src/ftxfont.c

   1 /* ftxfont.c -- FreeType font driver on X (without using XFT).
   2    Copyright (C) 2006-2012 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 #if defined HAVE_XFT || !defined HAVE_FREETYPE
  42 static
  43 #endif
  44 struct font_driver ftxfont_driver;
  45
  46 /* Prototypes for helper function.  */
  47 static GC *ftxfont_get_gcs (FRAME_PTR, unsigned long, unsigned long);
  48 static int ftxfont_draw_bitmap (FRAME_PTR, GC, GC *, struct font *,
  49                                 unsigned, int, int, XPoint *, int, int *,
  50                                 int);
  51 static void ftxfont_draw_background (FRAME_PTR, struct font *, GC,
  52                                      int, int, int);
  53
  54 struct ftxfont_frame_data
  55 {
  56   /* Background and foreground colors.  */
  57   XColor colors[2];
  58   /* GCs interpolating the above colors.  gcs[0] is for a color
  59    closest to BACKGROUND, and gcs[5] is for a color closest to
  60    FOREGROUND.  */
  61   GC gcs[6];
  62   struct ftxfont_frame_data *next;
  63 };
  64
  65
  66 /* Return an array of 6 GCs for antialiasing.  */
  67
  68 static GC *
  69 ftxfont_get_gcs (FRAME_PTR f, long unsigned int foreground, long unsigned int background)
  70 {
  71   XColor color;
  72   XGCValues xgcv;
  73   int i;
  74   struct ftxfont_frame_data *data = font_get_frame_data (f, &ftxfont_driver);
  75   struct ftxfont_frame_data *prev = NULL, *this = NULL, *new;
  76
  77   if (data)
  78     {
  79       for (this = data; this; prev = this, this = this->next)
  80         {
  81           if (this->colors[0].pixel < background)
  82             continue;
  83           if (this->colors[0].pixel > background)
  84             break;
  85           if (this->colors[1].pixel < foreground)
  86             continue;
  87           if (this->colors[1].pixel > foreground)
  88             break;
  89           return this->gcs;
  90         }
  91     }
  92
  93   new = malloc (sizeof *new);
  94   if (! new)
  95     return NULL;
  96   new->next = this;
  97   if (prev)
  98     {
  99       prev->next = new;
 100     }
 101   else if (font_put_frame_data (f, &ftxfont_driver, new) < 0)
 102     {
 103       free (new);
 104       return NULL;
 105     }
 106
 107   new->colors[0].pixel = background;
 108   new->colors[1].pixel = foreground;
 109
 110   BLOCK_INPUT;
 111   XQueryColors (FRAME_X_DISPLAY (f), FRAME_X_COLORMAP (f), new->colors, 2);
 112   for (i = 1; i < 7; i++)
 113     {
 114       /* Interpolate colors linearly.  Any better algorithm?  */
 115       color.red
 116         = (new->colors[1].red * i + new->colors[0].red * (8 - i)) / 8;
 117       color.green
 118         = (new->colors[1].green * i + new->colors[0].green * (8 - i)) / 8;
 119       color.blue
 120         = (new->colors[1].blue * i + new->colors[0].blue * (8 - i)) / 8;
 121       if (! x_alloc_nearest_color (f, FRAME_X_COLORMAP (f), &color))
 122         break;
 123       xgcv.foreground = color.pixel;
 124       new->gcs[i - 1] = XCreateGC (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f),
 125                                    GCForeground, &xgcv);
 126     }
 127   UNBLOCK_INPUT;
 128
 129   if (i < 7)
 130     {
 131       BLOCK_INPUT;
 132       for (i--; i >= 0; i--)
 133         XFreeGC (FRAME_X_DISPLAY (f), new->gcs[i]);
 134       UNBLOCK_INPUT;
 135       if (prev)
 136         prev->next = new->next;
 137       else if (data)
 138         font_put_frame_data (f, &ftxfont_driver, new->next);
 139       free (new);
 140       return NULL;
 141     }
 142   return new->gcs;
 143 }
 144
 145 static int
 146 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)
 147 {
 148   struct font_bitmap bitmap;
 149   unsigned char *b;
 150   int i, j;
 151
 152   if (ftfont_driver.get_bitmap (font, code, &bitmap, size > 0x100 ? 1 : 8) < 0)
 153     return 0;
 154   if (size > 0x100)
 155     {
 156       for (i = 0, b = bitmap.buffer; i < bitmap.rows;
 157            i++, b += bitmap.pitch)
 158         {
 159           for (j = 0; j < bitmap.width; j++)
 160             if (b[j / 8] & (1 << (7 - (j % 8))))
 161               {
 162                 p[n[0]].x = x + bitmap.left + j;
 163                 p[n[0]].y = y - bitmap.top + i;
 164                 if (++n[0] == size)
 165                   {
 166                     XDrawPoints (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f),
 167                                  gc_fore, p, size, CoordModeOrigin);
 168                     n[0] = 0;
 169                   }
 170               }
 171         }
 172       if (flush && n[0] > 0)
 173         XDrawPoints (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f),
 174                      gc_fore, p, n[0], CoordModeOrigin);
 175     }
 176   else
 177     {
 178       for (i = 0, b = bitmap.buffer; i < bitmap.rows;
 179            i++, b += bitmap.pitch)
 180         {
 181           for (j = 0; j < bitmap.width; j++)
 182             {
 183               int idx = (bitmap.bits_per_pixel == 1
 184                          ? ((b[j / 8] & (1 << (7 - (j % 8)))) ? 6 : -1)
 185                          : (b[j] >> 5) - 1);
 186
 187               if (idx >= 0)
 188                 {
 189                   XPoint *pp = p + size * idx;
 190
 191                   pp[n[idx]].x = x + bitmap.left + j;
 192                   pp[n[idx]].y = y - bitmap.top + i;
 193                   if (++(n[idx]) == size)
 194                     {
 195                       XDrawPoints (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f),
 196                                    idx == 6 ? gc_fore : gcs[idx], pp, size,
 197                                    CoordModeOrigin);
 198                       n[idx] = 0;
 199                     }
 200                 }
 201             }
 202         }
 203       if (flush)
 204         {
 205           for (i = 0; i < 6; i++)
 206             if (n[i] > 0)
 207               XDrawPoints (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f),
 208                            gcs[i], p + 0x100 * i, n[i], CoordModeOrigin);
 209           if (n[6] > 0)
 210             XDrawPoints (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f),
 211                          gc_fore, p + 0x600, n[6], CoordModeOrigin);
 212         }
 213     }
 214
 215   if (ftfont_driver.free_bitmap)
 216     ftfont_driver.free_bitmap (font, &bitmap);
 217
 218   return bitmap.advance;
 219 }
 220
 221 static void
 222 ftxfont_draw_background (FRAME_PTR f, struct font *font, GC gc, int x, int y,
 223                          int width)
 224 {
 225   XGCValues xgcv;
 226
 227   XGetGCValues (FRAME_X_DISPLAY (f), gc,
 228                 GCForeground | GCBackground, &xgcv);
 229   XSetForeground (FRAME_X_DISPLAY (f), gc, xgcv.background);
 230   XFillRectangle (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f), gc,
 231                   x, y - FONT_BASE (font), width, FONT_HEIGHT (font));
 232   XSetForeground (FRAME_X_DISPLAY (f), gc, xgcv.foreground);
 233 }
 234
 235 /* Prototypes for font-driver methods.  */
 236 static Lisp_Object ftxfont_list (Lisp_Object, Lisp_Object);
 237 static Lisp_Object ftxfont_match (Lisp_Object, Lisp_Object);
 238 static Lisp_Object ftxfont_open (FRAME_PTR, Lisp_Object, int);
 239 static void ftxfont_close (FRAME_PTR, struct font *);
 240 static int ftxfont_draw (struct glyph_string *, int, int, int, int, int);
 241
 242 static Lisp_Object
 243 ftxfont_list (Lisp_Object frame, Lisp_Object spec)
 244 {
 245   Lisp_Object list = ftfont_driver.list (frame, spec), tail;
 246
 247   for (tail = list; CONSP (tail); tail = XCDR (tail))
 248     ASET (XCAR (tail), FONT_TYPE_INDEX, Qftx);
 249   return list;
 250 }
 251
 252 static Lisp_Object
 253 ftxfont_match (Lisp_Object frame, Lisp_Object spec)
 254 {
 255   Lisp_Object entity = ftfont_driver.match (frame, spec);
 256
 257   if (VECTORP (entity))
 258     ASET (entity, FONT_TYPE_INDEX, Qftx);
 259   return entity;
 260 }
 261
 262 static Lisp_Object
 263 ftxfont_open (FRAME_PTR f, Lisp_Object entity, int pixel_size)
 264 {
 265   Lisp_Object font_object;
 266   struct font *font;
 267
 268   font_object = ftfont_driver.open (f, entity, pixel_size);
 269   if (NILP (font_object))
 270     return Qnil;
 271   font = XFONT_OBJECT (font_object);
 272   font->driver = &ftxfont_driver;
 273   return font_object;
 274 }
 275
 276 static void
 277 ftxfont_close (FRAME_PTR f, struct font *font)
 278 {
 279   ftfont_driver.close (f, font);
 280 }
 281
 282 static int
 283 ftxfont_draw (struct glyph_string *s, int from, int to, int x, int y, int with_background)
 284 {
 285   FRAME_PTR f = s->f;
 286   struct face *face = s->face;
 287   struct font *font = s->font;
 288   XPoint p[0x700];
 289   int n[7];
 290   unsigned *code;
 291   int len = to - from;
 292   int i;
 293   GC *gcs;
 294   int xadvance;
 295
 296   n[0] = n[1] = n[2] = n[3] = n[4] = n[5] = n[6] = 0;
 297
 298   BLOCK_INPUT;
 299   if (with_background)
 300     ftxfont_draw_background (f, font, s->gc, x, y, s->width);
 301   code = alloca (sizeof (unsigned) * len);
 302   for (i = 0; i < len; i++)
 303     code[i] = ((XCHAR2B_BYTE1 (s->char2b + from + i) << 8)
 304                | XCHAR2B_BYTE2 (s->char2b + from + i));
 305
 306   if (face->gc == s->gc)
 307     {
 308       gcs = ftxfont_get_gcs (f, face->foreground, face->background);
 309     }
 310   else
 311     {
 312       XGCValues xgcv;
 313       unsigned long mask = GCForeground | GCBackground;
 314
 315       XGetGCValues (FRAME_X_DISPLAY (f), s->gc, mask, &xgcv);
 316       gcs = ftxfont_get_gcs (f, xgcv.foreground, xgcv.background);
 317     }
 318
 319   if (gcs)
 320     {
 321       if (s->num_clips)
 322         for (i = 0; i < 6; i++)
 323           XSetClipRectangles (FRAME_X_DISPLAY (f), gcs[i], 0, 0,
 324                               s->clip, s->num_clips, Unsorted);
 325
 326       for (i = 0; i < len; i++)
 327         {
 328           xadvance = ftxfont_draw_bitmap (f, s->gc, gcs, font, code[i], x, y,
 329                                           p, 0x100, n, i + 1 == len);
 330           x += (s->padding_p ? 1 : xadvance);
 331         }
 332       if (s->num_clips)
 333         for (i = 0; i < 6; i++)
 334           XSetClipMask (FRAME_X_DISPLAY (f), gcs[i], None);
 335     }
 336   else
 337     {
 338       /* We can't draw with antialiasing.
 339          s->gc should already have a proper clipping setting. */
 340       for (i = 0; i < len; i++)
 341         {
 342           xadvance = ftxfont_draw_bitmap (f, s->gc, NULL, font, code[i], x, y,
 343                                           p, 0x700, n, i + 1 == len);
 344           x += (s->padding_p ? 1 : xadvance);
 345         }
 346     }
 347
 348   UNBLOCK_INPUT;
 349
 350   return len;
 351 }
 352
 353 static int
 354 ftxfont_end_for_frame (FRAME_PTR f)
 355 {
 356   struct ftxfont_frame_data *data = font_get_frame_data (f, &ftxfont_driver);
 357
 358   BLOCK_INPUT;
 359   while (data)
 360     {
 361       struct ftxfont_frame_data *next = data->next;
 362       int i;
 363
 364       for (i = 0; i < 6; i++)
 365         XFreeGC (FRAME_X_DISPLAY (f), data->gcs[i]);
 366       free (data);
 367       data = next;
 368     }
 369   UNBLOCK_INPUT;
 370   font_put_frame_data (f, &ftxfont_driver, NULL);
 371   return 0;
 372 }
 373
 374 \f
 375
 376 void
 377 syms_of_ftxfont (void)
 378 {
 379   DEFSYM (Qftx, "ftx");
 380
 381   ftxfont_driver = ftfont_driver;
 382   ftxfont_driver.type = Qftx;
 383   ftxfont_driver.list = ftxfont_list;
 384   ftxfont_driver.match = ftxfont_match;
 385   ftxfont_driver.open = ftxfont_open;
 386   ftxfont_driver.close = ftxfont_close;
 387   ftxfont_driver.draw = ftxfont_draw;
 388   ftxfont_driver.end_for_frame = ftxfont_end_for_frame;
 389   register_font_driver (&ftxfont_driver, NULL);
 390 }