dispnew.c 191 KB
Newer Older
Jim Blandy's avatar
Jim Blandy committed
1
/* Updating of data structures for redisplay.
2

Paul Eggert's avatar
Paul Eggert committed
3
Copyright (C) 1985-1988, 1993-1995, 1997-2019 Free Software Foundation,
4
Inc.
Jim Blandy's avatar
Jim Blandy committed
5 6 7

This file is part of GNU Emacs.

8
GNU Emacs is free software: you can redistribute it and/or modify
Jim Blandy's avatar
Jim Blandy committed
9
it under the terms of the GNU General Public License as published by
10 11
the Free Software Foundation, either version 3 of the License, or (at
your option) any later version.
Jim Blandy's avatar
Jim Blandy committed
12 13 14 15 16 17 18

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
19
along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
jave's avatar
jave committed
20

21
#include <config.h>
22

23
#include "sysstdio.h"
Paul Eggert's avatar
Paul Eggert committed
24
#include <stdlib.h>
Andreas Schwab's avatar
Andreas Schwab committed
25 26
#include <unistd.h>

27
#include "lisp.h"
28
#include "ptr-bounds.h"
Jim Blandy's avatar
Jim Blandy committed
29
#include "termchar.h"
30
/* cm.h must come after dispextern.h on Windows.  */
31 32
#include "dispextern.h"
#include "cm.h"
33
#include "buffer.h"
34
#include "keyboard.h"
Jim Blandy's avatar
Jim Blandy committed
35
#include "frame.h"
36
#include "termhooks.h"
Jim Blandy's avatar
Jim Blandy committed
37 38 39
#include "window.h"
#include "commands.h"
#include "disptab.h"
Richard M. Stallman's avatar
Richard M. Stallman committed
40
#include "blockinput.h"
Richard M. Stallman's avatar
Richard M. Stallman committed
41
#include "syssignal.h"
42
#include "systime.h"
Paul Eggert's avatar
Paul Eggert committed
43
#include "tparam.h"
Paul Eggert's avatar
Paul Eggert committed
44
#include "xwidget.h"
Daniel Colascione's avatar
Daniel Colascione committed
45
#include "pdumper.h"
Jim Blandy's avatar
Jim Blandy committed
46

47 48 49
#ifdef HAVE_WINDOW_SYSTEM
#include TERM_HEADER
#endif /* HAVE_WINDOW_SYSTEM */
50

51 52
#include <errno.h>

Paul Eggert's avatar
Paul Eggert committed
53
#include <fpending.h>
54

55 56 57
#ifdef WINDOWSNT
#include "w32.h"
#endif
Gerd Moellmann's avatar
Gerd Moellmann committed
58 59 60 61 62 63 64 65 66 67 68 69 70

/* Structure to pass dimensions around.  Used for character bounding
   boxes, glyph matrix dimensions and alike.  */

struct dim
{
  int width;
  int height;
};


/* Function prototypes.  */

71
static void update_frame_line (struct frame *, int, bool);
Andreas Schwab's avatar
Andreas Schwab committed
72 73
static int required_matrix_height (struct window *);
static int required_matrix_width (struct window *);
74
static void increment_row_positions (struct glyph_row *, ptrdiff_t, ptrdiff_t);
75 76 77 78 79 80
static void build_frame_matrix_from_window_tree (struct glyph_matrix *,
                                                 struct window *);
static void build_frame_matrix_from_leaf_window (struct glyph_matrix *,
                                                 struct window *);
static void adjust_decode_mode_spec_buffer (struct frame *);
static void fill_up_glyph_row_with_spaces (struct glyph_row *);
81
static void clear_window_matrices (struct window *, bool);
82
static void fill_up_glyph_row_area_with_spaces (struct glyph_row *, int);
83 84
static int scrolling_window (struct window *, bool);
static bool update_window_line (struct window *, int, bool *);
85
static void mirror_make_current (struct window *, int);
86
#ifdef GLYPH_DEBUG
87 88
static void check_matrix_pointers (struct glyph_matrix *,
                                   struct glyph_matrix *);
89
#endif
90
static void mirror_line_dance (struct window *, int, int, int *, char *);
91 92
static bool update_window_tree (struct window *, bool);
static bool update_window (struct window *, bool);
93
static bool update_frame_1 (struct frame *, bool, bool, bool, bool);
94
static bool scrolling (struct frame *);
95 96 97
static void set_window_cursor_after_update (struct window *);
static void adjust_frame_glyphs_for_window_redisplay (struct frame *);
static void adjust_frame_glyphs_for_frame_redisplay (struct frame *);
98
static void set_window_update_flags (struct window *w, bool on_p);
Jim Blandy's avatar
Jim Blandy committed
99

100
/* True means last display completed.  False means it was preempted.  */
Jim Blandy's avatar
Jim Blandy committed
101

102
bool display_completed;
Jim Blandy's avatar
Jim Blandy committed
103

104
/* True means SIGWINCH happened when not safe.  */
Jim Blandy's avatar
Jim Blandy committed
105

106
static bool delayed_size_change;
Jim Blandy's avatar
Jim Blandy committed
107

Gerd Moellmann's avatar
Gerd Moellmann committed
108
/* A glyph for a space.  */
Jim Blandy's avatar
Jim Blandy committed
109

Gerd Moellmann's avatar
Gerd Moellmann committed
110
struct glyph space_glyph;
Jim Blandy's avatar
Jim Blandy committed
111

112 113
#if defined GLYPH_DEBUG && defined ENABLE_CHECKING

Gerd Moellmann's avatar
Gerd Moellmann committed
114 115
/* Counts of allocated structures.  These counts serve to diagnose
   memory leaks and double frees.  */
Jim Blandy's avatar
Jim Blandy committed
116

117 118
static int glyph_matrix_count;
static int glyph_pool_count;
Jim Blandy's avatar
Jim Blandy committed
119

120 121
#endif /* GLYPH_DEBUG and ENABLE_CHECKING */

Gerd Moellmann's avatar
Gerd Moellmann committed
122 123
/* If non-null, the frame whose frame matrices are manipulated.  If
   null, window matrices are worked on.  */
Jim Blandy's avatar
Jim Blandy committed
124

Gerd Moellmann's avatar
Gerd Moellmann committed
125
static struct frame *frame_matrix_frame;
Jim Blandy's avatar
Jim Blandy committed
126

127
/* Convert vpos and hpos from frame to window and vice versa.
Gerd Moellmann's avatar
Gerd Moellmann committed
128
   This may only be used for terminal frames.  */
129

130
#ifdef GLYPH_DEBUG
Jim Blandy's avatar
Jim Blandy committed
131

132 133
static int window_to_frame_vpos (struct window *, int);
static int window_to_frame_hpos (struct window *, int);
Gerd Moellmann's avatar
Gerd Moellmann committed
134 135
#define WINDOW_TO_FRAME_VPOS(W, VPOS) window_to_frame_vpos ((W), (VPOS))
#define WINDOW_TO_FRAME_HPOS(W, HPOS) window_to_frame_hpos ((W), (HPOS))
Jim Blandy's avatar
Jim Blandy committed
136

137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159
/* One element of the ring buffer containing redisplay history
   information.  */

struct redisplay_history
{
  char trace[512 + 100];
};

/* The size of the history buffer.  */

#define REDISPLAY_HISTORY_SIZE	30

/* The redisplay history buffer.  */

static struct redisplay_history redisplay_history[REDISPLAY_HISTORY_SIZE];

/* Next free entry in redisplay_history.  */

static int history_idx;

/* A tick that's incremented each time something is added to the
   history.  */

160
static uprintmax_t history_tick;
Richard M. Stallman's avatar
Richard M. Stallman committed
161

162 163
/* Add to the redisplay history how window W has been displayed.
   MSG is a trace containing the information how W's glyph matrix
164
   has been constructed.  PAUSED_P means that the update
165 166 167
   has been interrupted for pending input.  */

static void
168
add_window_display_history (struct window *w, const char *msg, bool paused_p)
169 170
{
  char *buf;
Paul Eggert's avatar
Paul Eggert committed
171
  void *ptr = w;
172

173 174 175 176
  if (history_idx >= REDISPLAY_HISTORY_SIZE)
    history_idx = 0;
  buf = redisplay_history[history_idx].trace;
  ++history_idx;
Joakim Verona's avatar
Joakim Verona committed
177

178
  snprintf (buf, sizeof redisplay_history[0].trace,
179
	    "%"pMu": window %p (%s)%s\n%s",
180
	    history_tick++,
Paul Eggert's avatar
Paul Eggert committed
181
	    ptr,
182 183 184
	    ((BUFFERP (w->contents)
	      && STRINGP (BVAR (XBUFFER (w->contents), name)))
	     ? SSDATA (BVAR (XBUFFER (w->contents), name))
185 186 187
	     : "???"),
	    paused_p ? " ***paused***" : "",
	    msg);
Joakim Verona's avatar
Joakim Verona committed
188
}
189 190 191


/* Add to the redisplay history that frame F has been displayed.
192
   PAUSED_P means that the update has been interrupted for
193 194
   pending input.  */

jave's avatar
jave committed
195 196
static void
add_frame_display_history (struct frame *f, bool paused_p)
197 198
{
  char *buf;
Paul Eggert's avatar
Paul Eggert committed
199
  void *ptr = f;
200

201 202 203 204
  if (history_idx >= REDISPLAY_HISTORY_SIZE)
    history_idx = 0;
  buf = redisplay_history[history_idx].trace;
  ++history_idx;
205

206
  sprintf (buf, "%"pMu": update frame %p%s",
207
	   history_tick++,
Paul Eggert's avatar
Paul Eggert committed
208
	   ptr, paused_p ? " ***paused***" : "");
209 210 211 212 213
}


DEFUN ("dump-redisplay-history", Fdump_redisplay_history,
       Sdump_redisplay_history, 0, 0, "",
214
       doc: /* Dump redisplay history to stderr.  */)
Dan Nicolaescu's avatar
Dan Nicolaescu committed
215
  (void)
216 217 218 219 220 221 222 223 224 225 226 227 228 229
{
  int i;

  for (i = history_idx - 1; i != history_idx; --i)
    {
      if (i < 0)
	i = REDISPLAY_HISTORY_SIZE - 1;
      fprintf (stderr, "%s\n", redisplay_history[i].trace);
    }

  return Qnil;
}


230
#else /* not GLYPH_DEBUG */
Jim Blandy's avatar
Jim Blandy committed
231

232 233
#define WINDOW_TO_FRAME_VPOS(W, VPOS) ((VPOS) + WINDOW_TOP_EDGE_LINE (W))
#define WINDOW_TO_FRAME_HPOS(W, HPOS) ((HPOS) + WINDOW_LEFT_EDGE_COL (W))
Jim Blandy's avatar
Jim Blandy committed
234

235
#endif /* GLYPH_DEBUG */
Jim Blandy's avatar
Jim Blandy committed
236 237


238
#if defined PROFILING && !HAVE___EXECUTABLE_START
239 240
/* This function comes first in the Emacs executable and is used only
   to estimate the text start for profiling.  */
Jim Blandy's avatar
Jim Blandy committed
241
void
242
__executable_start (void)
Jim Blandy's avatar
Jim Blandy committed
243
{
244
  emacs_abort ();
245
}
246
#endif
Gerd Moellmann's avatar
Gerd Moellmann committed
247 248 249 250 251 252 253 254 255 256 257

/***********************************************************************
			    Glyph Matrices
 ***********************************************************************/

/* Allocate and return a glyph_matrix structure.  POOL is the glyph
   pool from which memory for the matrix should be allocated, or null
   for window-based redisplay where no glyph pools are used.  The
   member `pool' of the glyph matrix structure returned is set to
   POOL, the structure is otherwise zeroed.  */

258
static struct glyph_matrix *
259
new_glyph_matrix (struct glyph_pool *pool)
Jim Blandy's avatar
Jim Blandy committed
260
{
Dmitry Antipov's avatar
Dmitry Antipov committed
261
  struct glyph_matrix *result = xzalloc (sizeof *result);
Jim Blandy's avatar
Jim Blandy committed
262

263
#if defined GLYPH_DEBUG && defined ENABLE_CHECKING
Gerd Moellmann's avatar
Gerd Moellmann committed
264 265 266
  /* Increment number of allocated matrices.  This count is used
     to detect memory leaks.  */
  ++glyph_matrix_count;
267
#endif
Jim Blandy's avatar
Jim Blandy committed
268

Gerd Moellmann's avatar
Gerd Moellmann committed
269 270 271
  /* Set pool and return.  */
  result->pool = pool;
  return result;
Jim Blandy's avatar
Jim Blandy committed
272 273 274
}


Gerd Moellmann's avatar
Gerd Moellmann committed
275 276
/* Free glyph matrix MATRIX.  Passing in a null MATRIX is allowed.

277 278 279 280
   If GLYPH_DEBUG and ENABLE_CHECKING are in effect, the global counter
   glyph_matrix_count is decremented when a matrix is freed.  If the count
   gets negative, more structures were freed than allocated, i.e. one matrix
   was freed more than once or a bogus pointer was passed to this function.
281

Gerd Moellmann's avatar
Gerd Moellmann committed
282 283 284 285 286
   If MATRIX->pool is null, this means that the matrix manages its own
   glyph memory---this is done for matrices on X frames.  Freeing the
   matrix also frees the glyph memory in this case.  */

static void
287
free_glyph_matrix (struct glyph_matrix *matrix)
Jim Blandy's avatar
Jim Blandy committed
288
{
Gerd Moellmann's avatar
Gerd Moellmann committed
289 290 291 292
  if (matrix)
    {
      int i;

293
#if defined GLYPH_DEBUG && defined ENABLE_CHECKING
Gerd Moellmann's avatar
Gerd Moellmann committed
294 295
      /* Detect the case that more matrices are freed than were
	 allocated.  */
296 297 298
      --glyph_matrix_count;
      eassert (glyph_matrix_count >= 0);
#endif
Gerd Moellmann's avatar
Gerd Moellmann committed
299 300 301 302 303

      /* Free glyph memory if MATRIX owns it.  */
      if (matrix->pool == NULL)
	for (i = 0; i < matrix->rows_allocated; ++i)
	  xfree (matrix->rows[i].glyphs[LEFT_MARGIN_AREA]);
304

Gerd Moellmann's avatar
Gerd Moellmann committed
305 306 307 308 309
      /* Free row structures and the matrix itself.  */
      xfree (matrix->rows);
      xfree (matrix);
    }
}
Jim Blandy's avatar
Jim Blandy committed
310 311


Gerd Moellmann's avatar
Gerd Moellmann committed
312 313 314
/* Return the number of glyphs to reserve for a marginal area of
   window W.  TOTAL_GLYPHS is the number of glyphs in a complete
   display line of window W.  MARGIN gives the width of the marginal
315
   area in canonical character units.  */
Gerd Moellmann's avatar
Gerd Moellmann committed
316 317

static int
318
margin_glyphs_to_reserve (struct window *w, int total_glyphs, int margin)
Gerd Moellmann's avatar
Gerd Moellmann committed
319
{
320
  if (margin > 0)
Jim Blandy's avatar
Jim Blandy committed
321
    {
322
      int width = w->total_cols;
323
      double d = max (0, margin);
Gerd Moellmann's avatar
Gerd Moellmann committed
324
      d = min (width / 2 - 1, d);
325 326 327
      /* Since MARGIN is positive, we cannot possibly have less than
	 one glyph for the marginal area.  */
      return max (1, (int) ((double) total_glyphs / width * d));
Gerd Moellmann's avatar
Gerd Moellmann committed
328
    }
329
  return 0;
Gerd Moellmann's avatar
Gerd Moellmann committed
330 331
}

332
/* Return true if ROW's hash value is correct.
333 334
   Optimized away if ENABLE_CHECKING is not defined.  */

335
static bool
336 337
verify_row_hash (struct glyph_row *row)
{
338
  return row->hash == row_hash (row);
339
}
Jim Blandy's avatar
Jim Blandy committed
340

Gerd Moellmann's avatar
Gerd Moellmann committed
341 342
/* Adjust glyph matrix MATRIX on window W or on a frame to changed
   window sizes.
Jim Blandy's avatar
Jim Blandy committed
343

Gerd Moellmann's avatar
Gerd Moellmann committed
344 345 346 347 348
   W is null if the function is called for a frame glyph matrix.
   Otherwise it is the window MATRIX is a member of.  X and Y are the
   indices of the first column and row of MATRIX within the frame
   matrix, if such a matrix exists.  They are zero for purely
   window-based redisplay.  DIM is the needed size of the matrix.
349

Gerd Moellmann's avatar
Gerd Moellmann committed
350 351 352 353
   In window-based redisplay, where no frame matrices exist, glyph
   matrices manage their own glyph storage.  Otherwise, they allocate
   storage from a common frame glyph pool which can be found in
   MATRIX->pool.
354

Gerd Moellmann's avatar
Gerd Moellmann committed
355 356 357 358 359 360 361
   The reason for this memory management strategy is to avoid complete
   frame redraws if possible.  When we allocate from a common pool, a
   change of the location or size of a sub-matrix within the pool
   requires a complete redisplay of the frame because we cannot easily
   make sure that the current matrices of all windows still agree with
   what is displayed on the screen.  While this is usually fast, it
   leads to screen flickering.  */
362

Gerd Moellmann's avatar
Gerd Moellmann committed
363
static void
364
adjust_glyph_matrix (struct window *w, struct glyph_matrix *matrix, int x, int y, struct dim dim)
Gerd Moellmann's avatar
Gerd Moellmann committed
365 366 367
{
  int i;
  int new_rows;
368 369 370
  bool marginal_areas_changed_p = 0;
  bool header_line_changed_p = 0;
  bool header_line_p = 0;
Gerd Moellmann's avatar
Gerd Moellmann committed
371
  int left = -1, right = -1;
372
  int window_width = -1, window_height = -1;
Gerd Moellmann's avatar
Gerd Moellmann committed
373

Kenichi Handa's avatar
Kenichi Handa committed
374 375
  /* See if W had a header line that has disappeared now, or vice versa.
     Get W's size.  */
Gerd Moellmann's avatar
Gerd Moellmann committed
376 377
  if (w)
    {
Joakim Verona's avatar
Joakim Verona committed
378
      window_box (w, ANY_AREA, 0, 0, &window_width, &window_height);
Kenichi Handa's avatar
Kenichi Handa committed
379

380
      header_line_p = window_wants_header_line (w);
Gerd Moellmann's avatar
Change  
Gerd Moellmann committed
381
      header_line_changed_p = header_line_p != matrix->header_line_p;
Gerd Moellmann's avatar
Gerd Moellmann committed
382
    }
Gerd Moellmann's avatar
Change  
Gerd Moellmann committed
383
  matrix->header_line_p = header_line_p;
384

Kenichi Handa's avatar
Kenichi Handa committed
385 386
  /* If POOL is null, MATRIX is a window matrix for window-based redisplay.
     Do nothing if MATRIX' size, position, vscroll, and marginal areas
Gerd Moellmann's avatar
Gerd Moellmann committed
387 388
     haven't changed.  This optimization is important because preserving
     the matrix means preventing redisplay.  */
389
  eassume (w != NULL || matrix->pool != NULL);
Gerd Moellmann's avatar
Gerd Moellmann committed
390 391
  if (matrix->pool == NULL)
    {
392 393
      left = margin_glyphs_to_reserve (w, dim.width, w->left_margin_cols);
      right = margin_glyphs_to_reserve (w, dim.width, w->right_margin_cols);
394
      eassert (left >= 0 && right >= 0);
Gerd Moellmann's avatar
Gerd Moellmann committed
395 396 397 398
      marginal_areas_changed_p = (left != matrix->left_margin_glyphs
				  || right != matrix->right_margin_glyphs);

      if (!marginal_areas_changed_p
Joakim Verona's avatar
Joakim Verona committed
399
	  && !XFRAME (w->frame)->fonts_changed
Gerd Moellmann's avatar
Change  
Gerd Moellmann committed
400
	  && !header_line_changed_p
401 402
	  && matrix->window_pixel_left == WINDOW_LEFT_PIXEL_EDGE (w)
	  && matrix->window_pixel_top == WINDOW_TOP_PIXEL_EDGE (w)
Gerd Moellmann's avatar
Gerd Moellmann committed
403 404 405 406 407
	  && matrix->window_height == window_height
	  && matrix->window_vscroll == w->vscroll
	  && matrix->window_width == window_width)
	return;
    }
408

Gerd Moellmann's avatar
Gerd Moellmann committed
409 410 411
  /* Enlarge MATRIX->rows if necessary.  New rows are cleared.  */
  if (matrix->rows_allocated < dim.height)
    {
412
      int old_alloc = matrix->rows_allocated;
Gerd Moellmann's avatar
Gerd Moellmann committed
413
      new_rows = dim.height - matrix->rows_allocated;
414 415 416 417
      matrix->rows = xpalloc (matrix->rows, &matrix->rows_allocated,
			      new_rows, INT_MAX, sizeof *matrix->rows);
      memset (matrix->rows + old_alloc, 0,
	      (matrix->rows_allocated - old_alloc) * sizeof *matrix->rows);
Gerd Moellmann's avatar
Gerd Moellmann committed
418 419 420
    }
  else
    new_rows = 0;
421

Gerd Moellmann's avatar
Gerd Moellmann committed
422 423 424 425 426
  /* If POOL is not null, MATRIX is a frame matrix or a window matrix
     on a frame not using window-based redisplay.  Set up pointers for
     each row into the glyph pool.  */
  if (matrix->pool)
    {
427
      eassert (matrix->pool->glyphs);
428

Gerd Moellmann's avatar
Gerd Moellmann committed
429
      if (w)
430
	{
Gerd Moellmann's avatar
Gerd Moellmann committed
431
	  left = margin_glyphs_to_reserve (w, dim.width,
432
					   w->left_margin_cols);
Gerd Moellmann's avatar
Gerd Moellmann committed
433
	  right = margin_glyphs_to_reserve (w, dim.width,
434
					    w->right_margin_cols);
435
	}
Gerd Moellmann's avatar
Gerd Moellmann committed
436 437
      else
	left = right = 0;
438

Gerd Moellmann's avatar
Gerd Moellmann committed
439
      for (i = 0; i < dim.height; ++i)
440
	{
Gerd Moellmann's avatar
Gerd Moellmann committed
441
	  struct glyph_row *row = &matrix->rows[i];
442 443

	  row->glyphs[LEFT_MARGIN_AREA]
Gerd Moellmann's avatar
Gerd Moellmann committed
444 445 446
	    = (matrix->pool->glyphs
	       + (y + i) * matrix->pool->ncolumns
	       + x);
447

Gerd Moellmann's avatar
Gerd Moellmann committed
448
	  if (w == NULL
449
	      || (row == matrix->rows + dim.height - 1
450
		  && window_wants_mode_line (w))
Gerd Moellmann's avatar
Change  
Gerd Moellmann committed
451
	      || (row == matrix->rows && matrix->header_line_p))
Gerd Moellmann's avatar
Gerd Moellmann committed
452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468
	    {
	      row->glyphs[TEXT_AREA]
		= row->glyphs[LEFT_MARGIN_AREA];
	      row->glyphs[RIGHT_MARGIN_AREA]
		= row->glyphs[TEXT_AREA] + dim.width;
	      row->glyphs[LAST_AREA]
		= row->glyphs[RIGHT_MARGIN_AREA];
	    }
	  else
	    {
	      row->glyphs[TEXT_AREA]
		= row->glyphs[LEFT_MARGIN_AREA] + left;
	      row->glyphs[RIGHT_MARGIN_AREA]
		= row->glyphs[TEXT_AREA] + dim.width - left - right;
	      row->glyphs[LAST_AREA]
		= row->glyphs[LEFT_MARGIN_AREA] + dim.width;
	    }
469
	}
470

Gerd Moellmann's avatar
Gerd Moellmann committed
471 472 473 474 475 476
      matrix->left_margin_glyphs = left;
      matrix->right_margin_glyphs = right;
    }
  else
    {
      /* If MATRIX->pool is null, MATRIX is responsible for managing
Kenichi Handa's avatar
Kenichi Handa committed
477 478
	 its own memory.  It is a window matrix for window-based redisplay.
	 Allocate glyph memory from the heap.  */
Gerd Moellmann's avatar
Gerd Moellmann committed
479 480
      if (dim.width > matrix->matrix_w
	  || new_rows
Gerd Moellmann's avatar
Change  
Gerd Moellmann committed
481
	  || header_line_changed_p
Gerd Moellmann's avatar
Gerd Moellmann committed
482
	  || marginal_areas_changed_p)
Jim Blandy's avatar
Jim Blandy committed
483
	{
Gerd Moellmann's avatar
Gerd Moellmann committed
484 485
	  struct glyph_row *row = matrix->rows;
	  struct glyph_row *end = row + matrix->rows_allocated;
486

Gerd Moellmann's avatar
Gerd Moellmann committed
487 488 489
	  while (row < end)
	    {
	      row->glyphs[LEFT_MARGIN_AREA]
490 491
		= xnrealloc (row->glyphs[LEFT_MARGIN_AREA],
			     dim.width, sizeof (struct glyph));
492

493 494
	      /* The mode line, if displayed, never has marginal areas.  */
	      if ((row == matrix->rows + dim.height - 1
495
		   && !(w && window_wants_mode_line (w)))
Gerd Moellmann's avatar
Change  
Gerd Moellmann committed
496
		  || (row == matrix->rows && matrix->header_line_p))
Gerd Moellmann's avatar
Gerd Moellmann committed
497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515
		{
		  row->glyphs[TEXT_AREA]
		    = row->glyphs[LEFT_MARGIN_AREA];
		  row->glyphs[RIGHT_MARGIN_AREA]
		    = row->glyphs[TEXT_AREA] + dim.width;
		  row->glyphs[LAST_AREA]
		    = row->glyphs[RIGHT_MARGIN_AREA];
		}
	      else
		{
		  row->glyphs[TEXT_AREA]
		    = row->glyphs[LEFT_MARGIN_AREA] + left;
		  row->glyphs[RIGHT_MARGIN_AREA]
		    = row->glyphs[TEXT_AREA] + dim.width - left - right;
		  row->glyphs[LAST_AREA]
		    = row->glyphs[LEFT_MARGIN_AREA] + dim.width;
		}
	      ++row;
	    }
Jim Blandy's avatar
Jim Blandy committed
516 517
	}

518
      eassert (left >= 0 && right >= 0);
Gerd Moellmann's avatar
Gerd Moellmann committed
519 520 521
      matrix->left_margin_glyphs = left;
      matrix->right_margin_glyphs = right;
    }
522

Gerd Moellmann's avatar
Gerd Moellmann committed
523 524
  /* Number of rows to be used by MATRIX.  */
  matrix->nrows = dim.height;
525
  eassert (matrix->nrows >= 0);
Gerd Moellmann's avatar
Gerd Moellmann committed
526

527
  if (w)
Gerd Moellmann's avatar
Gerd Moellmann committed
528
    {
529
      if (matrix == w->current_matrix)
Jim Blandy's avatar
Jim Blandy committed
530
	{
531 532 533 534 535 536
	  /* Mark rows in a current matrix of a window as not having
	     valid contents.  It's important to not do this for
	     desired matrices.  When Emacs starts, it may already be
	     building desired matrices when this function runs.  */
	  if (window_width < 0)
	    window_width = window_box_width (w, -1);
537

538 539 540 541
	  /* Optimize the case that only the height has changed (C-x 2,
	     upper window).  Invalidate all rows that are no longer part
	     of the window.  */
	  if (!marginal_areas_changed_p
542 543 544
	      && !header_line_changed_p
	      && new_rows == 0
	      && dim.width == matrix->matrix_w
545 546
	      && matrix->window_pixel_left == WINDOW_LEFT_PIXEL_EDGE (w)
	      && matrix->window_pixel_top == WINDOW_TOP_PIXEL_EDGE (w)
547
	      && matrix->window_width == window_width)
548
	    {
549 550 551 552
	      /* Find the last row in the window.  */
	      for (i = 0; i < matrix->nrows && matrix->rows[i].enabled_p; ++i)
		if (MATRIX_ROW_BOTTOM_Y (matrix->rows + i) >= window_height)
		  {
553
		    ++i;
554 555
		    break;
		  }
556 557

	      /* Window end is invalid, if inside of the rows that
558
		 are invalidated below.  */
559
	      if (w->window_end_vpos >= i)
560
		w->window_end_valid = 0;
561

562
	      while (i < matrix->nrows)
563
		matrix->rows[i++].enabled_p = false;
564 565 566 567
	    }
	  else
	    {
	      for (i = 0; i < matrix->nrows; ++i)
568
		matrix->rows[i].enabled_p = false;
569
	    }
570 571 572 573
	  /* We've disabled the mode-line row, so force redrawing of
	     the mode line, if any, since otherwise it will remain
	     disabled in the current matrix, and expose events won't
	     redraw it.  */
574
	  if (window_wants_mode_line (w))
575
	    w->update_mode_line = 1;
Gerd Moellmann's avatar
Gerd Moellmann committed
576
	}
577
      else if (matrix == w->desired_matrix)
Gerd Moellmann's avatar
Gerd Moellmann committed
578
	{
579 580 581 582
	  /* Rows in desired matrices always have to be cleared;
	     redisplay expects this is the case when it runs, so it
	     had better be the case when we adjust matrices between
	     redisplays.  */
Gerd Moellmann's avatar
Gerd Moellmann committed
583
	  for (i = 0; i < matrix->nrows; ++i)
584
	    matrix->rows[i].enabled_p = false;
Jim Blandy's avatar
Jim Blandy committed
585 586
	}
    }
587 588


Gerd Moellmann's avatar
Gerd Moellmann committed
589 590 591 592 593 594 595 596 597
  /* Remember last values to be able to optimize frame redraws.  */
  matrix->matrix_x = x;
  matrix->matrix_y = y;
  matrix->matrix_w = dim.width;
  matrix->matrix_h = dim.height;

  /* Record the top y location and height of W at the time the matrix
     was last adjusted.  This is used to optimize redisplay above.  */
  if (w)
Jim Blandy's avatar
Jim Blandy committed
598
    {
599 600
      matrix->window_pixel_left = WINDOW_LEFT_PIXEL_EDGE (w);
      matrix->window_pixel_top = WINDOW_TOP_PIXEL_EDGE (w);
Gerd Moellmann's avatar
Gerd Moellmann committed
601 602 603 604 605
      matrix->window_height = window_height;
      matrix->window_width = window_width;
      matrix->window_vscroll = w->vscroll;
    }
}
Jim Blandy's avatar
Jim Blandy committed
606 607


Gerd Moellmann's avatar
Gerd Moellmann committed
608 609 610 611
/* Reverse the contents of rows in MATRIX between START and END.  The
   contents of the row at END - 1 end up at START, END - 2 at START +
   1 etc.  This is part of the implementation of rotate_matrix (see
   below).  */
612

Gerd Moellmann's avatar
Gerd Moellmann committed
613
static void
614
reverse_rows (struct glyph_matrix *matrix, int start, int end)
Gerd Moellmann's avatar
Gerd Moellmann committed
615 616
{
  int i, j;
617

Gerd Moellmann's avatar
Gerd Moellmann committed
618 619 620 621 622 623 624 625 626 627
  for (i = start, j = end - 1; i < j; ++i, --j)
    {
      /* Non-ISO HP/UX compiler doesn't like auto struct
	 initialization.  */
      struct glyph_row temp;
      temp = matrix->rows[i];
      matrix->rows[i] = matrix->rows[j];
      matrix->rows[j] = temp;
    }
}
628 629


Gerd Moellmann's avatar
Gerd Moellmann committed
630 631 632 633
/* Rotate the contents of rows in MATRIX in the range FIRST .. LAST -
   1 by BY positions.  BY < 0 means rotate left, i.e. towards lower
   indices.  (Note: this does not copy glyphs, only glyph pointers in
   row structures are moved around).
634

Gerd Moellmann's avatar
Gerd Moellmann committed
635 636 637 638 639 640 641 642
   The algorithm used for rotating the vector was, I believe, first
   described by Kernighan.  See the vector R as consisting of two
   sub-vectors AB, where A has length BY for BY >= 0.  The result
   after rotating is then BA.  Reverse both sub-vectors to get ArBr
   and reverse the result to get (ArBr)r which is BA.  Similar for
   rotating right.  */

void
643
rotate_matrix (struct glyph_matrix *matrix, int first, int last, int by)
Gerd Moellmann's avatar
Gerd Moellmann committed
644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667
{
  if (by < 0)
    {
      /* Up (rotate left, i.e. towards lower indices).  */
      by = -by;
      reverse_rows (matrix, first, first + by);
      reverse_rows (matrix, first + by, last);
      reverse_rows (matrix, first, last);
    }
  else if (by > 0)
    {
      /* Down (rotate right, i.e. towards higher indices).  */
      reverse_rows (matrix, last - by, last);
      reverse_rows (matrix, first, last - by);
      reverse_rows (matrix, first, last);
    }
}


/* Increment buffer positions in glyph rows of MATRIX.  Do it for rows
   with indices START <= index < END.  Increment positions by DELTA/
   DELTA_BYTES.  */

void
668
increment_matrix_positions (struct glyph_matrix *matrix, int start, int end,
669
			    ptrdiff_t delta, ptrdiff_t delta_bytes)
Gerd Moellmann's avatar
Gerd Moellmann committed
670 671
{
  /* Check that START and END are reasonable values.  */
672 673 674
  eassert (start >= 0 && start <= matrix->nrows);
  eassert (end >= 0 && end <= matrix->nrows);
  eassert (start <= end);
Gerd Moellmann's avatar
Gerd Moellmann committed
675 676

  for (; start < end; ++start)
677
    increment_row_positions (matrix->rows + start, delta, delta_bytes);
Gerd Moellmann's avatar
Gerd Moellmann committed
678 679 680
}


681 682
/* Clear the enable_p flags in a range of rows in glyph matrix MATRIX.
   START and END are the row indices of the first and last + 1 row to clear.  */
Gerd Moellmann's avatar
Gerd Moellmann committed
683 684

void
685
clear_glyph_matrix_rows (struct glyph_matrix *matrix, int start, int end)
Gerd Moellmann's avatar
Gerd Moellmann committed
686
{
687
  eassert (start <= end);
Chris Feng's avatar
Chris Feng committed
688 689 690
  eassert (start >= 0 && (start < matrix->nrows
			  /* matrix->nrows can be 0 for the initial frame.  */
			  || (matrix->nrows == 0)));
691
  eassert (end >= 0 && end <= matrix->nrows);
692

Gerd Moellmann's avatar
Gerd Moellmann committed
693
  for (; start < end; ++start)
694
    matrix->rows[start].enabled_p = false;
Gerd Moellmann's avatar
Gerd Moellmann committed
695 696 697 698 699
}


/* Clear MATRIX.

700 701 702
   Empty all rows in MATRIX by clearing their enabled_p flags.
   The function prepare_desired_row will eventually really clear a row
   when it sees one with a false enabled_p flag.
Gerd Moellmann's avatar
Gerd Moellmann committed
703

704
   Reset update hints to default values.  The only update hint
Gerd Moellmann's avatar
Gerd Moellmann committed
705 706 707
   currently present is the flag MATRIX->no_scrolling_p.  */

void
708
clear_glyph_matrix (struct glyph_matrix *matrix)
Gerd Moellmann's avatar
Gerd Moellmann committed
709 710 711
{
  if (matrix)
    {
712
      clear_glyph_matrix_rows (matrix, 0, matrix->nrows);
Gerd Moellmann's avatar
Gerd Moellmann committed
713 714 715
      matrix->no_scrolling_p = 0;
    }
}
716

Gerd Moellmann's avatar
Gerd Moellmann committed
717 718 719 720 721 722

/* Shift part of the glyph matrix MATRIX of window W up or down.
   Increment y-positions in glyph rows between START and END by DY,
   and recompute their visible height.  */

void
723
shift_glyph_matrix (struct window *w, struct glyph_matrix *matrix, int start, int end, int dy)
Gerd Moellmann's avatar
Gerd Moellmann committed
724 725
{
  int min_y, max_y;
726

727 728 729
  eassert (start <= end);
  eassert (start >= 0 && start < matrix->nrows);
  eassert (end >= 0 && end <= matrix->nrows);
730

731 732
  min_y = WINDOW_HEADER_LINE_HEIGHT (w);
  max_y = WINDOW_BOX_HEIGHT_NO_MODE_LINE (w);
733

Gerd Moellmann's avatar
Gerd Moellmann committed
734 735 736
  for (; start < end; ++start)
    {
      struct glyph_row *row = &matrix->rows[start];
737

Gerd Moellmann's avatar
Gerd Moellmann committed
738
      row->y += dy;
739
      row->visible_height = row->height;
740

Gerd Moellmann's avatar
Gerd Moellmann committed
741
      if (row->y < min_y)
742 743 744
	row->visible_height -= min_y - row->y;
      if (row->y + row->height > max_y)
	row->visible_height -= row->y + row->height - max_y;
745 746
      if (row->fringe_bitmap_periodic_p)
	row->redraw_fringe_bitmaps_p = 1;
Gerd Moellmann's avatar
Gerd Moellmann committed
747 748 749 750 751 752 753 754 755
    }
}


/* Mark all rows in current matrices of frame F as invalid.  Marking
   invalid is done by setting enabled_p to zero for all rows in a
   current matrix.  */

void
756
clear_current_matrices (register struct frame *f)
Gerd Moellmann's avatar
Gerd Moellmann committed
757 758 759 760 761
{
  /* Clear frame current matrix, if we have one.  */
  if (f->current_matrix)
    clear_glyph_matrix (f->current_matrix);

762
#if defined (HAVE_X_WINDOWS) && ! defined (USE_X_TOOLKIT) && ! defined (USE_GTK)
Gerd Moellmann's avatar
Gerd Moellmann committed
763 764 765
  /* Clear the matrix of the menu bar window, if such a window exists.
     The menu bar window is currently used to display menus on X when
     no toolkit support is compiled in.  */
766 767
  if (WINDOWP (f->menu_bar_window))
    clear_glyph_matrix (XWINDOW (f->menu_bar_window)->current_matrix);
768
#endif
Gerd Moellmann's avatar
Gerd Moellmann committed
769

770
#if defined (HAVE_WINDOW_SYSTEM) && ! defined (HAVE_EXT_TOOL_BAR)
771
  /* Clear the matrix of the tool-bar window, if any.  */
772 773
  if (WINDOWP (f->tool_bar_window))
    clear_glyph_matrix (XWINDOW (f->tool_bar_window)->current_matrix);
774
#endif
Gerd Moellmann's avatar
Gerd Moellmann committed
775 776

  /* Clear current window matrices.  */
777
  eassert (WINDOWP (FRAME_ROOT_WINDOW (f)));
Gerd Moellmann's avatar
Gerd Moellmann committed
778 779 780 781 782 783 784
  clear_window_matrices (XWINDOW (FRAME_ROOT_WINDOW (f)), 0);
}


/* Clear out all display lines of F for a coming redisplay.  */

void
785
clear_desired_matrices (register struct frame *f)
Gerd Moellmann's avatar
Gerd Moellmann committed
786 787 788
{
  if (f->desired_matrix)
    clear_glyph_matrix (f->desired_matrix);
789

790
#if defined (HAVE_X_WINDOWS) && ! defined (USE_X_TOOLKIT) && ! defined (USE_GTK)
791 792
  if (WINDOWP (f->menu_bar_window))
    clear_glyph_matrix (XWINDOW (f->menu_bar_window)->desired_matrix);
793
#endif
Gerd Moellmann's avatar
Gerd Moellmann committed
794

795
#if defined (HAVE_WINDOW_SYSTEM) && ! defined (HAVE_EXT_TOOL_BAR)
796 797
  if (WINDOWP (f->tool_bar_window))
    clear_glyph_matrix (XWINDOW (f->tool_bar_window)->desired_matrix);
798
#endif
Gerd Moellmann's avatar
Gerd Moellmann committed
799 800

  /* Do it for window matrices.  */
801
  eassert (WINDOWP (FRAME_ROOT_WINDOW (f)));
Gerd Moellmann's avatar
Gerd Moellmann committed
802 803 804 805
  clear_window_matrices (XWINDOW (FRAME_ROOT_WINDOW (f)), 1);
}


806 807
/* Clear matrices in window tree rooted in W.  If DESIRED_P,
   clear desired matrices, otherwise clear current matrices.  */
Gerd Moellmann's avatar
Gerd Moellmann committed
808 809

static void
810
clear_window_matrices (struct window *w, bool desired_p)
Gerd Moellmann's avatar
Gerd Moellmann committed
811 812 813
{
  while (w)
    {
814 815
      if (WINDOWP (w->contents))
	clear_window_matrices (XWINDOW (w->contents), desired_p);
Gerd Moellmann's avatar
Gerd Moellmann committed
816 817 818 819 820 821 822
      else
	{
	  if (desired_p)
	    clear_glyph_matrix (w->desired_matrix);
	  else
	    {
	      clear_glyph_matrix (w->current_matrix);
823
	      w->window_end_valid = 0;
Gerd Moellmann's avatar
Gerd Moellmann committed
824 825 826
	    }
	}

827
      w = NILP (w->next) ? 0 : XWINDOW (w->next);
Gerd Moellmann's avatar
Gerd Moellmann committed
828 829 830 831 832 833 834 835 836 837 838
    }
}



/***********************************************************************
			      Glyph Rows

      See dispextern.h for an overall explanation of glyph rows.
 ***********************************************************************/

839 840
/* Clear glyph row ROW.  NOTE: this code relies on the current
   layout of `glyphs' and `used' fields of `struct glyph_row'.  */
841

Gerd Moellmann's avatar
Gerd Moellmann committed
842
void
843
clear_glyph_row (struct glyph_row *row)
Gerd Moellmann's avatar
Gerd Moellmann committed
844
{
845
  enum { off = offsetof (struct glyph_row, used) };
846 847

  /* Zero everything except pointers in `glyphs'.  */
848
  memset (row->used, 0, sizeof *row - off);
Gerd Moellmann's avatar
Gerd Moellmann committed
849 850 851 852 853 854 855
}


/* Make ROW an empty, enabled row of canonical character height,
   in window W starting at y-position Y.  */

void
856
blank_row (struct window *w, struct glyph_row *row, int y)
Gerd Moellmann's avatar
Gerd Moellmann committed
857 858
{
  int min_y, max_y;
859

860 861
  min_y = WINDOW_HEADER_LINE_HEIGHT (w);
  max_y = WINDOW_BOX_HEIGHT_NO_MODE_LINE (w);
862

Gerd Moellmann's avatar
Gerd Moellmann committed
863 864
  clear_glyph_row (row);
  row->y = y;
865
  row->ascent = row->phys_ascent = 0;
866
  row->height = row->phys_height = FRAME_LINE_HEIGHT (XFRAME (w->frame));
867
  row->visible_height = row->height;
868

Gerd Moellmann's avatar
Gerd Moellmann committed
869
  if (row->y < min_y)
870 871 872
    row->visible_height -= min_y - row->y;
  if (row->y + row->height > max_y)
    row->visible_height -= row->y + row->height - max_y;
Gerd Moellmann's avatar
Gerd Moellmann committed
873

874
  row->enabled_p = true;
Gerd Moellmann's avatar
Gerd Moellmann committed
875 876 877 878 879 880 881 882 883
}


/* Increment buffer positions in glyph row ROW.  DELTA and DELTA_BYTES
   are the amounts by which to change positions.  Note that the first
   glyph of the text area of a row can have a buffer position even if
   the used count of the text area is zero.  Such rows display line
   ends.  */

884
static void
885
increment_row_positions (struct glyph_row *row,
886
			 ptrdiff_t delta, ptrdiff_t delta_bytes)
Gerd Moellmann's avatar
Gerd Moellmann committed
887 888 889 890 891 892 893 894
{
  int area, i;

  /* Increment start and end positions.  */
  MATRIX_ROW_START_CHARPOS (row) += delta;
  MATRIX_ROW_START_BYTEPOS (row) += delta_bytes;
  MATRIX_ROW_END_CHARPOS (row) += delta;
  MATRIX_ROW_END_BYTEPOS (row) += delta_bytes;
895 896 897 898
  CHARPOS (row->start.pos) += delta;
  BYTEPOS (row->start.pos) += delta_bytes;
  CHARPOS (row->end.pos) += delta;
  BYTEPOS (row->end.pos) += delta_bytes;
Gerd Moellmann's avatar
Gerd Moellmann committed
899

900 901 902
  if (!row->enabled_p)
    return;

Gerd Moellmann's avatar
Gerd Moellmann committed
903 904 905 906 907 908 909 910 911 912 913 914 915 916
  /* Increment positions in glyphs.  */
  for (area = 0; area < LAST_AREA; ++area)
    for (i = 0; i < row->used[area]; ++i)
      if (BUFFERP (row->glyphs[area][i].object)
	  && row->glyphs[area][i].charpos > 0)
	row->glyphs[area][i].charpos += delta;

  /* Capture the case of rows displaying a line end.  */
  if (row->used[TEXT_AREA] == 0
      && MATRIX_ROW_DISPLAYS_TEXT_P (row))
    row->glyphs[TEXT_AREA]->charpos += delta;
}


917
#if 0
Gerd Moellmann's avatar
Gerd Moellmann committed
918 919 920 921 922
/* Swap glyphs between two glyph rows A and B.  This exchanges glyph
   contents, i.e. glyph structure contents are exchanged between A and
   B without changing glyph pointers in A and B.  */

static void
Andreas Schwab's avatar
Andreas Schwab committed
923
swap_glyphs_in_rows (struct glyph_row *a, struct glyph_row *b)
Gerd Moellmann's avatar
Gerd Moellmann committed
924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954
{
  int area;

  for (area = 0; area < LAST_AREA; ++area)
    {
      /* Number of glyphs to swap.  */
      int max_used = max (a->used[area], b->used[area]);

      /* Start of glyphs in area of row A.  */
      struct glyph *glyph_a = a->glyphs[area];

      /* End + 1 of glyphs in area of row A.  */
      struct glyph *glyph_a_end = a->glyphs[max_used];

      /* Start of glyphs in area of row B.  */
      struct glyph *glyph_b = b->glyphs[area];

      while (glyph_a < glyph_a_end)
	{
	  /* Non-ISO HP/UX compiler doesn't like auto struct
             initialization.  */
	  struct glyph temp;
	  temp = *glyph_a;
	  *glyph_a = *glyph_b;
	  *glyph_b = temp;
	  ++glyph_a;
	  ++glyph_b;
	}
    }
}

955
#endif /* 0 */
Gerd Moellmann's avatar
Gerd Moellmann committed
956

957 958 959 960
/* Exchange pointers to glyph memory between glyph rows A and B.  Also
   exchange the used[] array and the hash values of the rows, because
   these should all go together for the row's hash value to be
   correct.  */
Gerd Moellmann's avatar
Gerd Moellmann committed
961

962
static void
963
swap_glyph_pointers (struct glyph_row *a, struct glyph_row *b)
Gerd Moellmann's avatar
Gerd Moellmann committed
964 965
{
  int i;
966 967
  unsigned hash_tem = a->hash;

Gerd Moellmann's avatar
Gerd Moellmann committed
968 969 970
  for (i = 0; i < LAST_AREA + 1; ++i)
    {
      struct glyph *temp = a->glyphs[i];
971

Gerd Moellmann's avatar
Gerd Moellmann committed
972 973
      a->glyphs[i] = b->glyphs[i];
      b->glyphs[i] = temp;
974 975 976 977 978 979 980
      if (i < LAST_AREA)
	{
	  short used_tem = a->used[i];

	  a->used[i] = b->used[i];
	  b->used[i] = used_tem;
	}
Gerd Moellmann's avatar
Gerd Moellmann committed
981
    }
982 983
  a->hash = b->hash;
  b->hash = hash_tem;
Gerd Moellmann's avatar
Gerd Moellmann committed
984 985 986
}


987 988 989 990
/* Copy glyph row structure FROM to glyph row structure TO, except that
   glyph pointers, the `used' counts, and the hash values in the structures
   are left unchanged.  NOTE: this code relies on the current layout of
   `glyphs', `used', `hash' and `x' fields of `struct glyph_row'.  */
Gerd Moellmann's avatar
Gerd Moellmann committed
991

992
static void
993
copy_row_except_pointers (struct glyph_row *to, struct glyph_row *from)
Gerd Moellmann's avatar
Gerd Moellmann committed
994
{
995
  enum { off = offsetof (struct glyph_row, x) };
996

997
  memcpy (&to->x, &from->x, sizeof *to - off);
Gerd Moellmann's avatar
Gerd Moellmann committed
998 999 1000 1001 1002 1003 1004 1005
}


/* Assign glyph row FROM to glyph row TO.  This works like a structure
   assignment TO = FROM, except that glyph pointers are not copied but
   exchanged between TO and FROM.  Pointers must be exchanged to avoid
   a memory leak.  */

1006
static void
1007
assign_row (struct glyph_row *to, struct glyph_row *from)
Gerd Moellmann's avatar
Gerd Moellmann committed
1008 1009 1010 1011 1012 1013 1014 1015 1016
{
  swap_glyph_pointers (to, from);
  copy_row_except_pointers (to, from);
}


/* Test whether the glyph memory of the glyph row WINDOW_ROW, which is
   a row in a window matrix, is a slice of the glyph memory of the
   glyph row FRAME_ROW which is a row in a frame glyph matrix.  Value
1017
   is true if the glyph memory of WINDOW_ROW is part of the glyph
Gerd Moellmann's avatar
Gerd Moellmann committed
1018 1019
   memory of FRAME_ROW.  */

1020
#ifdef GLYPH_DEBUG
1021

1022