1/*
2 * Copyright © 2018 Ebrahim Byagowi
3 *
4 * This is part of HarfBuzz, a text shaping library.
5 *
6 * Permission is hereby granted, without written agreement and without
7 * license or royalty fees, to use, copy, modify, and distribute this
8 * software and its documentation for any purpose, provided that the
9 * above copyright notice and the following two paragraphs appear in
10 * all copies of this software.
11 *
12 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
13 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
14 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
15 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
16 * DAMAGE.
17 *
18 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
19 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
20 * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
21 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
22 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
23 */
24#ifndef HB_AAT_LAYOUT_LCAR_TABLE_HH
25#define HB_AAT_LAYOUT_LCAR_TABLE_HH
26
27#include "hb-open-type.hh"
28#include "hb-aat-layout-common.hh"
29
30/*
31 * lcar -- Ligature caret
32 * https://developer.apple.com/fonts/TrueType-Reference-Manual/RM06/Chap6lcar.html
33 */
34#define HB_AAT_TAG_lcar HB_TAG('l','c','a','r')
35
36
37namespace AAT {
38
39typedef ArrayOf<HBINT16> LigCaretClassEntry;
40
41struct lcarFormat0
42{
43 unsigned int get_lig_carets (hb_font_t *font,
44 hb_direction_t direction,
45 hb_codepoint_t glyph,
46 unsigned int start_offset,
47 unsigned int *caret_count /* IN/OUT */,
48 hb_position_t *caret_array /* OUT */,
49 const void *base) const
50 {
51 const OffsetTo<LigCaretClassEntry>* entry_offset = lookupTable.get_value (glyph,
52 font->face->get_num_glyphs ());
53 const LigCaretClassEntry& array = entry_offset ? base+*entry_offset : Null (LigCaretClassEntry);
54 if (caret_count)
55 {
56 hb_array_t<const HBINT16> arr = array.sub_array (start_offset, caret_count);
57 for (unsigned int i = 0; i < arr.length; ++i)
58 caret_array[i] = font->em_scale_dir (arr[i], direction);
59 }
60 return array.len;
61 }
62
63 bool sanitize (hb_sanitize_context_t *c, const void *base) const
64 {
65 TRACE_SANITIZE (this);
66 return_trace (likely (c->check_struct (this) && lookupTable.sanitize (c, base)));
67 }
68
69 protected:
70 Lookup<OffsetTo<LigCaretClassEntry>>
71 lookupTable; /* data Lookup table associating glyphs */
72 public:
73 DEFINE_SIZE_MIN (2);
74};
75
76struct lcarFormat1
77{
78 unsigned int get_lig_carets (hb_font_t *font,
79 hb_direction_t direction,
80 hb_codepoint_t glyph,
81 unsigned int start_offset,
82 unsigned int *caret_count /* IN/OUT */,
83 hb_position_t *caret_array /* OUT */,
84 const void *base) const
85 {
86 const OffsetTo<LigCaretClassEntry>* entry_offset = lookupTable.get_value (glyph,
87 font->face->get_num_glyphs ());
88 const LigCaretClassEntry& array = entry_offset ? base+*entry_offset : Null (LigCaretClassEntry);
89 if (caret_count)
90 {
91 hb_array_t<const HBINT16> arr = array.sub_array (start_offset, caret_count);
92 for (unsigned int i = 0; i < arr.length; ++i)
93 {
94 hb_position_t x = 0, y = 0;
95 font->get_glyph_contour_point_for_origin (glyph, arr[i], direction, &x, &y);
96 caret_array[i] = HB_DIRECTION_IS_HORIZONTAL (direction) ? x : y;
97 }
98 }
99 return array.len;
100 }
101
102 bool sanitize (hb_sanitize_context_t *c, const void *base) const
103 {
104 TRACE_SANITIZE (this);
105 return_trace (likely (c->check_struct (this) && lookupTable.sanitize (c, base)));
106 }
107
108 protected:
109 Lookup<OffsetTo<LigCaretClassEntry>>
110 lookupTable; /* data Lookup table associating glyphs */
111 public:
112 DEFINE_SIZE_MIN (2);
113};
114
115struct lcar
116{
117 static constexpr hb_tag_t tableTag = HB_AAT_TAG_lcar;
118
119 unsigned int get_lig_carets (hb_font_t *font,
120 hb_direction_t direction,
121 hb_codepoint_t glyph,
122 unsigned int start_offset,
123 unsigned int *caret_count /* IN/OUT */,
124 hb_position_t *caret_array /* OUT */) const
125 {
126 switch (format)
127 {
128 case 0: return u.format0.get_lig_carets (font, direction, glyph, start_offset,
129 caret_count, caret_array, this);
130 case 1: return u.format1.get_lig_carets (font, direction, glyph, start_offset,
131 caret_count, caret_array, this);
132 default:if (caret_count) *caret_count = 0; return 0;
133 }
134 }
135
136 bool sanitize (hb_sanitize_context_t *c) const
137 {
138 TRACE_SANITIZE (this);
139 if (unlikely (!c->check_struct (this) || version.major != 1))
140 return_trace (false);
141
142 switch (format) {
143 case 0: return_trace (u.format0.sanitize (c, this));
144 case 1: return_trace (u.format1.sanitize (c, this));
145 default:return_trace (true);
146 }
147 }
148
149 protected:
150 FixedVersion<>version; /* Version number of the ligature caret table */
151 HBUINT16 format; /* Format of the ligature caret table. */
152 union {
153 lcarFormat0 format0;
154 lcarFormat0 format1;
155 } u;
156 public:
157 DEFINE_SIZE_MIN (8);
158};
159
160} /* namespace AAT */
161
162#endif /* HB_AAT_LAYOUT_LCAR_TABLE_HH */
163