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Diffstat (limited to '')
-rw-r--r-- | gfx/harfbuzz/src/hb-ot-os2-table.hh | 362 |
1 files changed, 362 insertions, 0 deletions
diff --git a/gfx/harfbuzz/src/hb-ot-os2-table.hh b/gfx/harfbuzz/src/hb-ot-os2-table.hh new file mode 100644 index 0000000000..5b017d56a6 --- /dev/null +++ b/gfx/harfbuzz/src/hb-ot-os2-table.hh @@ -0,0 +1,362 @@ +/* + * Copyright © 2011,2012 Google, Inc. + * Copyright © 2018 Ebrahim Byagowi + * + * This is part of HarfBuzz, a text shaping library. + * + * Permission is hereby granted, without written agreement and without + * license or royalty fees, to use, copy, modify, and distribute this + * software and its documentation for any purpose, provided that the + * above copyright notice and the following two paragraphs appear in + * all copies of this software. + * + * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR + * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES + * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN + * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH + * DAMAGE. + * + * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, + * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND + * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS + * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO + * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS. + * + * Google Author(s): Behdad Esfahbod + */ + +#ifndef HB_OT_OS2_TABLE_HH +#define HB_OT_OS2_TABLE_HH + +#include "hb-open-type.hh" +#include "hb-ot-os2-unicode-ranges.hh" + +#include "hb-set.hh" + +/* + * OS/2 and Windows Metrics + * https://docs.microsoft.com/en-us/typography/opentype/spec/os2 + */ +#define HB_OT_TAG_OS2 HB_TAG('O','S','/','2') + + +namespace OT { + +struct OS2V1Tail +{ + bool sanitize (hb_sanitize_context_t *c) const + { + TRACE_SANITIZE (this); + return_trace (c->check_struct (this)); + } + + public: + HBUINT32 ulCodePageRange1; + HBUINT32 ulCodePageRange2; + public: + DEFINE_SIZE_STATIC (8); +}; + +struct OS2V2Tail +{ + bool has_data () const { return sxHeight || sCapHeight; } + + const OS2V2Tail * operator -> () const { return this; } + + bool sanitize (hb_sanitize_context_t *c) const + { + TRACE_SANITIZE (this); + return_trace (c->check_struct (this)); + } + + public: + HBINT16 sxHeight; + HBINT16 sCapHeight; + HBUINT16 usDefaultChar; + HBUINT16 usBreakChar; + HBUINT16 usMaxContext; + public: + DEFINE_SIZE_STATIC (10); +}; + +struct OS2V5Tail +{ + inline bool get_optical_size (unsigned int *lower, unsigned int *upper) const + { + unsigned int lower_optical_size = usLowerOpticalPointSize; + unsigned int upper_optical_size = usUpperOpticalPointSize; + + /* Per https://docs.microsoft.com/en-us/typography/opentype/spec/os2#lps */ + if (lower_optical_size < upper_optical_size && + lower_optical_size >= 1 && lower_optical_size <= 0xFFFE && + upper_optical_size >= 2 && upper_optical_size <= 0xFFFF) + { + *lower = lower_optical_size; + *upper = upper_optical_size; + return true; + } + return false; + } + + bool sanitize (hb_sanitize_context_t *c) const + { + TRACE_SANITIZE (this); + return_trace (c->check_struct (this)); + } + + public: + HBUINT16 usLowerOpticalPointSize; + HBUINT16 usUpperOpticalPointSize; + public: + DEFINE_SIZE_STATIC (4); +}; + +struct OS2 +{ + static constexpr hb_tag_t tableTag = HB_OT_TAG_OS2; + + bool has_data () const { return usWeightClass || usWidthClass || usFirstCharIndex || usLastCharIndex; } + + const OS2V1Tail &v1 () const { return version >= 1 ? v1X : Null (OS2V1Tail); } + const OS2V2Tail &v2 () const { return version >= 2 ? v2X : Null (OS2V2Tail); } + const OS2V5Tail &v5 () const { return version >= 5 ? v5X : Null (OS2V5Tail); } + + enum selection_flag_t { + ITALIC = 1u<<0, + UNDERSCORE = 1u<<1, + NEGATIVE = 1u<<2, + OUTLINED = 1u<<3, + STRIKEOUT = 1u<<4, + BOLD = 1u<<5, + REGULAR = 1u<<6, + USE_TYPO_METRICS = 1u<<7, + WWS = 1u<<8, + OBLIQUE = 1u<<9 + }; + + bool is_italic () const { return fsSelection & ITALIC; } + bool is_oblique () const { return fsSelection & OBLIQUE; } + bool use_typo_metrics () const { return fsSelection & USE_TYPO_METRICS; } + + enum width_class_t { + FWIDTH_ULTRA_CONDENSED = 1, /* 50% */ + FWIDTH_EXTRA_CONDENSED = 2, /* 62.5% */ + FWIDTH_CONDENSED = 3, /* 75% */ + FWIDTH_SEMI_CONDENSED = 4, /* 87.5% */ + FWIDTH_NORMAL = 5, /* 100% */ + FWIDTH_SEMI_EXPANDED = 6, /* 112.5% */ + FWIDTH_EXPANDED = 7, /* 125% */ + FWIDTH_EXTRA_EXPANDED = 8, /* 150% */ + FWIDTH_ULTRA_EXPANDED = 9 /* 200% */ + }; + + float get_width () const + { + switch (usWidthClass) { + case FWIDTH_ULTRA_CONDENSED:return 50.f; + case FWIDTH_EXTRA_CONDENSED:return 62.5f; + case FWIDTH_CONDENSED: return 75.f; + case FWIDTH_SEMI_CONDENSED: return 87.5f; + default: + case FWIDTH_NORMAL: return 100.f; + case FWIDTH_SEMI_EXPANDED: return 112.5f; + case FWIDTH_EXPANDED: return 125.f; + case FWIDTH_EXTRA_EXPANDED: return 150.f; + case FWIDTH_ULTRA_EXPANDED: return 200.f; + } + } + + float map_wdth_to_widthclass(float width) const + { + if (width < 50) return 1.0f; + if (width > 200) return 9.0f; + + float ratio = (width - 50) / 12.5f; + int a = (int) floorf (ratio); + int b = (int) ceilf (ratio); + + /* follow this maping: + * https://docs.microsoft.com/en-us/typography/opentype/spec/os2#uswidthclass + */ + if (b <= 6) // 50-125 + { + if (a == b) return a + 1.0f; + } + else if (b == 7) // no mapping for 137.5 + { + a = 6; + b = 8; + } + else if (b == 8) + { + if (a == b) return 8.0f; // 150 + a = 6; + } + else + { + if (a == b && a == 12) return 9.0f; //200 + b = 12; + a = 8; + } + + float va = 50 + a * 12.5f; + float vb = 50 + b * 12.5f; + + float ret = a + (width - va) / (vb - va); + if (a <= 6) ret += 1.0f; + return ret; + } + + bool subset (hb_subset_context_t *c) const + { + TRACE_SUBSET (this); + OS2 *os2_prime = c->serializer->embed (this); + if (unlikely (!os2_prime)) return_trace (false); + + if (c->plan->user_axes_location->has (HB_TAG ('w','g','h','t')) && + !c->plan->pinned_at_default) + { + float weight_class = c->plan->user_axes_location->get (HB_TAG ('w','g','h','t')); + if (!c->serializer->check_assign (os2_prime->usWeightClass, + roundf (hb_clamp (weight_class, 1.0f, 1000.0f)), + HB_SERIALIZE_ERROR_INT_OVERFLOW)) + return_trace (false); + } + + if (c->plan->user_axes_location->has (HB_TAG ('w','d','t','h')) && + !c->plan->pinned_at_default) + { + float width = c->plan->user_axes_location->get (HB_TAG ('w','d','t','h')); + if (!c->serializer->check_assign (os2_prime->usWidthClass, + roundf (map_wdth_to_widthclass (width)), + HB_SERIALIZE_ERROR_INT_OVERFLOW)) + return_trace (false); + } + + if (c->plan->flags & HB_SUBSET_FLAGS_NO_PRUNE_UNICODE_RANGES) + return_trace (true); + + /* when --gids option is not used, no need to do collect_mapping that is + * iterating all codepoints in each subtable, which is not efficient */ + uint16_t min_cp, max_cp; + find_min_and_max_codepoint (c->plan->unicodes, &min_cp, &max_cp); + os2_prime->usFirstCharIndex = min_cp; + os2_prime->usLastCharIndex = max_cp; + + _update_unicode_ranges (c->plan->unicodes, os2_prime->ulUnicodeRange); + + return_trace (true); + } + + void _update_unicode_ranges (const hb_set_t *codepoints, + HBUINT32 ulUnicodeRange[4]) const + { + HBUINT32 newBits[4]; + for (unsigned int i = 0; i < 4; i++) + newBits[i] = 0; + + hb_codepoint_t cp = HB_SET_VALUE_INVALID; + while (codepoints->next (&cp)) { + unsigned int bit = _hb_ot_os2_get_unicode_range_bit (cp); + if (bit < 128) + { + unsigned int block = bit / 32; + unsigned int bit_in_block = bit % 32; + unsigned int mask = 1 << bit_in_block; + newBits[block] = newBits[block] | mask; + } + if (cp >= 0x10000 && cp <= 0x110000) + { + /* the spec says that bit 57 ("Non Plane 0") implies that there's + at least one codepoint beyond the BMP; so I also include all + the non-BMP codepoints here */ + newBits[1] = newBits[1] | (1 << 25); + } + } + + for (unsigned int i = 0; i < 4; i++) + ulUnicodeRange[i] = ulUnicodeRange[i] & newBits[i]; // set bits only if set in the original + } + + static void find_min_and_max_codepoint (const hb_set_t *codepoints, + uint16_t *min_cp, /* OUT */ + uint16_t *max_cp /* OUT */) + { + *min_cp = hb_min (0xFFFFu, codepoints->get_min ()); + *max_cp = hb_min (0xFFFFu, codepoints->get_max ()); + } + + /* https://github.com/Microsoft/Font-Validator/blob/520aaae/OTFontFileVal/val_OS2.cs#L644-L681 + * https://docs.microsoft.com/en-us/typography/legacy/legacy_arabic_fonts */ + enum font_page_t + { + FONT_PAGE_NONE = 0, + FONT_PAGE_HEBREW = 0xB100, /* Hebrew Windows 3.1 font page */ + FONT_PAGE_SIMP_ARABIC = 0xB200, /* Simplified Arabic Windows 3.1 font page */ + FONT_PAGE_TRAD_ARABIC = 0xB300, /* Traditional Arabic Windows 3.1 font page */ + FONT_PAGE_OEM_ARABIC = 0xB400, /* OEM Arabic Windows 3.1 font page */ + FONT_PAGE_SIMP_FARSI = 0xBA00, /* Simplified Farsi Windows 3.1 font page */ + FONT_PAGE_TRAD_FARSI = 0xBB00, /* Traditional Farsi Windows 3.1 font page */ + FONT_PAGE_THAI = 0xDE00 /* Thai Windows 3.1 font page */ + }; + font_page_t get_font_page () const + { return (font_page_t) (version == 0 ? fsSelection & 0xFF00 : 0); } + + unsigned get_size () const + { + unsigned result = min_size; + if (version >= 1) result += v1X.get_size (); + if (version >= 2) result += v2X.get_size (); + if (version >= 5) result += v5X.get_size (); + return result; + } + + bool sanitize (hb_sanitize_context_t *c) const + { + TRACE_SANITIZE (this); + if (unlikely (!c->check_struct (this))) return_trace (false); + if (unlikely (version >= 1 && !v1X.sanitize (c))) return_trace (false); + if (unlikely (version >= 2 && !v2X.sanitize (c))) return_trace (false); + if (unlikely (version >= 5 && !v5X.sanitize (c))) return_trace (false); + return_trace (true); + } + + public: + HBUINT16 version; + HBINT16 xAvgCharWidth; + HBUINT16 usWeightClass; + HBUINT16 usWidthClass; + HBUINT16 fsType; + HBINT16 ySubscriptXSize; + HBINT16 ySubscriptYSize; + HBINT16 ySubscriptXOffset; + HBINT16 ySubscriptYOffset; + HBINT16 ySuperscriptXSize; + HBINT16 ySuperscriptYSize; + HBINT16 ySuperscriptXOffset; + HBINT16 ySuperscriptYOffset; + HBINT16 yStrikeoutSize; + HBINT16 yStrikeoutPosition; + HBINT16 sFamilyClass; + HBUINT8 panose[10]; + HBUINT32 ulUnicodeRange[4]; + Tag achVendID; + HBUINT16 fsSelection; + HBUINT16 usFirstCharIndex; + HBUINT16 usLastCharIndex; + HBINT16 sTypoAscender; + HBINT16 sTypoDescender; + HBINT16 sTypoLineGap; + HBUINT16 usWinAscent; + HBUINT16 usWinDescent; + OS2V1Tail v1X; + OS2V2Tail v2X; + OS2V5Tail v5X; + public: + DEFINE_SIZE_MIN (78); +}; + +} /* namespace OT */ + + +#endif /* HB_OT_OS2_TABLE_HH */ |