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

200 lines
5.9 KiB
C++

/*
* Copyright © 2011,2012 Google, Inc.
*
* 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-private.hh"
#include "hb-ot-os2-unicode-ranges.hh"
#include "hb-subset-plan.hh"
namespace OT {
/*
* 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')
struct os2
{
static const hb_tag_t tableTag = HB_OT_TAG_os2;
inline bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return_trace (c->check_struct (this));
}
inline bool subset (hb_subset_plan_t *plan) const
{
hb_blob_t *os2_blob = OT::Sanitizer<OT::os2>().sanitize (hb_face_reference_table (plan->source, HB_OT_TAG_os2));
hb_blob_t *os2_prime_blob = hb_blob_create_sub_blob (os2_blob, 0, -1);
// TODO(grieger): move to hb_blob_copy_writable_or_fail
hb_blob_destroy (os2_blob);
OT::os2 *os2_prime = (OT::os2 *) hb_blob_get_data_writable (os2_prime_blob, nullptr);
if (unlikely (!os2_prime)) {
hb_blob_destroy (os2_prime_blob);
return false;
}
uint16_t min_cp, max_cp;
find_min_and_max_codepoint (plan->codepoints, &min_cp, &max_cp);
os2_prime->usFirstCharIndex.set (min_cp);
os2_prime->usLastCharIndex.set (max_cp);
_update_unicode_ranges (plan->codepoints, os2_prime->ulUnicodeRange);
bool result = hb_subset_plan_add_table(plan, HB_OT_TAG_os2, os2_prime_blob);
hb_blob_destroy (os2_prime_blob);
return result;
}
inline void _update_unicode_ranges (const hb_prealloced_array_t<hb_codepoint_t> &codepoints,
HBUINT32 ulUnicodeRange[4]) const
{
for (unsigned int i = 0; i < 4; i++)
ulUnicodeRange[i].set (0);
for (unsigned int i = 0; i < codepoints.len; i++)
{
hb_codepoint_t cp = codepoints[i];
unsigned int bit = hb_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;
ulUnicodeRange[block].set (ulUnicodeRange[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 */
ulUnicodeRange[1].set (ulUnicodeRange[1] | (1 << 25));
}
}
}
static inline void find_min_and_max_codepoint (const hb_prealloced_array_t<hb_codepoint_t> &codepoints,
uint16_t *min_cp, /* OUT */
uint16_t *max_cp /* OUT */)
{
hb_codepoint_t min = -1, max = 0;
for (unsigned int i = 0; i < codepoints.len; i++)
{
hb_codepoint_t cp = codepoints[i];
if (cp < min)
min = cp;
if (cp > max)
max = cp;
}
if (min > 0xFFFF)
min = 0xFFFF;
if (max > 0xFFFF)
max = 0xFFFF;
*min_cp = min;
*max_cp = max;
}
enum font_page_t {
HEBREW_FONT_PAGE = 0xB100, // Hebrew Windows 3.1 font page
SIMP_ARABIC_FONT_PAGE = 0xB200, // Simplified Arabic Windows 3.1 font page
TRAD_ARABIC_FONT_PAGE = 0xB300, // Traditional Arabic Windows 3.1 font page
OEM_ARABIC_FONT_PAGE = 0xB400, // OEM Arabic Windows 3.1 font page
SIMP_FARSI_FONT_PAGE = 0xBA00, // Simplified Farsi Windows 3.1 font page
TRAD_FARSI_FONT_PAGE = 0xBB00, // Traditional Farsi Windows 3.1 font page
THAI_FONT_PAGE = 0xDE00 // Thai Windows 3.1 font page
};
// https://github.com/Microsoft/Font-Validator/blob/520aaae/OTFontFileVal/val_OS2.cs#L644-L681
inline font_page_t get_font_page () const
{
if (version != 0)
return (font_page_t) 0;
return (font_page_t) (fsSelection & 0xFF00);
}
public:
HBUINT16 version;
/* Version 0 */
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;
/* Version 1 */
//HBUINT32 ulCodePageRange1;
//HBUINT32 ulCodePageRange2;
/* Version 2 */
//HBINT16 sxHeight;
//HBINT16 sCapHeight;
//HBUINT16 usDefaultChar;
//HBUINT16 usBreakChar;
//HBUINT16 usMaxContext;
/* Version 5 */
//HBUINT16 usLowerOpticalPointSize;
//HBUINT16 usUpperOpticalPointSize;
public:
DEFINE_SIZE_STATIC (78);
};
} /* namespace OT */
#endif /* HB_OT_OS2_TABLE_HH */