src/ftxfont.c

   1 /* ftxfont.c -- FreeType font driver on X (without using XFT).
   2    Copyright (C) 2006-2016 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 <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 "xterm.h"
  28 #include "frame.h"
  29 #include "blockinput.h"
  30 #include "font.h"
  31
  32 /* FTX font driver.  */
  33
  34 struct font_driver ftxfont_driver;
  35
  36 struct ftxfont_frame_data
  37 {
  38   /* Background and foreground colors.  */
  39   XColor colors[2];
  40   /* GCs interpolating the above colors.  gcs[0] is for a color
  41    closest to BACKGROUND, and gcs[5] is for a color closest to
  42    FOREGROUND.  */
  43   GC gcs[6];
  44   struct ftxfont_frame_data *next;
  45 };
  46
  47
  48 /* Return an array of 6 GCs for antialiasing.  */
  49
  50 static GC *
  51 ftxfont_get_gcs (struct frame *f, unsigned long foreground, unsigned long background)
  52 {
  53   XColor color;
  54   XGCValues xgcv;
  55   int i;
  56   struct ftxfont_frame_data *data = font_get_frame_data (f, Qftx);
  57   struct ftxfont_frame_data *prev = NULL, *this = NULL, *new;
  58
  59   if (data)
  60     {
  61       for (this = data; this; prev = this, this = this->next)
  62         {
  63           if (this->colors[0].pixel < background)
  64             continue;
  65           if (this->colors[0].pixel > background)
  66             break;
  67           if (this->colors[1].pixel < foreground)
  68             continue;
  69           if (this->colors[1].pixel > foreground)
  70             break;
  71           return this->gcs;
  72         }
  73     }
  74
  75   new = xmalloc (sizeof *new);
  76   new->next = this;
  77   if (prev)
  78       prev->next = new;
  79   font_put_frame_data (f, Qftx, new);
  80
  81   new->colors[0].pixel = background;
  82   new->colors[1].pixel = foreground;
  83
  84   block_input ();
  85   XQueryColors (FRAME_X_DISPLAY (f), FRAME_X_COLORMAP (f), new->colors, 2);
  86   for (i = 1; i < 7; i++)
  87     {
  88       /* Interpolate colors linearly.  Any better algorithm?  */
  89       color.red
  90         = (new->colors[1].red * i + new->colors[0].red * (8 - i)) / 8;
  91       color.green
  92         = (new->colors[1].green * i + new->colors[0].green * (8 - i)) / 8;
  93       color.blue
  94         = (new->colors[1].blue * i + new->colors[0].blue * (8 - i)) / 8;
  95       if (! x_alloc_nearest_color (f, FRAME_X_COLORMAP (f), &color))
  96         break;
  97       xgcv.foreground = color.pixel;
  98       new->gcs[i - 1] = XCreateGC (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f),
  99                                    GCForeground, &xgcv);
 100     }
 101   unblock_input ();
 102
 103   if (i < 7)
 104     {
 105       block_input ();
 106       for (i--; i >= 0; i--)
 107         XFreeGC (FRAME_X_DISPLAY (f), new->gcs[i]);
 108       unblock_input ();
 109       if (prev)
 110         prev->next = new->next;
 111       else if (data)
 112         font_put_frame_data (f, Qftx, new->next);
 113       xfree (new);
 114       return NULL;
 115     }
 116   return new->gcs;
 117 }
 118
 119 static int
 120 ftxfont_draw_bitmap (struct frame *f, GC gc_fore, GC *gcs, struct font *font,
 121                      unsigned int code, int x, int y, XPoint *p, int size,
 122                      int *n, bool flush)
 123 {
 124   struct font_bitmap bitmap;
 125   unsigned char *b;
 126   int i, j;
 127
 128   if (ftfont_driver.get_bitmap (font, code, &bitmap, size > 0x100 ? 1 : 8) < 0)
 129     return 0;
 130   if (size > 0x100)
 131     {
 132       for (i = 0, b = bitmap.buffer; i < bitmap.rows;
 133            i++, b += bitmap.pitch)
 134         {
 135           for (j = 0; j < bitmap.width; j++)
 136             if (b[j / 8] & (1 << (7 - (j % 8))))
 137               {
 138                 p[n[0]].x = x + bitmap.left + j;
 139                 p[n[0]].y = y - bitmap.top + i;
 140                 if (++n[0] == size)
 141                   {
 142                     XDrawPoints (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f),
 143                                  gc_fore, p, size, CoordModeOrigin);
 144                     n[0] = 0;
 145                   }
 146               }
 147         }
 148       if (flush && n[0] > 0)
 149         XDrawPoints (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f),
 150                      gc_fore, p, n[0], CoordModeOrigin);
 151     }
 152   else
 153     {
 154       for (i = 0, b = bitmap.buffer; i < bitmap.rows;
 155            i++, b += bitmap.pitch)
 156         {
 157           for (j = 0; j < bitmap.width; j++)
 158             {
 159               int idx = (bitmap.bits_per_pixel == 1
 160                          ? ((b[j / 8] & (1 << (7 - (j % 8)))) ? 6 : -1)
 161                          : (b[j] >> 5) - 1);
 162
 163               if (idx >= 0)
 164                 {
 165                   XPoint *pp = p + size * idx;
 166
 167                   pp[n[idx]].x = x + bitmap.left + j;
 168                   pp[n[idx]].y = y - bitmap.top + i;
 169                   if (++(n[idx]) == size)
 170                     {
 171                       XDrawPoints (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f),
 172                                    idx == 6 ? gc_fore : gcs[idx], pp, size,
 173                                    CoordModeOrigin);
 174                       n[idx] = 0;
 175                     }
 176                 }
 177             }
 178         }
 179       if (flush)
 180         {
 181           for (i = 0; i < 6; i++)
 182             if (n[i] > 0)
 183               XDrawPoints (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f),
 184                            gcs[i], p + 0x100 * i, n[i], CoordModeOrigin);
 185           if (n[6] > 0)
 186             XDrawPoints (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f),
 187                          gc_fore, p + 0x600, n[6], CoordModeOrigin);
 188         }
 189     }
 190
 191   if (ftfont_driver.free_bitmap)
 192     ftfont_driver.free_bitmap (font, &bitmap);
 193
 194   return bitmap.advance;
 195 }
 196
 197 static void
 198 ftxfont_draw_background (struct frame *f, struct font *font, GC gc, int x, int y,
 199                          int width)
 200 {
 201   XGCValues xgcv;
 202
 203   XGetGCValues (FRAME_X_DISPLAY (f), gc,
 204                 GCForeground | GCBackground, &xgcv);
 205   XSetForeground (FRAME_X_DISPLAY (f), gc, xgcv.background);
 206   XFillRectangle (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f), gc,
 207                   x, y - FONT_BASE (font), width, FONT_HEIGHT (font));
 208   XSetForeground (FRAME_X_DISPLAY (f), gc, xgcv.foreground);
 209 }
 210
 211 static Lisp_Object
 212 ftxfont_list (struct frame *f, Lisp_Object spec)
 213 {
 214   Lisp_Object list = ftfont_driver.list (f, spec), tail;
 215
 216   for (tail = list; CONSP (tail); tail = XCDR (tail))
 217     ASET (XCAR (tail), FONT_TYPE_INDEX, Qftx);
 218   return list;
 219 }
 220
 221 static Lisp_Object
 222 ftxfont_match (struct frame *f, Lisp_Object spec)
 223 {
 224   Lisp_Object entity = ftfont_driver.match (f, spec);
 225
 226   if (VECTORP (entity))
 227     ASET (entity, FONT_TYPE_INDEX, Qftx);
 228   return entity;
 229 }
 230
 231 static Lisp_Object
 232 ftxfont_open (struct frame *f, Lisp_Object entity, int pixel_size)
 233 {
 234   Lisp_Object font_object;
 235   struct font *font;
 236
 237   font_object = ftfont_driver.open (f, entity, pixel_size);
 238   if (NILP (font_object))
 239     return Qnil;
 240   font = XFONT_OBJECT (font_object);
 241   font->driver = &ftxfont_driver;
 242   return font_object;
 243 }
 244
 245 static void
 246 ftxfont_close (struct font *font)
 247 {
 248   ftfont_driver.close (font);
 249 }
 250
 251 static int
 252 ftxfont_draw (struct glyph_string *s, int from, int to, int x, int y,
 253               bool with_background)
 254 {
 255   struct frame *f = s->f;
 256   struct face *face = s->face;
 257   struct font *font = s->font;
 258   XPoint p[0x700];
 259   int n[7];
 260   unsigned *code;
 261   int len = to - from;
 262   int i;
 263   GC *gcs;
 264   int xadvance;
 265
 266   n[0] = n[1] = n[2] = n[3] = n[4] = n[5] = n[6] = 0;
 267
 268   USE_SAFE_ALLOCA;
 269   SAFE_NALLOCA (code, 1, len);
 270   block_input ();
 271   if (with_background)
 272     ftxfont_draw_background (f, font, s->gc, x, y, s->width);
 273   for (i = 0; i < len; i++)
 274     code[i] = ((XCHAR2B_BYTE1 (s->char2b + from + i) << 8)
 275                | XCHAR2B_BYTE2 (s->char2b + from + i));
 276
 277   if (face->gc == s->gc)
 278     {
 279       gcs = ftxfont_get_gcs (f, face->foreground, face->background);
 280     }
 281   else
 282     {
 283       XGCValues xgcv;
 284       unsigned long mask = GCForeground | GCBackground;
 285
 286       XGetGCValues (FRAME_X_DISPLAY (f), s->gc, mask, &xgcv);
 287       gcs = ftxfont_get_gcs (f, xgcv.foreground, xgcv.background);
 288     }
 289
 290   if (gcs)
 291     {
 292       if (s->num_clips)
 293         for (i = 0; i < 6; i++)
 294           XSetClipRectangles (FRAME_X_DISPLAY (f), gcs[i], 0, 0,
 295                               s->clip, s->num_clips, Unsorted);
 296
 297       for (i = 0; i < len; i++)
 298         {
 299           xadvance = ftxfont_draw_bitmap (f, s->gc, gcs, font, code[i], x, y,
 300                                           p, 0x100, n, i + 1 == len);
 301           x += (s->padding_p ? 1 : xadvance);
 302         }
 303       if (s->num_clips)
 304         for (i = 0; i < 6; i++)
 305           XSetClipMask (FRAME_X_DISPLAY (f), gcs[i], None);
 306     }
 307   else
 308     {
 309       /* We can't draw with antialiasing.
 310          s->gc should already have a proper clipping setting. */
 311       for (i = 0; i < len; i++)
 312         {
 313           xadvance = ftxfont_draw_bitmap (f, s->gc, NULL, font, code[i], x, y,
 314                                           p, 0x700, n, i + 1 == len);
 315           x += (s->padding_p ? 1 : xadvance);
 316         }
 317     }
 318
 319   unblock_input ();
 320   SAFE_FREE ();
 321
 322   return len;
 323 }
 324
 325 static int
 326 ftxfont_end_for_frame (struct frame *f)
 327 {
 328   struct ftxfont_frame_data *data = font_get_frame_data (f, Qftx);
 329
 330   block_input ();
 331   while (data)
 332     {
 333       struct ftxfont_frame_data *next = data->next;
 334       int i;
 335
 336       for (i = 0; i < 6; i++)
 337         XFreeGC (FRAME_X_DISPLAY (f), data->gcs[i]);
 338       xfree (data);
 339       data = next;
 340     }
 341   unblock_input ();
 342   font_put_frame_data (f, Qftx, NULL);
 343   return 0;
 344 }
 345
 346 \f
 347
 348 void
 349 syms_of_ftxfont (void)
 350 {
 351   DEFSYM (Qftx, "ftx");
 352
 353   ftxfont_driver = ftfont_driver;
 354   ftxfont_driver.type = Qftx;
 355   ftxfont_driver.list = ftxfont_list;
 356   ftxfont_driver.match = ftxfont_match;
 357   ftxfont_driver.open = ftxfont_open;
 358   ftxfont_driver.close = ftxfont_close;
 359   ftxfont_driver.draw = ftxfont_draw;
 360   ftxfont_driver.end_for_frame = ftxfont_end_for_frame;
 361   register_font_driver (&ftxfont_driver, NULL);
 362 }