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