dispnew.c 199 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, 1997-2020 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"
Jim Blandy's avatar
Jim Blandy committed
28
#include "termchar.h"
29
/* cm.h must come after dispextern.h on Windows.  */
30 31
#include "dispextern.h"
#include "cm.h"
32
#include "buffer.h"
33
#include "keyboard.h"
Jim Blandy's avatar
Jim Blandy committed
34
#include "frame.h"
35
#include "termhooks.h"
Jim Blandy's avatar
Jim Blandy committed
36 37 38
#include "window.h"
#include "commands.h"
#include "disptab.h"
Richard M. Stallman's avatar
Richard M. Stallman committed
39
#include "blockinput.h"
Richard M. Stallman's avatar
Richard M. Stallman committed
40
#include "syssignal.h"
41
#include "systime.h"
Paul Eggert's avatar
Paul Eggert committed
42
#include "tparam.h"
Paul Eggert's avatar
Paul Eggert committed
43
#include "xwidget.h"
Daniel Colascione's avatar
Daniel Colascione committed
44
#include "pdumper.h"
Jim Blandy's avatar
Jim Blandy committed
45

46 47 48
#ifdef HAVE_WINDOW_SYSTEM
#include TERM_HEADER
#endif /* HAVE_WINDOW_SYSTEM */
49

50 51
#include <errno.h>

Paul Eggert's avatar
Paul Eggert committed
52
#include <fpending.h>
53

54 55 56
#ifdef WINDOWSNT
#include "w32.h"
#endif
Gerd Moellmann's avatar
Gerd Moellmann committed
57 58 59 60 61 62 63 64 65 66 67 68 69

/* Structure to pass dimensions around.  Used for character bounding
   boxes, glyph matrix dimensions and alike.  */

struct dim
{
  int width;
  int height;
};


/* Function prototypes.  */

70
static void update_frame_line (struct frame *, int, bool);
Andreas Schwab's avatar
Andreas Schwab committed
71 72
static int required_matrix_height (struct window *);
static int required_matrix_width (struct window *);
73
static void increment_row_positions (struct glyph_row *, ptrdiff_t, ptrdiff_t);
74 75 76 77 78 79
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 *);
80
static void clear_window_matrices (struct window *, bool);
81
static void fill_up_glyph_row_area_with_spaces (struct glyph_row *, int);
82
static int scrolling_window (struct window *, int);
83
static bool update_window_line (struct window *, int, bool *);
84
static void mirror_make_current (struct window *, int);
85
#ifdef GLYPH_DEBUG
86 87
static void check_matrix_pointers (struct glyph_matrix *,
                                   struct glyph_matrix *);
88
#endif
89
static void mirror_line_dance (struct window *, int, int, int *, char *);
90 91
static bool update_window_tree (struct window *, bool);
static bool update_window (struct window *, bool);
92
static bool update_frame_1 (struct frame *, bool, bool, bool, bool);
93
static bool scrolling (struct frame *);
94 95 96
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 *);
97
static void set_window_update_flags (struct window *w, bool on_p);
Jim Blandy's avatar
Jim Blandy committed
98

99
/* True means last display completed.  False means it was preempted.  */
Jim Blandy's avatar
Jim Blandy committed
100

101
bool display_completed;
Jim Blandy's avatar
Jim Blandy committed
102

103
/* True means SIGWINCH happened when not safe.  */
Jim Blandy's avatar
Jim Blandy committed
104

105
static bool delayed_size_change;
Jim Blandy's avatar
Jim Blandy committed
106

Gerd Moellmann's avatar
Gerd Moellmann committed
107
/* A glyph for a space.  */
Jim Blandy's avatar
Jim Blandy committed
108

Gerd Moellmann's avatar
Gerd Moellmann committed
109
struct glyph space_glyph;
Jim Blandy's avatar
Jim Blandy committed
110

111 112
#if defined GLYPH_DEBUG && defined ENABLE_CHECKING

Gerd Moellmann's avatar
Gerd Moellmann committed
113 114
/* Counts of allocated structures.  These counts serve to diagnose
   memory leaks and double frees.  */
Jim Blandy's avatar
Jim Blandy committed
115

116 117
static int glyph_matrix_count;
static int glyph_pool_count;
Jim Blandy's avatar
Jim Blandy committed
118

119 120
#endif /* GLYPH_DEBUG and ENABLE_CHECKING */

Gerd Moellmann's avatar
Gerd Moellmann committed
121 122
/* If non-null, the frame whose frame matrices are manipulated.  If
   null, window matrices are worked on.  */
Jim Blandy's avatar
Jim Blandy committed
123

Gerd Moellmann's avatar
Gerd Moellmann committed
124
static struct frame *frame_matrix_frame;
Jim Blandy's avatar
Jim Blandy committed
125

126
/* Convert vpos and hpos from frame to window and vice versa.
Gerd Moellmann's avatar
Gerd Moellmann committed
127
   This may only be used for terminal frames.  */
128

129
#ifdef GLYPH_DEBUG
Jim Blandy's avatar
Jim Blandy committed
130

131 132
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
133 134
#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
135

136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158
/* 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.  */

Paul Eggert's avatar
Paul Eggert committed
159
static uintmax_t history_tick;
Richard M. Stallman's avatar
Richard M. Stallman committed
160

161 162
/* Add to the redisplay history how window W has been displayed.
   MSG is a trace containing the information how W's glyph matrix
163
   has been constructed.  PAUSED_P means that the update
164 165 166
   has been interrupted for pending input.  */

static void
167
add_window_display_history (struct window *w, const char *msg, bool paused_p)
168 169
{
  char *buf;
Paul Eggert's avatar
Paul Eggert committed
170
  void *ptr = w;
171

172 173 174 175
  if (history_idx >= REDISPLAY_HISTORY_SIZE)
    history_idx = 0;
  buf = redisplay_history[history_idx].trace;
  ++history_idx;
Joakim Verona's avatar
Joakim Verona committed
176

177
  snprintf (buf, sizeof redisplay_history[0].trace,
Paul Eggert's avatar
Paul Eggert committed
178
	    "%"PRIuMAX": window %p (%s)%s\n%s",
179
	    history_tick++,
Paul Eggert's avatar
Paul Eggert committed
180
	    ptr,
181 182 183
	    ((BUFFERP (w->contents)
	      && STRINGP (BVAR (XBUFFER (w->contents), name)))
	     ? SSDATA (BVAR (XBUFFER (w->contents), name))
184 185 186
	     : "???"),
	    paused_p ? " ***paused***" : "",
	    msg);
Joakim Verona's avatar
Joakim Verona committed
187
}
188 189 190


/* Add to the redisplay history that frame F has been displayed.
191
   PAUSED_P means that the update has been interrupted for
192 193
   pending input.  */

jave's avatar
jave committed
194 195
static void
add_frame_display_history (struct frame *f, bool paused_p)
196 197
{
  char *buf;
Paul Eggert's avatar
Paul Eggert committed
198
  void *ptr = f;
199

200 201 202 203
  if (history_idx >= REDISPLAY_HISTORY_SIZE)
    history_idx = 0;
  buf = redisplay_history[history_idx].trace;
  ++history_idx;
204

Paul Eggert's avatar
Paul Eggert committed
205
  sprintf (buf, "%"PRIuMAX": update frame %p%s",
206
	   history_tick++,
Paul Eggert's avatar
Paul Eggert committed
207
	   ptr, paused_p ? " ***paused***" : "");
208 209 210 211 212
}


DEFUN ("dump-redisplay-history", Fdump_redisplay_history,
       Sdump_redisplay_history, 0, 0, "",
213
       doc: /* Dump redisplay history to stderr.  */)
Dan Nicolaescu's avatar
Dan Nicolaescu committed
214
  (void)
215 216 217 218 219 220 221 222 223 224 225 226 227 228
{
  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;
}


229
#else /* not GLYPH_DEBUG */
Jim Blandy's avatar
Jim Blandy committed
230

231 232
#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
233

234
#endif /* GLYPH_DEBUG */
Jim Blandy's avatar
Jim Blandy committed
235 236


237
#if defined PROFILING && !HAVE___EXECUTABLE_START
238 239
/* 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
240
void
241
__executable_start (void)
Jim Blandy's avatar
Jim Blandy committed
242
{
243
  emacs_abort ();
244
}
245
#endif
Gerd Moellmann's avatar
Gerd Moellmann committed
246 247 248 249 250 251 252 253 254 255 256

/***********************************************************************
			    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.  */

257
static struct glyph_matrix *
258
new_glyph_matrix (struct glyph_pool *pool)
Jim Blandy's avatar
Jim Blandy committed
259
{
Dmitry Antipov's avatar
Dmitry Antipov committed
260
  struct glyph_matrix *result = xzalloc (sizeof *result);
Jim Blandy's avatar
Jim Blandy committed
261

262
#if defined GLYPH_DEBUG && defined ENABLE_CHECKING
Gerd Moellmann's avatar
Gerd Moellmann committed
263 264 265
  /* Increment number of allocated matrices.  This count is used
     to detect memory leaks.  */
  ++glyph_matrix_count;
266
#endif
Jim Blandy's avatar
Jim Blandy committed
267

Gerd Moellmann's avatar
Gerd Moellmann committed
268 269 270
  /* Set pool and return.  */
  result->pool = pool;
  return result;
Jim Blandy's avatar
Jim Blandy committed
271 272 273
}


Gerd Moellmann's avatar
Gerd Moellmann committed
274 275
/* Free glyph matrix MATRIX.  Passing in a null MATRIX is allowed.

276 277 278 279
   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.
280

Gerd Moellmann's avatar
Gerd Moellmann committed
281 282 283 284 285
   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
286
free_glyph_matrix (struct glyph_matrix *matrix)
Jim Blandy's avatar
Jim Blandy committed
287
{
Gerd Moellmann's avatar
Gerd Moellmann committed
288 289 290 291
  if (matrix)
    {
      int i;

292
#if defined GLYPH_DEBUG && defined ENABLE_CHECKING
Gerd Moellmann's avatar
Gerd Moellmann committed
293 294
      /* Detect the case that more matrices are freed than were
	 allocated.  */
295 296 297
      --glyph_matrix_count;
      eassert (glyph_matrix_count >= 0);
#endif
Gerd Moellmann's avatar
Gerd Moellmann committed
298 299 300 301 302

      /* 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]);
303

Gerd Moellmann's avatar
Gerd Moellmann committed
304 305 306 307 308
      /* Free row structures and the matrix itself.  */
      xfree (matrix->rows);
      xfree (matrix);
    }
}
Jim Blandy's avatar
Jim Blandy committed
309 310


Gerd Moellmann's avatar
Gerd Moellmann committed
311 312 313
/* 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
314
   area in canonical character units.  */
Gerd Moellmann's avatar
Gerd Moellmann committed
315 316

static int
317
margin_glyphs_to_reserve (struct window *w, int total_glyphs, int margin)
Gerd Moellmann's avatar
Gerd Moellmann committed
318
{
319
  if (margin > 0)
Jim Blandy's avatar
Jim Blandy committed
320
    {
321
      int width = w->total_cols;
322
      double d = max (0, margin);
Gerd Moellmann's avatar
Gerd Moellmann committed
323
      d = min (width / 2 - 1, d);
324 325 326
      /* 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
327
    }
328
  return 0;
Gerd Moellmann's avatar
Gerd Moellmann committed
329 330
}

331
/* Return true if ROW's hash value is correct.
332 333
   Optimized away if ENABLE_CHECKING is not defined.  */

334
static bool
335 336
verify_row_hash (struct glyph_row *row)
{
337
  return row->hash == row_hash (row);
338
}
Jim Blandy's avatar
Jim Blandy committed
339

Gerd Moellmann's avatar
Gerd Moellmann committed
340 341
/* Adjust glyph matrix MATRIX on window W or on a frame to changed
   window sizes.
Jim Blandy's avatar
Jim Blandy committed
342

Gerd Moellmann's avatar
Gerd Moellmann committed
343 344 345 346 347
   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.
348

Gerd Moellmann's avatar
Gerd Moellmann committed
349 350 351 352
   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.
353

Gerd Moellmann's avatar
Gerd Moellmann committed
354 355 356 357 358 359 360
   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.  */
361

Gerd Moellmann's avatar
Gerd Moellmann committed
362
static void
363
adjust_glyph_matrix (struct window *w, struct glyph_matrix *matrix, int x, int y, struct dim dim)
Gerd Moellmann's avatar
Gerd Moellmann committed
364 365 366
{
  int i;
  int new_rows;
367
  bool marginal_areas_changed_p = 0;
368 369
  bool tab_line_changed_p = 0;
  bool tab_line_p = 0;
370 371
  bool header_line_changed_p = 0;
  bool header_line_p = 0;
Gerd Moellmann's avatar
Gerd Moellmann committed
372
  int left = -1, right = -1;
373
  int window_width = -1, window_height = -1;
Gerd Moellmann's avatar
Gerd Moellmann committed
374

Kenichi Handa's avatar
Kenichi Handa committed
375 376
  /* 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
377 378
  if (w)
    {
Joakim Verona's avatar
Joakim Verona committed
379
      window_box (w, ANY_AREA, 0, 0, &window_width, &window_height);
Kenichi Handa's avatar
Kenichi Handa committed
380

381 382 383
      tab_line_p = window_wants_tab_line (w);
      tab_line_changed_p = tab_line_p != matrix->tab_line_p;

384
      header_line_p = window_wants_header_line (w);
Gerd Moellmann's avatar
Change  
Gerd Moellmann committed
385
      header_line_changed_p = header_line_p != matrix->header_line_p;
Gerd Moellmann's avatar
Gerd Moellmann committed
386
    }
387
  matrix->tab_line_p = tab_line_p;
Gerd Moellmann's avatar
Change  
Gerd Moellmann committed
388
  matrix->header_line_p = header_line_p;
389

Kenichi Handa's avatar
Kenichi Handa committed
390 391
  /* 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
392 393
     haven't changed.  This optimization is important because preserving
     the matrix means preventing redisplay.  */
394
  eassume (w != NULL || matrix->pool != NULL);
Gerd Moellmann's avatar
Gerd Moellmann committed
395 396
  if (matrix->pool == NULL)
    {
397 398
      left = margin_glyphs_to_reserve (w, dim.width, w->left_margin_cols);
      right = margin_glyphs_to_reserve (w, dim.width, w->right_margin_cols);
399
      eassert (left >= 0 && right >= 0);
Gerd Moellmann's avatar
Gerd Moellmann committed
400 401 402 403
      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
404
	  && !XFRAME (w->frame)->fonts_changed
405
	  && !tab_line_changed_p
Gerd Moellmann's avatar
Change  
Gerd Moellmann committed
406
	  && !header_line_changed_p
407 408
	  && 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
409 410 411 412 413
	  && matrix->window_height == window_height
	  && matrix->window_vscroll == w->vscroll
	  && matrix->window_width == window_width)
	return;
    }
414

Gerd Moellmann's avatar
Gerd Moellmann committed
415 416 417
  /* Enlarge MATRIX->rows if necessary.  New rows are cleared.  */
  if (matrix->rows_allocated < dim.height)
    {
418
      int old_alloc = matrix->rows_allocated;
Gerd Moellmann's avatar
Gerd Moellmann committed
419
      new_rows = dim.height - matrix->rows_allocated;
420 421 422 423
      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
424 425 426
    }
  else
    new_rows = 0;
427

Gerd Moellmann's avatar
Gerd Moellmann committed
428 429 430 431 432
  /* 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)
    {
433
      eassert (matrix->pool->glyphs);
434

Gerd Moellmann's avatar
Gerd Moellmann committed
435
      if (w)
436
	{
Gerd Moellmann's avatar
Gerd Moellmann committed
437
	  left = margin_glyphs_to_reserve (w, dim.width,
438
					   w->left_margin_cols);
Gerd Moellmann's avatar
Gerd Moellmann committed
439
	  right = margin_glyphs_to_reserve (w, dim.width,
440
					    w->right_margin_cols);
441
	}
Gerd Moellmann's avatar
Gerd Moellmann committed
442 443
      else
	left = right = 0;
444

Gerd Moellmann's avatar
Gerd Moellmann committed
445
      for (i = 0; i < dim.height; ++i)
446
	{
Gerd Moellmann's avatar
Gerd Moellmann committed
447
	  struct glyph_row *row = &matrix->rows[i];
448 449

	  row->glyphs[LEFT_MARGIN_AREA]
Gerd Moellmann's avatar
Gerd Moellmann committed
450 451 452
	    = (matrix->pool->glyphs
	       + (y + i) * matrix->pool->ncolumns
	       + x);
453

Gerd Moellmann's avatar
Gerd Moellmann committed
454
	  if (w == NULL
455
	      || (row == matrix->rows + dim.height - 1
456
		  && window_wants_mode_line (w))
457
	      || (row == matrix->rows && matrix->tab_line_p)
458 459 460 461
	      || (row == matrix->rows
		  && !matrix->tab_line_p && matrix->header_line_p)
	      || (row == (matrix->rows + 1)
		  && matrix->tab_line_p && matrix->header_line_p))
Gerd Moellmann's avatar
Gerd Moellmann committed
462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478
	    {
	      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;
	    }
479
	}
480

Gerd Moellmann's avatar
Gerd Moellmann committed
481 482 483 484 485 486
      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
487 488
	 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
489 490
      if (dim.width > matrix->matrix_w
	  || new_rows
491
	  || tab_line_changed_p
Gerd Moellmann's avatar
Change  
Gerd Moellmann committed
492
	  || header_line_changed_p
Gerd Moellmann's avatar
Gerd Moellmann committed
493
	  || marginal_areas_changed_p)
Jim Blandy's avatar
Jim Blandy committed
494
	{
Gerd Moellmann's avatar
Gerd Moellmann committed
495 496
	  struct glyph_row *row = matrix->rows;
	  struct glyph_row *end = row + matrix->rows_allocated;
497

Gerd Moellmann's avatar
Gerd Moellmann committed
498 499 500
	  while (row < end)
	    {
	      row->glyphs[LEFT_MARGIN_AREA]
501 502
		= xnrealloc (row->glyphs[LEFT_MARGIN_AREA],
			     dim.width, sizeof (struct glyph));
503

504 505
	      /* The mode line, if displayed, never has marginal areas.  */
	      if ((row == matrix->rows + dim.height - 1
506
		   && !(w && window_wants_mode_line (w)))
507
		  || (row == matrix->rows && matrix->tab_line_p)
508 509 510 511
		  || (row == matrix->rows
		      && !matrix->tab_line_p && matrix->header_line_p)
		  || (row == (matrix->rows + 1)
		      && matrix->tab_line_p && matrix->header_line_p))
Gerd Moellmann's avatar
Gerd Moellmann committed
512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530
		{
		  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
531 532
	}

533
      eassert (left >= 0 && right >= 0);
Gerd Moellmann's avatar
Gerd Moellmann committed
534 535
      matrix->left_margin_glyphs = left;
      matrix->right_margin_glyphs = right;
536 537 538 539

      /* If we are resizing a window, make sure the previous mode-line
	 row of the window's current matrix is no longer marked as such.  */
      if (w && matrix == w->current_matrix
540
	  && matrix->nrows > 0
541 542 543
	  && dim.height != matrix->nrows
	  && matrix->nrows <= matrix->rows_allocated)
	MATRIX_MODE_LINE_ROW (matrix)->mode_line_p = false;
Gerd Moellmann's avatar
Gerd Moellmann committed
544
    }
545

Gerd Moellmann's avatar
Gerd Moellmann committed
546 547
  /* Number of rows to be used by MATRIX.  */
  matrix->nrows = dim.height;
548
  eassert (matrix->nrows >= 0);
Gerd Moellmann's avatar
Gerd Moellmann committed
549

550
  if (w)
Gerd Moellmann's avatar
Gerd Moellmann committed
551
    {
552
      if (matrix == w->current_matrix)
Jim Blandy's avatar
Jim Blandy committed
553
	{
554 555 556 557 558 559
	  /* 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);
560

561 562 563 564
	  /* 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
565
	      && !tab_line_changed_p
566 567 568
	      && !header_line_changed_p
	      && new_rows == 0
	      && dim.width == matrix->matrix_w
569 570
	      && matrix->window_pixel_left == WINDOW_LEFT_PIXEL_EDGE (w)
	      && matrix->window_pixel_top == WINDOW_TOP_PIXEL_EDGE (w)
571
	      && matrix->window_width == window_width)
572
	    {
573 574 575 576
	      /* 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)
		  {
577
		    ++i;
578 579
		    break;
		  }
580 581

	      /* Window end is invalid, if inside of the rows that
582
		 are invalidated below.  */
583
	      if (w->window_end_vpos >= i)
584
		w->window_end_valid = 0;
585

586
	      while (i < matrix->nrows)
587
		matrix->rows[i++].enabled_p = false;
588 589 590 591
	    }
	  else
	    {
	      for (i = 0; i < matrix->nrows; ++i)
592
		matrix->rows[i].enabled_p = false;
593
	    }
594 595 596 597
	  /* 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.  */
598
	  if (window_wants_mode_line (w))
599
	    w->update_mode_line = 1;
Gerd Moellmann's avatar
Gerd Moellmann committed
600
	}
601
      else if (matrix == w->desired_matrix)
Gerd Moellmann's avatar
Gerd Moellmann committed
602
	{
603 604 605 606
	  /* 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
607
	  for (i = 0; i < matrix->nrows; ++i)
608
	    matrix->rows[i].enabled_p = false;
Jim Blandy's avatar
Jim Blandy committed
609 610
	}
    }
611 612


Gerd Moellmann's avatar
Gerd Moellmann committed
613 614 615 616 617 618 619 620 621
  /* 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
622
    {
623 624
      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
625 626 627 628 629
      matrix->window_height = window_height;
      matrix->window_width = window_width;
      matrix->window_vscroll = w->vscroll;
    }
}
Jim Blandy's avatar
Jim Blandy committed
630 631


Gerd Moellmann's avatar
Gerd Moellmann committed
632 633 634 635
/* 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).  */
636

Gerd Moellmann's avatar
Gerd Moellmann committed
637
static void
638
reverse_rows (struct glyph_matrix *matrix, int start, int end)
Gerd Moellmann's avatar
Gerd Moellmann committed
639 640
{
  int i, j;
641

Gerd Moellmann's avatar
Gerd Moellmann committed
642 643 644 645 646 647 648 649 650 651
  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;
    }
}
652 653


Gerd Moellmann's avatar
Gerd Moellmann committed
654 655 656 657
/* 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).
658

Gerd Moellmann's avatar
Gerd Moellmann committed
659 660 661 662 663 664 665 666
   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
667
rotate_matrix (struct glyph_matrix *matrix, int first, int last, int by)
Gerd Moellmann's avatar
Gerd Moellmann committed
668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691
{
  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
692
increment_matrix_positions (struct glyph_matrix *matrix, int start, int end,
693
			    ptrdiff_t delta, ptrdiff_t delta_bytes)
Gerd Moellmann's avatar
Gerd Moellmann committed
694 695
{
  /* Check that START and END are reasonable values.  */
696 697 698
  eassert (start >= 0 && start <= matrix->nrows);
  eassert (end >= 0 && end <= matrix->nrows);
  eassert (start <= end);
Gerd Moellmann's avatar
Gerd Moellmann committed
699 700

  for (; start < end; ++start)
701
    increment_row_positions (matrix->rows + start, delta, delta_bytes);
Gerd Moellmann's avatar
Gerd Moellmann committed
702 703 704
}


705 706
/* 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
707 708

void
709
clear_glyph_matrix_rows (struct glyph_matrix *matrix, int start, int end)
Gerd Moellmann's avatar
Gerd Moellmann committed
710
{
711
  eassert (start <= end);
Chris Feng's avatar
Chris Feng committed
712 713 714
  eassert (start >= 0 && (start < matrix->nrows
			  /* matrix->nrows can be 0 for the initial frame.  */
			  || (matrix->nrows == 0)));
715
  eassert (end >= 0 && end <= matrix->nrows);
716

Gerd Moellmann's avatar
Gerd Moellmann committed
717
  for (; start < end; ++start)
718
    matrix->rows[start].enabled_p = false;
Gerd Moellmann's avatar
Gerd Moellmann committed
719 720 721 722 723
}


/* Clear MATRIX.

724 725 726
   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
727

728
   Reset update hints to default values.  The only update hint
Gerd Moellmann's avatar
Gerd Moellmann committed
729 730 731
   currently present is the flag MATRIX->no_scrolling_p.  */

void
732
clear_glyph_matrix (struct glyph_matrix *matrix)
Gerd Moellmann's avatar
Gerd Moellmann committed
733 734 735
{
  if (matrix)
    {
736
      clear_glyph_matrix_rows (matrix, 0, matrix->nrows);
Gerd Moellmann's avatar
Gerd Moellmann committed
737 738 739
      matrix->no_scrolling_p = 0;
    }
}
740

Gerd Moellmann's avatar
Gerd Moellmann committed
741 742 743 744 745 746

/* 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
747
shift_glyph_matrix (struct window *w, struct glyph_matrix *matrix, int start, int end, int dy)
Gerd Moellmann's avatar
Gerd Moellmann committed
748 749
{
  int min_y, max_y;
750

751 752 753
  eassert (start <= end);
  eassert (start >= 0 && start < matrix->nrows);
  eassert (end >= 0 && end <= matrix->nrows);
754

755
  min_y = WINDOW_TAB_LINE_HEIGHT (w) + WINDOW_HEADER_LINE_HEIGHT (w);
756
  max_y = WINDOW_BOX_HEIGHT_NO_MODE_LINE (w);
757

Gerd Moellmann's avatar
Gerd Moellmann committed
758 759 760
  for (; start < end; ++start)
    {
      struct glyph_row *row = &matrix->rows[start];
761

Gerd Moellmann's avatar
Gerd Moellmann committed
762
      row->y += dy;
763
      row->visible_height = row->height;
764

Gerd Moellmann's avatar
Gerd Moellmann committed
765
      if (row->y < min_y)
766 767 768
	row->visible_height -= min_y - row->y;
      if (row->y + row->height > max_y)
	row->visible_height -= row->y + row->height - max_y;
769 770
      if (row->fringe_bitmap_periodic_p)
	row->redraw_fringe_bitmaps_p = 1;
Gerd Moellmann's avatar
Gerd Moellmann committed
771 772 773 774 775 776 777 778 779
    }
}


/* 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
780
clear_current_matrices (register struct frame *f)
Gerd Moellmann's avatar
Gerd Moellmann committed
781 782 783 784 785
{
  /* Clear frame current matrix, if we have one.  */
  if (f->current_matrix)
    clear_glyph_matrix (f->current_matrix);

786
#if defined (HAVE_X_WINDOWS) && ! defined (USE_X_TOOLKIT) && ! defined (USE_GTK)
Gerd Moellmann's avatar
Gerd Moellmann committed
787 788 789
  /* 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.  */
790 791
  if (WINDOWP (f->menu_bar_window))
    clear_glyph_matrix (XWINDOW (f->menu_bar_window)->current_matrix);
792
#endif
Gerd Moellmann's avatar
Gerd Moellmann committed
793

794 795 796 797 798 799
#if defined (HAVE_WINDOW_SYSTEM)
  /* Clear the matrix of the tab-bar window, if any.  */
  if (WINDOWP (f->tab_bar_window))
    clear_glyph_matrix (XWINDOW (f->tab_bar_window)->current_matrix);
#endif

800
#if defined (HAVE_WINDOW_SYSTEM) && ! defined (HAVE_EXT_TOOL_BAR)
801
  /* Clear the matrix of the tool-bar window, if any.  */
802 803
  if (WINDOWP (f->tool_bar_window))
    clear_glyph_matrix (XWINDOW (f->tool_bar_window)->current_matrix);
804
#endif
Gerd Moellmann's avatar
Gerd Moellmann committed
805 806

  /* Clear current window matrices.  */
807
  eassert (WINDOWP (FRAME_ROOT_WINDOW (f)));
Gerd Moellmann's avatar
Gerd Moellmann committed
808 809 810 811 812 813 814
  clear_window_matrices (XWINDOW (FRAME_ROOT_WINDOW (f)), 0);
}


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

void
815
clear_desired_matrices (register struct frame *f)
Gerd Moellmann's avatar
Gerd Moellmann committed
816 817 818
{
  if (f->desired_matrix)
    clear_glyph_matrix (f->desired_matrix);
819

820
#if defined (HAVE_X_WINDOWS) && ! defined (USE_X_TOOLKIT) && ! defined (USE_GTK)
821 822
  if (WINDOWP (f->menu_bar_window))
    clear_glyph_matrix (XWINDOW (f->menu_bar_window)->desired_matrix);
823
#endif
Gerd Moellmann's avatar
Gerd Moellmann committed
824

825 826 827 828 829
#if defined (HAVE_WINDOW_SYSTEM)
  if (WINDOWP (f->tab_bar_window))
    clear_glyph_matrix (XWINDOW (f->tab_bar_window)->desired_matrix);
#endif

830
#if defined (HAVE_WINDOW_SYSTEM) && ! defined (HAVE_EXT_TOOL_BAR)
831 832
  if (WINDOWP (f->tool_bar_window))
    clear_glyph_matrix (XWINDOW (f->tool_bar_window)->desired_matrix);
833
#endif
Gerd Moellmann's avatar
Gerd Moellmann committed
834 835

  /* Do it for window matrices.  */
836
  eassert (WINDOWP (FRAME_ROOT_WINDOW (f)));
Gerd Moellmann's avatar
Gerd Moellmann committed
837 838 839 840
  clear_window_matrices (XWINDOW (FRAME_ROOT_WINDOW (f)), 1);
}


841 842
/* 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
843 844

static void
845
clear_window_matrices (struct window *w, bool desired_p)
Gerd Moellmann's avatar
Gerd Moellmann committed
846 847 848
{
  while (w)
    {
849 850
      if (WINDOWP (w->contents))
	clear_window_matrices (XWINDOW (w->contents), desired_p);
Gerd Moellmann's avatar
Gerd Moellmann committed
851 852 853 854 855 856 857
      else
	{
	  if (desired_p)
	    clear_glyph_matrix (w->desired_matrix);
	  else
	    {
	      clear_glyph_matrix (w->current_matrix);
858
	      w->window_end_valid = 0;
Gerd Moellmann's avatar
Gerd Moellmann committed
859 860 861
	    }
	}

862
      w = NILP (w->next) ? 0 : XWINDOW (w->next);
Gerd Moellmann's avatar
Gerd Moellmann committed
863 864 865 866 867 868 869 870 871 872 873
    }
}


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

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

874 875
/* Clear glyph row ROW.  NOTE: this code relies on the current
   layout of `glyphs' and `used' fields of `struct glyph_row'.  */
876

Gerd Moellmann's avatar
Gerd Moellmann committed
877
void
878
clear_glyph_row (struct glyph_row *row)
Gerd Moellmann's avatar
Gerd Moellmann committed
879
{
880
  enum { off = offsetof (struct glyph_row, used) };
881 882

  /* Zero everything except pointers in `glyphs'.  */
Paul Eggert's avatar
Paul Eggert committed
883
  memset ((char *) row + off, 0, sizeof *row - off);
Gerd Moellmann's avatar
Gerd Moellmann committed
884 885 886 887 888 889 890
}


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

void
891
blank_row (struct window *w, struct glyph_row *row, int y)
Gerd Moellmann's avatar
Gerd Moellmann committed
892 893
{
  int min_y, max_y;
894

895
  min_y = WINDOW_TAB_LINE_HEIGHT (w) + WINDOW_HEADER_LINE_HEIGHT (w);
896
  max_y = WINDOW_BOX_HEIGHT_NO_MODE_LINE (w);
897

Gerd Moellmann's avatar
Gerd Moellmann committed
898 899
  clear_glyph_row (row);
  row->y = y;
900
  row->ascent = row->phys_ascent = 0;
901
  row->height = row->phys_height = FRAME_LINE_HEIGHT (XFRAME (w->frame));
902
  row->visible_height = row->height;
903

Gerd Moellmann's avatar
Gerd Moellmann committed
904
  if (row->y < min_y)
905 906 907
    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
908

909
  row->enabled_p = true;
Gerd Moellmann's avatar
Gerd Moellmann committed
910 911 912 913 914 915 916 917 918
}


/* 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.  */

919
static void
920
increment_row_positions (struct glyph_row *row,
921
			 ptrdiff_t delta, ptrdiff_t delta_bytes)
Gerd Moellmann's avatar
Gerd Moellmann committed
922 923 924 925 926 927 928 929
{
  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;
930 931 932 933
  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
934

935 936 937
  if (!row->enabled_p)
    return;

Gerd Moellmann's avatar
Gerd Moellmann committed
938 939 940 941 942 943 944 945 946 947 948 949 950 951
  /* 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;
}


952
#if 0
Gerd Moellmann's avatar
Gerd Moellmann committed
953 954 955 956 957
/* 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
958
swap_glyphs_in_rows (struct glyph_row *a, struct glyph_row *b)
Gerd Moellmann's avatar
Gerd Moellmann committed
959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989
{
  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;
	}
    }
}

990
#endif /* 0 */
Gerd Moellmann's avatar
Gerd Moellmann committed
991

992 993 994 995
/* 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
996

997
static void
998
swap_glyph_pointers (struct glyph_row *a, struct glyph_row *b)
Gerd Moellmann's avatar
Gerd Moellmann committed
999 1000
{
  int i;
1001 1002
  unsigned hash_tem = a->hash;

Gerd Moellmann's avatar
Gerd Moellmann committed
1003 1004 1005
  for (i = 0; i < LAST_AREA + 1; ++i)
    {
      struct glyph *temp = a->glyphs[i];
1006

Gerd Moellmann's avatar
Gerd Moellmann committed
1007 1008
      a->glyphs[i] = b->glyphs[i];
      b->glyphs[i] = temp;
1009 1010 1011 1012 1013 1014 1015
      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
1016
    }
1017 1018
  a->hash = b->hash;
  b->hash = hash_tem;
Gerd Moellmann's avatar
Gerd Moellmann committed
1019 1020 1021
}


1022 1023 1024 1025
/* 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
1026

1027
static void
1028
copy_row_except_pointers (struct glyph_row *to, struct glyph_row *from)
Gerd Moellmann's avatar
Gerd Moellmann committed
1029
{
1030
  enum { off = offsetof (struct glyph_row, x) };
1031

1032
  memcpy (&to->x, &from->x, sizeof *to - off);
Gerd Moellmann's avatar
Gerd Moellmann committed
1033 1034 1035 1036 1037 1038 1039 1040
}


/* 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.  */

1041
static void
1042
assign_row (struct glyph_row *to, struct glyph_row *from)
Gerd Moellmann's avatar
Gerd Moellmann committed
1043 1044 1045 1046 1047 1048 1049 1050 1051
{
  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
1052
   is true if the glyph memory of WINDOW_ROW is part of the glyph
Gerd Moellmann's avatar
Gerd Moellmann committed
1053 1054
   memory of FRAME_ROW.  */

1055