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harfbuzz/src/hb-ot-os2-table.hh

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/*
* 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->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);
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);
}
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 */
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