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

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/*
* Copyright © 2018 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): Garret Rieger
*/
#ifndef HB_OT_HDMX_TABLE_HH
#define HB_OT_HDMX_TABLE_HH
#include "hb-open-type.hh"
/*
* hdmx -- Horizontal Device Metrics
* https://docs.microsoft.com/en-us/typography/opentype/spec/hdmx
*/
#define HB_OT_TAG_hdmx HB_TAG('h','d','m','x')
namespace OT {
struct DeviceRecord
{
struct SubsetView
{
const DeviceRecord *source_device_record;
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unsigned int sizeDeviceRecord;
hb_subset_plan_t *subset_plan;
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inline void init (const DeviceRecord *source_device_record,
unsigned int sizeDeviceRecord,
hb_subset_plan_t *subset_plan)
{
this->source_device_record = source_device_record;
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this->sizeDeviceRecord = sizeDeviceRecord;
this->subset_plan = subset_plan;
}
inline unsigned int len () const
{
return this->subset_plan->glyphs.len;
}
inline const HBUINT8* operator [] (unsigned int i) const
{
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if (unlikely (i >= len ())) return nullptr;
hb_codepoint_t gid = this->subset_plan->glyphs [i];
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const HBUINT8* width = &(this->source_device_record->widthsZ[gid]);
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if (width < ((const HBUINT8 *) this->source_device_record) + sizeDeviceRecord)
return width;
else
return nullptr;
}
};
static inline unsigned int get_size (unsigned int count)
{
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return hb_ceil_to_4 (min_size + count * HBUINT8::static_size);
}
inline bool serialize (hb_serialize_context_t *c, const SubsetView &subset_view)
{
TRACE_SERIALIZE (this);
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unsigned int size = get_size (subset_view.len ());
if (unlikely (!c->allocate_size<DeviceRecord> (size)))
{
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DEBUG_MSG(SUBSET, nullptr, "Couldn't allocate enough space for DeviceRecord: %d.",
size);
return_trace (false);
}
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this->pixelSize.set (subset_view.source_device_record->pixelSize);
this->maxWidth.set (subset_view.source_device_record->maxWidth);
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for (unsigned int i = 0; i < subset_view.len (); i++)
{
const HBUINT8 *width = subset_view[i];
if (!width)
{
DEBUG_MSG(SUBSET, nullptr, "HDMX width for new gid %d is missing.", i);
return_trace (false);
}
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widthsZ[i].set (*width);
}
return_trace (true);
}
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inline bool sanitize (hb_sanitize_context_t *c, unsigned int sizeDeviceRecord) const
{
TRACE_SANITIZE (this);
return_trace (likely (c->check_struct (this) &&
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c->check_range (this, sizeDeviceRecord)));
}
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HBUINT8 pixelSize; /* Pixel size for following widths (as ppem). */
HBUINT8 maxWidth; /* Maximum width. */
UnsizedArrayOf<HBUINT8> widthsZ; /* Array of widths (numGlyphs is from the 'maxp' table). */
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public:
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DEFINE_SIZE_ARRAY (2, widthsZ);
};
struct hdmx
{
static const hb_tag_t tableTag = HB_OT_TAG_hdmx;
inline unsigned int get_size (void) const
{
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return min_size + numRecords * sizeDeviceRecord;
}
inline const DeviceRecord& operator [] (unsigned int i) const
{
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if (unlikely (i >= numRecords)) return Null (DeviceRecord);
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return StructAtOffset<DeviceRecord> (&this->dataZ, i * sizeDeviceRecord);
}
inline bool serialize (hb_serialize_context_t *c, const hdmx *source_hdmx, hb_subset_plan_t *plan)
{
TRACE_SERIALIZE (this);
if (unlikely (!c->extend_min ((*this)))) return_trace (false);
this->version.set (source_hdmx->version);
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this->numRecords.set (source_hdmx->numRecords);
this->sizeDeviceRecord.set (DeviceRecord::get_size (plan->glyphs.len));
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for (unsigned int i = 0; i < source_hdmx->numRecords; i++)
{
DeviceRecord::SubsetView subset_view;
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subset_view.init (&(*source_hdmx)[i], source_hdmx->sizeDeviceRecord, plan);
if (!c->start_embed<DeviceRecord> ()->serialize (c, subset_view))
return_trace (false);
}
return_trace (true);
}
static inline size_t get_subsetted_size (const hdmx *source_hdmx, hb_subset_plan_t *plan)
{
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return min_size + source_hdmx->numRecords * DeviceRecord::get_size (plan->glyphs.len);
}
inline bool subset (hb_subset_plan_t *plan) const
{
size_t dest_size = get_subsetted_size (this, plan);
hdmx *dest = (hdmx *) malloc (dest_size);
if (unlikely (!dest))
{
DEBUG_MSG(SUBSET, nullptr, "Unable to alloc %lu for hdmx subset output.", (unsigned long) dest_size);
return false;
}
hb_serialize_context_t c (dest, dest_size);
hdmx *hdmx_prime = c.start_serialize<hdmx> ();
if (!hdmx_prime || !hdmx_prime->serialize (&c, this, plan))
{
free (dest);
DEBUG_MSG(SUBSET, nullptr, "Failed to serialize write new hdmx.");
return false;
}
c.end_serialize ();
hb_blob_t *hdmx_prime_blob = hb_blob_create ((const char *) dest,
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dest_size,
HB_MEMORY_MODE_READONLY,
dest,
free);
bool result = plan->add_table (HB_OT_TAG_hdmx, hdmx_prime_blob);
hb_blob_destroy (hdmx_prime_blob);
return result;
}
inline bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
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return_trace (c->check_struct (this) && version == 0 &&
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!hb_unsigned_mul_overflows (numRecords, sizeDeviceRecord) &&
sizeDeviceRecord >= DeviceRecord::min_size &&
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c->check_range (this, get_size ()));
}
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protected:
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HBUINT16 version; /* Table version number (0) */
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HBUINT16 numRecords; /* Number of device records. */
HBUINT32 sizeDeviceRecord; /* Size of a device record, 32-bit aligned. */
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UnsizedArrayOf<HBUINT8> dataZ; /* Array of device records. */
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public:
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DEFINE_SIZE_ARRAY (8, dataZ);
};
} /* namespace OT */
#endif /* HB_OT_HDMX_TABLE_HH */