1 /* PSPP - a program for statistical analysis.
2 Copyright (C) 2009, 2010, 2011, 2013, 2014, 2016 Free Software Foundation, Inc.
4 This program is free software: you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation, either version 3 of the License, or
7 (at your option) any later version.
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program. If not, see <http://www.gnu.org/licenses/>. */
25 #include "libpspp/assertion.h"
26 #include "libpspp/hash-functions.h"
27 #include "libpspp/hmap.h"
28 #include "libpspp/pool.h"
29 #include "output/render.h"
30 #include "output/tab.h"
31 #include "output/table-item.h"
32 #include "output/table.h"
34 #include "gl/minmax.h"
35 #include "gl/xalloc.h"
38 #define _(msgid) gettext (msgid)
40 /* This file uses TABLE_HORZ and TABLE_VERT enough to warrant abbreviating. */
44 /* A layout for rendering a specific table on a specific device.
46 May represent the layout of an entire table presented to
47 render_page_create(), or a rectangular subregion of a table broken out using
48 render_break_next() to allow a table to be broken across multiple pages.
50 A page's size is not limited to the size passed in as part of render_params.
51 render_pager breaks a render_page into smaller render_pages that will fit in
52 the available space. */
55 const struct render_params *params; /* Parameters of the target device. */
56 struct table *table; /* Table rendered. */
59 /* Region of 'table' to render.
61 The horizontal cells rendered are the leftmost h[H][0], then
62 r[H][0] through r[H][1], exclusive, then the rightmost h[H][1].
64 The vertical cells rendered are the topmost h[V][0], then r[V][0]
65 through r[V][1], exclusive, then the bottommost h[V][1].
67 n[H] = h[H][0] + (r[H][1] - r[H][0]) + h[H][1]
68 n[V] = h[V][0] + (r[V][1] - r[V][0]) + h[V][1]
70 int h[TABLE_N_AXES][2];
71 int r[TABLE_N_AXES][2];
76 cp[H] represents x positions within the table.
78 cp[H][1] = the width of the leftmost vertical rule.
79 cp[H][2] = cp[H][1] + the width of the leftmost column.
80 cp[H][3] = cp[H][2] + the width of the second-from-left vertical rule.
82 cp[H][2 * nc] = x position of the rightmost vertical rule.
83 cp[H][2 * nc + 1] = total table width including all rules.
85 Similarly, cp[V] represents y positions within the table.
87 cp[V][1] = the height of the topmost horizontal rule.
88 cp[V][2] = cp[V][1] + the height of the topmost row.
89 cp[V][3] = cp[V][2] + the height of the second-from-top horizontal rule.
91 cp[V][2 * nr] = y position of the bottommost horizontal rule.
92 cp[V][2 * nr + 1] = total table height including all rules.
94 Rules and columns can have width or height 0, in which case consecutive
95 values in this array are equal. */
96 int *cp[TABLE_N_AXES];
98 /* render_break_next() can break a table such that some cells are not fully
99 contained within a render_page. This will happen if a cell is too wide
100 or two tall to fit on a single page, or if a cell spans multiple rows or
101 columns and the page only includes some of those rows or columns.
103 This hash table contains "struct render_overflow"s that represents each
104 such cell that doesn't completely fit on this page.
106 Each overflow cell borders at least one header edge of the table and may
107 border more. (A single table cell that is so large that it fills the
108 entire page can overflow on all four sides!) */
109 struct hmap overflows;
111 /* If a single column (or row) is too wide (or tall) to fit on a page
112 reasonably, then render_break_next() will split a single row or column
113 across multiple render_pages. This member indicates when this has
116 is_edge_cutoff[H][0] is true if pixels have been cut off the left side
117 of the leftmost column in this page, and false otherwise.
119 is_edge_cutoff[H][1] is true if pixels have been cut off the right side
120 of the rightmost column in this page, and false otherwise.
122 is_edge_cutoff[V][0] and is_edge_cutoff[V][1] are similar for the top
123 and bottom of the table.
125 The effect of is_edge_cutoff is to prevent rules along the edge in
126 question from being rendered.
128 When is_edge_cutoff is true for a given edge, the 'overflows' hmap will
129 contain a node for each cell along that edge. */
130 bool is_edge_cutoff[TABLE_N_AXES][2];
132 /* If part of a joined cell would be cut off by breaking a table along
133 'axis' at the rule with offset 'z' (where 0 <= z <= n[axis]), then
134 join_crossing[axis][z] is the thickness of the rule that would be cut
137 This is used to know to allocate extra space for breaking at such a
138 position, so that part of the cell's content is not lost.
140 This affects breaking a table only when headers are present. When
141 headers are not present, the rule's thickness is used for cell content,
142 so no part of the cell's content is lost (and in fact it is duplicated
143 across both pages). */
144 int *join_crossing[TABLE_N_AXES];
147 static struct render_page *render_page_create (const struct render_params *,
148 struct table *, int min_width);
150 struct render_page *render_page_ref (const struct render_page *page_);
151 static void render_page_unref (struct render_page *);
153 /* Returns the offset in struct render_page's cp[axis] array of the rule with
154 index RULE_IDX. That is, if RULE_IDX is 0, then the offset is that of the
155 leftmost or topmost rule; if RULE_IDX is 1, then the offset is that of the
156 next rule to the right (or below); and so on. */
158 rule_ofs (int rule_idx)
163 /* Returns the offset in struct render_page's cp[axis] array of the rule with
164 index RULE_IDX_R, which counts from the right side (or bottom) of the page
165 left (or up), according to whether AXIS is H or V, respectively. That is,
166 if RULE_IDX_R is 0, then the offset is that of the rightmost or bottommost
167 rule; if RULE_IDX is 1, then the offset is that of the next rule to the left
168 (or above); and so on. */
170 rule_ofs_r (const struct render_page *page, int axis, int rule_idx_r)
172 return (page->n[axis] - rule_idx_r) * 2;
175 /* Returns the offset in struct render_page's cp[axis] array of the cell with
176 index CELL_IDX. That is, if CELL_IDX is 0, then the offset is that of the
177 leftmost or topmost cell; if CELL_IDX is 1, then the offset is that of the
178 next cell to the right (or below); and so on. */
180 cell_ofs (int cell_idx)
182 return cell_idx * 2 + 1;
185 /* Returns the width of PAGE along AXIS from OFS0 to OFS1, exclusive. */
187 axis_width (const struct render_page *page, int axis, int ofs0, int ofs1)
189 return page->cp[axis][ofs1] - page->cp[axis][ofs0];
192 /* Returns the width of the headers in PAGE along AXIS. */
194 headers_width (const struct render_page *page, int axis)
196 int h0 = page->h[axis][0];
197 int w0 = axis_width (page, axis, rule_ofs (0), cell_ofs (h0));
198 int n = page->n[axis];
199 int h1 = page->h[axis][1];
200 int w1 = axis_width (page, axis, rule_ofs_r (page, axis, h1), cell_ofs (n));
204 /* Returns the width of cell X along AXIS in PAGE. */
206 cell_width (const struct render_page *page, int axis, int x)
208 return axis_width (page, axis, cell_ofs (x), cell_ofs (x) + 1);
211 /* Returns the width of rule X along AXIS in PAGE. */
213 rule_width (const struct render_page *page, int axis, int x)
215 return axis_width (page, axis, rule_ofs (x), rule_ofs (x) + 1);
218 /* Returns the width of rule X along AXIS in PAGE. */
220 rule_width_r (const struct render_page *page, int axis, int x)
222 int ofs = rule_ofs_r (page, axis, x);
223 return axis_width (page, axis, ofs, ofs + 1);
226 /* Returns the width of cells X0 through X1, exclusive, along AXIS in PAGE. */
228 joined_width (const struct render_page *page, int axis, int x0, int x1)
230 return axis_width (page, axis, cell_ofs (x0), cell_ofs (x1) - 1);
233 /* Returns the width of the widest cell, excluding headers, along AXIS in
236 max_cell_width (const struct render_page *page, int axis)
238 int n = page->n[axis];
239 int x0 = page->h[axis][0];
240 int x1 = n - page->h[axis][1];
243 for (int x = x0; x < x1; x++)
245 int w = cell_width (page, axis, x);
252 /* A cell that doesn't completely fit on the render_page. */
253 struct render_overflow
255 struct hmap_node node; /* In render_page's 'overflows' hmap. */
257 /* Occupied region of page.
259 d[H][0] is the leftmost column.
260 d[H][1] is the rightmost column, plus 1.
261 d[V][0] is the top row.
262 d[V][1] is the bottom row, plus 1.
264 The cell in its original table might occupy a larger region. This
265 member reflects the size of the cell in the current render_page, after
266 trimming off any rows or columns due to page-breaking. */
269 /* The space that has been trimmed off the cell:
271 overflow[H][0]: space trimmed off its left side.
272 overflow[H][1]: space trimmed off its right side.
273 overflow[V][0]: space trimmed off its top.
274 overflow[V][1]: space trimmed off its bottom.
276 During rendering, this information is used to position the rendered
277 portion of the cell within the available space.
279 When a cell is rendered, sometimes it is permitted to spill over into
280 space that is ordinarily reserved for rules. Either way, this space is
281 still included in overflow values.
283 Suppose, for example, that a cell that joins 2 columns has a width of 60
284 pixels and content "abcdef", that the 2 columns that it joins have
285 widths of 20 and 30 pixels, respectively, and that therefore the rule
286 between the two joined columns has a width of 10 (20 + 10 + 30 = 60).
287 It might render like this, if each character is 10x10, and showing a few
288 extra table cells for context:
296 If this render_page is broken at the rule that separates "gh" from
297 "ijk", then the page that contains the left side of the "abcdef" cell
298 will have overflow[H][1] of 10 + 30 = 40 for its portion of the cell,
299 and the page that contains the right side of the cell will have
300 overflow[H][0] of 20 + 10 = 30. The two resulting pages would look like
318 int overflow[TABLE_N_AXES][2];
321 /* Returns a hash value for (,Y). */
323 hash_cell (int x, int y)
325 return hash_int (x + (y << 16), 0);
328 /* Searches PAGE's set of render_overflow for one whose top-left cell is
329 (X,Y). Returns it, if there is one, otherwise a null pointer. */
330 static const struct render_overflow *
331 find_overflow (const struct render_page *page, int x, int y)
333 if (!hmap_is_empty (&page->overflows))
335 const struct render_overflow *of;
337 HMAP_FOR_EACH_WITH_HASH (of, struct render_overflow, node,
338 hash_cell (x, y), &page->overflows)
339 if (x == of->d[H] && y == of->d[V])
346 /* Row or column dimensions. Used to figure the size of a table in
347 render_page_create() and discarded after that. */
350 /* Width without considering rows (or columns) that span more than one (or
354 /* Width taking spanned rows (or columns) into consideration. */
358 /* Modifies the 'width' members of the N elements of ROWS so that their sum,
359 when added to rule widths RULES[1] through RULES[N - 1] inclusive, is at
362 distribute_spanned_width (int width,
363 struct render_row *rows, const int *rules, int n)
365 /* Sum up the unspanned widths of the N rows for use as weights. */
366 int total_unspanned = 0;
367 for (int x = 0; x < n; x++)
368 total_unspanned += rows[x].unspanned;
369 for (int x = 0; x < n - 1; x++)
370 total_unspanned += rules[x + 1];
371 if (total_unspanned >= width)
374 /* The algorithm used here is based on the following description from HTML 4:
376 For cells that span multiple columns, a simple approach consists of
377 apportioning the min/max widths evenly to each of the constituent
378 columns. A slightly more complex approach is to use the min/max
379 widths of unspanned cells to weight how spanned widths are
380 apportioned. Experiments suggest that a blend of the two approaches
381 gives good results for a wide range of tables.
383 We blend the two approaches half-and-half, except that we cannot use the
384 unspanned weights when 'total_unspanned' is 0 (because that would cause a
387 The calculation we want to do is this:
390 w1 = width * (column's unspanned width) / (total unspanned width)
391 (column's width) = (w0 + w1) / 2
393 We implement it as a precise calculation in integers by multiplying w0 and
394 w1 by the common denominator of all three calculations (d), dividing that
395 out in the column width calculation, and then keeping the remainder for
398 (We actually compute the unspanned width of a column as twice the
399 unspanned width, plus the width of the rule on the left, plus the width of
400 the rule on the right. That way each rule contributes to both the cell on
401 its left and on its right.)
403 long long int d0 = n;
404 long long int d1 = 2LL * MAX (total_unspanned, 1);
405 long long int d = d0 * d1;
406 if (total_unspanned > 0)
408 long long int w = d / 2;
409 for (int x = 0; x < n; x++)
412 if (total_unspanned > 0)
414 long long int unspanned = rows[x].unspanned * 2LL;
416 unspanned += rules[x + 1];
418 unspanned += rules[x];
419 w += width * unspanned * d0;
422 rows[x].width = MAX (rows[x].width, w / d);
423 w -= rows[x].width * d;
427 /* Initializes PAGE->cp[AXIS] from the row widths in ROWS and the rule widths
430 accumulate_row_widths (const struct render_page *page, enum table_axis axis,
431 const struct render_row *rows, const int *rules)
433 int n = page->n[axis];
434 int *cp = page->cp[axis];
436 for (int z = 0; z < n; z++)
438 cp[1] = cp[0] + rules[z];
439 cp[2] = cp[1] + rows[z].width;
442 cp[1] = cp[0] + rules[n];
445 /* Returns the sum of widths of the N ROWS and N+1 RULES. */
447 calculate_table_width (int n, const struct render_row *rows, int *rules)
450 for (int x = 0; x < n; x++)
451 width += rows[x].width;
452 for (int x = 0; x <= n; x++)
458 /* Rendering utility functions. */
460 /* Returns the line style to use for drawing a rule of the given TYPE. */
461 static enum render_line_style
462 rule_to_render_type (unsigned char type)
467 return RENDER_LINE_NONE;
469 return RENDER_LINE_SINGLE;
471 return RENDER_LINE_DASHED;
473 return RENDER_LINE_THICK;
475 return RENDER_LINE_THIN;
477 return RENDER_LINE_DOUBLE;
483 /* Returns the width of the rule in TABLE that is at offset Z along axis A, if
484 rendered with PARAMS. */
486 measure_rule (const struct render_params *params, const struct table *table,
487 enum table_axis a, int z)
489 enum table_axis b = !a;
491 /* Determine all types of rules that are present, as a bitmap in 'rules'
492 where rule type 't' is present if bit 2**t is set. */
493 struct cell_color color;
494 unsigned int rules = 0;
497 for (d[b] = 0; d[b] < table->n[b]; d[b]++)
498 rules |= 1u << table_get_rule (table, a, d[H], d[V], &color);
500 /* Turn off TAL_NONE because it has width 0 and we needn't bother. However,
501 if the device doesn't support margins, make sure that there is at least a
502 small gap between cells (but we don't need any at the left or right edge
504 if (rules & (1u << TAL_NONE))
506 rules &= ~(1u << TAL_NONE);
507 if (z > 0 && z < table->n[a] && !params->supports_margins && a == H)
508 rules |= 1u << TAL_SOLID;
511 /* Calculate maximum width of the rules that are present. */
513 for (size_t i = 0; i < TABLE_N_STROKES; i++)
514 if (rules & (1u << i))
515 width = MAX (width, params->line_widths[a][rule_to_render_type (i)]);
519 /* Allocates and returns a new render_page using PARAMS and TABLE. Allocates
520 space for rendering a table with dimensions given in N. The caller must
521 initialize most of the members itself. */
522 static struct render_page *
523 render_page_allocate__ (const struct render_params *params,
524 struct table *table, int n[TABLE_N_AXES])
526 struct render_page *page = xmalloc (sizeof *page);
527 page->params = params;
533 for (int i = 0; i < TABLE_N_AXES; i++)
535 page->cp[i] = xmalloc ((2 * n[i] + 2) * sizeof *page->cp[i]);
536 page->join_crossing[i] = xzalloc ((n[i] + 1)
537 * sizeof *page->join_crossing[i]);
540 hmap_init (&page->overflows);
541 memset (page->is_edge_cutoff, 0, sizeof page->is_edge_cutoff);
546 /* Allocates and returns a new render_page using PARAMS and TABLE. Allocates
547 space for all of the members of the new page, but the caller must initialize
548 the 'cp' member itself. */
549 static struct render_page *
550 render_page_allocate (const struct render_params *params, struct table *table)
552 struct render_page *page = render_page_allocate__ (params, table, table->n);
553 for (enum table_axis a = 0; a < TABLE_N_AXES; a++)
555 page->h[a][0] = table->h[a][0];
556 page->h[a][1] = table->h[a][1];
557 page->r[a][0] = table->h[a][0];
558 page->r[a][1] = table->n[a] - table->h[a][1];
563 /* Allocates and returns a new render_page for PARAMS and TABLE, initializing
564 cp[H] in the new page from ROWS and RULES. The caller must still initialize
566 static struct render_page *
567 create_page_with_exact_widths (const struct render_params *params,
569 const struct render_row *rows, int *rules)
571 struct render_page *page = render_page_allocate (params, table);
572 accumulate_row_widths (page, H, rows, rules);
576 /* Allocates and returns a new render_page for PARAMS and TABLE.
578 Initializes cp[H] in the new page by setting the width of each row 'i' to
579 somewhere between the minimum cell width ROW_MIN[i].width and the maximum
580 ROW_MAX[i].width. Sets the width of rules to those in RULES.
582 W_MIN is the sum of ROWS_MIN[].width.
584 W_MAX is the sum of ROWS_MAX[].width.
586 The caller must still initialize cp[V]. */
587 static struct render_page *
588 create_page_with_interpolated_widths (const struct render_params *params,
590 const struct render_row *rows_min,
591 const struct render_row *rows_max,
592 int w_min, int w_max, const int *rules)
594 const int n = table->n[H];
595 const long long int avail = params->size[H] - w_min;
596 const long long int wanted = w_max - w_min;
600 struct render_page *page = render_page_allocate (params, table);
602 int *cph = page->cp[H];
604 long long int w = wanted / 2;
605 for (int x = 0; x < n; x++)
607 w += avail * (rows_max[x].width - rows_min[x].width);
608 int extra = w / wanted;
611 cph[1] = cph[0] + rules[x];
612 cph[2] = cph[1] + rows_min[x].width + extra;
615 cph[1] = cph[0] + rules[n];
617 assert (page->cp[H][n * 2 + 1] == params->size[H]);
622 set_join_crossings (struct render_page *page, enum table_axis axis,
623 const struct table_cell *cell, int *rules)
625 for (int z = cell->d[axis][0] + 1; z <= cell->d[axis][1] - 1; z++)
626 page->join_crossing[axis][z] = rules[z];
629 /* Maps a contiguous range of cells from a page to the underlying table along
630 the horizpntal or vertical dimension. */
633 int p0; /* First ordinate in the page. */
634 int t0; /* First ordinate in the table. */
635 int n; /* Number of ordinates in page and table. */
638 /* Initializes M to a mapping from PAGE to PAGE->table along axis A. The
639 mapping includes ordinate Z (in PAGE). */
641 get_map (const struct render_page *page, enum table_axis a, int z,
644 if (z < page->h[a][0])
648 m->n = page->h[a][0];
650 else if (z < page->n[a] - page->h[a][1])
652 m->p0 = page->h[a][0];
653 m->t0 = page->r[a][0];
654 m->n = page->r[a][1] - page->r[a][0];
658 m->p0 = page->n[a] - page->h[a][1];
659 m->t0 = page->table->n[a] - page->table->h[a][1];
660 m->n = page->h[a][1];
664 /* Initializes CELL with the contents of the table cell at column X and row Y
665 within PAGE. When CELL is no longer needed, the caller is responsible for
666 freeing it by calling table_cell_free(CELL).
668 The caller must ensure that CELL is destroyed before TABLE is unref'ed.
670 This is equivalent to table_get_cell(), except X and Y are in terms of the
671 page's rows and columns rather than the underlying table's. */
673 render_get_cell (const struct render_page *page, int x, int y,
674 struct table_cell *cell)
676 int d[TABLE_N_AXES] = { [H] = x, [V] = y };
677 struct map map[TABLE_N_AXES];
679 for (enum table_axis a = 0; a < TABLE_N_AXES; a++)
681 struct map *m = &map[a];
682 get_map (page, a, d[a], m);
683 d[a] += m->t0 - m->p0;
685 table_get_cell (page->table, d[H], d[V], cell);
687 for (enum table_axis a = 0; a < TABLE_N_AXES; a++)
689 struct map *m = &map[a];
691 for (int i = 0; i < 2; i++)
692 cell->d[a][i] -= m->t0 - m->p0;
693 cell->d[a][0] = MAX (cell->d[a][0], m->p0);
694 cell->d[a][1] = MIN (cell->d[a][1], m->p0 + m->n);
698 /* Creates and returns a new render_page for rendering TABLE on a device
701 The new render_page will be suitable for rendering on a device whose page
702 size is PARAMS->size, but the caller is responsible for actually breaking it
703 up to fit on such a device, using the render_break abstraction. */
704 static struct render_page *
705 render_page_create (const struct render_params *params, struct table *table,
710 int nc = table_nc (table);
711 int nr = table_nr (table);
713 /* Figure out rule widths. */
714 int *rules[TABLE_N_AXES];
715 for (enum table_axis axis = 0; axis < TABLE_N_AXES; axis++)
717 int n = table->n[axis] + 1;
719 rules[axis] = xnmalloc (n, sizeof *rules);
720 for (int z = 0; z < n; z++)
721 rules[axis][z] = measure_rule (params, table, axis, z);
724 /* Calculate minimum and maximum widths of cells that do not
725 span multiple columns. */
726 struct render_row *columns[2];
727 for (int i = 0; i < 2; i++)
728 columns[i] = xzalloc (nc * sizeof *columns[i]);
729 for (int y = 0; y < nr; y++)
730 for (int x = 0; x < nc; )
732 struct table_cell cell;
734 table_get_cell (table, x, y, &cell);
735 if (y == cell.d[V][0])
737 if (table_cell_colspan (&cell) == 1)
740 params->measure_cell_width (params->aux, &cell,
742 for (int i = 0; i < 2; i++)
743 if (columns[i][x].unspanned < w[i])
744 columns[i][x].unspanned = w[i];
750 /* Distribute widths of spanned columns. */
751 for (int i = 0; i < 2; i++)
752 for (int x = 0; x < nc; x++)
753 columns[i][x].width = columns[i][x].unspanned;
754 for (int y = 0; y < nr; y++)
755 for (int x = 0; x < nc; )
757 struct table_cell cell;
759 table_get_cell (table, x, y, &cell);
760 if (y == cell.d[V][0] && table_cell_colspan (&cell) > 1)
764 params->measure_cell_width (params->aux, &cell, &w[MIN], &w[MAX]);
765 for (int i = 0; i < 2; i++)
766 distribute_spanned_width (w[i], &columns[i][cell.d[H][0]],
767 rules[H], table_cell_colspan (&cell));
772 for (int i = 0; i < 2; i++)
773 distribute_spanned_width (min_width, &columns[i][0], rules[H], nc);
775 /* In pathological cases, spans can cause the minimum width of a column to
776 exceed the maximum width. This bollixes our interpolation algorithm
777 later, so fix it up. */
778 for (int i = 0; i < nc; i++)
779 if (columns[MIN][i].width > columns[MAX][i].width)
780 columns[MAX][i].width = columns[MIN][i].width;
782 /* Decide final column widths. */
784 for (int i = 0; i < 2; i++)
785 table_widths[i] = calculate_table_width (table_nc (table),
786 columns[i], rules[H]);
788 struct render_page *page;
789 if (table_widths[MAX] <= params->size[H])
791 /* Fits even with maximum widths. Use them. */
792 page = create_page_with_exact_widths (params, table, columns[MAX],
795 else if (table_widths[MIN] <= params->size[H])
797 /* Fits with minimum widths, so distribute the leftover space. */
798 page = create_page_with_interpolated_widths (
799 params, table, columns[MIN], columns[MAX],
800 table_widths[MIN], table_widths[MAX], rules[H]);
804 /* Doesn't fit even with minimum widths. Assign minimums for now, and
805 later we can break it horizontally into multiple pages. */
806 page = create_page_with_exact_widths (params, table, columns[MIN],
810 /* Calculate heights of cells that do not span multiple rows. */
811 struct render_row *rows = xzalloc (nr * sizeof *rows);
812 for (int y = 0; y < nr; y++)
813 for (int x = 0; x < nc; )
815 struct render_row *r = &rows[y];
816 struct table_cell cell;
818 render_get_cell (page, x, y, &cell);
819 if (y == cell.d[V][0])
821 if (table_cell_rowspan (&cell) == 1)
823 int w = joined_width (page, H, cell.d[H][0], cell.d[H][1]);
824 int h = params->measure_cell_height (params->aux, &cell, w);
825 if (h > r->unspanned)
826 r->unspanned = r->width = h;
829 set_join_crossings (page, V, &cell, rules[V]);
831 if (table_cell_colspan (&cell) > 1)
832 set_join_crossings (page, H, &cell, rules[H]);
836 for (int i = 0; i < 2; i++)
839 /* Distribute heights of spanned rows. */
840 for (int y = 0; y < nr; y++)
841 for (int x = 0; x < nc; )
843 struct table_cell cell;
845 render_get_cell (page, x, y, &cell);
846 if (y == cell.d[V][0] && table_cell_rowspan (&cell) > 1)
848 int w = joined_width (page, H, cell.d[H][0], cell.d[H][1]);
849 int h = params->measure_cell_height (params->aux, &cell, w);
850 distribute_spanned_width (h, &rows[cell.d[V][0]], rules[V],
851 table_cell_rowspan (&cell));
856 /* Decide final row heights. */
857 accumulate_row_widths (page, V, rows, rules[V]);
860 /* Measure headers. If they are "too big", get rid of them. */
861 for (enum table_axis axis = 0; axis < TABLE_N_AXES; axis++)
863 int hw = headers_width (page, axis);
864 if (hw * 2 >= page->params->size[axis]
865 || hw + max_cell_width (page, axis) > page->params->size[axis])
867 page->h[axis][0] = page->h[axis][1] = 0;
868 page->r[axis][0] = 0;
869 page->r[axis][1] = page->n[axis];
879 /* Increases PAGE's reference count. */
881 render_page_ref (const struct render_page *page_)
883 struct render_page *page = CONST_CAST (struct render_page *, page_);
888 /* Decreases PAGE's reference count and destroys PAGE if this causes the
889 reference count to fall to zero. */
891 render_page_unref (struct render_page *page)
893 if (page != NULL && --page->ref_cnt == 0)
895 struct render_overflow *overflow, *next;
896 HMAP_FOR_EACH_SAFE (overflow, next, struct render_overflow, node,
899 hmap_destroy (&page->overflows);
901 table_unref (page->table);
903 for (int i = 0; i < TABLE_N_AXES; ++i)
905 free (page->join_crossing[i]);
913 /* Returns the size of PAGE along AXIS. (This might be larger than the page
914 size specified in the parameters passed to render_page_create(). Use a
915 render_break to break up a render_page into page-sized chunks.) */
917 render_page_get_size (const struct render_page *page, enum table_axis axis)
919 return page->cp[axis][page->n[axis] * 2 + 1];
923 render_page_get_best_breakpoint (const struct render_page *page, int height)
925 /* If there's no room for at least the top row and the rules above and below
926 it, don't include any of the table. */
927 if (page->cp[V][3] > height)
930 /* Otherwise include as many rows and rules as we can. */
931 for (int y = 5; y <= 2 * page->n[V] + 1; y += 2)
932 if (page->cp[V][y] > height)
933 return page->cp[V][y - 2];
937 /* Drawing render_pages. */
939 /* This is like table_get_rule() except:
941 - D is in terms of the page's rows and column rather than the underlying
944 - The result is in the form of a render_line_style. */
945 static enum render_line_style
946 get_rule (const struct render_page *page, enum table_axis axis,
947 const int d_[TABLE_N_AXES], struct cell_color *color)
949 int d[TABLE_N_AXES] = { d_[0] / 2, d_[1] / 2 };
952 enum table_axis a = axis;
953 if (d[a] < page->h[a][0])
955 else if (d[a] <= page->n[a] - page->h[a][1])
957 if (page->h[a][0] && d[a] == page->h[a][0])
959 else if (page->h[a][1] && d[a] == page->n[a] - page->h[a][1])
960 d2 = page->table->n[a] - page->h[a][1];
961 d[a] += page->r[a][0] - page->h[a][0];
964 d[a] += ((page->table->n[a] - page->table->h[a][1])
965 - (page->n[a] - page->h[a][1]));
967 enum table_axis b = !axis;
969 get_map (page, b, d[b], &m);
972 int r = table_get_rule (page->table, axis, d[H], d[V], color);
976 int r2 = table_get_rule (page->table, axis, d[H], d[V], color);
977 r = table_rule_combine (r, r2);
979 return rule_to_render_type (r);
989 render_direction_rtl (void)
991 /* TRANSLATORS: Do not translate this string. If the script of your language
992 reads from right to left (eg Persian, Arabic, Hebrew etc), then replace
993 this string with "output-direction-rtl". Otherwise either leave it
994 untranslated or copy it verbatim. */
995 const char *dir = _("output-direction-ltr");
996 if ( 0 == strcmp ("output-direction-rtl", dir))
999 if ( 0 != strcmp ("output-direction-ltr", dir))
1000 fprintf (stderr, "This localisation has been incorrectly translated. "
1001 "Complain to the translator.\n");
1007 render_rule (const struct render_page *page, const int ofs[TABLE_N_AXES],
1008 const int d[TABLE_N_AXES])
1010 enum render_line_style styles[TABLE_N_AXES][2];
1011 struct cell_color colors[TABLE_N_AXES][2];
1013 for (enum table_axis a = 0; a < TABLE_N_AXES; a++)
1015 enum table_axis b = !a;
1017 styles[a][0] = styles[a][1] = RENDER_LINE_NONE;
1020 || (page->is_edge_cutoff[a][0] && d[a] == 0)
1021 || (page->is_edge_cutoff[a][1] && d[a] == page->n[a] * 2))
1028 int e[TABLE_N_AXES];
1032 styles[a][0] = get_rule (page, a, e, &colors[a][0]);
1035 if (d[b] / 2 < page->n[b])
1036 styles[a][1] = get_rule (page, a, d, &colors[a][1]);
1040 styles[a][0] = styles[a][1] = get_rule (page, a, d, &colors[a][0]);
1041 colors[a][1] = colors[a][0];
1045 if (styles[H][0] != RENDER_LINE_NONE || styles[H][1] != RENDER_LINE_NONE
1046 || styles[V][0] != RENDER_LINE_NONE || styles[V][1] != RENDER_LINE_NONE)
1048 int bb[TABLE_N_AXES][2];
1050 bb[H][0] = ofs[H] + page->cp[H][d[H]];
1051 bb[H][1] = ofs[H] + page->cp[H][d[H] + 1];
1052 if (page->params->rtl)
1054 int temp = bb[H][0];
1055 bb[H][0] = render_page_get_size (page, H) - bb[H][1];
1056 bb[H][1] = render_page_get_size (page, H) - temp;
1058 bb[V][0] = ofs[V] + page->cp[V][d[V]];
1059 bb[V][1] = ofs[V] + page->cp[V][d[V] + 1];
1060 page->params->draw_line (page->params->aux, bb, styles, colors);
1065 render_cell (const struct render_page *page, const int ofs[TABLE_N_AXES],
1066 const struct table_cell *cell)
1068 int bb[TABLE_N_AXES][2];
1069 int clip[TABLE_N_AXES][2];
1071 bb[H][0] = clip[H][0] = ofs[H] + page->cp[H][cell->d[H][0] * 2 + 1];
1072 bb[H][1] = clip[H][1] = ofs[H] + page->cp[H][cell->d[H][1] * 2];
1073 if (page->params->rtl)
1075 int temp = bb[H][0];
1076 bb[H][0] = clip[H][0] = render_page_get_size (page, H) - bb[H][1];
1077 bb[H][1] = clip[H][1] = render_page_get_size (page, H) - temp;
1079 bb[V][0] = clip[V][0] = ofs[V] + page->cp[V][cell->d[V][0] * 2 + 1];
1080 bb[V][1] = clip[V][1] = ofs[V] + page->cp[V][cell->d[V][1] * 2];
1082 enum table_valign valign = cell->style->cell_style.valign;
1083 if (valign != TABLE_VALIGN_TOP)
1085 int height = page->params->measure_cell_height (
1086 page->params->aux, cell, bb[H][1] - bb[H][0]);
1087 int extra = bb[V][1] - bb[V][0] - height;
1090 if (valign == TABLE_VALIGN_CENTER)
1096 const struct render_overflow *of = find_overflow (
1097 page, cell->d[H][0], cell->d[V][0]);
1099 for (enum table_axis axis = 0; axis < TABLE_N_AXES; axis++)
1101 if (of->overflow[axis][0])
1103 bb[axis][0] -= of->overflow[axis][0];
1104 if (cell->d[axis][0] == 0 && !page->is_edge_cutoff[axis][0])
1105 clip[axis][0] = ofs[axis] + page->cp[axis][cell->d[axis][0] * 2];
1107 if (of->overflow[axis][1])
1109 bb[axis][1] += of->overflow[axis][1];
1110 if (cell->d[axis][1] == page->n[axis]
1111 && !page->is_edge_cutoff[axis][1])
1112 clip[axis][1] = ofs[axis] + page->cp[axis][cell->d[axis][1] * 2
1117 int spill[TABLE_N_AXES][2];
1118 for (enum table_axis axis = 0; axis < TABLE_N_AXES; axis++)
1120 spill[axis][0] = rule_width (page, axis, cell->d[axis][0]) / 2;
1121 spill[axis][1] = rule_width (page, axis, cell->d[axis][1]) / 2;
1124 int color_idx = (cell->d[V][0] < page->h[V][0]
1125 || page->n[V] - (cell->d[V][0] + 1) < page->h[V][1]
1127 : (cell->d[V][0] - page->h[V][0]) & 1);
1128 page->params->draw_cell (page->params->aux, cell, color_idx,
1132 /* Draws the cells of PAGE indicated in BB. */
1134 render_page_draw_cells (const struct render_page *page,
1135 int ofs[TABLE_N_AXES], int bb[TABLE_N_AXES][2])
1137 for (int y = bb[V][0]; y < bb[V][1]; y++)
1138 for (int x = bb[H][0]; x < bb[H][1]; )
1139 if (!is_rule (x) && !is_rule (y))
1141 struct table_cell cell;
1143 render_get_cell (page, x / 2, y / 2, &cell);
1144 if (y / 2 == bb[V][0] / 2 || y / 2 == cell.d[V][0])
1145 render_cell (page, ofs, &cell);
1146 x = rule_ofs (cell.d[H][1]);
1151 for (int y = bb[V][0]; y < bb[V][1]; y++)
1152 for (int x = bb[H][0]; x < bb[H][1]; x++)
1153 if (is_rule (x) || is_rule (y))
1155 int d[TABLE_N_AXES];
1158 render_rule (page, ofs, d);
1162 /* Renders PAGE, by calling the 'draw_line' and 'draw_cell' functions from the
1163 render_params provided to render_page_create(). */
1165 render_page_draw (const struct render_page *page, int ofs[TABLE_N_AXES])
1167 int bb[TABLE_N_AXES][2];
1170 bb[H][1] = page->n[H] * 2 + 1;
1172 bb[V][1] = page->n[V] * 2 + 1;
1174 render_page_draw_cells (page, ofs, bb);
1177 /* Returns the greatest value i, 0 <= i < n, such that cp[i] <= x0. */
1179 get_clip_min_extent (int x0, const int cp[], int n)
1186 int middle = low + (high - low) / 2;
1188 if (cp[middle] <= x0)
1200 /* Returns the least value i, 0 <= i < n, such that cp[i] >= x1. */
1202 get_clip_max_extent (int x1, const int cp[], int n)
1209 int middle = low + (high - low) / 2;
1211 if (cp[middle] >= x1)
1212 best = high = middle;
1217 while (best > 0 && cp[best - 1] == cp[best])
1223 /* Renders the cells of PAGE that intersect (X,Y)-(X+W,Y+H), by calling the
1224 'draw_line' and 'draw_cell' functions from the render_params provided to
1225 render_page_create(). */
1227 render_page_draw_region (const struct render_page *page,
1228 int ofs[TABLE_N_AXES], int clip[TABLE_N_AXES][2])
1230 int bb[TABLE_N_AXES][2];
1232 bb[H][0] = get_clip_min_extent (clip[H][0], page->cp[H], page->n[H] * 2 + 1);
1233 bb[H][1] = get_clip_max_extent (clip[H][1], page->cp[H], page->n[H] * 2 + 1);
1234 bb[V][0] = get_clip_min_extent (clip[V][0], page->cp[V], page->n[V] * 2 + 1);
1235 bb[V][1] = get_clip_max_extent (clip[V][1], page->cp[V], page->n[V] * 2 + 1);
1237 render_page_draw_cells (page, ofs, bb);
1240 /* Breaking up tables to fit on a page. */
1242 /* An iterator for breaking render_pages into smaller chunks. */
1245 struct render_page *page; /* Page being broken up. */
1246 enum table_axis axis; /* Axis along which 'page' is being broken. */
1247 int z; /* Next cell along 'axis'. */
1248 int pixel; /* Pixel offset within cell 'z' (usually 0). */
1249 int hw; /* Width of headers of 'page' along 'axis'. */
1252 static int needed_size (const struct render_break *, int cell);
1253 static bool cell_is_breakable (const struct render_break *, int cell);
1254 static struct render_page *render_page_select (const struct render_page *,
1259 /* Initializes render_break B for breaking PAGE along AXIS.
1260 Takes ownership of PAGE. */
1262 render_break_init (struct render_break *b, struct render_page *page,
1263 enum table_axis axis)
1267 b->z = page->h[axis][0];
1269 b->hw = headers_width (page, axis);
1272 /* Initializes B as a render_break structure for which
1273 render_break_has_next() always returns false. */
1275 render_break_init_empty (struct render_break *b)
1278 b->axis = TABLE_HORZ;
1284 /* Frees B and unrefs the render_page that it owns. */
1286 render_break_destroy (struct render_break *b)
1290 render_page_unref (b->page);
1295 /* Returns true if B still has cells that are yet to be returned,
1296 false if all of B's page has been processed. */
1298 render_break_has_next (const struct render_break *b)
1300 const struct render_page *page = b->page;
1301 enum table_axis axis = b->axis;
1303 return page != NULL && b->z < page->n[axis] - page->h[axis][1];
1306 /* Returns a new render_page that is up to SIZE pixels wide along B's axis.
1307 Returns a null pointer if B has already been completely broken up, or if
1308 SIZE is too small to reasonably render any cells. The latter will never
1309 happen if SIZE is at least as large as the page size passed to
1310 render_page_create() along B's axis. */
1311 static struct render_page *
1312 render_break_next (struct render_break *b, int size)
1314 const struct render_page *page = b->page;
1315 enum table_axis axis = b->axis;
1316 struct render_page *subpage;
1318 if (!render_break_has_next (b))
1323 for (z = b->z; z < page->n[axis] - page->h[axis][1]; z++)
1325 int needed = needed_size (b, z + 1);
1328 if (cell_is_breakable (b, z))
1330 /* If there is no right header and we render a partial cell on
1331 the right side of the body, then we omit the rightmost rule of
1332 the body. Otherwise the rendering is deceptive because it
1333 looks like the whole cell is present instead of a partial
1336 This is similar to code for the left side in needed_size(). */
1337 int rule_allowance = (page->h[axis][1]
1339 : rule_width (page, axis, z));
1341 /* The amount that, if we added cell 'z', the rendering would
1342 overfill the allocated 'size'. */
1343 int overhang = needed - size - rule_allowance;
1345 /* The width of cell 'z'. */
1346 int cell_size = cell_width (page, axis, z);
1348 /* The amount trimmed off the left side of 'z',
1349 and the amount left to render. */
1350 int cell_ofs = z == b->z ? b->pixel : 0;
1351 int cell_left = cell_size - cell_ofs;
1353 /* A small but visible width. */
1354 int em = page->params->font_size[axis];
1356 /* If some of the cell remains to render,
1357 and there would still be some of the cell left afterward,
1358 then partially render that much of the cell. */
1359 pixel = (cell_left && cell_left > overhang
1360 ? cell_left - overhang + cell_ofs
1363 /* If there would be only a tiny amount of the cell left after
1364 rendering it partially, reduce the amount rendered slightly
1365 to make the output look a little better. */
1366 if (pixel + em > cell_size)
1367 pixel = MAX (pixel - em, 0);
1369 /* If we're breaking vertically, then consider whether the cells
1370 being broken have a better internal breakpoint than the exact
1371 number of pixels available, which might look bad e.g. because
1372 it breaks in the middle of a line of text. */
1373 if (axis == TABLE_VERT && page->params->adjust_break)
1374 for (int x = 0; x < page->n[H]; )
1376 struct table_cell cell;
1378 render_get_cell (page, x, z, &cell);
1379 int w = joined_width (page, H, cell.d[H][0], cell.d[H][1]);
1380 int better_pixel = page->params->adjust_break (
1381 page->params->aux, &cell, w, pixel);
1384 if (better_pixel < pixel)
1386 if (better_pixel > (z == b->z ? b->pixel : 0))
1388 pixel = better_pixel;
1391 else if (better_pixel == 0 && z != b->z)
1403 if (z == b->z && !pixel)
1406 subpage = render_page_select (page, axis, b->z, b->pixel,
1408 pixel ? cell_width (page, axis, z) - pixel
1415 /* Returns the width that would be required along B's axis to render a page
1416 from B's current position up to but not including CELL. */
1418 needed_size (const struct render_break *b, int cell)
1420 const struct render_page *page = b->page;
1421 enum table_axis axis = b->axis;
1423 /* Width of left header not including its rightmost rule. */
1424 int size = axis_width (page, axis, 0, rule_ofs (page->h[axis][0]));
1426 /* If we have a pixel offset and there is no left header, then we omit the
1427 leftmost rule of the body. Otherwise the rendering is deceptive because
1428 it looks like the whole cell is present instead of a partial cell.
1430 Otherwise (if there are headers) we will be merging two rules: the
1431 rightmost rule in the header and the leftmost rule in the body. We assume
1432 that the width of a merged rule is the larger of the widths of either rule
1434 if (b->pixel == 0 || page->h[axis][0])
1435 size += MAX (rule_width (page, axis, page->h[axis][0]),
1436 rule_width (page, axis, b->z));
1438 /* Width of body, minus any pixel offset in the leftmost cell. */
1439 size += joined_width (page, axis, b->z, cell) - b->pixel;
1441 /* Width of rightmost rule in body merged with leftmost rule in headers. */
1442 size += MAX (rule_width_r (page, axis, page->h[axis][1]),
1443 rule_width (page, axis, cell));
1445 /* Width of right header not including its leftmost rule. */
1446 size += axis_width (page, axis, rule_ofs_r (page, axis, page->h[axis][1]),
1447 rule_ofs_r (page, axis, 0));
1449 /* Join crossing. */
1450 if (page->h[axis][0] && page->h[axis][1])
1451 size += page->join_crossing[axis][b->z];
1456 /* Returns true if CELL along B's axis may be broken across a page boundary.
1458 This is just a heuristic. Breaking cells across page boundaries can save
1459 space, but it looks ugly. */
1461 cell_is_breakable (const struct render_break *b, int cell)
1463 const struct render_page *page = b->page;
1464 enum table_axis axis = b->axis;
1466 return cell_width (page, axis, cell) >= page->params->min_break[axis];
1473 const struct render_params *params;
1475 struct render_page **pages;
1476 size_t n_pages, allocated_pages;
1479 struct render_break x_break;
1480 struct render_break y_break;
1483 static const struct render_page *
1484 render_pager_add_table (struct render_pager *p, struct table *table,
1487 if (p->n_pages >= p->allocated_pages)
1488 p->pages = x2nrealloc (p->pages, &p->allocated_pages, sizeof *p->pages);
1490 struct render_page *page = render_page_create (p->params, table, min_width);
1491 p->pages[p->n_pages++] = page;
1496 render_pager_start_page (struct render_pager *p)
1498 render_break_init (&p->x_break, render_page_ref (p->pages[p->cur_page++]),
1500 render_break_init_empty (&p->y_break);
1504 add_footnote_page (struct render_pager *p, const struct table_item *item)
1506 const struct footnote **f;
1507 size_t n_footnotes = table_collect_footnotes (item, &f);
1511 struct tab_table *t = tab_create (1, n_footnotes);
1512 for (size_t i = 0; i < n_footnotes; i++)
1514 tab_text_format (t, 0, i, TAB_LEFT, "%s. %s",
1515 f[i]->marker, f[i]->content);
1517 tab_add_style (t, 0, i, f[i]->style);
1519 render_pager_add_table (p, &t->table, 0);
1525 add_text_page (struct render_pager *p, const struct table_item_text *t,
1531 struct tab_table *tab = tab_create (1, 1);
1532 tab_text (tab, 0, 0, 0, t->content);
1533 for (size_t i = 0; i < t->n_footnotes; i++)
1534 tab_add_footnote (tab, 0, 0, t->footnotes[i]);
1536 tab->styles[0] = area_style_clone (tab->container, t->style);
1537 render_pager_add_table (p, &tab->table, min_width);
1541 add_layers_page (struct render_pager *p,
1542 const struct table_item_layers *layers, int min_width)
1547 struct tab_table *tab = tab_create (1, layers->n_layers);
1548 for (size_t i = 0; i < layers->n_layers; i++)
1550 const struct table_item_layer *layer = &layers->layers[i];
1551 tab_text (tab, 0, i, 0, layer->content);
1552 for (size_t j = 0; j < layer->n_footnotes; j++)
1553 tab_add_footnote (tab, 0, i, layer->footnotes[j]);
1556 tab->styles[0] = area_style_clone (tab->container, layers->style);
1557 render_pager_add_table (p, &tab->table, min_width);
1560 /* Creates and returns a new render_pager for rendering TABLE_ITEM on the
1561 device with the given PARAMS. */
1562 struct render_pager *
1563 render_pager_create (const struct render_params *params,
1564 const struct table_item *table_item)
1566 const struct table *table = table_item_get_table (table_item);
1568 struct render_pager *p = xzalloc (sizeof *p);
1571 struct render_page *page = render_page_create (params, table_ref (table), 0);
1572 struct render_break b;
1573 render_break_init (&b, page, H);
1574 struct render_page *subpage = render_break_next (&b, p->params->size[H]);
1575 int title_width = subpage ? subpage->cp[H][2 * subpage->n[H] + 1] : 0;
1576 render_page_unref (subpage);
1577 render_break_destroy (&b);
1580 add_text_page (p, table_item_get_title (table_item), title_width);
1583 add_layers_page (p, table_item_get_layers (table_item), title_width);
1586 render_pager_add_table (p, table_ref (table_item_get_table (table_item)), 0);
1589 add_text_page (p, table_item_get_caption (table_item), 0);
1592 add_footnote_page (p, table_item);
1594 render_pager_start_page (p);
1601 render_pager_destroy (struct render_pager *p)
1605 render_break_destroy (&p->x_break);
1606 render_break_destroy (&p->y_break);
1607 for (size_t i = 0; i < p->n_pages; i++)
1608 render_page_unref (p->pages[i]);
1614 /* Returns true if P has content remaining to render, false if rendering is
1617 render_pager_has_next (const struct render_pager *p_)
1619 struct render_pager *p = CONST_CAST (struct render_pager *, p_);
1621 while (!render_break_has_next (&p->y_break))
1623 render_break_destroy (&p->y_break);
1624 if (!render_break_has_next (&p->x_break))
1626 render_break_destroy (&p->x_break);
1627 if (p->cur_page >= p->n_pages)
1629 render_break_init_empty (&p->x_break);
1630 render_break_init_empty (&p->y_break);
1633 render_pager_start_page (p);
1637 &p->y_break, render_break_next (&p->x_break, p->params->size[H]), V);
1642 /* Draws a chunk of content from P to fit in a space that has vertical size
1643 SPACE and the horizontal size specified in the render_params passed to
1644 render_page_create(). Returns the amount of space actually used by the
1645 rendered chunk, which will be 0 if SPACE is too small to render anything or
1646 if no content remains (use render_pager_has_next() to distinguish these
1649 render_pager_draw_next (struct render_pager *p, int space)
1651 int ofs[TABLE_N_AXES] = { 0, 0 };
1652 size_t start_page = SIZE_MAX;
1654 while (render_pager_has_next (p))
1656 if (start_page == p->cur_page)
1658 start_page = p->cur_page;
1660 struct render_page *page
1661 = render_break_next (&p->y_break, space - ofs[V]);
1665 render_page_draw (page, ofs);
1666 ofs[V] += render_page_get_size (page, V);
1667 render_page_unref (page);
1672 /* Draws all of P's content. */
1674 render_pager_draw (const struct render_pager *p)
1676 render_pager_draw_region (p, 0, 0, INT_MAX, INT_MAX);
1679 /* Draws the region of P's content that lies in the region (X,Y)-(X+W,Y+H).
1680 Some extra content might be drawn; the device should perform clipping as
1683 render_pager_draw_region (const struct render_pager *p,
1684 int x, int y, int w, int h)
1686 int ofs[TABLE_N_AXES] = { 0, 0 };
1687 int clip[TABLE_N_AXES][2];
1691 for (size_t i = 0; i < p->n_pages; i++)
1693 const struct render_page *page = p->pages[i];
1694 int size = render_page_get_size (page, V);
1696 clip[V][0] = MAX (y, ofs[V]) - ofs[V];
1697 clip[V][1] = MIN (y + h, ofs[V] + size) - ofs[V];
1698 if (clip[V][1] > clip[V][0])
1699 render_page_draw_region (page, ofs, clip);
1705 /* Returns the size of P's content along AXIS; i.e. the content's width if AXIS
1706 is TABLE_HORZ and its length if AXIS is TABLE_VERT. */
1708 render_pager_get_size (const struct render_pager *p, enum table_axis axis)
1712 for (size_t i = 0; i < p->n_pages; i++)
1714 int subsize = render_page_get_size (p->pages[i], axis);
1715 size = axis == H ? MAX (size, subsize) : size + subsize;
1722 render_pager_get_best_breakpoint (const struct render_pager *p, int height)
1727 for (i = 0; i < p->n_pages; i++)
1729 int size = render_page_get_size (p->pages[i], V);
1730 if (y + size >= height)
1731 return render_page_get_best_breakpoint (p->pages[i], height - y) + y;
1738 /* render_page_select() and helpers. */
1740 struct render_page_selection
1742 const struct render_page *page; /* Page whose slice we are selecting. */
1743 struct render_page *subpage; /* New page under construction. */
1744 enum table_axis a; /* Axis of 'page' along which 'subpage' is a slice. */
1745 enum table_axis b; /* The opposite of 'a'. */
1746 int z0; /* First cell along 'a' being selected. */
1747 int z1; /* Last cell being selected, plus 1. */
1748 int p0; /* Number of pixels to trim off left side of z0. */
1749 int p1; /* Number of pixels to trim off right side of z1-1. */
1752 static void cell_to_subpage (struct render_page_selection *,
1753 const struct table_cell *,
1754 int subcell[TABLE_N_AXES]);
1755 static const struct render_overflow *find_overflow_for_cell (
1756 struct render_page_selection *, const struct table_cell *);
1757 static struct render_overflow *insert_overflow (struct render_page_selection *,
1758 const struct table_cell *);
1760 /* Creates and returns a new render_page whose contents are a subregion of
1761 PAGE's contents. The new render_page includes cells Z0 through Z1
1762 (exclusive) along AXIS, plus any headers on AXIS.
1764 If P0 is nonzero, then it is a number of pixels to exclude from the left or
1765 top (according to AXIS) of cell Z0. Similarly, P1 is a number of pixels to
1766 exclude from the right or bottom of cell Z1 - 1. (P0 and P1 are used to
1767 render cells that are too large to fit on a single page.)
1769 The whole of axis !AXIS is included. (The caller may follow up with another
1770 call to render_page_select() to select on !AXIS to select on that axis as
1773 The caller retains ownership of PAGE, which is not modified. */
1774 static struct render_page *
1775 render_page_select (const struct render_page *page, enum table_axis axis,
1776 int z0, int p0, int z1, int p1)
1778 enum table_axis a = axis;
1779 enum table_axis b = !a;
1781 /* Optimize case where all of PAGE is selected by just incrementing the
1783 if (z0 == page->h[a][0] && p0 == 0
1784 && z1 == page->n[a] - page->h[a][1] && p1 == 0)
1786 struct render_page *page_rw = CONST_CAST (struct render_page *, page);
1791 /* Allocate subpage. */
1792 int trim[2] = { z0 - page->h[a][0], (page->n[a] - page->h[a][1]) - z1 };
1793 int n[TABLE_N_AXES] = { [H] = page->n[H], [V] = page->n[V] };
1794 n[a] -= trim[0] + trim[1];
1795 struct render_page *subpage = render_page_allocate__ (
1796 page->params, table_ref (page->table), n);
1797 for (enum table_axis k = 0; k < TABLE_N_AXES; k++)
1799 subpage->h[k][0] = page->h[k][0];
1800 subpage->h[k][1] = page->h[k][1];
1801 subpage->r[k][0] = page->r[k][0];
1802 subpage->r[k][1] = page->r[k][1];
1804 subpage->r[a][0] += trim[0];
1805 subpage->r[a][1] -= trim[1];
1807 /* An edge is cut off if it was cut off in PAGE or if we're trimming pixels
1808 off that side of the page and there are no headers. */
1809 subpage->is_edge_cutoff[a][0] =
1810 subpage->h[a][0] == 0 && (p0 || (z0 == 0 && page->is_edge_cutoff[a][0]));
1811 subpage->is_edge_cutoff[a][1] =
1812 subpage->h[a][1] == 0 && (p1 || (z1 == page->n[a]
1813 && page->is_edge_cutoff[a][1]));
1814 subpage->is_edge_cutoff[b][0] = page->is_edge_cutoff[b][0];
1815 subpage->is_edge_cutoff[b][1] = page->is_edge_cutoff[b][1];
1817 /* Select join crossings from PAGE into subpage. */
1818 int *jc = subpage->join_crossing[a];
1819 for (int z = 0; z < page->h[a][0]; z++)
1820 *jc++ = page->join_crossing[a][z];
1821 for (int z = z0; z <= z1; z++)
1822 *jc++ = page->join_crossing[a][z];
1823 for (int z = page->n[a] - page->h[a][1]; z < page->n[a]; z++)
1824 *jc++ = page->join_crossing[a][z];
1825 assert (jc == &subpage->join_crossing[a][subpage->n[a] + 1]);
1827 memcpy (subpage->join_crossing[b], page->join_crossing[b],
1828 (subpage->n[b] + 1) * sizeof **subpage->join_crossing);
1830 /* Select widths from PAGE into subpage. */
1831 int *scp = page->cp[a];
1832 int *dcp = subpage->cp[a];
1834 for (int z = 0; z <= rule_ofs (subpage->h[a][0]); z++, dcp++)
1836 int w = !z && subpage->is_edge_cutoff[a][0] ? 0 : scp[z + 1] - scp[z];
1837 dcp[1] = dcp[0] + w;
1839 for (int z = cell_ofs (z0); z <= cell_ofs (z1 - 1); z++, dcp++)
1841 dcp[1] = dcp[0] + (scp[z + 1] - scp[z]);
1842 if (z == cell_ofs (z0))
1845 if (page->h[a][0] && page->h[a][1])
1846 dcp[1] += page->join_crossing[a][z / 2];
1848 if (z == cell_ofs (z1 - 1))
1851 for (int z = rule_ofs_r (page, a, subpage->h[a][1]);
1852 z <= rule_ofs_r (page, a, 0); z++, dcp++)
1854 if (z == rule_ofs_r (page, a, 0) && subpage->is_edge_cutoff[a][1])
1857 dcp[1] = dcp[0] + (scp[z + 1] - scp[z]);
1859 assert (dcp == &subpage->cp[a][2 * subpage->n[a] + 1]);
1861 for (int z = 0; z < page->n[b] * 2 + 2; z++)
1862 subpage->cp[b][z] = page->cp[b][z];
1864 /* Add new overflows. */
1865 struct render_page_selection s = {
1876 if (!page->h[a][0] || z0 > page->h[a][0] || p0)
1877 for (int z = 0; z < page->n[b]; )
1879 int d[TABLE_N_AXES];
1883 struct table_cell cell;
1884 render_get_cell (page, d[H], d[V], &cell);
1885 bool overflow0 = p0 || cell.d[a][0] < z0;
1886 bool overflow1 = cell.d[a][1] > z1 || (cell.d[a][1] == z1 && p1);
1887 if (overflow0 || overflow1)
1889 struct render_overflow *ro = insert_overflow (&s, &cell);
1893 ro->overflow[a][0] += p0 + axis_width (
1894 page, a, cell_ofs (cell.d[a][0]), cell_ofs (z0));
1895 if (page->h[a][0] && page->h[a][1])
1896 ro->overflow[a][0] -= page->join_crossing[a][cell.d[a][0]
1902 ro->overflow[a][1] += p1 + axis_width (
1903 page, a, cell_ofs (z1), cell_ofs (cell.d[a][1]));
1904 if (page->h[a][0] && page->h[a][1])
1905 ro->overflow[a][1] -= page->join_crossing[a][cell.d[a][1]];
1911 if (!page->h[a][1] || z1 < page->n[a] - page->h[a][1] || p1)
1912 for (int z = 0; z < page->n[b]; )
1914 int d[TABLE_N_AXES];
1918 struct table_cell cell;
1919 render_get_cell (page, d[H], d[V], &cell);
1920 if ((cell.d[a][1] > z1 || (cell.d[a][1] == z1 && p1))
1921 && find_overflow_for_cell (&s, &cell) == NULL)
1923 struct render_overflow *ro = insert_overflow (&s, &cell);
1924 ro->overflow[a][1] += p1 + axis_width (page, a, cell_ofs (z1),
1925 cell_ofs (cell.d[a][1]));
1930 /* Copy overflows from PAGE into subpage. */
1931 struct render_overflow *ro;
1932 HMAP_FOR_EACH (ro, struct render_overflow, node, &page->overflows)
1934 struct table_cell cell;
1936 table_get_cell (page->table, ro->d[H], ro->d[V], &cell);
1937 if (cell.d[a][1] > z0 && cell.d[a][0] < z1
1938 && find_overflow_for_cell (&s, &cell) == NULL)
1939 insert_overflow (&s, &cell);
1945 /* Given CELL, a table_cell within S->page, stores in SUBCELL the (x,y)
1946 coordinates of the top-left cell as it will appear in S->subpage.
1948 CELL must actually intersect the region of S->page that is being selected
1949 by render_page_select() or the results will not make any sense. */
1951 cell_to_subpage (struct render_page_selection *s,
1952 const struct table_cell *cell, int subcell[TABLE_N_AXES])
1954 enum table_axis a = s->a;
1955 enum table_axis b = s->b;
1956 int ha0 = s->subpage->h[a][0];
1958 subcell[a] = MAX (cell->d[a][0] - s->z0 + ha0, ha0);
1959 subcell[b] = cell->d[b][0];
1962 /* Given CELL, a table_cell within S->page, returns the render_overflow for
1963 that cell in S->subpage, if there is one, and a null pointer otherwise.
1965 CELL must actually intersect the region of S->page that is being selected
1966 by render_page_select() or the results will not make any sense. */
1967 static const struct render_overflow *
1968 find_overflow_for_cell (struct render_page_selection *s,
1969 const struct table_cell *cell)
1973 cell_to_subpage (s, cell, subcell);
1974 return find_overflow (s->subpage, subcell[H], subcell[V]);
1977 /* Given CELL, a table_cell within S->page, inserts a render_overflow for that
1978 cell in S->subpage (which must not already exist). Initializes the new
1979 render_overflow's 'overflow' member from the overflow for CELL in S->page,
1982 CELL must actually intersect the region of S->page that is being selected
1983 by render_page_select() or the results will not make any sense. */
1984 static struct render_overflow *
1985 insert_overflow (struct render_page_selection *s,
1986 const struct table_cell *cell)
1988 struct render_overflow *of = xzalloc (sizeof *of);
1989 cell_to_subpage (s, cell, of->d);
1990 hmap_insert (&s->subpage->overflows, &of->node,
1991 hash_cell (of->d[H], of->d[V]));
1993 const struct render_overflow *old
1994 = find_overflow (s->page, cell->d[H][0], cell->d[V][0]);
1996 memcpy (of->overflow, old->overflow, sizeof of->overflow);