Implement meta table parsing

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Ebrahim Byagowi 2019-07-22 18:46:52 +04:30 committed by GitHub
parent a51aa951b5
commit 41ab56e095
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4 changed files with 99 additions and 7 deletions

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@ -88,6 +88,7 @@ HB_BASE_sources = \
hb-ot-math-table.hh \ hb-ot-math-table.hh \
hb-ot-math.cc \ hb-ot-math.cc \
hb-ot-maxp-table.hh \ hb-ot-maxp-table.hh \
hb-ot-meta-table.hh \
hb-ot-metrics.cc \ hb-ot-metrics.cc \
hb-ot-metrics.hh \ hb-ot-metrics.hh \
hb-ot-name-language-static.hh \ hb-ot-name-language-static.hh \

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@ -62,6 +62,7 @@ HB_OT_ACCELERATOR (OT, name)
#ifndef HB_NO_STAT #ifndef HB_NO_STAT
HB_OT_TABLE (OT, STAT) HB_OT_TABLE (OT, STAT)
#endif #endif
HB_OT_TABLE (OT, meta)
/* Vertical layout. */ /* Vertical layout. */
HB_OT_TABLE (OT, vhea) HB_OT_TABLE (OT, vhea)

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@ -48,6 +48,7 @@
#include "hb-ot-layout-gpos-table.hh" #include "hb-ot-layout-gpos-table.hh"
#include "hb-ot-layout-base-table.hh" // Just so we compile it; unused otherwise. #include "hb-ot-layout-base-table.hh" // Just so we compile it; unused otherwise.
#include "hb-ot-layout-jstf-table.hh" // Just so we compile it; unused otherwise. #include "hb-ot-layout-jstf-table.hh" // Just so we compile it; unused otherwise.
#include "hb-ot-meta-table.hh" // Just so we compile it; unused otherwise.
#include "hb-ot-name-table.hh" #include "hb-ot-name-table.hh"
#include "hb-ot-os2-table.hh" #include "hb-ot-os2-table.hh"

89
src/hb-ot-meta-table.hh Normal file
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@ -0,0 +1,89 @@
/*
* Copyright © 2019 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.
*/
#ifndef HB_OT_META_TABLE_HH
#define HB_OT_META_TABLE_HH
#include "hb-open-type.hh"
/*
* meta -- Metadata Table
* https://docs.microsoft.com/en-us/typography/opentype/spec/meta
* https://developer.apple.com/fonts/TrueType-Reference-Manual/RM06/Chap6meta.html
*/
#define HB_OT_TAG_meta HB_TAG('m','e','t','a')
namespace OT {
struct DataMap
{
bool sanitize (hb_sanitize_context_t *c, const void *base) const
{
TRACE_SANITIZE (this);
return_trace (likely (c->check_struct (this) &&
dataZ.sanitize (c, base, dataLength)));
}
protected:
Tag tag; /* A tag indicating the type of metadata. */
LOffsetTo<UnsizedArrayOf<HBUINT8>>
dataZ; /* Offset in bytes from the beginning of the
* metadata table to the data for this tag. */
HBUINT32 dataLength; /* Length of the data. The data is not required to
* be padded to any byte boundary. */
public:
DEFINE_SIZE_STATIC (12);
};
struct meta
{
static constexpr hb_tag_t tableTag = HB_OT_TAG_meta;
bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return_trace (likely (c->check_struct (this) &&
version == 1 &&
dataMaps.sanitize (c, this)));
}
protected:
HBUINT32 version; /* Version number of the metadata table — set to 1. */
HBUINT32 flags; /* Flags — currently unused; set to 0. */
HBUINT32 dataOffset; /* Per Apple specification:
* Offset from the beginning of the table to the data.
* Per OT specification:
* Reserved. Not used; should be set to 0. */
LArrayOf<DataMap>
dataMaps; /* Array of data map records. */
public:
DEFINE_SIZE_ARRAY (16, dataMaps);
};
} /* namespace OT */
#endif /* HB_OT_META_TABLE_HH */