcs[idx], pp, size,
 171                                    CoordModeOrigin);
 172                       n[idx] = 0;
 173                     }
 174                 }
 175             }
 176         }
 177       if (flush)
 178         {
 179           for (i = 0; i < 6; i++)
 180             if (n[i] > 0)
 181               XDrawPoints (FRAME_X_DISPLAY (f), FRAME_X_DRAWABLE (f),
 182                            gcs[i], p + 0x100 * i, n[i], CoordModeOrigin);
 183           if (n[6] > 0)
 184             XDrawPoints (FRAME_X_DISPLAY (f), FRAME_X_DRAWABLE (f),
 185                          gc_fore, p + 0x600, n[6], CoordModeOrigin);
 186         }
 187     }
 188
 189   /* There is no ftfont_free_bitmap, so do not try to free BITMAP.  */
 190
 191   return bitmap.advance;
 192 }
 193
 194 static void
 195 ftxfont_draw_background (struct frame *f, struct font *font, GC gc, int x, int y,
 196                          int width)
 197 {
 198   XGCValues xgcv;
 199
 200   XGetGCValues (FRAME_X_DISPLAY (f), gc,
 201                 GCForeground | GCBackground, &xgcv);
 202   XSetForeground (FRAME_X_DISPLAY (f), gc, xgcv.background);
 203   XFillRectangle (FRAME_X_DISPLAY (f), FRAME_X_DRAWABLE (f), gc,
 204                   x, y - FONT_BASE (font), width, FONT_HEIGHT (font));
 205   XSetForeground (FRAME_X_DISPLAY (f), gc, xgcv.foreground);
 206 }
 207
 208 static Lisp_Object
 209 ftxfont_list (struct frame *f, Lisp_Object spec)
 210 {
 211   Lisp_Object list = ftfont_list (f, spec), tail;
 212
 213   for (tail = list; CONSP (tail); tail = XCDR (tail))
 214     ASET (XCAR (tail), FONT_TYPE_INDEX, Qftx);
 215   return list;
 216 }
 217
 218 static Lisp_Object
 219 ftxfont_match (struct frame *f, Lisp_Object spec)
 220 {
 221   Lisp_Object entity = ftfont_match (f, spec);
 222
 223   if (VECTORP (entity))
 224     ASET (entity, FONT_TYPE_INDEX, Qftx);
 225   return entity;
 226 }
 227
 228 static Lisp_Object
 229 ftxfont_open (struct frame *f, Lisp_Object entity, int pixel_size)
 230 {
 231   Lisp_Object font_object = ftfont_open (f, entity, pixel_size);
 232   if (NILP (font_object))
 233     return Qnil;
 234   struct font *font = XFONT_OBJECT (font_object);
 235   font->driver = &ftxfont_driver;
 236   return font_object;
 237 }
 238
 239 static void
 240 ftxfont_close (struct font *font)
 241 {
 242   ftfont_close (font);
 243 }
 244
 245 static int
 246 ftxfont_draw (struct glyph_string *s, int from, int to, int x, int y,
 247               bool with_background)
 248 {
 249   struct frame *f = s->f;
 250   struct face *face = s->face;
 251   struct font *font = s->font;
 252   XPoint p[0x700];
 253   int n[7];
 254   unsigned *code;
 255   int len = to - from;
 256   int i;
 257   GC *gcs;
 258   int xadvance;
 259
 260   n[0] = n[1] = n[2] = n[3] = n[4] = n[5] = n[6] = 0;
 261
 262   USE_SAFE_ALLOCA;
 263   SAFE_NALLOCA (code, 1, len);
 264   block_input ();
 265   if (with_background)
 266     ftxfont_draw_background (f, font, s->gc, x, y, s->width);
 267   for (i = 0; i < len; i++)
 268     code[i] = ((XCHAR2B_BYTE1 (s->char2b + from + i) << 8)
 269                | XCHAR2B_BYTE2 (s->char2b + from + i));
 270
 271   if (face->gc == s->gc)
 272     {
 273       gcs = ftxfont_get_gcs (f, face->foreground, face->background);
 274     }
 275   else
 276     {
 277       XGCValues xgcv;
 278       unsigned long mask = GCForeground | GCBackground;
 279
 280       XGetGCValues (FRAME_X_DISPLAY (f), s->gc, mask, &xgcv);
 281       gcs = ftxfont_get_gcs (f, xgcv.foreground, xgcv.background);
 282     }
 283
 284   if (gcs)
 285     {
 286       if (s->num_clips)
 287         for (i = 0; i < 6; i++)
 288           XSetClipRectangles (FRAME_X_DISPLAY (f), gcs[i], 0, 0,
 289                               s->clip, s->num_clips, Unsorted);
 290
 291       for (i = 0; i < len; i++)
 292         {
 293           xadvance = ftxfont_draw_bitmap (f, s->gc, gcs, font, code[i], x, y,
 294                                           p, 0x100, n, i + 1 == len);
 295           x += (s->padding_p ? 1 : xadvance);
 296         }
 297       if (s->num_clips)
 298         for (i = 0; i < 6; i++)
 299           XSetClipMask (FRAME_X_DISPLAY (f), gcs[i], None);
 300     }
 301   else
 302     {
 303       /* We can't draw with antialiasing.
 304          s->gc should already have a proper clipping setting. */
 305       for (i = 0; i < len; i++)
 306         {
 307           xadvance = ftxfont_draw_bitmap (f, s->gc, NULL, font, code[i], x, y,
 308                                           p, 0x700, n, i + 1 == len);
 309           x += (s->padding_p ? 1 : xadvance);
 310         }
 311     }
 312
 313   unblock_input ();
 314   SAFE_FREE ();
 315
 316   return len;
 317 }
 318
 319 static int
 320 ftxfont_end_for_frame (struct frame *f)
 321 {
 322   struct ftxfont_frame_data *data = font_get_frame_data (f, Qftx);
 323
 324   block_input ();
 325   while (data)
 326     {
 327       struct ftxfont_frame_data *next = data->next;
 328       int i;
 329
 330       for (i = 0; i < 6; i++)
 331         XFreeGC (FRAME_X_DISPLAY (f), data->gcs[i]);
 332       xfree (data);
 333       data = next;
 334     }
 335   unblock_input ();
 336   font_put_frame_data (f, Qftx, NULL);
 337   return 0;
 338 }
 339
 340 \f
 341
 342 struct font_driver const ftxfont_driver =
 343   {
 344   /* We can't draw a text without device dependent functions.  */
 345   .type = LISPSYM_INITIALLY (Qftx),
 346   .get_cache = ftfont_get_cache,
 347   .list = ftxfont_list,
 348   .match = ftxfont_match,
 349   .list_family = ftfont_list_family,
 350   .open = ftxfont_open,
 351   .close = ftxfont_close,
 352   .has_char = ftfont_has_char,
 353   .encode_char = ftfont_encode_char,
 354   .text_extents = ftfont_text_extents,
 355   .draw = ftxfont_draw,
 356   .get_bitmap = ftfont_get_bitmap,
 357   .anchor_point = ftfont_anchor_point,
 358 #ifdef HAVE_LIBOTF
 359   .otf_capability = ftfont_otf_capability,
 360 #endif
 361   .end_for_frame = ftxfont_end_for_frame,
 362 #if defined HAVE_M17N_FLT && defined HAVE_LIBOTF
 363   .shape = ftfont_shape,
 364 #endif
 365 #ifdef HAVE_OTF_GET_VARIATION_GLYPHS
 366   .get_variation_glyphs = ftfont_variation_glyphs,
 367 #endif
 368   .filter_properties = ftfont_filter_properties,
 369   .combining_capability = ftfont_combining_capability,
 370   };
 371
 372 void
 373 syms_of_ftxfont (void)
 374 {
 375   DEFSYM (Qftx, "ftx");
 376   register_font_driver (&ftxfont_driver, NULL);
 377 }