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
34#include "hb-set.hh"
35
36/*
37 * OS/2 and Windows Metrics
38 * https://docs.microsoft.com/en-us/typography/opentype/spec/os2
39 */
40#define HB_OT_TAG_OS2 HB_TAG('O','S','/','2')
41
42
43namespace OT {
44
45struct OS2V1Tail
46{
47 bool sanitize (hb_sanitize_context_t *c) const
48 {
49 TRACE_SANITIZE (this);
50 return_trace (c->check_struct (this));
51 }
52
53 public:
54 HBUINT32 ulCodePageRange1;
55 HBUINT32 ulCodePageRange2;
56 public:
57 DEFINE_SIZE_STATIC (8);
58};
59
60struct OS2V2Tail
61{
62 bool has_data () const { return sxHeight || sCapHeight; }
63
64 const OS2V2Tail * operator -> () const { return this; }
65
66 bool sanitize (hb_sanitize_context_t *c) const
67 {
68 TRACE_SANITIZE (this);
69 return_trace (c->check_struct (this));
70 }
71
72 public:
73 HBINT16 sxHeight;
74 HBINT16 sCapHeight;
75 HBUINT16 usDefaultChar;
76 HBUINT16 usBreakChar;
77 HBUINT16 usMaxContext;
78 public:
79 DEFINE_SIZE_STATIC (10);
80};
81
82struct OS2V5Tail
83{
84 inline bool get_optical_size (unsigned int *lower, unsigned int *upper) const
85 {
86 unsigned int lower_optical_size = usLowerOpticalPointSize;
87 unsigned int upper_optical_size = usUpperOpticalPointSize;
88
89 /* Per https://docs.microsoft.com/en-us/typography/opentype/spec/os2#lps */
90 if (lower_optical_size < upper_optical_size &&
91 lower_optical_size >= 1 && lower_optical_size <= 0xFFFE &&
92 upper_optical_size >= 2 && upper_optical_size <= 0xFFFF)
93 {
94 *lower = lower_optical_size;
95 *upper = upper_optical_size;
96 return true;
97 }
98 return false;
99 }
100
101 bool sanitize (hb_sanitize_context_t *c) const
102 {
103 TRACE_SANITIZE (this);
104 return_trace (c->check_struct (this));
105 }
106
107 public:
108 HBUINT16 usLowerOpticalPointSize;
109 HBUINT16 usUpperOpticalPointSize;
110 public:
111 DEFINE_SIZE_STATIC (4);
112};
113
114struct OS2
115{
116 static constexpr hb_tag_t tableTag = HB_OT_TAG_OS2;
117
118 bool has_data () const { return usWeightClass || usWidthClass || usFirstCharIndex || usLastCharIndex; }
119
120 const OS2V1Tail &v1 () const { return version >= 1 ? v1X : Null (OS2V1Tail); }
121 const OS2V2Tail &v2 () const { return version >= 2 ? v2X : Null (OS2V2Tail); }
122 const OS2V5Tail &v5 () const { return version >= 5 ? v5X : Null (OS2V5Tail); }
123
124 enum selection_flag_t {
125 ITALIC = 1u<<0,
126 UNDERSCORE = 1u<<1,
127 NEGATIVE = 1u<<2,
128 OUTLINED = 1u<<3,
129 STRIKEOUT = 1u<<4,
130 BOLD = 1u<<5,
131 REGULAR = 1u<<6,
132 USE_TYPO_METRICS = 1u<<7,
133 WWS = 1u<<8,
134 OBLIQUE = 1u<<9
135 };
136
137 bool is_italic () const { return fsSelection & ITALIC; }
138 bool is_oblique () const { return fsSelection & OBLIQUE; }
139 bool use_typo_metrics () const { return fsSelection & USE_TYPO_METRICS; }
140
141 enum width_class_t {
142 FWIDTH_ULTRA_CONDENSED = 1, /* 50% */
143 FWIDTH_EXTRA_CONDENSED = 2, /* 62.5% */
144 FWIDTH_CONDENSED = 3, /* 75% */
145 FWIDTH_SEMI_CONDENSED = 4, /* 87.5% */
146 FWIDTH_NORMAL = 5, /* 100% */
147 FWIDTH_SEMI_EXPANDED = 6, /* 112.5% */
148 FWIDTH_EXPANDED = 7, /* 125% */
149 FWIDTH_EXTRA_EXPANDED = 8, /* 150% */
150 FWIDTH_ULTRA_EXPANDED = 9 /* 200% */
151 };
152
153 float get_width () const
154 {
155 switch (usWidthClass) {
156 case FWIDTH_ULTRA_CONDENSED:return 50.f;
157 case FWIDTH_EXTRA_CONDENSED:return 62.5f;
158 case FWIDTH_CONDENSED: return 75.f;
159 case FWIDTH_SEMI_CONDENSED: return 87.5f;
160 default:
161 case FWIDTH_NORMAL: return 100.f;
162 case FWIDTH_SEMI_EXPANDED: return 112.5f;
163 case FWIDTH_EXPANDED: return 125.f;
164 case FWIDTH_EXTRA_EXPANDED: return 150.f;
165 case FWIDTH_ULTRA_EXPANDED: return 200.f;
166 }
167 }
168
169 bool subset (hb_subset_context_t *c) const
170 {
171 TRACE_SUBSET (this);
172 OS2 *os2_prime = c->serializer->embed (this);
173 if (unlikely (!os2_prime)) return_trace (false);
174
175 uint16_t min_cp, max_cp;
176 find_min_and_max_codepoint (c->plan->unicodes, &min_cp, &max_cp);
177 os2_prime->usFirstCharIndex = min_cp;
178 os2_prime->usLastCharIndex = max_cp;
179
180 _update_unicode_ranges (c->plan->unicodes, os2_prime->ulUnicodeRange);
181
182 return_trace (true);
183 }
184
185 void _update_unicode_ranges (const hb_set_t *codepoints,
186 HBUINT32 ulUnicodeRange[4]) const
187 {
188 HBUINT32 newBits[4];
189 for (unsigned int i = 0; i < 4; i++)
190 newBits[i] = 0;
191
192 hb_codepoint_t cp = HB_SET_VALUE_INVALID;
193 while (codepoints->next (&cp)) {
194 unsigned int bit = _hb_ot_os2_get_unicode_range_bit (cp);
195 if (bit < 128)
196 {
197 unsigned int block = bit / 32;
198 unsigned int bit_in_block = bit % 32;
199 unsigned int mask = 1 << bit_in_block;
200 newBits[block] = newBits[block] | mask;
201 }
202 if (cp >= 0x10000 && cp <= 0x110000)
203 {
204 /* the spec says that bit 57 ("Non Plane 0") implies that there's
205 at least one codepoint beyond the BMP; so I also include all
206 the non-BMP codepoints here */
207 newBits[1] = newBits[1] | (1 << 25);
208 }
209 }
210
211 for (unsigned int i = 0; i < 4; i++)
212 ulUnicodeRange[i] = ulUnicodeRange[i] & newBits[i]; // set bits only if set in the original
213 }
214
215 static void find_min_and_max_codepoint (const hb_set_t *codepoints,
216 uint16_t *min_cp, /* OUT */
217 uint16_t *max_cp /* OUT */)
218 {
219 *min_cp = codepoints->get_min ();
220 *max_cp = codepoints->get_max ();
221 }
222
223 /* https://github.com/Microsoft/Font-Validator/blob/520aaae/OTFontFileVal/val_OS2.cs#L644-L681 */
224 enum font_page_t {
225 HEBREW_FONT_PAGE = 0xB100, // Hebrew Windows 3.1 font page
226 SIMP_ARABIC_FONT_PAGE = 0xB200, // Simplified Arabic Windows 3.1 font page
227 TRAD_ARABIC_FONT_PAGE = 0xB300, // Traditional Arabic Windows 3.1 font page
228 OEM_ARABIC_FONT_PAGE = 0xB400, // OEM Arabic Windows 3.1 font page
229 SIMP_FARSI_FONT_PAGE = 0xBA00, // Simplified Farsi Windows 3.1 font page
230 TRAD_FARSI_FONT_PAGE = 0xBB00, // Traditional Farsi Windows 3.1 font page
231 THAI_FONT_PAGE = 0xDE00 // Thai Windows 3.1 font page
232 };
233 font_page_t get_font_page () const
234 { return (font_page_t) (version == 0 ? fsSelection & 0xFF00 : 0); }
235
236 unsigned get_size () const
237 {
238 unsigned result = min_size;
239 if (version >= 1) result += v1X.get_size ();
240 if (version >= 2) result += v2X.get_size ();
241 if (version >= 5) result += v5X.get_size ();
242 return result;
243 }
244
245 bool sanitize (hb_sanitize_context_t *c) const
246 {
247 TRACE_SANITIZE (this);
248 if (unlikely (!c->check_struct (this))) return_trace (false);
249 if (unlikely (version >= 1 && !v1X.sanitize (c))) return_trace (false);
250 if (unlikely (version >= 2 && !v2X.sanitize (c))) return_trace (false);
251 if (unlikely (version >= 5 && !v5X.sanitize (c))) return_trace (false);
252 return_trace (true);
253 }
254
255 public:
256 HBUINT16 version;
257 HBINT16 xAvgCharWidth;
258 HBUINT16 usWeightClass;
259 HBUINT16 usWidthClass;
260 HBUINT16 fsType;
261 HBINT16 ySubscriptXSize;
262 HBINT16 ySubscriptYSize;
263 HBINT16 ySubscriptXOffset;
264 HBINT16 ySubscriptYOffset;
265 HBINT16 ySuperscriptXSize;
266 HBINT16 ySuperscriptYSize;
267 HBINT16 ySuperscriptXOffset;
268 HBINT16 ySuperscriptYOffset;
269 HBINT16 yStrikeoutSize;
270 HBINT16 yStrikeoutPosition;
271 HBINT16 sFamilyClass;
272 HBUINT8 panose[10];
273 HBUINT32 ulUnicodeRange[4];
274 Tag achVendID;
275 HBUINT16 fsSelection;
276 HBUINT16 usFirstCharIndex;
277 HBUINT16 usLastCharIndex;
278 HBINT16 sTypoAscender;
279 HBINT16 sTypoDescender;
280 HBINT16 sTypoLineGap;
281 HBUINT16 usWinAscent;
282 HBUINT16 usWinDescent;
283 OS2V1Tail v1X;
284 OS2V2Tail v2X;
285 OS2V5Tail v5X;
286 public:
287 DEFINE_SIZE_MIN (78);
288};
289
290} /* namespace OT */
291
292
293#endif /* HB_OT_OS2_TABLE_HH */
294