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-var-mvar-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 OS2V2Tail * operator -> () { return this; }
67
68 bool sanitize (hb_sanitize_context_t *c) const
69 {
70 TRACE_SANITIZE (this);
71 return_trace (c->check_struct (this));
72 }
73
74 public:
75 HBINT16 sxHeight;
76 HBINT16 sCapHeight;
77 HBUINT16 usDefaultChar;
78 HBUINT16 usBreakChar;
79 HBUINT16 usMaxContext;
80 public:
81 DEFINE_SIZE_STATIC (10);
82};
83
84struct OS2V5Tail
85{
86 inline bool get_optical_size (unsigned int *lower, unsigned int *upper) const
87 {
88 unsigned int lower_optical_size = usLowerOpticalPointSize;
89 unsigned int upper_optical_size = usUpperOpticalPointSize;
90
91 /* Per https://docs.microsoft.com/en-us/typography/opentype/spec/os2#lps */
92 if (lower_optical_size < upper_optical_size &&
93 lower_optical_size >= 1 && lower_optical_size <= 0xFFFE &&
94 upper_optical_size >= 2 && upper_optical_size <= 0xFFFF)
95 {
96 *lower = lower_optical_size;
97 *upper = upper_optical_size;
98 return true;
99 }
100 return false;
101 }
102
103 bool sanitize (hb_sanitize_context_t *c) const
104 {
105 TRACE_SANITIZE (this);
106 return_trace (c->check_struct (this));
107 }
108
109 public:
110 HBUINT16 usLowerOpticalPointSize;
111 HBUINT16 usUpperOpticalPointSize;
112 public:
113 DEFINE_SIZE_STATIC (4);
114};
115
116struct OS2
117{
118 static constexpr hb_tag_t tableTag = HB_OT_TAG_OS2;
119
120 bool has_data () const { return usWeightClass || usWidthClass || usFirstCharIndex || usLastCharIndex; }
121
122 const OS2V1Tail &v1 () const { return version >= 1 ? v1X : Null (OS2V1Tail); }
123 const OS2V2Tail &v2 () const { return version >= 2 ? v2X : Null (OS2V2Tail); }
124 const OS2V5Tail &v5 () const { return version >= 5 ? v5X : Null (OS2V5Tail); }
125
126 enum selection_flag_t {
127 ITALIC = 1u<<0,
128 UNDERSCORE = 1u<<1,
129 NEGATIVE = 1u<<2,
130 OUTLINED = 1u<<3,
131 STRIKEOUT = 1u<<4,
132 BOLD = 1u<<5,
133 REGULAR = 1u<<6,
134 USE_TYPO_METRICS = 1u<<7,
135 WWS = 1u<<8,
136 OBLIQUE = 1u<<9
137 };
138
139 bool is_italic () const { return fsSelection & ITALIC; }
140 bool is_oblique () const { return fsSelection & OBLIQUE; }
141 bool use_typo_metrics () const { return fsSelection & USE_TYPO_METRICS; }
142
143 enum width_class_t {
144 FWIDTH_ULTRA_CONDENSED = 1, /* 50% */
145 FWIDTH_EXTRA_CONDENSED = 2, /* 62.5% */
146 FWIDTH_CONDENSED = 3, /* 75% */
147 FWIDTH_SEMI_CONDENSED = 4, /* 87.5% */
148 FWIDTH_NORMAL = 5, /* 100% */
149 FWIDTH_SEMI_EXPANDED = 6, /* 112.5% */
150 FWIDTH_EXPANDED = 7, /* 125% */
151 FWIDTH_EXTRA_EXPANDED = 8, /* 150% */
152 FWIDTH_ULTRA_EXPANDED = 9 /* 200% */
153 };
154
155 float get_width () const
156 {
157 switch (usWidthClass) {
158 case FWIDTH_ULTRA_CONDENSED:return 50.f;
159 case FWIDTH_EXTRA_CONDENSED:return 62.5f;
160 case FWIDTH_CONDENSED: return 75.f;
161 case FWIDTH_SEMI_CONDENSED: return 87.5f;
162 default:
163 case FWIDTH_NORMAL: return 100.f;
164 case FWIDTH_SEMI_EXPANDED: return 112.5f;
165 case FWIDTH_EXPANDED: return 125.f;
166 case FWIDTH_EXTRA_EXPANDED: return 150.f;
167 case FWIDTH_ULTRA_EXPANDED: return 200.f;
168 }
169 }
170
171 float map_wdth_to_widthclass(float width) const
172 {
173 if (width < 50) return 1.0f;
174 if (width > 200) return 9.0f;
175
176 float ratio = (width - 50) / 12.5f;
177 int a = (int) floorf (ratio);
178 int b = (int) ceilf (ratio);
179
180 /* follow this maping:
181 * https://docs.microsoft.com/en-us/typography/opentype/spec/os2#uswidthclass
182 */
183 if (b <= 6) // 50-125
184 {
185 if (a == b) return a + 1.0f;
186 }
187 else if (b == 7) // no mapping for 137.5
188 {
189 a = 6;
190 b = 8;
191 }
192 else if (b == 8)
193 {
194 if (a == b) return 8.0f; // 150
195 a = 6;
196 }
197 else
198 {
199 if (a == b && a == 12) return 9.0f; //200
200 b = 12;
201 a = 8;
202 }
203
204 float va = 50 + a * 12.5f;
205 float vb = 50 + b * 12.5f;
206
207 float ret = a + (width - va) / (vb - va);
208 if (a <= 6) ret += 1.0f;
209 return ret;
210 }
211
212 bool subset (hb_subset_context_t *c) const
213 {
214 TRACE_SUBSET (this);
215 OS2 *os2_prime = c->serializer->embed (this);
216 if (unlikely (!os2_prime)) return_trace (false);
217
218#ifndef HB_NO_VAR
219 if (c->plan->normalized_coords)
220 {
221 auto &MVAR = *c->plan->source->table.MVAR;
222 auto *table = os2_prime;
223
224 HB_ADD_MVAR_VAR (HB_OT_METRICS_TAG_HORIZONTAL_ASCENDER, sTypoAscender);
225 HB_ADD_MVAR_VAR (HB_OT_METRICS_TAG_HORIZONTAL_DESCENDER, sTypoDescender);
226 HB_ADD_MVAR_VAR (HB_OT_METRICS_TAG_HORIZONTAL_LINE_GAP, sTypoLineGap);
227 HB_ADD_MVAR_VAR (HB_OT_METRICS_TAG_HORIZONTAL_CLIPPING_ASCENT, usWinAscent);
228 HB_ADD_MVAR_VAR (HB_OT_METRICS_TAG_HORIZONTAL_CLIPPING_DESCENT, usWinDescent);
229 HB_ADD_MVAR_VAR (HB_OT_METRICS_TAG_SUBSCRIPT_EM_X_SIZE, ySubscriptXSize);
230 HB_ADD_MVAR_VAR (HB_OT_METRICS_TAG_SUBSCRIPT_EM_Y_SIZE, ySubscriptYSize);
231 HB_ADD_MVAR_VAR (HB_OT_METRICS_TAG_SUBSCRIPT_EM_X_OFFSET, ySubscriptXOffset);
232 HB_ADD_MVAR_VAR (HB_OT_METRICS_TAG_SUBSCRIPT_EM_Y_OFFSET, ySubscriptYOffset);
233 HB_ADD_MVAR_VAR (HB_OT_METRICS_TAG_SUPERSCRIPT_EM_X_SIZE, ySuperscriptXSize);
234 HB_ADD_MVAR_VAR (HB_OT_METRICS_TAG_SUPERSCRIPT_EM_Y_SIZE, ySuperscriptYSize);
235 HB_ADD_MVAR_VAR (HB_OT_METRICS_TAG_SUPERSCRIPT_EM_X_OFFSET, ySuperscriptXOffset);
236 HB_ADD_MVAR_VAR (HB_OT_METRICS_TAG_SUPERSCRIPT_EM_Y_OFFSET, ySuperscriptYOffset);
237 HB_ADD_MVAR_VAR (HB_OT_METRICS_TAG_STRIKEOUT_SIZE, yStrikeoutSize);
238 HB_ADD_MVAR_VAR (HB_OT_METRICS_TAG_STRIKEOUT_OFFSET, yStrikeoutPosition);
239
240 if (os2_prime->version >= 2)
241 {
242 auto *table = & const_cast<OS2V2Tail &> (os2_prime->v2 ());
243 HB_ADD_MVAR_VAR (HB_OT_METRICS_TAG_X_HEIGHT, sxHeight);
244 HB_ADD_MVAR_VAR (HB_OT_METRICS_TAG_CAP_HEIGHT, sCapHeight);
245 }
246 }
247#endif
248
249 if (c->plan->user_axes_location.has (HB_TAG ('w','g','h','t')) &&
250 !c->plan->pinned_at_default)
251 {
252 float weight_class = c->plan->user_axes_location.get (HB_TAG ('w','g','h','t')).middle;
253 if (!c->serializer->check_assign (os2_prime->usWeightClass,
254 roundf (hb_clamp (weight_class, 1.0f, 1000.0f)),
255 HB_SERIALIZE_ERROR_INT_OVERFLOW))
256 return_trace (false);
257 }
258
259 if (c->plan->user_axes_location.has (HB_TAG ('w','d','t','h')) &&
260 !c->plan->pinned_at_default)
261 {
262 float width = c->plan->user_axes_location.get (HB_TAG ('w','d','t','h')).middle;
263 if (!c->serializer->check_assign (os2_prime->usWidthClass,
264 roundf (map_wdth_to_widthclass (width)),
265 HB_SERIALIZE_ERROR_INT_OVERFLOW))
266 return_trace (false);
267 }
268
269 if (c->plan->flags & HB_SUBSET_FLAGS_NO_PRUNE_UNICODE_RANGES)
270 return_trace (true);
271
272 os2_prime->usFirstCharIndex = hb_min (0xFFFFu, c->plan->unicodes.get_min ());
273 os2_prime->usLastCharIndex = hb_min (0xFFFFu, c->plan->unicodes.get_max ());
274
275 _update_unicode_ranges (&c->plan->unicodes, os2_prime->ulUnicodeRange);
276
277 return_trace (true);
278 }
279
280 void _update_unicode_ranges (const hb_set_t *codepoints,
281 HBUINT32 ulUnicodeRange[4]) const
282 {
283 HBUINT32 newBits[4];
284 for (unsigned int i = 0; i < 4; i++)
285 newBits[i] = 0;
286
287 /* This block doesn't show up in profiles. If it ever did,
288 * we can rewrite it to iterate over OS/2 ranges and use
289 * set iteration to check if the range matches. */
290 for (auto cp : *codepoints)
291 {
292 unsigned int bit = _hb_ot_os2_get_unicode_range_bit (cp);
293 if (bit < 128)
294 {
295 unsigned int block = bit / 32;
296 unsigned int bit_in_block = bit % 32;
297 unsigned int mask = 1 << bit_in_block;
298 newBits[block] = newBits[block] | mask;
299 }
300 if (cp >= 0x10000 && cp <= 0x110000)
301 {
302 /* the spec says that bit 57 ("Non Plane 0") implies that there's
303 at least one codepoint beyond the BMP; so I also include all
304 the non-BMP codepoints here */
305 newBits[1] = newBits[1] | (1 << 25);
306 }
307 }
308
309 for (unsigned int i = 0; i < 4; i++)
310 ulUnicodeRange[i] = ulUnicodeRange[i] & newBits[i]; // set bits only if set in the original
311 }
312
313 /* https://github.com/Microsoft/Font-Validator/blob/520aaae/OTFontFileVal/val_OS2.cs#L644-L681
314 * https://docs.microsoft.com/en-us/typography/legacy/legacy_arabic_fonts */
315 enum font_page_t
316 {
317 FONT_PAGE_NONE = 0,
318 FONT_PAGE_HEBREW = 0xB100, /* Hebrew Windows 3.1 font page */
319 FONT_PAGE_SIMP_ARABIC = 0xB200, /* Simplified Arabic Windows 3.1 font page */
320 FONT_PAGE_TRAD_ARABIC = 0xB300, /* Traditional Arabic Windows 3.1 font page */
321 FONT_PAGE_OEM_ARABIC = 0xB400, /* OEM Arabic Windows 3.1 font page */
322 FONT_PAGE_SIMP_FARSI = 0xBA00, /* Simplified Farsi Windows 3.1 font page */
323 FONT_PAGE_TRAD_FARSI = 0xBB00, /* Traditional Farsi Windows 3.1 font page */
324 FONT_PAGE_THAI = 0xDE00 /* Thai Windows 3.1 font page */
325 };
326 font_page_t get_font_page () const
327 { return (font_page_t) (version == 0 ? fsSelection & 0xFF00 : 0); }
328
329 unsigned get_size () const
330 {
331 unsigned result = min_size;
332 if (version >= 1) result += v1X.get_size ();
333 if (version >= 2) result += v2X.get_size ();
334 if (version >= 5) result += v5X.get_size ();
335 return result;
336 }
337
338 bool sanitize (hb_sanitize_context_t *c) const
339 {
340 TRACE_SANITIZE (this);
341 if (unlikely (!c->check_struct (this))) return_trace (false);
342 if (unlikely (version >= 1 && !v1X.sanitize (c))) return_trace (false);
343 if (unlikely (version >= 2 && !v2X.sanitize (c))) return_trace (false);
344 if (unlikely (version >= 5 && !v5X.sanitize (c))) return_trace (false);
345 return_trace (true);
346 }
347
348 public:
349 HBUINT16 version;
350 HBINT16 xAvgCharWidth;
351 HBUINT16 usWeightClass;
352 HBUINT16 usWidthClass;
353 HBUINT16 fsType;
354 HBINT16 ySubscriptXSize;
355 HBINT16 ySubscriptYSize;
356 HBINT16 ySubscriptXOffset;
357 HBINT16 ySubscriptYOffset;
358 HBINT16 ySuperscriptXSize;
359 HBINT16 ySuperscriptYSize;
360 HBINT16 ySuperscriptXOffset;
361 HBINT16 ySuperscriptYOffset;
362 HBINT16 yStrikeoutSize;
363 HBINT16 yStrikeoutPosition;
364 HBINT16 sFamilyClass;
365 HBUINT8 panose[10];
366 HBUINT32 ulUnicodeRange[4];
367 Tag achVendID;
368 HBUINT16 fsSelection;
369 HBUINT16 usFirstCharIndex;
370 HBUINT16 usLastCharIndex;
371 HBINT16 sTypoAscender;
372 HBINT16 sTypoDescender;
373 HBINT16 sTypoLineGap;
374 HBUINT16 usWinAscent;
375 HBUINT16 usWinDescent;
376 OS2V1Tail v1X;
377 OS2V2Tail v2X;
378 OS2V5Tail v5X;
379 public:
380 DEFINE_SIZE_MIN (78);
381};
382
383} /* namespace OT */
384
385
386#endif /* HB_OT_OS2_TABLE_HH */
387