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-private.hh"
#include "hb-subset-plan.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;
unsigned int size_device_record;
hb_subset_plan_t *subset_plan;
inline void init(const DeviceRecord *source_device_record,
unsigned int size_device_record,
hb_subset_plan_t *subset_plan)
{
this->source_device_record = source_device_record;
this->size_device_record = size_device_record;
this->subset_plan = subset_plan;
}
inline unsigned int len () const
{
return this->subset_plan->glyphs.len;
}
inline const HBUINT8* operator [] (unsigned int i) const
{
if (unlikely (i >= len())) return nullptr;
hb_codepoint_t gid = this->subset_plan->glyphs [i];
const HBUINT8* width = &(this->source_device_record->widths[gid]);
if (width < ((const HBUINT8 *) this->source_device_record) + size_device_record)
return width;
else
return nullptr;
}
};
static inline unsigned int get_size (unsigned int count)
{
unsigned int raw_size = min_size + count * HBUINT8::static_size;
if (raw_size % 4)
/* Align to 32 bits */
return raw_size + (4 - (raw_size % 4));
return raw_size;
}
inline bool serialize (hb_serialize_context_t *c, const SubsetView &subset_view)
{
TRACE_SERIALIZE (this);
if (unlikely (!c->allocate_size<DeviceRecord> (get_size (subset_view.len()))))
return_trace (false);
this->pixel_size.set (subset_view.source_device_record->pixel_size);
this->max_width.set (subset_view.source_device_record->max_width);
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);
}
widths[i].set (*width);
}
return_trace (true);
}
inline bool sanitize (hb_sanitize_context_t *c, unsigned int size_device_record) const
{
TRACE_SANITIZE (this);
return_trace (likely (c->check_struct (this) &&
c->check_range (this, size_device_record)));
}
HBUINT8 pixel_size; /* Pixel size for following widths (as ppem). */
HBUINT8 max_width; /* Maximum width. */
HBUINT8 widths[VAR]; /* Array of widths (numGlyphs is from the 'maxp' table). */
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public:
DEFINE_SIZE_ARRAY (2, widths);
};
struct hdmx
{
static const hb_tag_t tableTag = HB_OT_TAG_hdmx;
inline unsigned int get_size (void) const
{
return min_size + num_records * size_device_record;
}
inline const DeviceRecord& operator [] (unsigned int i) const
{
if (unlikely (i >= num_records)) return Null(DeviceRecord);
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return StructAtOffset<DeviceRecord> (this->data, i * size_device_record);
}
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);
this->num_records.set (source_hdmx->num_records);
this->size_device_record.set (DeviceRecord::get_size (plan->glyphs.len));
for (unsigned int i = 0; i < source_hdmx->num_records; i++)
{
DeviceRecord::SubsetView subset_view;
subset_view.init (&(*source_hdmx)[i], source_hdmx->size_device_record, plan);
if (!c->start_embed<DeviceRecord> ()->serialize (c, subset_view))
return_trace (false);
}
return_trace (true);
}
static inline size_t get_subsetted_size (hb_subset_plan_t *plan)
{
return min_size + DeviceRecord::get_size (plan->glyphs.len);
}
inline bool subset (hb_subset_plan_t *plan) const
{
size_t dest_size = get_subsetted_size (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);
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 &&
!hb_unsigned_mul_overflows (num_records, size_device_record) &&
size_device_record >= 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) */
HBUINT16 num_records; /* Number of device records. */
HBUINT32 size_device_record; /* Size of a device record, 32-bit aligned. */
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HBUINT8 data[VAR]; /* Array of device records. */
public:
DEFINE_SIZE_ARRAY (8, data);
};
} /* namespace OT */
#endif /* HB_OT_HDMX_TABLE_HH */