src/ftxfont.c

   1 /* ftxfont.c -- FreeType font driver on X (without using XFT).
   2    Copyright (C) 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
   3    Copyright (C) 2006, 2007, 2008, 2009, 2010
   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 P_ ((FRAME_PTR, unsigned long, unsigned long));
  43 static int ftxfont_draw_bitmap P_ ((FRAME_PTR, GC, GC *, struct font *,
  44                                     unsigned, int, int, XPoint *, int, int *,
  45                                     int));
  46 static void ftxfont_draw_backgrond P_ ((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 (f, foreground, background)
  65      FRAME_PTR f;
  66      unsigned long foreground, background;
  67 {
  68   XColor color;
  69   XGCValues xgcv;
  70   int i;
  71   struct ftxfont_frame_data *data = font_get_frame_data (f, &ftxfont_driver);
  72   struct ftxfont_frame_data *prev = NULL, *this = NULL, *new;
  73
  74   if (data)
  75     {
  76       for (this = data; this; prev = this, this = this->next)
  77         {
  78           if (this->colors[0].pixel < background)
  79             continue;
  80           if (this->colors[0].pixel > background)
  81             break;
  82           if (this->colors[1].pixel < foreground)
  83             continue;
  84           if (this->colors[1].pixel > foreground)
  85             break;
  86           return this->gcs;
  87         }
  88     }
  89
  90   new = malloc (sizeof (struct ftxfont_frame_data));
  91   if (! new)
  92     return NULL;
  93   new->next = this;
  94   if (prev)
  95     {
  96       prev->next = new;
  97     }
  98   else if (font_put_frame_data (f, &ftxfont_driver, new) < 0)
  99     {
 100       free (new);
 101       return NULL;
 102     }
 103
 104   new->colors[0].pixel = background;
 105   new->colors[1].pixel = foreground;
 106
 107   BLOCK_INPUT;
 108   XQueryColors (FRAME_X_DISPLAY (f), FRAME_X_COLORMAP (f), new->colors, 2);
 109   for (i = 1; i < 7; i++)
 110     {
 111       /* Interpolate colors linearly.  Any better algorithm?  */
 112       color.red
 113         = (new->colors[1].red * i + new->colors[0].red * (8 - i)) / 8;
 114       color.green
 115         = (new->colors[1].green * i + new->colors[0].green * (8 - i)) / 8;
 116       color.blue
 117         = (new->colors[1].blue * i + new->colors[0].blue * (8 - i)) / 8;
 118       if (! x_alloc_nearest_color (f, FRAME_X_COLORMAP (f), &color))
 119         break;
 120       xgcv.foreground = color.pixel;
 121       new->gcs[i - 1] = XCreateGC (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f),
 122                                    GCForeground, &xgcv);
 123     }
 124   UNBLOCK_INPUT;
 125
 126   if (i < 7)
 127     {
 128       BLOCK_INPUT;
 129       for (i--; i >= 0; i--)
 130         XFreeGC (FRAME_X_DISPLAY (f), new->gcs[i]);
 131       UNBLOCK_INPUT;
 132       if (prev)
 133         prev->next = new->next;
 134       else if (data)
 135         font_put_frame_data (f, &ftxfont_driver, new->next);
 136       free (new);
 137       return NULL;
 138     }
 139   return new->gcs;
 140 }
 141
 142 static int
 143 ftxfont_draw_bitmap (f, gc_fore, gcs, font, code, x, y, p, size, n, flush)
 144      FRAME_PTR f;
 145      GC gc_fore, *gcs;
 146      struct font *font;
 147      unsigned code;
 148      int x, y;
 149      XPoint *p;
 150      int size, *n;
 151      int flush;
 152 {
 153   struct font_bitmap bitmap;
 154   unsigned char *b;
 155   int i, j;
 156
 157   if (ftfont_driver.get_bitmap (font, code, &bitmap, size > 0x100 ? 1 : 8) < 0)
 158     return 0;
 159   if (size > 0x100)
 160     {
 161       for (i = 0, b = bitmap.buffer; i < bitmap.rows;
 162            i++, b += bitmap.pitch)
 163         {
 164           for (j = 0; j < bitmap.width; j++)
 165             if (b[j / 8] & (1 << (7 - (j % 8))))
 166               {
 167                 p[n[0]].x = x + bitmap.left + j;
 168                 p[n[0]].y = y - bitmap.top + i;
 169                 if (++n[0] == size)
 170                   {
 171                     XDrawPoints (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f),
 172                                  gc_fore, p, size, CoordModeOrigin);
 173                     n[0] = 0;
 174                   }
 175               }
 176         }
 177       if (flush && n[0] > 0)
 178         XDrawPoints (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f),
 179                      gc_fore, p, n[0], CoordModeOrigin);
 180     }
 181   else
 182     {
 183       for (i = 0, b = bitmap.buffer; i < bitmap.rows;
 184            i++, b += bitmap.pitch)
 185         {
 186           for (j = 0; j < bitmap.width; j++)
 187             {
 188               int idx = (bitmap.bits_per_pixel == 1
 189                          ? ((b[j / 8] & (1 << (7 - (j % 8)))) ? 6 : -1)
 190                          : (b[j] >> 5) - 1);
 191
 192               if (idx >= 0)
 193                 {
 194                   XPoint *pp = p + size * idx;
 195
 196                   pp[n[idx]].x = x + bitmap.left + j;
 197                   pp[n[idx]].y = y - bitmap.top + i;
 198                   if (++(n[idx]) == size)
 199                     {
 200                       XDrawPoints (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f),
 201                                    idx == 6 ? gc_fore : gcs[idx], pp, size,
 202                                    CoordModeOrigin);
 203                       n[idx] = 0;
 204                     }
 205                 }
 206             }
 207         }
 208       if (flush)
 209         {
 210           for (i = 0; i < 6; i++)
 211             if (n[i] > 0)
 212               XDrawPoints (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f),
 213                            gcs[i], p + 0x100 * i, n[i], CoordModeOrigin);
 214           if (n[6] > 0)
 215             XDrawPoints (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f),
 216                          gc_fore, p + 0x600, n[6], CoordModeOrigin);
 217         }
 218     }
 219
 220   if (ftfont_driver.free_bitmap)
 221     ftfont_driver.free_bitmap (font, &bitmap);
 222
 223   return bitmap.advance;
 224 }
 225
 226 static void
 227 ftxfont_draw_backgrond (f, font, gc, x, y, width)
 228      FRAME_PTR f;
 229      struct font *font;
 230      GC gc;
 231      int x, y, width;
 232 {
 233   XGCValues xgcv;
 234
 235   XGetGCValues (FRAME_X_DISPLAY (f), gc,
 236                 GCForeground | GCBackground, &xgcv);
 237   XSetForeground (FRAME_X_DISPLAY (f), gc, xgcv.background);
 238   XFillRectangle (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f), gc,
 239                   x, y - FONT_BASE (font), width, FONT_HEIGHT (font));
 240   XSetForeground (FRAME_X_DISPLAY (f), gc, xgcv.foreground);
 241 }
 242
 243 /* Prototypes for font-driver methods.  */
 244 static Lisp_Object ftxfont_list P_ ((Lisp_Object, Lisp_Object));
 245 static Lisp_Object ftxfont_match P_ ((Lisp_Object, Lisp_Object));
 246 static Lisp_Object ftxfont_open P_ ((FRAME_PTR, Lisp_Object, int));
 247 static void ftxfont_close P_ ((FRAME_PTR, struct font *));
 248 static int ftxfont_draw P_ ((struct glyph_string *, int, int, int, int, int));
 249
 250 struct font_driver ftxfont_driver;
 251
 252 static Lisp_Object
 253 ftxfont_list (frame, spec)
 254      Lisp_Object frame;
 255      Lisp_Object spec;
 256 {
 257   Lisp_Object list = ftfont_driver.list (frame, spec), tail;
 258
 259   for (tail = list; CONSP (tail); tail = XCDR (tail))
 260     ASET (XCAR (tail), FONT_TYPE_INDEX, Qftx);
 261   return list;
 262 }
 263
 264 static Lisp_Object
 265 ftxfont_match (frame, spec)
 266      Lisp_Object frame;
 267      Lisp_Object spec;
 268 {
 269   Lisp_Object entity = ftfont_driver.match (frame, spec);
 270
 271   if (VECTORP (entity))
 272     ASET (entity, FONT_TYPE_INDEX, Qftx);
 273   return entity;
 274 }
 275
 276 static Lisp_Object
 277 ftxfont_open (f, entity, pixel_size)
 278      FRAME_PTR f;
 279      Lisp_Object entity;
 280      int pixel_size;
 281 {
 282   Lisp_Object font_object;
 283   struct font *font;
 284
 285   font_object = ftfont_driver.open (f, entity, pixel_size);
 286   if (NILP (font_object))
 287     return Qnil;
 288   font = XFONT_OBJECT (font_object);
 289   font->driver = &ftxfont_driver;
 290   return font_object;
 291 }
 292
 293 static void
 294 ftxfont_close (f, font)
 295      FRAME_PTR f;
 296      struct font *font;
 297 {
 298   ftfont_driver.close (f, font);
 299 }
 300
 301 static int
 302 ftxfont_draw (s, from, to, x, y, with_background)
 303      struct glyph_string *s;
 304      int from, to, x, y, with_background;
 305 {
 306   FRAME_PTR f = s->f;
 307   struct face *face = s->face;
 308   struct font *font = s->font;
 309   XPoint p[0x700];
 310   int n[7];
 311   unsigned *code;
 312   int len = to - from;
 313   int i;
 314   GC *gcs;
 315   int xadvance;
 316
 317   n[0] = n[1] = n[2] = n[3] = n[4] = n[5] = n[6] = 0;
 318
 319   BLOCK_INPUT;
 320   if (with_background)
 321     ftxfont_draw_backgrond (f, font, s->gc, x, y, s->width);
 322   code = alloca (sizeof (unsigned) * len);
 323   for (i = 0; i < len; i++)
 324     code[i] = ((XCHAR2B_BYTE1 (s->char2b + from + i) << 8)
 325                | XCHAR2B_BYTE2 (s->char2b + from + i));
 326
 327   if (face->gc == s->gc)
 328     {
 329       gcs = ftxfont_get_gcs (f, face->foreground, face->background);
 330     }
 331   else
 332     {
 333       XGCValues xgcv;
 334       unsigned long mask = GCForeground | GCBackground;
 335
 336       XGetGCValues (FRAME_X_DISPLAY (f), s->gc, mask, &xgcv);
 337       gcs = ftxfont_get_gcs (f, xgcv.foreground, xgcv.background);
 338     }
 339
 340   if (gcs)
 341     {
 342       if (s->num_clips)
 343         for (i = 0; i < 6; i++)
 344           XSetClipRectangles (FRAME_X_DISPLAY (f), gcs[i], 0, 0,
 345                               s->clip, s->num_clips, Unsorted);
 346
 347       for (i = 0; i < len; i++)
 348         {
 349           xadvance = ftxfont_draw_bitmap (f, s->gc, gcs, font, code[i], x, y,
 350                                           p, 0x100, n, i + 1 == len);
 351           x += (s->padding_p ? 1 : xadvance);
 352         }
 353       if (s->num_clips)
 354         for (i = 0; i < 6; i++)
 355           XSetClipMask (FRAME_X_DISPLAY (f), gcs[i], None);
 356     }
 357   else
 358     {
 359       /* We can't draw with antialiasing.
 360          s->gc should already have a proper clipping setting. */
 361       for (i = 0; i < len; i++)
 362         {
 363           xadvance = ftxfont_draw_bitmap (f, s->gc, NULL, font, code[i], x, y,
 364                                           p, 0x700, n, i + 1 == len);
 365           x += (s->padding_p ? 1 : xadvance);
 366         }
 367     }
 368
 369   UNBLOCK_INPUT;
 370
 371   return len;
 372 }
 373
 374 static int
 375 ftxfont_end_for_frame (f)
 376      FRAME_PTR f;
 377 {
 378   struct ftxfont_frame_data *data = font_get_frame_data (f, &ftxfont_driver);
 379
 380   BLOCK_INPUT;
 381   while (data)
 382     {
 383       struct ftxfont_frame_data *next = data->next;
 384       int i;
 385
 386       for (i = 0; i < 6; i++)
 387         XFreeGC (FRAME_X_DISPLAY (f), data->gcs[i]);
 388       free (data);
 389       data = next;
 390     }
 391   UNBLOCK_INPUT;
 392   font_put_frame_data (f, &ftxfont_driver, NULL);
 393   return 0;
 394 }
 395
 396 \f
 397
 398 void
 399 syms_of_ftxfont ()
 400 {
 401   DEFSYM (Qftx, "ftx");
 402
 403   ftxfont_driver = ftfont_driver;
 404   ftxfont_driver.type = Qftx;
 405   ftxfont_driver.list = ftxfont_list;
 406   ftxfont_driver.match = ftxfont_match;
 407   ftxfont_driver.open = ftxfont_open;
 408   ftxfont_driver.close = ftxfont_close;
 409   ftxfont_driver.draw = ftxfont_draw;
 410   ftxfont_driver.end_for_frame = ftxfont_end_for_frame;
 411   register_font_driver (&ftxfont_driver, NULL);
 412 }
 413
 414 /* arch-tag: 59bd3469-5330-413f-b29d-1aa36492abe8
 415    (do not change this comment) */