1/*
2 * Copyright © 2011,2012 Google, Inc.
3 * Copyright © 2018 Ebrahim Byagowi
4 *
5 * This is part of HarfBuzz, a text shaping library.
6 *
7 * Permission is hereby granted, without written agreement and without
8 * license or royalty fees, to use, copy, modify, and distribute this
9 * software and its documentation for any purpose, provided that the
10 * above copyright notice and the following two paragraphs appear in
11 * all copies of this software.
12 *
13 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
14 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
15 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
16 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
17 * DAMAGE.
18 *
19 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
20 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
21 * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
22 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
23 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
24 *
25 * Google Author(s): Behdad Esfahbod
26 */
27
28#ifndef HB_OT_OS2_TABLE_HH
29#define HB_OT_OS2_TABLE_HH
30
31#include "hb-open-type.hh"
32#include "hb-ot-os2-unicode-ranges.hh"
33#include "hb-ot-cmap-table.hh"
34
35#include "hb-set.hh"
36
37/*
38 * OS/2 and Windows Metrics
39 * https://docs.microsoft.com/en-us/typography/opentype/spec/os2
40 */
41#define HB_OT_TAG_OS2 HB_TAG('O','S','/','2')
42
43
44namespace OT {
45
46struct OS2V1Tail
47{
48 bool sanitize (hb_sanitize_context_t *c) const
49 {
50 TRACE_SANITIZE (this);
51 return_trace (c->check_struct (this));
52 }
53
54 public:
55 HBUINT32 ulCodePageRange1;
56 HBUINT32 ulCodePageRange2;
57 public:
58 DEFINE_SIZE_STATIC (8);
59};
60
61struct OS2V2Tail
62{
63 bool has_data () const { return sxHeight || sCapHeight; }
64
65 const OS2V2Tail * operator -> () const { return this; }
66
67 bool sanitize (hb_sanitize_context_t *c) const
68 {
69 TRACE_SANITIZE (this);
70 return_trace (c->check_struct (this));
71 }
72
73 public:
74 HBINT16 sxHeight;
75 HBINT16 sCapHeight;
76 HBUINT16 usDefaultChar;
77 HBUINT16 usBreakChar;
78 HBUINT16 usMaxContext;
79 public:
80 DEFINE_SIZE_STATIC (10);
81};
82
83struct OS2V5Tail
84{
85 inline bool get_optical_size (unsigned int *lower, unsigned int *upper) const
86 {
87 unsigned int lower_optical_size = usLowerOpticalPointSize;
88 unsigned int upper_optical_size = usUpperOpticalPointSize;
89
90 /* Per https://docs.microsoft.com/en-us/typography/opentype/spec/os2#lps */
91 if (lower_optical_size < upper_optical_size &&
92 lower_optical_size >= 1 && lower_optical_size <= 0xFFFE &&
93 upper_optical_size >= 2 && upper_optical_size <= 0xFFFF)
94 {
95 *lower = lower_optical_size;
96 *upper = upper_optical_size;
97 return true;
98 }
99 return false;
100 }
101
102 bool sanitize (hb_sanitize_context_t *c) const
103 {
104 TRACE_SANITIZE (this);
105 return_trace (c->check_struct (this));
106 }
107
108 public:
109 HBUINT16 usLowerOpticalPointSize;
110 HBUINT16 usUpperOpticalPointSize;
111 public:
112 DEFINE_SIZE_STATIC (4);
113};
114
115struct OS2
116{
117 static constexpr hb_tag_t tableTag = HB_OT_TAG_OS2;
118
119 bool has_data () const { return usWeightClass || usWidthClass || usFirstCharIndex || usLastCharIndex; }
120
121 const OS2V1Tail &v1 () const { return version >= 1 ? v1X : Null (OS2V1Tail); }
122 const OS2V2Tail &v2 () const { return version >= 2 ? v2X : Null (OS2V2Tail); }
123 const OS2V5Tail &v5 () const { return version >= 5 ? v5X : Null (OS2V5Tail); }
124
125 enum selection_flag_t {
126 ITALIC = 1u<<0,
127 UNDERSCORE = 1u<<1,
128 NEGATIVE = 1u<<2,
129 OUTLINED = 1u<<3,
130 STRIKEOUT = 1u<<4,
131 BOLD = 1u<<5,
132 REGULAR = 1u<<6,
133 USE_TYPO_METRICS = 1u<<7,
134 WWS = 1u<<8,
135 OBLIQUE = 1u<<9
136 };
137
138 bool is_italic () const { return fsSelection & ITALIC; }
139 bool is_oblique () const { return fsSelection & OBLIQUE; }
140 bool use_typo_metrics () const { return fsSelection & USE_TYPO_METRICS; }
141
142 enum width_class_t {
143 FWIDTH_ULTRA_CONDENSED = 1, /* 50% */
144 FWIDTH_EXTRA_CONDENSED = 2, /* 62.5% */
145 FWIDTH_CONDENSED = 3, /* 75% */
146 FWIDTH_SEMI_CONDENSED = 4, /* 87.5% */
147 FWIDTH_NORMAL = 5, /* 100% */
148 FWIDTH_SEMI_EXPANDED = 6, /* 112.5% */
149 FWIDTH_EXPANDED = 7, /* 125% */
150 FWIDTH_EXTRA_EXPANDED = 8, /* 150% */
151 FWIDTH_ULTRA_EXPANDED = 9 /* 200% */
152 };
153
154 float get_width () const
155 {
156 switch (usWidthClass) {
157 case FWIDTH_ULTRA_CONDENSED:return 50.f;
158 case FWIDTH_EXTRA_CONDENSED:return 62.5f;
159 case FWIDTH_CONDENSED: return 75.f;
160 case FWIDTH_SEMI_CONDENSED: return 87.5f;
161 default:
162 case FWIDTH_NORMAL: return 100.f;
163 case FWIDTH_SEMI_EXPANDED: return 112.5f;
164 case FWIDTH_EXPANDED: return 125.f;
165 case FWIDTH_EXTRA_EXPANDED: return 150.f;
166 case FWIDTH_ULTRA_EXPANDED: return 200.f;
167 }
168 }
169
170 bool subset (hb_subset_context_t *c) const
171 {
172 TRACE_SUBSET (this);
173 OS2 *os2_prime = c->serializer->embed (this);
174 if (unlikely (!os2_prime)) return_trace (false);
175
176 hb_set_t unicodes;
177 if (!c->plan->glyphs_requested->is_empty ())
178 {
179 hb_map_t unicode_glyphid_map;
180
181 OT::cmap::accelerator_t cmap;
182 cmap.init (c->plan->source);
183 cmap.collect_mapping (&unicodes, &unicode_glyphid_map);
184 cmap.fini ();
185
186 if (c->plan->unicodes->is_empty ()) unicodes.clear ();
187 else hb_set_set (&unicodes, c->plan->unicodes);
188
189 + unicode_glyphid_map.iter ()
190 | hb_filter (c->plan->glyphs_requested, hb_second)
191 | hb_map (hb_first)
192 | hb_sink (unicodes)
193 ;
194 }
195 /* when --gids option is not used, no need to do collect_mapping that is
196 * iterating all codepoints in each subtable, which is not efficient */
197 uint16_t min_cp, max_cp;
198 find_min_and_max_codepoint (unicodes.is_empty () ? c->plan->unicodes : &unicodes, &min_cp, &max_cp);
199 os2_prime->usFirstCharIndex = min_cp;
200 os2_prime->usLastCharIndex = max_cp;
201
202 _update_unicode_ranges (unicodes.is_empty () ? c->plan->unicodes : &unicodes, os2_prime->ulUnicodeRange);
203
204 return_trace (true);
205 }
206
207 void _update_unicode_ranges (const hb_set_t *codepoints,
208 HBUINT32 ulUnicodeRange[4]) const
209 {
210 HBUINT32 newBits[4];
211 for (unsigned int i = 0; i < 4; i++)
212 newBits[i] = 0;
213
214 hb_codepoint_t cp = HB_SET_VALUE_INVALID;
215 while (codepoints->next (&cp)) {
216 unsigned int bit = _hb_ot_os2_get_unicode_range_bit (cp);
217 if (bit < 128)
218 {
219 unsigned int block = bit / 32;
220 unsigned int bit_in_block = bit % 32;
221 unsigned int mask = 1 << bit_in_block;
222 newBits[block] = newBits[block] | mask;
223 }
224 if (cp >= 0x10000 && cp <= 0x110000)
225 {
226 /* the spec says that bit 57 ("Non Plane 0") implies that there's
227 at least one codepoint beyond the BMP; so I also include all
228 the non-BMP codepoints here */
229 newBits[1] = newBits[1] | (1 << 25);
230 }
231 }
232
233 for (unsigned int i = 0; i < 4; i++)
234 ulUnicodeRange[i] = ulUnicodeRange[i] & newBits[i]; // set bits only if set in the original
235 }
236
237 static void find_min_and_max_codepoint (const hb_set_t *codepoints,
238 uint16_t *min_cp, /* OUT */
239 uint16_t *max_cp /* OUT */)
240 {
241 *min_cp = hb_min (0xFFFFu, codepoints->get_min ());
242 *max_cp = hb_min (0xFFFFu, codepoints->get_max ());
243 }
244
245 /* https://github.com/Microsoft/Font-Validator/blob/520aaae/OTFontFileVal/val_OS2.cs#L644-L681 */
246 enum font_page_t
247 {
248 FONT_PAGE_HEBREW = 0xB100, /* Hebrew Windows 3.1 font page */
249 FONT_PAGE_SIMP_ARABIC = 0xB200, /* Simplified Arabic Windows 3.1 font page */
250 FONT_PAGE_TRAD_ARABIC = 0xB300, /* Traditional Arabic Windows 3.1 font page */
251 FONT_PAGE_OEM_ARABIC = 0xB400, /* OEM Arabic Windows 3.1 font page */
252 FONT_PAGE_SIMP_FARSI = 0xBA00, /* Simplified Farsi Windows 3.1 font page */
253 FONT_PAGE_TRAD_FARSI = 0xBB00, /* Traditional Farsi Windows 3.1 font page */
254 FONT_PAGE_THAI = 0xDE00 /* Thai Windows 3.1 font page */
255 };
256 font_page_t get_font_page () const
257 { return (font_page_t) (version == 0 ? fsSelection & 0xFF00 : 0); }
258
259 unsigned get_size () const
260 {
261 unsigned result = min_size;
262 if (version >= 1) result += v1X.get_size ();
263 if (version >= 2) result += v2X.get_size ();
264 if (version >= 5) result += v5X.get_size ();
265 return result;
266 }
267
268 bool sanitize (hb_sanitize_context_t *c) const
269 {
270 TRACE_SANITIZE (this);
271 if (unlikely (!c->check_struct (this))) return_trace (false);
272 if (unlikely (version >= 1 && !v1X.sanitize (c))) return_trace (false);
273 if (unlikely (version >= 2 && !v2X.sanitize (c))) return_trace (false);
274 if (unlikely (version >= 5 && !v5X.sanitize (c))) return_trace (false);
275 return_trace (true);
276 }
277
278 public:
279 HBUINT16 version;
280 HBINT16 xAvgCharWidth;
281 HBUINT16 usWeightClass;
282 HBUINT16 usWidthClass;
283 HBUINT16 fsType;
284 HBINT16 ySubscriptXSize;
285 HBINT16 ySubscriptYSize;
286 HBINT16 ySubscriptXOffset;
287 HBINT16 ySubscriptYOffset;
288 HBINT16 ySuperscriptXSize;
289 HBINT16 ySuperscriptYSize;
290 HBINT16 ySuperscriptXOffset;
291 HBINT16 ySuperscriptYOffset;
292 HBINT16 yStrikeoutSize;
293 HBINT16 yStrikeoutPosition;
294 HBINT16 sFamilyClass;
295 HBUINT8 panose[10];
296 HBUINT32 ulUnicodeRange[4];
297 Tag achVendID;
298 HBUINT16 fsSelection;
299 HBUINT16 usFirstCharIndex;
300 HBUINT16 usLastCharIndex;
301 HBINT16 sTypoAscender;
302 HBINT16 sTypoDescender;
303 HBINT16 sTypoLineGap;
304 HBUINT16 usWinAscent;
305 HBUINT16 usWinDescent;
306 OS2V1Tail v1X;
307 OS2V2Tail v2X;
308 OS2V5Tail v5X;
309 public:
310 DEFINE_SIZE_MIN (78);
311};
312
313} /* namespace OT */
314
315
316#endif /* HB_OT_OS2_TABLE_HH */
317