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/* catdvi - get text from DVI files
Copyright (C) 1999 Antti-Juhani Kaijanaho <gaia@iki.fi>
Copyright (C) 2000-02 Bjoern Brill <brill@fs.math.uni-frankfurt.de>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <assert.h>
#include <stdlib.h>
#include "page2.h"
#include "util.h"
#include "glyphops.h"
#include "layout.h"
/* Return value like with strcmp and friends. */
static int compare_boxes(struct box_t a, struct box_t b)
{
if (a.y > b.y) return 1;
if (a.y < b.y) return -1;
assert(a.y == b.y);
if (a.x > b.x) return 1;
if (a.x < b.x) return -1;
assert(a.x == b.x);
return 0;
}
struct point_t {
sint32 x;
sint32 y;
};
static int point_in_box(const struct point_t * point, const struct box_t * box)
{
assert(box);
assert(point);
return(
box->x <= point->x &&
(box->x + box->width) >= point->x &&
(box->y - box->height) <= point->y &&
box->y >= point->y
);
}
/* Set to 1 when catdvi is invoked with the --sequential option */
int page_sequential = 0;
/* Set to 1 when catdvi is invoked with the --list-page-numbers option */
int page_list_numbers = 0;
/* List support variables. Note that most insertions happen near the
previous insertion, so it's beneficial to keep a pointer to the
last inserted node. */
struct list_node_t * list_head;
struct list_node_t * list_tail;
struct list_node_t * list_latest; /* Node that was inserted last. */
/* flags to avoid the page_adjust_*() loops over the whole page when
* there's nothing to adjust.
*/
static int page_has_diacritics;
static int page_has_texmext;
static int page_has_radicals;
static void swap_nodes(struct list_node_t * one, struct list_node_t * other)
{
assert(one != 0);
assert(other != 0);
assert(one->next == other);
assert(one == other->prev);
one->next = other->next;
other->prev = one->prev;
other->next = one;
one->prev = other;
if (one->next == 0) {
list_tail = one;
} else {
one->next->prev = one;
}
if (other->prev == 0) {
list_head = other;
} else {
other->prev->next = other;
}
assert(other->next == one);
assert(other == one->prev);
}
/* move list_latest into its correct position in the list */
static void bubble(void)
{
while (1) {
assert(list_latest != 0);
/* If it is in correct position now, end here. */
if ((list_latest->prev == 0
|| compare_boxes(list_latest->prev->b, list_latest->b) <= 0)
&& (list_latest->next == 0
|| compare_boxes(list_latest->b, list_latest->next->b) <= 0)) {
return;
}
/* If it is too left, we must bubble it one position to the right. */
if (list_latest->next != 0
&& compare_boxes(list_latest->b, list_latest->next->b) > 0) {
swap_nodes(list_latest, list_latest->next);
continue;
}
/* If it is too right, we must bubble it one position to the left. */
if (list_latest->prev != 0
&& compare_boxes(list_latest->prev->b, list_latest->b) > 0) {
assert(list_latest->prev->next == list_latest);
swap_nodes(list_latest->prev, list_latest);
continue;
}
NOTREACHED;
}
NOTREACHED;
}
/* move some random node into its correct position in the list */
static void bubble_node(struct list_node_t * p)
{
list_latest = p;
bubble();
}
static void insert_list(struct box_t box)
{
struct list_node_t * new;
new = malloc(sizeof(struct list_node_t));
if (new == 0) enomem();
new->b = box;
if (list_head == 0 || list_tail == 0 || list_latest == 0) {
assert(list_head == 0);
assert(list_tail == 0);
assert(list_latest == 0);
new->next = new->prev = 0;
list_head = list_tail = list_latest = new;
return;
}
/* The list is nonempty. */
assert(list_head != 0);
assert(list_tail != 0);
assert(list_latest != 0);
/* The insertion algorithm is this: insert the node after the
latest insertion, and then bubble it into its correct
position. */
new->next = list_latest->next;
list_latest->next = new;
new->prev = list_latest;
list_latest = new;
if (new->next == 0) {
list_tail = new;
} else {
new->next->prev = new;
}
assert(list_latest->prev->next == list_latest);
assert(list_latest->next == 0 || list_latest->next->prev == list_latest);
/* sort by position except in sequential mode */
if (!page_sequential) bubble();
}
/* These two are set by command line options */
struct pageref_t page_start_output = {0, 0, 0, PRF_PHYSICAL};
struct pageref_t page_last_output = {SINT32_MAX, 0, 0, PRF_PHYSICAL};
static struct pageref_t current_page = {0, 0, 0, PRF_INVALID};
void page_begin(sint32 count0)
{
/* If necessary, delete the previous page's data structure. */
if (list_head != 0 || list_tail != 0 || list_latest != 0) {
struct list_node_t * p;
assert(list_head != 0);
assert(list_tail != 0);
assert(list_latest != 0);
p = list_head;
while (p != 0) {
struct list_node_t * next;
if (p == list_head) list_head = 0;
if (p == list_latest) list_latest = 0;
if (p == list_tail) list_tail = 0;
next = p->next;
free(p);
p = next;
}
}
assert(list_head == 0);
assert(list_tail == 0);
assert(list_latest == 0);
/* reset per page flags */
page_has_diacritics = 0;
page_has_texmext = 0;
page_has_radicals = 0;
/* keep track of page numbering */
if(current_page.flavour == PRF_INVALID) {
/* here comes the very first page of the document */
current_page.physical = 1;
current_page.count0 = count0;
if (count0 < 0) current_page.chapter = 1;
else current_page.chapter = 0;
/* number chapters from 0 to accomodate frontmatter */
current_page.flavour = PRF_COMPLETE;
}
else {
/* just another ordinary page */
current_page.physical += 1;
if (pageref_count0_cmp(current_page.count0, count0) >= 0) {
/* count0 has not increased, so start new chapter */
current_page.chapter += 1;
}
current_page.count0 = count0;
}
}
void page_set_glyph(
font_t font, glyph_t glyph,
sint32 width, sint32 height, sint32 depth, sint32 axis_height,
sint32 x, sint32 y
)
{
struct box_t b;
enum glyph_hint_t hint;
b.x = x;
b.y = y;
b.width = width;
b.height = height;
b.depth = depth;
b.glyph = glyph;
b.font = font;
b.axis_height = axis_height;
b.flags = 0;
b.axis = 0;
/* Make sure some fundamental assumptions are true */
if(b.width < 0) {
/* We can treat backspacing glyphs as empty boxes here, since
* advancing the DVI h register has already been taken care of.
*/
pmesg(
60,
"PAGE_SET_GLYPH: negative glyph width %li treated as 0\n",
b.width
);
b.width = 0;
}
if(b.height < 0) {
/* A submarine! This really should not happen. */
warning(
"Negative glyph height %li treated as 0.\n",
b.height
);
b.height = 0;
}
/* depth < 0 does occur from time to time. Main source are small
* glyphs with tight bounding box centered on the math axis.
* We leave this as it is to keep the math axis in the centre;
* so use max(0, b.depth) instead of b.depth for some calculations.
* We do however make an additional consistency check:
*/
if(b.depth < -b.height) {
/* A glyph from Down Under! */
warning("Inconsistent font metrics, depth < -height. Fixed.\n");
pmesg(
60,
"PAGE_SET_GLYPH: upside down glyph, depth=%li, height=%li\n",
b.depth,
b.height
);
b.depth = -b.height;
}
hint = glyph_get_hint(glyph);
if(hint & GH_DIACRITIC) {
b.flags |= BF_SWIMMING | BF_DIACRITIC ;
page_has_diacritics = 1;
}
if(hint & GH_EXTENSIBLE_RECIPE) {
b.flags |= BF_SWIMMING;
page_has_texmext = 1;
}
else if(hint & GH_ON_AXIS) {
b.flags |= BF_SWIMMING | BF_ON_AXIS | BF_HAS_AXIS ;
b.axis = y + (-height + depth)/2;
page_has_texmext = 1;
}
else if(hint & GH_RADICAL) {
b.flags |= BF_SWIMMING | BF_RADICAL ;
page_has_radicals = 1;
}
else if(axis_height > 0) {
b.flags |= BF_HAS_AXIS;
b.axis = y - axis_height;
}
insert_list(b);
}
static void page_pair_accenting(
struct list_node_t * pbase,
struct list_node_t * pdiacritic,
int direction
);
void page_end(void)
{
pmesg(50, "BEGIN page_end\n");
if (
pageref_cmp(&page_start_output, ¤t_page) > 0 ||
pageref_cmp(&page_last_output, ¤t_page) < 0
) {
if(msglevel >= 80) {
pmesg(80, "skipping page by user request:\n ");
pageref_print(¤t_page, stderr);
}
pmesg(50, "END page_end\n");
return;
}
if(page_list_numbers) {
pageref_print(¤t_page, stdout);
pmesg(50, "END page_end\n");
return;
}
if(page_sequential) page_print_sequential();
else page_print_formatted();
pmesg(50, "END page_end\n");
return;
}
void page_adjust_diacritics(void)
{
int trouble = 0;
int direction = 0;
struct list_node_t *p, *s, *q, *pb;
struct box_t dia_box;
struct point_t dia_center;
pmesg(50, "BEGIN page_adjust_diacritics\n");
if(!page_has_diacritics) {
pmesg(80, "nothing to do\n");
pmesg(50, "END page_adjust_diacritics\n");
return;
}
for (p = list_head; p != 0; p = s) {
s = p->next;
/* p-> is a moving target */
if (!(p->b.flags & BF_DIACRITIC)) continue;
trouble = 0;
pb = 0;
dia_box = p->b;
dia_center.x = dia_box.x + dia_box.width / 2;
dia_center.y = dia_box.y - dia_box.height / 2;
/* Search corresponding base box. There are complex overlayed
* constructions we can't handle. Therefore, we try to find all
* possible candidates and abort when more than one is found.
*/
/* search backwards */
for(q = p->prev; q != 0; q = q->prev) {
if (abs(dia_box.y - q->b.y) > 3*(dia_box.height + q->b.height))
/* too far off to find anything useful */
break;
if (point_in_box(&dia_center, &q->b)) {
/* I got you babe */
if(pb != 0) {
/* we are not alone...too bad */
trouble = 1;
break;
}
pb = q;
direction = -1;
}
}
if(trouble) {
pmesg(
80,
"page_adjust_diacritics: trouble with diacritic %#lx\n",
dia_box.glyph
);
continue;
}
/* search forward */
for(q = p->next; q != 0; q = q->next) {
if (abs(dia_box.y - q->b.y) > 3*(dia_box.height + q->b.height))
/* too far off to find anything useful */
break;
if (point_in_box(&dia_center, &q->b)) {
/* I got you babe */
if(pb != 0) {
/* we are not alone...too bad */
trouble = 1;
break;
}
pb = q;
direction = 1;
}
}
if(trouble) {
pmesg(
80,
"page_adjust_diacritics: trouble with diacritic %#lx\n",
dia_box.glyph
);
continue;
}
if(pb == 0) {
pmesg(
80,
"page_adjust_diacritics: no base glyph for diacritic %#lx\n",
dia_box.glyph
);
/* a lone diacritic. assume it just belongs where it is */
p->b.flags &= ~(BF_SWIMMING | BF_DIACRITIC);
continue;
}
/* Found the one and only one. Let's get closer. */
page_pair_accenting(pb, p, direction);
}
pmesg(50, "END page_adjust_diacritics\n");
}
static void page_pair_accenting(
struct list_node_t * pbase,
struct list_node_t * pdiacritic,
int direction
)
{
glyph_t dcv;
assert(pdiacritic->b.flags & BF_DIACRITIC);
assert(abs(direction) == 1);
pmesg(
80,
"detected accenting: base=%#lx, diacritic=%#lx\n",
pbase->b.glyph,
pdiacritic->b.glyph
);
dcv = diacritic_combining_variant(pdiacritic->b.glyph);
if(dcv) {
/* OK this one can be handeled within the unicode framework */
/* move diacritic right after base glyph */
if(direction == -1) {
/* base before diacritic */
while(pdiacritic->prev != pbase) {
swap_nodes(pdiacritic->prev, pdiacritic);
}
}
else {
/* base after diacritic */
while(pdiacritic->prev != pbase) {
swap_nodes(pdiacritic, pdiacritic->next);
/* note swap_nodes() is order sensitive */
}
}
/* Make the combining diacritic occupy the same space as the
* accented glyph would. That's the only way to statisfy all
* ordering and spacing assumptions in this program. And nearly
* consequent.
*/
pdiacritic->b.width = pbase->b.width;
pdiacritic->b.height = max(
pbase->b.height,
pdiacritic->b.height + pbase->b.y - pdiacritic->b.y
);
pdiacritic->b.x = pbase->b.x;
pdiacritic->b.y = pbase->b.y;
pdiacritic->b.glyph = dcv;
pdiacritic->b.flags &= ~(BF_SWIMMING | BF_DIACRITIC);
}
else {
/* A strange guy. Won't combine. Just put him in line so he can't
* clobber up things. Like in real life.
*/
pdiacritic->b.height =
pdiacritic->b.height + pbase->b.y - pdiacritic->b.y;
pdiacritic->b.y = pbase->b.y;
pdiacritic->b.flags &= ~(BF_SWIMMING | BF_DIACRITIC);
/* keep the list ordered */
if(!page_sequential) bubble_node(pdiacritic);
}
}
/************************************************************************
* the hairy texmext stuff
************************************************************************/
typedef struct interval32_t interval32_t;
struct interval32_t {
sint32 a;
sint32 b;
};
static int interval32_contains(const interval32_t * this, sint32 x)
{
int res;
res = (this->a <= x) && (x <= this->b);
pmesg(
150,
"interval32_contains: %ld %s [%ld, %ld]\n",
x,
res ? "in" : "not in",
this->a,
this->b
);
return res;
}
typedef struct searchinfo_t searchinfo_t;
struct searchinfo_t {
interval32_t searched_y;
interval32_t x;
interval32_t y;
interval32_t top;
interval32_t axis;
int require_axis;
int test_start;
struct list_node_t * start;
struct list_node_t * first_found;
};
static int page_match_box(
const struct searchinfo_t * quest,
const struct list_node_t * candidate
)
{
int matches;
const struct box_t * cb;
cb = &(candidate->b);
/* The candidate's x, y and top ( == y - height) values must match the ones
* we're searching for. If candidate has a known math axis, it must match.
* require_axis says whether we require it to have a known math axis.
*/
matches =
interval32_contains(&(quest->x), cb->x) &&
interval32_contains(&(quest->y), cb->y) &&
interval32_contains(&(quest->top), cb->y - cb->height) &&
(
(cb->flags & BF_HAS_AXIS) ?
interval32_contains(&(quest->axis), cb->axis) :
!quest->require_axis
); /* yes these parentheses _are_ neccessary */
return(matches);
}
/* Return values:
* 0 - no box matches the given criteria
* 1 - some boxes match the given criteria, and all of them have the same y
* 2 - some boxes match the given criteria, but different y values occur.
*
* If some boxes match, quest->first_found will point to guess what.
*/
static int page_grb_unique_y(
struct searchinfo_t * quest
)
{
interval32_t * range;
struct list_node_t * p;
struct list_node_t * start_up, * start_down;
sint32 y;
int have_y = 0;
range = &(quest->searched_y);
assert(interval32_contains(range, quest->start->b.y));
start_up = quest->test_start ? quest->start : quest->start->prev;
start_down = quest->start->next;
quest->first_found = NULL;
for(p = start_up; p != NULL; p = p->prev) {
if(!interval32_contains(range, p->b.y)) break;
if(p->b.flags & BF_SWIMMING) continue;
if(page_match_box(quest, p)) {
if(have_y) {
if(p->b.y != y) {
return 2;
}
}
else {
quest->first_found = p;
y = p->b.y;
have_y = 1;
}
}
}
for(p = start_down; p != NULL; p = p->next) {
if(!interval32_contains(range, p->b.y)) break;
if(p->b.flags & BF_SWIMMING) continue;
if(page_match_box(quest, p)) {
if(have_y) {
if(p->b.y != y) {
return 2;
}
}
else {
quest->first_found = p;
y = p->b.y;
have_y = 1;
}
}
}
return have_y;
}
enum srestrict_t {
SRS_MIN_VAL = -1, /* always first */
SRS_REQUIRE_AXIS,
SRS_NARROW,
SRS_VERY_NARROW,
SRS_MOREMATH_SIDE,
SRS_LESSMATH_SIDE,
SRS_MAX_VAL /* always last */
};
static int srestrict_conflicts[SRS_MAX_VAL] = {
0, /* SRS_REQUIRE_AXIS */
1 << SRS_VERY_NARROW, /* SRS_NARROW */
1 << SRS_NARROW, /* SRS_VERY_NARROW */
1 << SRS_MOREMATH_SIDE, /* SRS_MOREMATH_SIDE */
1 << SRS_LESSMATH_SIDE /* SRS_LESSMATH_SIDE */
};
/* Recurse through all subsets of the set of search restrictions.
* Return values:
* 0 - No box conforms to the given set of restrictions. Cut that branch.
* 1 - The given restrictions or a further refinement have lead to a unique
* y value.
* 2 - There were boxes conforming to the given set of restrictions, but
* the refinements I've tried haven't lead to a unique y value.
*/
static int page_grb_recursion(
struct searchinfo_t * quest,
struct list_node_t * swimmer,
enum srestrict_t try_restrict,
int srestricts
)
{
struct searchinfo_t newquest;
int res;
struct box_t * pb;
sint32 d;
static char indents[] = " ";
char * indent;
indent = indents + lengthof(indents) + try_restrict - SRS_MAX_VAL;
pmesg(130, "%sBEGIN page_grb_recursion\n", indent);
pmesg(150, "%spage_grb_recursion: try_restrict=%d\n", indent, try_restrict);
if(try_restrict < 0) {
/* The set of applicable search restrictions is already settled.
* Really DO something.
*/
res = page_grb_unique_y(quest);
pmesg(
150,
"%spage_grb_recursion: srestricts=%#4x, unique_y result %d\n",
indent,
srestricts,
res
);
pmesg(130, "%sEND page_grb_recursion\n", indent);
return res;
}
/* Try without imposing a new restriction first */
res = page_grb_recursion(quest, swimmer, try_restrict - 1, srestricts);
if(res <= 1) {
pmesg(130, "%sEND page_grb_recursion\n", indent);
return res;
}
/* This hasn't been restrictive enough, try adding "our" restriction. */
if(srestrict_conflicts[try_restrict] & srestricts) {
/* We can't add "our" restriction - conflict. But our caller could
* try others.
*/
pmesg(150, "%spage_grb_recursion: tried conflicting restrictions\n", indent);
pmesg(130, "%sEND page_grb_recursion\n", indent);
return(2);
}
pb = &(swimmer->b);
d = ((pb->height + pb->depth) + pb->width) / 20;
/* (arithmetic mean of total height and width of swimmer)/10 */
newquest = *quest;
switch(try_restrict) {
case SRS_REQUIRE_AXIS:
newquest.require_axis = 1;
break;
case SRS_NARROW:
newquest.x.a = max(newquest.x.a, pb->x - 30*d);
newquest.x.b = min(newquest.x.b, pb->x + 40*d);
/* 10 for the swimmer itself */
break;
case SRS_MOREMATH_SIDE:
if(glyph_get_hint(pb->glyph) & GH_MOREMATH_LEFT) {
newquest.x.b = pb->x + pb->width;
}
else {
newquest.x.a = pb->x;
}
break;
case SRS_LESSMATH_SIDE:
if(glyph_get_hint(pb->glyph) & GH_MOREMATH_LEFT) {
newquest.x.a = pb->x;
}
else {
newquest.x.b = pb->x + pb->width;
}
break;
case SRS_VERY_NARROW:
newquest.x.a = max(newquest.x.a, pb->x - 15*d);
newquest.x.b = min(newquest.x.b, pb->x + 25*d);
/* 10 for the swimmer itself */
break;
default:
NOTREACHED;
}
res = page_grb_recursion(
&newquest,
swimmer,
try_restrict - 1,
srestricts | (1 << try_restrict)
);
quest->first_found = newquest.first_found;
pmesg(130, "%sEND page_grb_recursion\n", indent);
if(res == 1) return 1;
else return 2;
}
/* The fonts in "TeX math extension" encoding are somewhat different from
* the others. The glyphs are centered on the "math axis" (about the height
* of a minus sign above the baseline of the surrounding text/formula). The
* y coordinate of the glyphs reference point is mostly meaningless (and in
* Knuths cmex fonts the glyphs are "hanging down" from the reference
* point). We know the math axis: its the arithmethic mean of (y - height)
* and (y + depth). But we have to move the glyph to the _baseline_ for
* proper text formatting, hence we need to deduce the baseline somehow.
*
* TeX gets the height of the math axis above the baseline from a parameter
* named axis_height in the font metrics of the currently used math symbol
* font. This parameter is only present in TFM files for fonts with "TeX math
* symbols" encoding and it is not easy to be sure which axis height was
* in effect when the math extension glyph was set, given only the DVI file.
*
* Therefore, we try another approach first: we look at the surrounding
* boxes. If every box in some reasonable neighbourhood that is dissected
* by the math axis has the same baseline, this must be the baseline of
* the formula. Only if this approach fails we resort to guessing
* axis_height by looking at the loaded math symbol fonts.
*/
static struct list_node_t * page_guess_reference_box(
struct list_node_t * swimmer
)
{
struct searchinfo_t quest;
struct box_t * pb;
pmesg(50, "BEGIN page_guess_reference_box\n");
pmesg(
80,
"page_guess_reference_box: y=%ld, axis=%ld\n",
swimmer->b.y,
swimmer->b.axis
);
pb = &(swimmer->b);
assert(pb->flags & BF_SWIMMING);
assert(pb->flags & BF_HAS_AXIS);
quest.x.a = SINT32_MIN;
quest.x.b = SINT32_MAX;
quest.y.a = pb->axis;
quest.y.b = pb->y + pb->depth;
quest.top.a = SINT32_MIN;
quest.top.b = pb->axis;
quest.axis.a = pb->axis - 2;
quest.axis.b = pb->axis + 2; /* allow small rounding errors */
quest.require_axis = 0;
quest.test_start = 0;
quest.start = swimmer;
if(page_sequential) {
sint32 h;
h = pb->height + pb->depth;
quest.searched_y.a = pb->axis - 3*h;
quest.searched_y.b = pb->axis + 3*h;
}
else {
quest.searched_y.a = min(pb->axis, pb->y);
quest.searched_y.b = pb->y + pb->depth;
}
if(page_grb_recursion(&quest, swimmer, SRS_MAX_VAL - 1, 0) == 1) {
pmesg(50, "END page_guess_reference_box\n");
return quest.first_found;
}
else {
pmesg(50, "END page_guess_reference_box\n");
return NULL;
}
}
void page_adjust_texmext(void)
{
struct list_node_t * p, * s, * ref;
sint32 new_y, delta;
pmesg(50, "BEGIN page_adjust_texmext\n");
if(!page_has_texmext) {
pmesg(80, "nothing to do\n");
pmesg(50, "END page_adjust_texmext\n");
return;
}
for (p = list_head; p != 0; p = s) {
s = p->next;
/* p-> is a moving target */
if (!(p->b.flags & BF_ON_AXIS)) continue;
assert(p->b.flags & BF_HAS_AXIS);
assert(p->b.flags & BF_SWIMMING);
pmesg(
80,
"page_adjust_texmext: glyph=%#6lx, y=%ld\n",
p->b.glyph,
p->b.y
);
if(p->b.axis_height > 0) {
ref = NULL;
pmesg(
80,
"page_adjust_texmext: known axis_height=%ld\n",
p->b.axis_height
);
}
else {
ref = page_guess_reference_box(p);
pmesg(
80,
"page_adjust_texmext:%s reference box found\n",
ref ? "" : " no"
);
}
if(ref != NULL) new_y = ref->b.y;
else new_y = p->b.axis + abs(p->b.axis_height);
pmesg(80, "page_adjust_texmext: new_y=%ld\n", new_y);
delta = new_y - p->b.y;
p->b.y = new_y;
p->b.height += delta;
p->b.depth -= delta;
p->b.axis_height = p->b.y - p->b.axis;
p->b.flags &= ~(BF_SWIMMING | BF_ON_AXIS);
if(!page_sequential) bubble_node(p);
}
pmesg(50, "END page_adjust_texmext\n");
}
static struct list_node_t * page_find_lowest_box(struct searchinfo_t * quest)
{
interval32_t * range;
struct list_node_t * p, * low;
struct list_node_t * start_up, * start_down;
range = &(quest->searched_y);
assert(interval32_contains(range, quest->start->b.y));
start_up = quest->test_start ? quest->start : quest->start->prev;
start_down = quest->start->next;
quest->first_found = NULL;
low = NULL;
for(p = start_up; p != NULL; p = p->prev) {
if(!interval32_contains(range, p->b.y)) break;
if(p->b.flags & BF_SWIMMING) continue;
if(page_match_box(quest, p)) {
if(low == NULL || p->b.y > low->b.y) low = p;
}
}
for(p = start_down; p != NULL; p = p->next) {
if(!interval32_contains(range, p->b.y)) break;
if(p->b.flags & BF_SWIMMING) continue;
if(page_match_box(quest, p)) {
if(low == NULL || p->b.y > low->b.y) low = p;
}
}
quest->first_found = low;
return low;
}
/* TeX's radical signs are hanging down from their reference point. We move
* them to the baseline of the lowest glyph in the radicant (that's where
* the bottom tip ought to be) or, if there's no radicant, to the y position
* of the bottom tip.
*/
void page_adjust_radicals(void)
{
struct list_node_t * p, * s, * lowest;
sint32 new_y, delta;
struct searchinfo_t quest;
pmesg(50, "BEGIN page_adjust_radicals\n");
if(!page_has_radicals) {
pmesg(80, "nothing to do\n");
pmesg(50, "END page_adjust_radicals\n");
return;
}
for (p = list_head; p != 0; p = s) {
s = p->next;
/* p-> is a moving target */
if (!(p->b.flags & BF_RADICAL)) continue;
assert(p->b.flags & BF_SWIMMING);
pmesg(
80,
"page_adjust_radicals: glyph=%#6lx, y=%ld\n",
p->b.glyph,
p->b.y
);
/* put the radical on the baseline of the lowest box in the radicant */
quest.x.a = p->b.x;
quest.x.b = SINT32_MAX;
/* FIXME: Once we have rudimentary rules support, we can search
* for the rule forming the radicals top and take its length as
* the width of the radicant.
*/
quest.y.a = p->b.y - p->b.height;
quest.y.b = p->b.y + p->b.depth;
quest.top = quest.y;
quest.axis.a = SINT32_MIN;
quest.axis.b = SINT32_MAX;
quest.require_axis = 0;
quest.test_start = 0;
quest.start = p;
if(page_sequential) {
sint32 h;
h = p->b.height + p->b.depth;
quest.searched_y.a = p->b.y - h;
quest.searched_y.b = p->b.y + 2*h;
}
else {
quest.searched_y = quest.y;
}
lowest = page_find_lowest_box(&quest);
pmesg(
80,
"page_adjust_radicals:%s lowest box found\n",
lowest ? "" : " no"
);
if(lowest != NULL) new_y = lowest->b.y;
else new_y = p->b.y + p->b.depth;
pmesg(80, "page_adjust_radicals: new_y=%ld\n", new_y);
delta = new_y - p->b.y;
p->b.y = new_y;
p->b.height += delta;
p->b.depth -= delta;
p->b.flags &= ~(BF_SWIMMING | BF_RADICAL);
if(!page_sequential) bubble_node(p);
}
pmesg(50, "END page_adjust_radicals\n");
}
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