1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
|
/* packaging.h
Copyright 2009 Taco Hoekwater <taco@luatex.org>
This file is part of LuaTeX.
LuaTeX 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.
LuaTeX 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 Lesser General Public
License for more details.
You should have received a copy of the GNU General Public License along
with LuaTeX; if not, see <http://www.gnu.org/licenses/>.
*/
#ifndef PACKAGING_H
# define PACKAGING_H
/* We define some constants used when calling |hpack| to deal with font expansion. */
typedef enum {
exactly = 0, /*a box dimension is pre-specified */
additional, /*a box dimension is increased from the natural one */
cal_expand_ratio, /* calculate amount for font expansion after breaking paragraph into lines */
subst_ex_font /* substitute fonts */
} hpack_subtypes;
# define substituted 3 /* |subtype| of kern nodes that should be substituted */
extern void scan_spec(group_code c);
extern void scan_full_spec(group_code c, int spec_direction, int justpack);
extern scaled total_stretch[5];
extern scaled total_shrink[5]; /* glue found by |hpack| or |vpack| */
extern int last_badness; /* badness of the most recently packaged box */
extern halfword adjust_tail; /* tail of adjustment list */
extern halfword pre_adjust_tail;
extern int font_expand_ratio; /* current expansion ratio */
extern halfword last_leftmost_char;
extern halfword last_rightmost_char;
extern halfword next_char_p; /* pointer to the next char of an implicit kern */
extern halfword prev_char_p; /* pointer to the previous char of an implicit kern */
extern void set_prev_char_p(halfword p);
extern scaled char_stretch(halfword p);
extern scaled char_shrink(halfword p);
extern scaled kern_stretch(halfword p);
extern scaled kern_shrink(halfword p);
extern void do_subst_font(halfword p, int ex_ratio);
extern scaled char_pw(halfword p, int side);
extern halfword new_margin_kern(scaled w, halfword p, int side);
# define update_adjust_list(A) do { \
if (A == null) \
normal_error("pre vadjust", "adjust_tail or pre_adjust_tail is null"); \
vlink(A) = adjust_ptr(p); \
while (vlink(A) != null) \
A = vlink(A); \
} while (0)
extern halfword filtered_hpack(halfword p, halfword qt, scaled w, int m, int grp, int d, int just_pack, halfword attr);
extern scaled_whd natural_sizes(halfword p, halfword pp, glue_ratio g_mult, int g_sign, int g_order, int d);
extern halfword hpack(halfword p, scaled w, int m, int d);
extern int pack_begin_line;
extern halfword vpackage(halfword p, scaled h, int m, scaled l, int d);
extern halfword filtered_vpackage(halfword p, scaled h, int m, scaled l, int grp, int d, int just_pack, halfword attr);
extern void finish_vcenter(void);
extern void package(int c);
extern void append_to_vlist(halfword b, int location);
# define vpack(A,B,C,D) vpackage(A,B,C,max_dimen,D) /* special case of unconstrained depth */
extern halfword prune_page_top(halfword p, boolean s);
extern scaled active_height[10]; /* distance from first active node to~|cur_p| */
# define cur_height active_height[1] /* the natural height */
# define awful_bad 07777777777 /* more than a billion demerits */
# define deplorable 100000 /* more than |inf_bad|, but less than |awful_bad| */
extern scaled best_height_plus_depth; /* height of the best box, without stretching or shrinking */
extern halfword vert_break(halfword p, scaled h, scaled d);
extern halfword vsplit(halfword n, scaled h, int m); /* extracts a page of height |h| from box |n| */
# define box_code 0 /* |chr_code| for `\.{\\box}' */
# define copy_code 1 /* |chr_code| for `\.{\\copy}' */
# define last_box_code 2 /* |chr_code| for `\.{\\lastbox}' */
# define vsplit_code 3 /* |chr_code| for `\.{\\vsplit}' */
# define tpack_code 4
# define vpack_code 5
# define hpack_code 6
# define vtop_code 7 /* |chr_code| for `\.{\\vtop}' */
# define tail_page_disc disc_ptr[copy_code] /* last item removed by page builder */
# define page_disc disc_ptr[last_box_code] /* first item removed by page builder */
# define split_disc disc_ptr[vsplit_code] /* first item removed by \.{\\vsplit} */
extern halfword disc_ptr[(vsplit_code + 1)]; /* list pointers */
/*
Now let's turn to the question of how \.{\\hbox} is treated. We actually need to
consider also a slightly larger context, since constructions like
`\.{\\setbox3=}\penalty0\.{\\hbox...}' and
`\.{\\leaders}\penalty0\.{\\hbox...}' and
`\.{\\lower3.8pt\\hbox...}'
are supposed to invoke quite different actions after the box has been packaged.
Conversely, constructions like `\.{\\setbox3=}' can be followed by a variety of
different kinds of boxes, and we would like to encode such things in an efficient
way.
In other words, there are two problems: To represent the context of a box, and to
represent its type. The first problem is solved by putting a ``context code'' on
the |save_stack|, just below the two entries that give the dimensions produced by
|scan_spec|. The context code is either a (signed) shift amount, or it is a large
integer |>=box_flag|, where |box_flag=@t$2^{30}$@>|. Codes |box_flag| through
|box_flag+biggest_reg| represent `\.{\\setbox0}' through
`\.{\\setbox}|biggest_reg|'; codes |box_flag+biggest_reg+1| through
|box_flag+2*biggest_reg| represent `\.{\\global\\setbox0}' through
`\.{\\global\\setbox}|biggest_reg|'; code |box_flag+2*number_regs| represents
`\.{\\shipout}'; and codes |box_flag+2*number_regs+1| through
|box_flag+2*number_regs+3| represent `\.{\\leaders}', `\.{\\cleaders}', and
`\.{\\xleaders}'.
The second problem is solved by giving the command code |make_box| to all control
sequences that produce a box, and by using the following |chr_code| values to
distinguish between them: |box_code|, |copy_code|, |last_box_code|,
|vsplit_code|, |vtop_code|, |vtop_code+vmode|, and |vtop_code+hmode|, where the
latter two are used denote \.{\\vbox} and \.{\\hbox}, respectively.
*/
# define box_flag 010000000000 /* context code for `\.{\\setbox0}' */
# define global_box_flag (box_flag+number_regs) /* context code for `\.{\\global\\setbox0}' */
# define max_global_box_flag (global_box_flag+number_regs)
# define ship_out_flag (max_global_box_flag+1) /* context code for `\.{\\shipout}' */
# define lua_scan_flag (max_global_box_flag+2) /* context code for |scan_list| */
# define leader_flag (max_global_box_flag+3) /* context code for `\.{\\leaders}' */
extern void begin_box(int box_context);
#define math_skip_boundary(n) \
(n && type(n) == glue_node && (subtype(n) == space_skip_subtype || subtype(n) == xspace_skip_subtype))
extern int ignore_math_skip(halfword p) ;
#endif
|
