dispnew.c 76.3 KB
Newer Older
Jim Blandy's avatar
Jim Blandy committed
1
/* Updating of data structures for redisplay.
Richard M. Stallman's avatar
Richard M. Stallman committed
2
   Copyright (C) 1985, 86, 87, 88, 93, 94, 95, 97, 1998
3
       Free Software Foundation, Inc.
Jim Blandy's avatar
Jim Blandy committed
4 5 6 7 8

This file is part of GNU Emacs.

GNU Emacs is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
9
the Free Software Foundation; either version 2, or (at your option)
Jim Blandy's avatar
Jim Blandy committed
10 11 12 13 14 15 16 17 18
any later version.

GNU Emacs is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with GNU Emacs; see the file COPYING.  If not, write to
19 20
the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */
Jim Blandy's avatar
Jim Blandy committed
21 22 23 24


#include <signal.h>

25
#include <config.h>
26 27

#include <stdio.h>
Jim Blandy's avatar
Jim Blandy committed
28 29
#include <ctype.h>

30
#include "lisp.h"
Jim Blandy's avatar
Jim Blandy committed
31 32
#include "termchar.h"
#include "termopts.h"
Richard M. Stallman's avatar
Richard M. Stallman committed
33
#include "termhooks.h"
34
/* cm.h must come after dispextern.h on Windows.  */
35 36
#include "dispextern.h"
#include "cm.h"
Jim Blandy's avatar
Jim Blandy committed
37
#include "buffer.h"
38
#include "charset.h"
Jim Blandy's avatar
Jim Blandy committed
39
#include "frame.h"
Jim Blandy's avatar
Jim Blandy committed
40 41 42 43
#include "window.h"
#include "commands.h"
#include "disptab.h"
#include "indent.h"
44
#include "intervals.h"
Richard M. Stallman's avatar
Richard M. Stallman committed
45
#include "blockinput.h"
Jim Blandy's avatar
Jim Blandy committed
46

47 48 49
/* I don't know why DEC Alpha OSF1 fail to compile this file if we
   include the following file.  */
/* #include "systty.h" */
Richard M. Stallman's avatar
Richard M. Stallman committed
50
#include "syssignal.h"
Jim Blandy's avatar
Jim Blandy committed
51

Jim Blandy's avatar
Jim Blandy committed
52 53 54 55
#ifdef HAVE_X_WINDOWS
#include "xterm.h"
#endif	/* HAVE_X_WINDOWS */

56 57 58 59
#ifdef HAVE_NTGUI
#include "w32term.h"
#endif /* HAVE_NTGUI */

60 61 62
/* Include systime.h after xterm.h to avoid double inclusion of time.h. */
#include "systime.h"

63 64
#include <errno.h>

Jim Blandy's avatar
Jim Blandy committed
65 66
#define max(a, b) ((a) > (b) ? (a) : (b))
#define min(a, b) ((a) < (b) ? (a) : (b))
Karl Heuer's avatar
Karl Heuer committed
67 68
#define minmax(floor, val, ceil) \
	((val) < (floor) ? (floor) : (val) > (ceil) ? (ceil) : (val))
Jim Blandy's avatar
Jim Blandy committed
69 70 71 72

/* Get number of chars of output now in the buffer of a stdio stream.
   This ought to be built in in stdio, but it isn't.
   Some s- files override this because their stdio internals differ.  */
73
#ifdef __GNU_LIBRARY__
Roland McGrath's avatar
Roland McGrath committed
74 75 76
/* The s- file might have overridden the definition with one that works for
   the system's C library.  But we are using the GNU C library, so this is
   the right definition for every system.  */
77 78 79
#ifdef GNU_LIBRARY_PENDING_OUTPUT_COUNT
#define PENDING_OUTPUT_COUNT GNU_LIBRARY_PENDING_OUTPUT_COUNT
#else
80
#undef	PENDING_OUTPUT_COUNT
81
#define	PENDING_OUTPUT_COUNT(FILE) ((FILE)->__bufp - (FILE)->__buffer)
82 83
#endif
#else /* not __GNU_LIBRARY__ */
84
#ifndef PENDING_OUTPUT_COUNT
Jim Blandy's avatar
Jim Blandy committed
85 86
#define PENDING_OUTPUT_COUNT(FILE) ((FILE)->_ptr - (FILE)->_base)
#endif
87
#endif
Jim Blandy's avatar
Jim Blandy committed
88

89 90
static void change_frame_size_1 ();

Jim Blandy's avatar
Jim Blandy committed
91
/* Nonzero upon entry to redisplay means do not assume anything about
Jim Blandy's avatar
Jim Blandy committed
92
   current contents of actual terminal frame; clear and redraw it.  */
Jim Blandy's avatar
Jim Blandy committed
93

Jim Blandy's avatar
Jim Blandy committed
94
int frame_garbaged;
Jim Blandy's avatar
Jim Blandy committed
95 96 97 98 99 100 101 102 103 104

/* Nonzero means last display completed.  Zero means it was preempted. */

int display_completed;

/* Lisp variable visible-bell; enables use of screen-flash
   instead of audible bell.  */

int visible_bell;

Jim Blandy's avatar
Jim Blandy committed
105
/* Invert the color of the whole frame, at a low level.  */
Jim Blandy's avatar
Jim Blandy committed
106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133

int inverse_video;

/* Line speed of the terminal.  */

int baud_rate;

/* nil or a symbol naming the window system under which emacs is
   running ('x is the only current possibility).  */

Lisp_Object Vwindow_system;

/* Version number of X windows: 10, 11 or nil.  */
Lisp_Object Vwindow_system_version;

/* Vector of glyph definitions.  Indexed by glyph number,
   the contents are a string which is how to output the glyph.

   If Vglyph_table is nil, a glyph is output by using its low 8 bits
   as a character code.  */

Lisp_Object Vglyph_table;

/* Display table to use for vectors that don't specify their own.  */

Lisp_Object Vstandard_display_table;

/* Nonzero means reading single-character input with prompt
Jim Blandy's avatar
Jim Blandy committed
134 135 136
   so put cursor on minibuffer after the prompt.
   positive means at end of text in echo area;
   negative means at beginning of line.  */
Jim Blandy's avatar
Jim Blandy committed
137
int cursor_in_echo_area;
138 139

Lisp_Object Qdisplay_table;
Jim Blandy's avatar
Jim Blandy committed
140

Jim Blandy's avatar
Jim Blandy committed
141
/* The currently selected frame.
Morten Welinder's avatar
Morten Welinder committed
142 143
   In a single-frame version, this variable always holds the address of
   the_only_frame.  */
Jim Blandy's avatar
Jim Blandy committed
144

Jim Blandy's avatar
Jim Blandy committed
145
FRAME_PTR selected_frame;
Jim Blandy's avatar
Jim Blandy committed
146

Jim Blandy's avatar
Jim Blandy committed
147 148
/* A frame which is not just a minibuffer, or 0 if there are no such
   frames.  This is usually the most recent such frame that was
Morten Welinder's avatar
Morten Welinder committed
149 150
   selected.  In a single-frame version, this variable always holds
   the address of the_only_frame.  */
Jim Blandy's avatar
Jim Blandy committed
151
FRAME_PTR last_nonminibuf_frame;
Jim Blandy's avatar
Jim Blandy committed
152

Jim Blandy's avatar
Jim Blandy committed
153
/* This is a vector, made larger whenever it isn't large enough,
Jim Blandy's avatar
Jim Blandy committed
154 155 156
   which is used inside `update_frame' to hold the old contents
   of the FRAME_PHYS_LINES of the frame being updated.  */
struct frame_glyphs **ophys_lines;
Jim Blandy's avatar
Jim Blandy committed
157 158 159 160 161 162 163 164 165
/* Length of vector currently allocated.  */
int ophys_lines_length;

FILE *termscript;	/* Stdio stream being used for copy of all output.  */

struct cm Wcm;		/* Structure for info on cursor positioning */

int delayed_size_change;  /* 1 means SIGWINCH happened when not safe.  */

Jim Blandy's avatar
Jim Blandy committed
166 167 168 169
DEFUN ("redraw-frame", Fredraw_frame, Sredraw_frame, 1, 1, 0,
  "Clear frame FRAME and output again what is supposed to appear on it.")
  (frame)
     Lisp_Object frame;
Jim Blandy's avatar
Jim Blandy committed
170
{
Jim Blandy's avatar
Jim Blandy committed
171
  FRAME_PTR f;
Jim Blandy's avatar
Jim Blandy committed
172

Jim Blandy's avatar
Jim Blandy committed
173 174 175
  CHECK_LIVE_FRAME (frame, 0);
  f = XFRAME (frame);
  update_begin (f);
176 177
  if (FRAME_MSDOS_P (f))
    set_terminal_modes ();
Jim Blandy's avatar
Jim Blandy committed
178
  clear_frame ();
179
  clear_frame_records (f);
Jim Blandy's avatar
Jim Blandy committed
180
  update_end (f);
Jim Blandy's avatar
Jim Blandy committed
181 182 183 184
  fflush (stdout);
  windows_or_buffers_changed++;
  /* Mark all windows as INaccurate,
     so that every window will have its redisplay done.  */
Jim Blandy's avatar
Jim Blandy committed
185 186
  mark_window_display_accurate (FRAME_ROOT_WINDOW (f), 0);
  f->garbaged = 0;
Jim Blandy's avatar
Jim Blandy committed
187 188 189
  return Qnil;
}

Jim Blandy's avatar
Jim Blandy committed
190 191
redraw_frame (f)
     FRAME_PTR f;
Jim Blandy's avatar
Jim Blandy committed
192
{
Jim Blandy's avatar
Jim Blandy committed
193
  Lisp_Object frame;
194
  XSETFRAME (frame, f);
Jim Blandy's avatar
Jim Blandy committed
195
  Fredraw_frame (frame);
Jim Blandy's avatar
Jim Blandy committed
196 197
}

198 199 200 201 202 203 204
DEFUN ("redraw-display", Fredraw_display, Sredraw_display, 0, 0, "",
  "Clear and redisplay all visible frames.")
  ()
{
  Lisp_Object tail, frame;

  FOR_EACH_FRAME (tail, frame)
205
    if (FRAME_VISIBLE_P (XFRAME (frame)))
206 207 208 209 210
      Fredraw_frame (frame);

  return Qnil;
}

211 212 213 214 215 216 217 218 219 220 221 222 223 224
/* This is used when frame_garbaged is set.
   Redraw the individual frames marked as garbaged.  */

void
redraw_garbaged_frames ()
{
  Lisp_Object tail, frame;

  FOR_EACH_FRAME (tail, frame)
    if (FRAME_VISIBLE_P (XFRAME (frame))
	&& FRAME_GARBAGED_P (XFRAME (frame)))
      Fredraw_frame (frame);
}

Jim Blandy's avatar
Jim Blandy committed
225

Jim Blandy's avatar
Jim Blandy committed
226 227 228
static struct frame_glyphs *
make_frame_glyphs (frame, empty)
     register FRAME_PTR frame;
Jim Blandy's avatar
Jim Blandy committed
229 230 231
     int empty;
{
  register int i;
232
  register width = FRAME_WINDOW_WIDTH (frame);
Jim Blandy's avatar
Jim Blandy committed
233
  register height = FRAME_HEIGHT (frame);
234 235
  register struct frame_glyphs *new
    = (struct frame_glyphs *) xmalloc (sizeof (struct frame_glyphs));
Jim Blandy's avatar
Jim Blandy committed
236

Jim Blandy's avatar
Jim Blandy committed
237
  SET_GLYPHS_FRAME (new, frame);
Jim Blandy's avatar
Jim Blandy committed
238 239 240 241
  new->height = height;
  new->width = width;
  new->used = (int *) xmalloc (height * sizeof (int));
  new->glyphs = (GLYPH **) xmalloc (height * sizeof (GLYPH *));
242
  new->charstarts = (int **) xmalloc (height * sizeof (int *));
Jim Blandy's avatar
Jim Blandy committed
243 244 245 246 247
  new->highlight = (char *) xmalloc (height * sizeof (char));
  new->enable = (char *) xmalloc (height * sizeof (char));
  bzero (new->enable, height * sizeof (char));
  new->bufp = (int *) xmalloc (height * sizeof (int));

248 249
#ifdef HAVE_WINDOW_SYSTEM
  if (FRAME_WINDOW_P (frame))
Jim Blandy's avatar
Jim Blandy committed
250 251 252 253 254
    {
      new->top_left_x = (short *) xmalloc (height * sizeof (short));
      new->top_left_y = (short *) xmalloc (height * sizeof (short));
      new->pix_width = (short *) xmalloc (height * sizeof (short));
      new->pix_height = (short *) xmalloc (height * sizeof (short));
255
      new->max_ascent = (short *) xmalloc (height * sizeof (short));
Jim Blandy's avatar
Jim Blandy committed
256
    }
257
#endif /* HAVE_WINDOW_SYSTEM */
Jim Blandy's avatar
Jim Blandy committed
258 259 260 261

  if (empty)
    {
      /* Make the buffer used by decode_mode_spec.  This buffer is also
Jim Blandy's avatar
Jim Blandy committed
262
         used as temporary storage when updating the frame.  See scroll.c. */
Jim Blandy's avatar
Jim Blandy committed
263
      unsigned int total_glyphs = (width + 2) * sizeof (GLYPH);
264
      unsigned int total_charstarts = (width + 2) * sizeof (int);
Jim Blandy's avatar
Jim Blandy committed
265 266 267

      new->total_contents = (GLYPH *) xmalloc (total_glyphs);
      bzero (new->total_contents, total_glyphs);
268 269

      new->total_charstarts = (int *) xmalloc (total_charstarts);
270
      bzero (new->total_charstarts, total_charstarts);
Jim Blandy's avatar
Jim Blandy committed
271 272 273 274 275 276 277 278 279
    }
  else
    {
      unsigned int total_glyphs = height * (width + 2) * sizeof (GLYPH);

      new->total_contents = (GLYPH *) xmalloc (total_glyphs);
      bzero (new->total_contents, total_glyphs);
      for (i = 0; i < height; i++)
	new->glyphs[i] = new->total_contents + i * (width + 2) + 1;
280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298

      if (!FRAME_TERMCAP_P (frame))
	{
	  unsigned int total_charstarts = height * (width + 2) * sizeof (int);

	  new->total_charstarts = (int *) xmalloc (total_charstarts);
	  bzero (new->total_charstarts, total_charstarts);
	  for (i = 0; i < height; i++)
	    new->charstarts[i] = new->total_charstarts + i * (width + 2) + 1;
	}
      else
	{
	  /* Without a window system, we don't really need charstarts.
	     So use a small amount of space to make enough data structure
	     to prevent crashes in display_text_line.  */
	  new->total_charstarts = (int *) xmalloc ((width + 2) * sizeof (int));
	  for (i = 0; i < height; i++)
	    new->charstarts[i] = new->total_charstarts;
	}
Jim Blandy's avatar
Jim Blandy committed
299 300 301 302 303
    }

  return new;
}

304
void
Jim Blandy's avatar
Jim Blandy committed
305 306 307
free_frame_glyphs (frame, glyphs)
     FRAME_PTR frame;
     struct frame_glyphs *glyphs;
Jim Blandy's avatar
Jim Blandy committed
308 309
{
  if (glyphs->total_contents)
310
    xfree (glyphs->total_contents);
311 312
  if (glyphs->total_charstarts)
    xfree (glyphs->total_charstarts);
Jim Blandy's avatar
Jim Blandy committed
313

314 315 316 317 318
  xfree (glyphs->used);
  xfree (glyphs->glyphs);
  xfree (glyphs->highlight);
  xfree (glyphs->enable);
  xfree (glyphs->bufp);
319 320
  if (glyphs->charstarts)
    xfree (glyphs->charstarts);
Jim Blandy's avatar
Jim Blandy committed
321

322 323
#ifdef HAVE_WINDOW_SYSTEM
  if (FRAME_WINDOW_P (frame))
Jim Blandy's avatar
Jim Blandy committed
324
    {
325 326 327 328 329
      xfree (glyphs->top_left_x);
      xfree (glyphs->top_left_y);
      xfree (glyphs->pix_width);
      xfree (glyphs->pix_height);
      xfree (glyphs->max_ascent);
Jim Blandy's avatar
Jim Blandy committed
330
    }
331
#endif /* HAVE_WINDOW_SYSTEM */
Jim Blandy's avatar
Jim Blandy committed
332

333
  xfree (glyphs);
Jim Blandy's avatar
Jim Blandy committed
334 335
}

336
void
Jim Blandy's avatar
Jim Blandy committed
337 338
remake_frame_glyphs (frame)
     FRAME_PTR frame;
Jim Blandy's avatar
Jim Blandy committed
339
{
Jim Blandy's avatar
Jim Blandy committed
340 341 342 343 344 345 346 347
  if (FRAME_CURRENT_GLYPHS (frame))
    free_frame_glyphs (frame, FRAME_CURRENT_GLYPHS (frame));
  if (FRAME_DESIRED_GLYPHS (frame))
    free_frame_glyphs (frame, FRAME_DESIRED_GLYPHS (frame));
  if (FRAME_TEMP_GLYPHS (frame))
    free_frame_glyphs (frame, FRAME_TEMP_GLYPHS (frame));

  if (FRAME_MESSAGE_BUF (frame))
348 349 350 351 352 353 354
    {
      /* Reallocate the frame's message buffer; remember that
	 echo_area_glyphs may be pointing here.  */
      char *old_message_buf = FRAME_MESSAGE_BUF (frame);

      FRAME_MESSAGE_BUF (frame)
	= (char *) xrealloc (FRAME_MESSAGE_BUF (frame),
355
			     FRAME_MESSAGE_BUF_SIZE (frame) + 1);
356 357 358 359 360 361

      if (echo_area_glyphs == old_message_buf)
	echo_area_glyphs = FRAME_MESSAGE_BUF (frame);
      if (previous_echo_glyphs == old_message_buf)
	previous_echo_glyphs = FRAME_MESSAGE_BUF (frame);
    }
Jim Blandy's avatar
Jim Blandy committed
362
  else
Jim Blandy's avatar
Jim Blandy committed
363
    FRAME_MESSAGE_BUF (frame)
364
      = (char *) xmalloc (FRAME_MESSAGE_BUF_SIZE (frame) + 1);
Jim Blandy's avatar
Jim Blandy committed
365

Jim Blandy's avatar
Jim Blandy committed
366 367 368
  FRAME_CURRENT_GLYPHS (frame) = make_frame_glyphs (frame, 0);
  FRAME_DESIRED_GLYPHS (frame) = make_frame_glyphs (frame, 0);
  FRAME_TEMP_GLYPHS (frame) = make_frame_glyphs (frame, 1);
369
  if (FRAME_WINDOW_P (frame) || frame == selected_frame)
370
    SET_FRAME_GARBAGED (frame);
Jim Blandy's avatar
Jim Blandy committed
371 372
}

Jim Blandy's avatar
Jim Blandy committed
373
/* Return the hash code of contents of line VPOS in frame-matrix M.  */
Jim Blandy's avatar
Jim Blandy committed
374 375 376

static int
line_hash_code (m, vpos)
Jim Blandy's avatar
Jim Blandy committed
377
     register struct frame_glyphs *m;
Jim Blandy's avatar
Jim Blandy committed
378 379 380 381 382 383 384 385
     int vpos;
{
  register GLYPH *body, *end;
  register int h = 0;

  if (!m->enable[vpos])
    return 0;

386
  /* Give all highlighted lines the same hash code
Jim Blandy's avatar
Jim Blandy committed
387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422
     so as to encourage scrolling to leave them in place.  */
  if (m->highlight[vpos])
    return -1;

  body = m->glyphs[vpos];

  if (must_write_spaces)
    while (1)
      {
	GLYPH g = *body++;

	if (g == 0)
	  break;
	h = (((h << 4) + (h >> 24)) & 0x0fffffff) + g - SPACEGLYPH;
      }
  else
    while (1)
      {
	GLYPH g = *body++;

	if (g == 0)
	  break;
	h = (((h << 4) + (h >> 24)) & 0x0fffffff) + g;
      }

  if (h)
    return h;
  return 1;
}

/* Return number of characters in line in M at vpos VPOS,
   except don't count leading and trailing spaces
   unless the terminal requires those to be explicitly output.  */

static unsigned int
line_draw_cost (m, vpos)
Jim Blandy's avatar
Jim Blandy committed
423
     struct frame_glyphs *m;
Jim Blandy's avatar
Jim Blandy committed
424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465
     int vpos;
{
  register GLYPH *beg = m->glyphs[vpos];
  register GLYPH *end = m->glyphs[vpos] + m->used[vpos];
  register int i;
  register int tlen = GLYPH_TABLE_LENGTH;
  register Lisp_Object *tbase = GLYPH_TABLE_BASE;

  /* Ignore trailing and leading spaces if we can.  */
  if (!must_write_spaces)
    {
      while ((end != beg) && (*end == SPACEGLYPH))
	--end;
      if (end == beg)
	return (0); /* All blank line. */

      while (*beg == SPACEGLYPH)
	++beg;
    }

  /* If we don't have a glyph-table, each glyph is one character,
     so return the number of glyphs.  */
  if (tbase == 0)
    return end - beg;

  /* Otherwise, scan the glyphs and accumulate their total size in I.  */
  i = 0;
  while ((beg <= end) && *beg)
    {
      register GLYPH g = *beg++;

      if (GLYPH_SIMPLE_P (tbase, tlen, g))
	i += 1;
      else
	i += GLYPH_LENGTH (tbase, g);
    }
  return i;
}

/* The functions on this page are the interface from xdisp.c to redisplay.

   The only other interface into redisplay is through setting
Jim Blandy's avatar
Jim Blandy committed
466 467
   FRAME_CURSOR_X (frame) and FRAME_CURSOR_Y (frame)
   and SET_FRAME_GARBAGED (frame).  */
Jim Blandy's avatar
Jim Blandy committed
468 469 470

/* cancel_line eliminates any request to display a line at position `vpos' */

Jim Blandy's avatar
Jim Blandy committed
471
cancel_line (vpos, frame)
Jim Blandy's avatar
Jim Blandy committed
472
     int vpos;
Jim Blandy's avatar
Jim Blandy committed
473
     register FRAME_PTR frame;
Jim Blandy's avatar
Jim Blandy committed
474
{
Jim Blandy's avatar
Jim Blandy committed
475
  FRAME_DESIRED_GLYPHS (frame)->enable[vpos] = 0;
Jim Blandy's avatar
Jim Blandy committed
476 477
}

Jim Blandy's avatar
Jim Blandy committed
478 479
clear_frame_records (frame)
     register FRAME_PTR frame;
Jim Blandy's avatar
Jim Blandy committed
480
{
Jim Blandy's avatar
Jim Blandy committed
481
  bzero (FRAME_CURRENT_GLYPHS (frame)->enable, FRAME_HEIGHT (frame));
Jim Blandy's avatar
Jim Blandy committed
482 483
}

484 485 486 487 488 489 490 491 492 493 494 495 496 497
/* Clear out all display lines for a coming redisplay.  */

void
init_desired_glyphs (frame)
     register FRAME_PTR frame;
{
  register struct frame_glyphs *desired_glyphs = FRAME_DESIRED_GLYPHS (frame);
  int vpos;
  int height = FRAME_HEIGHT (frame);

  for (vpos = 0; vpos < height; vpos++)
    desired_glyphs->enable[vpos] = 0;
}

Jim Blandy's avatar
Jim Blandy committed
498 499 500
/* Prepare to display on line VPOS starting at HPOS within it.  */

void
Jim Blandy's avatar
Jim Blandy committed
501 502
get_display_line (frame, vpos, hpos)
     register FRAME_PTR frame;
Jim Blandy's avatar
Jim Blandy committed
503 504 505
     int vpos;
     register int hpos;
{
Jim Blandy's avatar
Jim Blandy committed
506 507
  register struct frame_glyphs *glyphs;
  register struct frame_glyphs *desired_glyphs = FRAME_DESIRED_GLYPHS (frame);
Jim Blandy's avatar
Jim Blandy committed
508 509
  register GLYPH *p;

510
  if (vpos < 0)
Jim Blandy's avatar
Jim Blandy committed
511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537
    abort ();

  if (! desired_glyphs->enable[vpos])
    {
      desired_glyphs->used[vpos] = 0;
      desired_glyphs->highlight[vpos] = 0;
      desired_glyphs->enable[vpos] = 1;
    }

  if (hpos > desired_glyphs->used[vpos])
    {
      GLYPH *g = desired_glyphs->glyphs[vpos] + desired_glyphs->used[vpos];
      GLYPH *end = desired_glyphs->glyphs[vpos] + hpos;

      desired_glyphs->used[vpos] = hpos;
      while (g != end)
	*g++ = SPACEGLYPH;
    }
}

/* Like bcopy except never gets confused by overlap.  */

void
safe_bcopy (from, to, size)
     char *from, *to;
     int size;
{
538
  if (size <= 0 || from == to)
Jim Blandy's avatar
Jim Blandy committed
539 540
    return;

541 542 543 544 545 546 547 548
  /* If the source and destination don't overlap, then bcopy can
     handle it.  If they do overlap, but the destination is lower in
     memory than the source, we'll assume bcopy can handle that.  */
  if (to < from || from + size <= to)
    bcopy (from, to, size);

  /* Otherwise, we'll copy from the end.  */
  else
Jim Blandy's avatar
Jim Blandy committed
549
    {
550 551
      register char *endf = from + size;
      register char *endt = to + size;
Jim Blandy's avatar
Jim Blandy committed
552 553 554 555 556

      /* If TO - FROM is large, then we should break the copy into
	 nonoverlapping chunks of TO - FROM bytes each.  However, if
	 TO - FROM is small, then the bcopy function call overhead
	 makes this not worth it.  The crossover point could be about
557 558
	 anywhere.  Since I don't think the obvious copy loop is too
	 bad, I'm trying to err in its favor.  */
Jim Blandy's avatar
Jim Blandy committed
559 560 561 562 563 564 565 566
      if (to - from < 64)
	{
	  do
	    *--endt = *--endf;
	  while (endf != from);
	}
      else
	{
567
	  for (;;)
Jim Blandy's avatar
Jim Blandy committed
568 569 570 571
	    {
	      endt -= (to - from);
	      endf -= (to - from);

572 573 574
	      if (endt < to)
		break;

Jim Blandy's avatar
Jim Blandy committed
575 576
	      bcopy (endf, endt, to - from);
	    }
577 578

	  /* If SIZE wasn't a multiple of TO - FROM, there will be a
Jim Blandy's avatar
Jim Blandy committed
579 580 581 582 583 584 585
	     little left over.  The amount left over is
	     (endt + (to - from)) - to, which is endt - from.  */
	  bcopy (from, to, endt - from);
	}
    }
}     

Jim Blandy's avatar
Jim Blandy committed
586
/* Rotate a vector of SIZE bytes right, by DISTANCE bytes.
Jim Blandy's avatar
Jim Blandy committed
587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609
   DISTANCE may be negative.  */

static void
rotate_vector (vector, size, distance)
     char *vector;
     int size;
     int distance;
{
  char *temp = (char *) alloca (size);

  if (distance < 0)
    distance += size;

  bcopy (vector, temp + distance, size - distance);
  bcopy (vector + size - distance, temp, distance);
  bcopy (temp, vector, size);
}

/* Scroll lines from vpos FROM up to but not including vpos END
   down by AMOUNT lines (AMOUNT may be negative).
   Returns nonzero if done, zero if terminal cannot scroll them.  */

int
610
scroll_frame_lines (frame, from, end, amount, newpos)
Jim Blandy's avatar
Jim Blandy committed
611
     register FRAME_PTR frame;
612
     int from, end, amount, newpos;
Jim Blandy's avatar
Jim Blandy committed
613 614
{
  register int i;
Jim Blandy's avatar
Jim Blandy committed
615 616
  register struct frame_glyphs *current_frame
    = FRAME_CURRENT_GLYPHS (frame);
617
  int pos_adjust;
618
  int width = FRAME_WINDOW_WIDTH (frame);
Jim Blandy's avatar
Jim Blandy committed
619 620 621 622 623 624 625 626 627

  if (!line_ins_del_ok)
    return 0;

  if (amount == 0)
    return 1;

  if (amount > 0)
    {
Jim Blandy's avatar
Jim Blandy committed
628
      update_begin (frame);
Jim Blandy's avatar
Jim Blandy committed
629 630 631 632 633 634
      set_terminal_window (end + amount);
      if (!scroll_region_ok)
	ins_del_lines (end, -amount);
      ins_del_lines (from, amount);
      set_terminal_window (0);

Jim Blandy's avatar
Jim Blandy committed
635
      rotate_vector (current_frame->glyphs + from,
Jim Blandy's avatar
Jim Blandy committed
636 637 638
		     sizeof (GLYPH *) * (end + amount - from),
		     amount * sizeof (GLYPH *));

639
      rotate_vector (current_frame->charstarts + from,
640 641 642
		     sizeof (int *) * (end + amount - from),
		     amount * sizeof (int *));

643 644 645 646 647 648 649 650 651 652 653 654
      safe_bcopy (current_frame->used + from,
		  current_frame->used + from + amount,
		  (end - from) * sizeof current_frame->used[0]);

      safe_bcopy (current_frame->highlight + from,
		  current_frame->highlight + from + amount,
		  (end - from) * sizeof current_frame->highlight[0]);

      safe_bcopy (current_frame->enable + from,
		  current_frame->enable + from + amount,
		  (end - from) * sizeof current_frame->enable[0]);

655 656
      /* Adjust the lines by an amount
	 that puts the first of them at NEWPOS.  */
657
      pos_adjust = newpos - current_frame->charstarts[from + amount][0];
658 659 660

      /* Offset each char position in the charstarts lines we moved
	 by pos_adjust.  */
661
      for (i = from + amount; i < end + amount; i++)
662
	{
663
	  int *line = current_frame->charstarts[i];
664
	  int col;
665 666 667
	  for (col = 0; col < width; col++)
	    if (line[col] > 0)
	      line[col] += pos_adjust;
668
	}
669
      for (i = from; i < from + amount; i++)
670
	{
671
	  int *line = current_frame->charstarts[i];
672 673
	  int col;
	  line[0] = -1;
674
	  for (col = 0; col < width; col++)
675 676 677
	    line[col] = 0;
	}

Jim Blandy's avatar
Jim Blandy committed
678 679
      /* Mark the lines made empty by scrolling as enabled, empty and
	 normal video.  */
Jim Blandy's avatar
Jim Blandy committed
680 681 682 683
      bzero (current_frame->used + from,
	     amount * sizeof current_frame->used[0]);
      bzero (current_frame->highlight + from,
	     amount * sizeof current_frame->highlight[0]);
Jim Blandy's avatar
Jim Blandy committed
684 685
      for (i = from; i < from + amount; i++)
	{
Jim Blandy's avatar
Jim Blandy committed
686
	  current_frame->glyphs[i][0] = '\0';
687
	  current_frame->charstarts[i][0] = -1;
Jim Blandy's avatar
Jim Blandy committed
688
	  current_frame->enable[i] = 1;
Jim Blandy's avatar
Jim Blandy committed
689 690
	}

Jim Blandy's avatar
Jim Blandy committed
691 692 693
      safe_bcopy (current_frame->bufp + from,
		  current_frame->bufp + from + amount,
		  (end - from) * sizeof current_frame->bufp[0]);
Jim Blandy's avatar
Jim Blandy committed
694

695 696
#ifdef HAVE_WINDOW_SYSTEM
      if (FRAME_WINDOW_P (frame))
Jim Blandy's avatar
Jim Blandy committed
697
	{
Jim Blandy's avatar
Jim Blandy committed
698 699 700
	  safe_bcopy (current_frame->top_left_x + from,
		      current_frame->top_left_x + from + amount,
		      (end - from) * sizeof current_frame->top_left_x[0]);
Jim Blandy's avatar
Jim Blandy committed
701

Jim Blandy's avatar
Jim Blandy committed
702 703 704
	  safe_bcopy (current_frame->top_left_y + from,
		      current_frame->top_left_y + from + amount,
		      (end - from) * sizeof current_frame->top_left_y[0]);
Jim Blandy's avatar
Jim Blandy committed
705

Jim Blandy's avatar
Jim Blandy committed
706 707 708
	  safe_bcopy (current_frame->pix_width + from,
		      current_frame->pix_width + from + amount,
		      (end - from) * sizeof current_frame->pix_width[0]);
Jim Blandy's avatar
Jim Blandy committed
709

Jim Blandy's avatar
Jim Blandy committed
710 711 712
	  safe_bcopy (current_frame->pix_height + from,
		      current_frame->pix_height + from + amount,
		      (end - from) * sizeof current_frame->pix_height[0]);
713 714 715 716

	  safe_bcopy (current_frame->max_ascent + from,
		      current_frame->max_ascent + from + amount,
		      (end - from) * sizeof current_frame->max_ascent[0]);
Jim Blandy's avatar
Jim Blandy committed
717
	}
718
#endif /* HAVE_WINDOW_SYSTEM */
Jim Blandy's avatar
Jim Blandy committed
719

Jim Blandy's avatar
Jim Blandy committed
720
      update_end (frame);
Jim Blandy's avatar
Jim Blandy committed
721 722 723
    }
  if (amount < 0)
    {
Jim Blandy's avatar
Jim Blandy committed
724
      update_begin (frame);
Jim Blandy's avatar
Jim Blandy committed
725 726 727 728 729 730
      set_terminal_window (end);
      ins_del_lines (from + amount, amount);
      if (!scroll_region_ok)
	ins_del_lines (end + amount, -amount);
      set_terminal_window (0);

Jim Blandy's avatar
Jim Blandy committed
731
      rotate_vector (current_frame->glyphs + from + amount,
Jim Blandy's avatar
Jim Blandy committed
732 733 734
		     sizeof (GLYPH *) * (end - from - amount),
		     amount * sizeof (GLYPH *));

735
      rotate_vector (current_frame->charstarts + from + amount,
736 737 738
		     sizeof (int *) * (end - from - amount),
		     amount * sizeof (int *));

739 740 741 742 743 744 745 746 747 748 749 750
      safe_bcopy (current_frame->used + from,
		  current_frame->used + from + amount,
		  (end - from) * sizeof current_frame->used[0]);

      safe_bcopy (current_frame->highlight + from,
		  current_frame->highlight + from + amount,
		  (end - from) * sizeof current_frame->highlight[0]);

      safe_bcopy (current_frame->enable + from,
		  current_frame->enable + from + amount,
		  (end - from) * sizeof current_frame->enable[0]);

751 752
      /* Adjust the lines by an amount
	 that puts the first of them at NEWPOS.  */
753
      pos_adjust = newpos - current_frame->charstarts[from + amount][0];
754 755 756 757 758

      /* Offset each char position in the charstarts lines we moved
	 by pos_adjust.  */
      for (i = from + amount; i < end + amount; i++)
	{
759
	  int *line = current_frame->charstarts[i];
760
	  int col;
761 762 763
	  for (col = 0; col < width; col++)
	    if (line[col] > 0)
	      line[col] += pos_adjust;
764
	}
765
      for (i = end + amount; i < end; i++)
766
	{
767
	  int *line = current_frame->charstarts[i];
768 769
	  int col;
	  line[0] = -1;
770
	  for (col = 0; col < width; col++)
771 772 773
	    line[col] = 0;
	}

Jim Blandy's avatar
Jim Blandy committed
774 775
      /* Mark the lines made empty by scrolling as enabled, empty and
	 normal video.  */
Jim Blandy's avatar
Jim Blandy committed
776 777 778 779
      bzero (current_frame->used + end + amount,
	     - amount * sizeof current_frame->used[0]);
      bzero (current_frame->highlight + end + amount,
	     - amount * sizeof current_frame->highlight[0]);
Jim Blandy's avatar
Jim Blandy committed
780 781
      for (i = end + amount; i < end; i++)
	{
Jim Blandy's avatar
Jim Blandy committed
782
	  current_frame->glyphs[i][0] = '\0';
783
	  current_frame->charstarts[i][0] = 0;
Jim Blandy's avatar
Jim Blandy committed
784
	  current_frame->enable[i] = 1;
Jim Blandy's avatar
Jim Blandy committed
785 786
	}

Jim Blandy's avatar
Jim Blandy committed
787 788 789
      safe_bcopy (current_frame->bufp + from,
		  current_frame->bufp + from + amount,
		  (end - from) * sizeof current_frame->bufp[0]);
Jim Blandy's avatar
Jim Blandy committed
790

791 792
#ifdef HAVE_WINDOW_SYSTEM
      if (FRAME_WINDOW_P (frame))
Jim Blandy's avatar
Jim Blandy committed
793
	{
Jim Blandy's avatar
Jim Blandy committed
794 795 796
	  safe_bcopy (current_frame->top_left_x + from,
		      current_frame->top_left_x + from + amount,
		      (end - from) * sizeof current_frame->top_left_x[0]);
Jim Blandy's avatar
Jim Blandy committed
797

Jim Blandy's avatar
Jim Blandy committed
798 799 800
	  safe_bcopy (current_frame->top_left_y + from,
		      current_frame->top_left_y + from + amount,
		      (end - from) * sizeof current_frame->top_left_y[0]);
Jim Blandy's avatar
Jim Blandy committed
801

Jim Blandy's avatar
Jim Blandy committed
802 803 804
	  safe_bcopy (current_frame->pix_width + from,
		      current_frame->pix_width + from + amount,
		      (end - from) * sizeof current_frame->pix_width[0]);
Jim Blandy's avatar
Jim Blandy committed
805

Jim Blandy's avatar
Jim Blandy committed
806 807 808
	  safe_bcopy (current_frame->pix_height + from,
		      current_frame->pix_height + from + amount,
		      (end - from) * sizeof current_frame->pix_height[0]);
809 810 811 812

	  safe_bcopy (current_frame->max_ascent + from,
		      current_frame->max_ascent + from + amount,
		      (end - from) * sizeof current_frame->max_ascent[0]);
Jim Blandy's avatar
Jim Blandy committed
813
	}
814
#endif /* HAVE_WINDOW_SYSTEM */
Jim Blandy's avatar
Jim Blandy committed
815

Jim Blandy's avatar
Jim Blandy committed
816
      update_end (frame);
Jim Blandy's avatar
Jim Blandy committed
817 818 819 820
    }
  return 1;
}

Jim Blandy's avatar
Jim Blandy committed
821
/* After updating a window W that isn't the full frame wide,
Jim Blandy's avatar
Jim Blandy committed
822
   copy all the columns that W does not occupy
Jim Blandy's avatar
Jim Blandy committed
823 824
   into the FRAME_DESIRED_GLYPHS (frame) from the FRAME_PHYS_GLYPHS (frame)
   so that update_frame will not change those columns.  */
Jim Blandy's avatar
Jim Blandy committed
825 826 827 828 829

preserve_other_columns (w)
     struct window *w;
{
  register int vpos;
Jim Blandy's avatar
Jim Blandy committed
830 831
  register struct frame_glyphs *current_frame, *desired_frame;
  register FRAME_PTR frame = XFRAME (w->frame);
832 833
  int start = WINDOW_LEFT_MARGIN (w);
  int end = WINDOW_RIGHT_EDGE (w);
Jim Blandy's avatar
Jim Blandy committed
834 835
  int bot = XFASTINT (w->top) + XFASTINT (w->height);

Jim Blandy's avatar
Jim Blandy committed
836 837
  current_frame = FRAME_CURRENT_GLYPHS (frame);
  desired_frame = FRAME_DESIRED_GLYPHS (frame);
Jim Blandy's avatar
Jim Blandy committed
838 839 840

  for (vpos = XFASTINT (w->top); vpos < bot; vpos++)
    {
Jim Blandy's avatar
Jim Blandy committed
841
      if (current_frame->enable[vpos] && desired_frame->enable[vpos])
Jim Blandy's avatar
Jim Blandy committed
842 843 844 845 846
	{
	  if (start > 0)
	    {
	      int len;

Jim Blandy's avatar
Jim Blandy committed
847
	      bcopy (current_frame->glyphs[vpos],
848
		     desired_frame->glyphs[vpos],
849
		     start * sizeof (current_frame->glyphs[vpos][0]));
850 851
	      bcopy (current_frame->charstarts[vpos],
		     desired_frame->charstarts[vpos],
852
		     start * sizeof (current_frame->charstarts[vpos][0]));
Jim Blandy's avatar
Jim Blandy committed
853 854 855
	      len = min (start, current_frame->used[vpos]);
	      if (desired_frame->used[vpos] < len)
		desired_frame->used[vpos] = len;
Jim Blandy's avatar
Jim Blandy committed
856
	    }
Jim Blandy's avatar
Jim Blandy committed
857 858
	  if (current_frame->used[vpos] > end
	      && desired_frame->used[vpos] < current_frame->used[vpos])
Jim Blandy's avatar
Jim Blandy committed
859
	    {
Jim Blandy's avatar
Jim Blandy committed
860
	      while (desired_frame->used[vpos] < end)
861 862 863 864 865
		{
		  int used = desired_frame->used[vpos]++;
		  desired_frame->glyphs[vpos][used] = SPACEGLYPH;
		  desired_frame->glyphs[vpos][used] = 0;
		}
Jim Blandy's avatar
Jim Blandy committed
866 867
	      bcopy (current_frame->glyphs[vpos] + end,
		     desired_frame->glyphs[vpos] + end,
868
		     ((current_frame->used[vpos] - end)
869
		      * sizeof (current_frame->glyphs[vpos][0])));
870 871 872
	      bcopy (current_frame->charstarts[vpos] + end,
		     desired_frame->charstarts[vpos] + end,
		     ((current_frame->used[vpos] - end)
873
		      * sizeof (current_frame->charstarts[vpos][0])));
Jim Blandy's avatar
Jim Blandy committed
874
	      desired_frame->used[vpos] = current_frame->used[vpos];
Jim Blandy's avatar
Jim Blandy committed
875 876 877 878 879 880 881
	    }
	}
    }
}

#if 0

Jim Blandy's avatar
Jim Blandy committed
882
/* If window w does not need to be updated and isn't the full frame wide,
Jim Blandy's avatar
Jim Blandy committed
883
 copy all the columns that w does occupy
Jim Blandy's avatar
Jim Blandy committed
884 885
 into the FRAME_DESIRED_LINES (frame) from the FRAME_PHYS_LINES (frame)
 so that update_frame will not change those columns.
Jim Blandy's avatar
Jim Blandy committed
886 887 888 889 890 891 892

 Have not been able to figure out how to use this correctly.  */

preserve_my_columns (w)
     struct window *w;
{
  register int vpos, fin;
Jim Blandy's avatar
Jim Blandy committed
893 894
  register struct frame_glyphs *l1, *l2;
  register FRAME_PTR frame = XFRAME (w->frame);
895 896
  int start = WINDOW_LEFT_MARGIN (w);
  int end = WINDOW_RIGHT_EDGE (w);
Jim Blandy's avatar
Jim Blandy committed
897 898 899 900
  int bot = XFASTINT (w->top) + XFASTINT (w->height);

  for (vpos = XFASTINT (w->top); vpos < bot; vpos++)
    {
Jim Blandy's avatar
Jim Blandy committed
901 902
      if ((l1 = FRAME_DESIRED_GLYPHS (frame)->glyphs[vpos + 1])
	  && (l2 = FRAME_PHYS_GLYPHS (frame)->glyphs[vpos + 1]))
Jim Blandy's avatar
Jim Blandy committed
903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918
	{
	  if (l2->length > start && l1->length < l2->length)
	    {
	      fin = l2->length;
	      if (fin > end) fin = end;
	      while (l1->length < start)
		l1->body[l1->length++] = ' ';
	      bcopy (l2->body + start, l1->body + start, fin - start);
	      l1->length = fin;
	    }
	}
    }
}

#endif

919
/* Adjust by ADJUST the charstart values in window W
920
   after vpos VPOS, which counts relative to the frame
921 922 923 924 925 926 927 928
   (not relative to W itself).  */

void
adjust_window_charstarts (w, vpos, adjust)
     struct window *w;
     int vpos;
     int adjust;
{
929
  int left = WINDOW_LEFT_MARGIN (w);
930
  int top = XFASTINT (w->top);
931 932
  int right = left + window_internal_width (w);
  int bottom = top + window_internal_height (w);
933 934
  int i;

935
  for (i = vpos + 1; i < bottom; i++)
936 937 938 939 940 941 942 943 944
    {
      int *charstart
	= FRAME_CURRENT_GLYPHS (XFRAME (WINDOW_FRAME (w)))->charstarts[i];
      int j;
      for (j = left; j < right; j++)
	if (charstart[j] > 0)
	  charstart[j] += adjust;
    }
}
945

946 947 948 949
/* Check the charstarts values in the area of window W
   for internal consistency.  We cannot check that they are "right";
   we can only look for something nonsensical.  */

950 951 952 953 954 955 956
verify_charstarts (w)
     struct window *w;
{
  FRAME_PTR f = XFRAME (WINDOW_FRAME (w));
  int i;
  int top = XFASTINT (w->top);
  int bottom = top + window_internal_height (w);
957
  int left = WINDOW_LEFT_MARGIN (w);
958 959
  int right = left + window_internal_width (w);
  int next_line;
960 961
  int truncate = (XINT (w->hscroll)
		  || (truncate_partial_width_windows
962
		      && !WINDOW_FULL_WIDTH_P (w))
963
		  || !NILP (XBUFFER (w->buffer)->truncate_lines));
964 965 966 967 968

  for (i = top; i < bottom; i++)
    {
      int j;
      int last;
969
      int *charstart = FRAME_CURRENT_GLYPHS (f)->charstarts[i];
970 971

      if (i != top)
972 973 974 975 976 977 978 979 980 981 982 983 984 985
	{
	  if (truncate)
	    {
	      /* If we are truncating lines, allow a jump
		 in charstarts from one line to the next.  */
	      if (charstart[left] < next_line)
		abort ();
	    }
	  else
	    {
	      if (charstart[left] != next_line)
		abort ();
	    }
	}
986 987 988 989

      for (j = left; j < right; j++)
	if (charstart[j] > 0)
	  last = charstart[j];
990 991 992 993 994 995 996 997 998
      /* Record where the next line should start.  */
      next_line = last;
      if (BUF_ZV (XBUFFER (w->buffer)) != last)
	{
	  /* If there's a newline between the two lines, count that.  */
	  int endchar = *BUF_CHAR_ADDRESS (XBUFFER (w->buffer), last);
	  if (endchar == '\n')
	    next_line++;
	}
999 1000
    }
}
1001

Jim Blandy's avatar
Jim Blandy committed
1002 1003 1004 1005 1006 1007 1008 1009
/* On discovering that the redisplay for a window was no good,
   cancel the columns of that window, so that when the window is
   displayed over again get_display_line will not complain.  */

cancel_my_columns (w)
     struct window *w;
{
  register int vpos;
1010 1011
  register struct frame_glyphs *desired_glyphs
    = FRAME_DESIRED_GLYPHS (XFRAME (w->frame));
1012
  register int start = WINDOW_LEFT_MARGIN (w);
Jim Blandy's avatar
Jim Blandy committed
1013 1014 1015 1016 1017 1018 1019 1020
  register int bot = XFASTINT (w->top) + XFASTINT (w->height);

  for (vpos = XFASTINT (w->top); vpos < bot; vpos++)
    if (desired_glyphs->enable[vpos]
	&& desired_glyphs->used[vpos] >= start)
      desired_glyphs->used[vpos] = start;
}

Jim Blandy's avatar
Jim Blandy committed
1021
/* These functions try to perform directly and immediately on the frame
Jim Blandy's avatar
Jim Blandy committed
1022 1023 1024
   the necessary output for one change in the buffer.
   They may return 0 meaning nothing was done if anything is difficult,
   or 1 meaning the output was performed properly.
Jim Blandy's avatar
Jim Blandy committed
1025
   They assume that the frame was up to date before the buffer
1026
   change being displayed.  They make various other assumptions too;
Jim Blandy's avatar
Jim Blandy committed
1027 1028 1029 1030 1031 1032
   see command_loop_1 where these are called.  */

int
direct_output_for_insert (g)
     int g;
{
Jim Blandy's avatar
Jim Blandy committed
1033 1034 1035
  register FRAME_PTR frame = selected_frame;
  register struct frame_glyphs *current_frame
    = FRAME_CURRENT_GLYPHS (frame);
Jim Blandy's avatar
Jim Blandy committed
1036 1037 1038 1039 1040 1041 1042 1043

#ifndef COMPILER_REGISTER_BUG
  register
#endif /* COMPILER_REGISTER_BUG */
    struct window *w = XWINDOW (selected_window);
#ifndef COMPILER_REGISTER_BUG
  register
#endif /* COMPILER_REGISTER_BUG */
Jim Blandy's avatar
Jim Blandy committed
1044
    int hpos = FRAME_CURSOR_X (frame);
Jim Blandy's avatar
Jim Blandy committed
1045 1046 1047
#ifndef COMPILER_REGISTER_BUG
  register
#endif /* COMPILER_REGISTER_BUG */
Jim Blandy's avatar
Jim Blandy committed
1048
    int vpos = FRAME_CURSOR_Y (frame);
Jim Blandy's avatar
Jim Blandy committed
1049

1050
  /* Give up if about to continue line.  */
1051
  if (hpos >= WINDOW_LEFT_MARGIN (w) + window_internal_width (w) - 1
1052
    
Jim Blandy's avatar
Jim Blandy committed
1053
  /* Avoid losing if cursor is in invisible text off left margin */
1054
      || (XINT (w->hscroll) && hpos == WINDOW_LEFT_MARGIN (w))
Jim Blandy's avatar
Jim Blandy committed
1055 1056
    
  /* Give up if cursor outside window (in minibuf, probably) */
1057
      || cursor_in_echo_area
Jim Blandy's avatar
Jim Blandy committed
1058 1059
      || FRAME_CURSOR_Y (frame) < XFASTINT (w->top)
      || FRAME_CURSOR_Y (frame) >= XFASTINT (w->top) + XFASTINT (w->height)
Jim Blandy's avatar
Jim Blandy committed
1060