src/ftxfont.c

   1 /* ftxfont.c -- FreeType font driver on X (without using XFT).
   2    Copyright (C) 2006-2011 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 <setjmp.h>
  25 #include <X11/Xlib.h>
  26
  27 #include "lisp.h"
  28 #include "dispextern.h"
  29 #include "xterm.h"
  30 #include "frame.h"
  31 #include "blockinput.h"
  32 #include "character.h"
  33 #include "charset.h"
  34 #include "fontset.h"
  35 #include "font.h"
  36
  37 /* FTX font driver.  */
  38
  39 static Lisp_Object Qftx;
  40
  41 /* Prototypes for helper function.  */
  42 static GC *ftxfont_get_gcs (FRAME_PTR, unsigned long, unsigned long);
  43 static int ftxfont_draw_bitmap (FRAME_PTR, GC, GC *, struct font *,
  44                                 unsigned, int, int, XPoint *, int, int *,
  45                                 int);
  46 static void ftxfont_draw_backgrond (FRAME_PTR, struct font *, GC,
  47                                     int, int, int);
  48
  49 struct ftxfont_frame_data
  50 {
  51   /* Background and foreground colors.  */
  52   XColor colors[2];
  53   /* GCs interporationg the above colors.  gcs[0] is for a color
  54    closest to BACKGROUND, and gcs[5] is for a color closest to
  55    FOREGROUND.  */
  56   GC gcs[6];
  57   struct ftxfont_frame_data *next;
  58 };
  59
  60
  61 /* Return an array of 6 GCs for antialiasing.  */
  62
  63 static GC *
  64 ftxfont_get_gcs (FRAME_PTR f, long unsigned int foreground, long unsigned int background)
  65 {
  66   XColor color;
  67   XGCValues xgcv;
  68   int i;
  69   struct ftxfont_frame_data *data = font_get_frame_data (f, &ftxfont_driver);
  70   struct ftxfont_frame_data *prev = NULL, *this = NULL, *new;
  71
  72   if (data)
  73     {
  74       for (this = data; this; prev = this, this = this->next)
  75         {
  76           if (this->colors[0].pixel < background)
  77             continue;
  78           if (this->colors[0].pixel > background)
  79             break;
  80           if (this->colors[1].pixel < foreground)
  81             continue;
  82           if (this->colors[1].pixel > foreground)
  83             break;
  84           return this->gcs;
  85         }
  86     }
  87
  88   new = malloc (sizeof (struct ftxfont_frame_data));
  89   if (! new)
  90     return NULL;
  91   new->next = this;
  92   if (prev)
  93     {
  94       prev->next = new;
  95     }
  96   else if (font_put_frame_data (f, &ftxfont_driver, new) < 0)
  97     {
  98       free (new);
  99       return NULL;
 100     }
 101
 102   new->colors[0].pixel = background;
 103   new->colors[1].pixel = foreground;
 104
 105   BLOCK_INPUT;
 106   XQueryColors (FRAME_X_DISPLAY (f), FRAME_X_COLORMAP (f), new->colors, 2);
 107   for (i = 1; i < 7; i++)
 108     {
 109       /* Interpolate colors linearly.  Any better algorithm?  */
 110       color.red
 111         = (new->colors[1].red * i + new->colors[0].red * (8 - i)) / 8;
 112       color.green
 113         = (new->colors[1].green * i + new->colors[0].green * (8 - i)) / 8;
 114       color.blue
 115         = (new->colors[1].blue * i + new->colors[0].blue * (8 - i)) / 8;
 116       if (! x_alloc_nearest_color (f, FRAME_X_COLORMAP (f), &color))
 117         break;
 118       xgcv.foreground = color.pixel;
 119       new->gcs[i - 1] = XCreateGC (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f),
 120                                    GCForeground, &xgcv);
 121     }
 122   UNBLOCK_INPUT;
 123
 124   if (i < 7)
 125     {
 126       BLOCK_INPUT;
 127       for (i--; i >= 0; i--)
 128         XFreeGC (FRAME_X_DISPLAY (f), new->gcs[i]);
 129       UNBLOCK_INPUT;
 130       if (prev)
 131         prev->next = new->next;
 132       else if (data)
 133         font_put_frame_data (f, &ftxfont_driver, new->next);
 134       free (new);
 135       return NULL;
 136     }
 137   return new->gcs;
 138 }
 139
 140 static int
 141 ftxfont_draw_bitmap (FRAME_PTR f, GC gc_fore, GC *gcs, struct font *font, unsigned int code, int x, int y, XPoint *p, int size, int *n, int flush)
 142 {
 143   struct font_bitmap bitmap;
 144   unsigned char *b;
 145   int i, j;
 146
 147   if (ftfont_driver.get_bitmap (font, code, &bitmap, size > 0x100 ? 1 : 8) < 0)
 148     return 0;
 149   if (size > 0x100)
 150     {
 151       for (i = 0, b = bitmap.buffer; i < bitmap.rows;
 152            i++, b += bitmap.pitch)
 153         {
 154           for (j = 0; j < bitmap.width; j++)
 155             if (b[j / 8] & (1 << (7 - (j % 8))))
 156               {
 157                 p[n[0]].x = x + bitmap.left + j;
 158                 p[n[0]].y = y - bitmap.top + i;
 159                 if (++n[0] == size)
 160                   {
 161                     XDrawPoints (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f),
 162                                  gc_fore, p, size, CoordModeOrigin);
 163                     n[0] = 0;
 164                   }
 165               }
 166         }
 167       if (flush && n[0] > 0)
 168         XDrawPoints (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f),
 169                      gc_fore, p, n[0], CoordModeOrigin);
 170     }
 171   else
 172     {
 173       for (i = 0, b = bitmap.buffer; i < bitmap.rows;
 174            i++, b += bitmap.pitch)
 175         {
 176           for (j = 0; j < bitmap.width; j++)
 177             {
 178               int idx = (bitmap.bits_per_pixel == 1
 179                          ? ((b[j / 8] & (1 << (7 - (j % 8)))) ? 6 : -1)
 180                          : (b[j] >> 5) - 1);
 181
 182               if (idx >= 0)
 183                 {
 184                   XPoint *pp = p + size * idx;
 185
 186                   pp[n[idx]].x = x + bitmap.left + j;
 187                   pp[n[idx]].y = y - bitmap.top + i;
 188                   if (++(n[idx]) == size)
 189                     {
 190                       XDrawPoints (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f),
 191                                    idx == 6 ? gc_fore : gcs[idx], pp, size,
 192                                    CoordModeOrigin);
 193                       n[idx] = 0;
 194                     }
 195                 }
 196             }
 197         }
 198       if (flush)
 199         {
 200           for (i = 0; i < 6; i++)
 201             if (n[i] > 0)
 202               XDrawPoints (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f),
 203                            gcs[i], p + 0x100 * i, n[i], CoordModeOrigin);
 204           if (n[6] > 0)
 205             XDrawPoints (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f),
 206                          gc_fore, p + 0x600, n[6], CoordModeOrigin);
 207         }
 208     }
 209
 210   if (ftfont_driver.free_bitmap)
 211     ftfont_driver.free_bitmap (font, &bitmap);
 212
 213   return bitmap.advance;
 214 }
 215
 216 static void
 217 ftxfont_draw_backgrond (FRAME_PTR f, struct font *font, GC gc, int x, int y, int width)
 218 {
 219   XGCValues xgcv;
 220
 221   XGetGCValues (FRAME_X_DISPLAY (f), gc,
 222                 GCForeground | GCBackground, &xgcv);
 223   XSetForeground (FRAME_X_DISPLAY (f), gc, xgcv.background);
 224   XFillRectangle (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f), gc,
 225                   x, y - FONT_BASE (font), width, FONT_HEIGHT (font));
 226   XSetForeground (FRAME_X_DISPLAY (f), gc, xgcv.foreground);
 227 }
 228
 229 /* Prototypes for font-driver methods.  */
 230 static Lisp_Object ftxfont_list (Lisp_Object, Lisp_Object);
 231 static Lisp_Object ftxfont_match (Lisp_Object, Lisp_Object);
 232 static Lisp_Object ftxfont_open (FRAME_PTR, Lisp_Object, int);
 233 static void ftxfont_close (FRAME_PTR, struct font *);
 234 static int ftxfont_draw (struct glyph_string *, int, int, int, int, int);
 235
 236 struct font_driver ftxfont_driver;
 237
 238 static Lisp_Object
 239 ftxfont_list (Lisp_Object frame, Lisp_Object spec)
 240 {
 241   Lisp_Object list = ftfont_driver.list (frame, spec), tail;
 242
 243   for (tail = list; CONSP (tail); tail = XCDR (tail))
 244     ASET (XCAR (tail), FONT_TYPE_INDEX, Qftx);
 245   return list;
 246 }
 247
 248 static Lisp_Object
 249 ftxfont_match (Lisp_Object frame, Lisp_Object spec)
 250 {
 251   Lisp_Object entity = ftfont_driver.match (frame, spec);
 252
 253   if (VECTORP (entity))
 254     ASET (entity, FONT_TYPE_INDEX, Qftx);
 255   return entity;
 256 }
 257
 258 static Lisp_Object
 259 ftxfont_open (FRAME_PTR f, Lisp_Object entity, int pixel_size)
 260 {
 261   Lisp_Object font_object;
 262   struct font *font;
 263
 264   font_object = ftfont_driver.open (f, entity, pixel_size);
 265   if (NILP (font_object))
 266     return Qnil;
 267   font = XFONT_OBJECT (font_object);
 268   font->driver = &ftxfont_driver;
 269   return font_object;
 270 }
 271
 272 static void
 273 ftxfont_close (FRAME_PTR f, struct font *font)
 274 {
 275   ftfont_driver.close (f, font);
 276 }
 277
 278 static int
 279 ftxfont_draw (struct glyph_string *s, int from, int to, int x, int y, int with_background)
 280 {
 281   FRAME_PTR f = s->f;
 282   struct face *face = s->face;
 283   struct font *font = s->font;
 284   XPoint p[0x700];
 285   int n[7];
 286   unsigned *code;
 287   int len = to - from;
 288   int i;
 289   GC *gcs;
 290   int xadvance;
 291
 292   n[0] = n[1] = n[2] = n[3] = n[4] = n[5] = n[6] = 0;
 293
 294   BLOCK_INPUT;
 295   if (with_background)
 296     ftxfont_draw_backgrond (f, font, s->gc, x, y, s->width);
 297   code = alloca (sizeof (unsigned) * len);
 298   for (i = 0; i < len; i++)
 299     code[i] = ((XCHAR2B_BYTE1 (s->char2b + from + i) << 8)
 300                | XCHAR2B_BYTE2 (s->char2b + from + i));
 301
 302   if (face->gc == s->gc)
 303     {
 304       gcs = ftxfont_get_gcs (f, face->foreground, face->background);
 305     }
 306   else
 307     {
 308       XGCValues xgcv;
 309       unsigned long mask = GCForeground | GCBackground;
 310
 311       XGetGCValues (FRAME_X_DISPLAY (f), s->gc, mask, &xgcv);
 312       gcs = ftxfont_get_gcs (f, xgcv.foreground, xgcv.background);
 313     }
 314
 315   if (gcs)
 316     {
 317       if (s->num_clips)
 318         for (i = 0; i < 6; i++)
 319           XSetClipRectangles (FRAME_X_DISPLAY (f), gcs[i], 0, 0,
 320                               s->clip, s->num_clips, Unsorted);
 321
 322       for (i = 0; i < len; i++)
 323         {
 324           xadvance = ftxfont_draw_bitmap (f, s->gc, gcs, font, code[i], x, y,
 325                                           p, 0x100, n, i + 1 == len);
 326           x += (s->padding_p ? 1 : xadvance);
 327         }
 328       if (s->num_clips)
 329         for (i = 0; i < 6; i++)
 330           XSetClipMask (FRAME_X_DISPLAY (f), gcs[i], None);
 331     }
 332   else
 333     {
 334       /* We can't draw with antialiasing.
 335          s->gc should already have a proper clipping setting. */
 336       for (i = 0; i < len; i++)
 337         {
 338           xadvance = ftxfont_draw_bitmap (f, s->gc, NULL, font, code[i], x, y,
 339                                           p, 0x700, n, i + 1 == len);
 340           x += (s->padding_p ? 1 : xadvance);
 341         }
 342     }
 343
 344   UNBLOCK_INPUT;
 345
 346   return len;
 347 }
 348
 349 static int
 350 ftxfont_end_for_frame (FRAME_PTR f)
 351 {
 352   struct ftxfont_frame_data *data = font_get_frame_data (f, &ftxfont_driver);
 353
 354   BLOCK_INPUT;
 355   while (data)
 356     {
 357       struct ftxfont_frame_data *next = data->next;
 358       int i;
 359
 360       for (i = 0; i < 6; i++)
 361         XFreeGC (FRAME_X_DISPLAY (f), data->gcs[i]);
 362       free (data);
 363       data = next;
 364     }
 365   UNBLOCK_INPUT;
 366   font_put_frame_data (f, &ftxfont_driver, NULL);
 367   return 0;
 368 }
 369
 370 \f
 371
 372 void
 373 syms_of_ftxfont (void)
 374 {
 375   DEFSYM (Qftx, "ftx");
 376
 377   ftxfont_driver = ftfont_driver;
 378   ftxfont_driver.type = Qftx;
 379   ftxfont_driver.list = ftxfont_list;
 380   ftxfont_driver.match = ftxfont_match;
 381   ftxfont_driver.open = ftxfont_open;
 382   ftxfont_driver.close = ftxfont_close;
 383   ftxfont_driver.draw = ftxfont_draw;
 384   ftxfont_driver.end_for_frame = ftxfont_end_for_frame;
 385   register_font_driver (&ftxfont_driver, NULL);
 386 }
 387