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/*
* Copyright © 2015 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_GLYF_TABLE_HH
#define HB_OT_GLYF_TABLE_HH
#include "hb-open-type-private.hh"
#include "hb-ot-head-table.hh"
namespace OT {
/*
* loca -- Index to Location
*/
#define HB_OT_TAG_loca HB_TAG('l','o','c','a')
struct loca
{
friend struct glyf;
static const hb_tag_t tableTag = HB_OT_TAG_loca;
inline bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return_trace (true);
}
protected:
UINT8 dataX[VAR]; /* Location data. */
DEFINE_SIZE_ARRAY (0, dataX);
};
/*
* glyf -- TrueType Glyph Data
*/
#define HB_OT_TAG_glyf HB_TAG('g','l','y','f')
struct glyf
{
static const hb_tag_t tableTag = HB_OT_TAG_glyf;
inline bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
/* We don't check for anything specific here. The users of the
* struct do all the hard work... */
return_trace (true);
}
struct GlyphHeader
{
INT16 numberOfContours; /* If the number of contours is
* greater than or equal to zero,
* this is a simple glyph; if negative,
* this is a composite glyph. */
FWORD xMin; /* Minimum x for coordinate data. */
FWORD yMin; /* Minimum y for coordinate data. */
FWORD xMax; /* Maximum x for coordinate data. */
FWORD yMax; /* Maximum y for coordinate data. */
DEFINE_SIZE_STATIC (10);
};
struct accelerator_t
{
inline void init (hb_face_t *face)
{
hb_blob_t *head_blob = Sanitizer<head>::sanitize (face->reference_table (HB_OT_TAG_head));
const head *head_table = Sanitizer<head>::lock_instance (head_blob);
if ((unsigned int) head_table->indexToLocFormat > 1 || head_table->glyphDataFormat != 0)
{
/* Unknown format. Leave num_glyphs=0, that takes care of disabling us. */
hb_blob_destroy (head_blob);
return;
}
short_offset = 0 == head_table->indexToLocFormat;
hb_blob_destroy (head_blob);
loca_blob = Sanitizer<loca>::sanitize (face->reference_table (HB_OT_TAG_loca));
loca_table = Sanitizer<loca>::lock_instance (loca_blob);
glyf_blob = Sanitizer<glyf>::sanitize (face->reference_table (HB_OT_TAG_glyf));
glyf_table = Sanitizer<glyf>::lock_instance (glyf_blob);
num_glyphs = MAX (1u, hb_blob_get_length (loca_blob) / (short_offset ? 2 : 4)) - 1;
glyf_len = hb_blob_get_length (glyf_blob);
}
inline void fini (void)
{
hb_blob_destroy (loca_blob);
hb_blob_destroy (glyf_blob);
}
inline bool get_extents (hb_codepoint_t glyph,
hb_glyph_extents_t *extents) const
{
if (unlikely (glyph >= num_glyphs))
return false;
unsigned int start_offset, end_offset;
if (short_offset)
{
const UINT16 *offsets = (const UINT16 *) loca_table->dataX;
start_offset = 2 * offsets[glyph];
end_offset = 2 * offsets[glyph + 1];
}
else
{
const UINT32 *offsets = (const UINT32 *) loca_table->dataX;
start_offset = offsets[glyph];
end_offset = offsets[glyph + 1];
}
if (start_offset > end_offset || end_offset > glyf_len)
return false;
if (end_offset - start_offset < GlyphHeader::static_size)
return true; /* Empty glyph; zero extents. */
const GlyphHeader &glyph_header = StructAtOffset<GlyphHeader> (glyf_table, start_offset);
extents->x_bearing = MIN (glyph_header.xMin, glyph_header.xMax);
extents->y_bearing = MAX (glyph_header.yMin, glyph_header.yMax);
extents->width = MAX (glyph_header.xMin, glyph_header.xMax) - extents->x_bearing;
extents->height = MIN (glyph_header.yMin, glyph_header.yMax) - extents->y_bearing;
return true;
}
private:
bool short_offset;
unsigned int num_glyphs;
const loca *loca_table;
const glyf *glyf_table;
hb_blob_t *loca_blob;
hb_blob_t *glyf_blob;
unsigned int glyf_len;
};
protected:
UINT8 dataX[VAR]; /* Glyphs data. */
DEFINE_SIZE_ARRAY (0, dataX);
};
} /* namespace OT */
#endif /* HB_OT_GLYF_TABLE_HH */
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