153 lines
4.1 KiB
C++
153 lines
4.1 KiB
C++
/*
|
|
* Copyright © 2017 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_VAR_AVAR_TABLE_HH
|
|
#define HB_OT_VAR_AVAR_TABLE_HH
|
|
|
|
#include "hb-open-type.hh"
|
|
|
|
/*
|
|
* avar -- Axis Variations
|
|
* https://docs.microsoft.com/en-us/typography/opentype/spec/avar
|
|
*/
|
|
|
|
#define HB_OT_TAG_avar HB_TAG('a','v','a','r')
|
|
|
|
|
|
namespace OT {
|
|
|
|
|
|
struct AxisValueMap
|
|
{
|
|
bool sanitize (hb_sanitize_context_t *c) const
|
|
{
|
|
TRACE_SANITIZE (this);
|
|
return_trace (c->check_struct (this));
|
|
}
|
|
|
|
public:
|
|
F2DOT14 fromCoord; /* A normalized coordinate value obtained using
|
|
* default normalization. */
|
|
F2DOT14 toCoord; /* The modified, normalized coordinate value. */
|
|
|
|
public:
|
|
DEFINE_SIZE_STATIC (4);
|
|
};
|
|
|
|
struct SegmentMaps : ArrayOf<AxisValueMap>
|
|
{
|
|
int map (int value) const
|
|
{
|
|
/* The following special-cases are not part of OpenType, which requires
|
|
* that at least -1, 0, and +1 must be mapped. But we include these as
|
|
* part of a better error recovery scheme. */
|
|
|
|
if (len < 2)
|
|
{
|
|
if (!len)
|
|
return value;
|
|
else /* len == 1*/
|
|
return value - arrayZ[0].fromCoord + arrayZ[0].toCoord;
|
|
}
|
|
|
|
if (value <= arrayZ[0].fromCoord)
|
|
return value - arrayZ[0].fromCoord + arrayZ[0].toCoord;
|
|
|
|
unsigned int i;
|
|
unsigned int count = len;
|
|
for (i = 1; i < count && value > arrayZ[i].fromCoord; i++)
|
|
;
|
|
|
|
if (value >= arrayZ[i].fromCoord)
|
|
return value - arrayZ[i].fromCoord + arrayZ[i].toCoord;
|
|
|
|
if (unlikely (arrayZ[i-1].fromCoord == arrayZ[i].fromCoord))
|
|
return arrayZ[i-1].toCoord;
|
|
|
|
int denom = arrayZ[i].fromCoord - arrayZ[i-1].fromCoord;
|
|
return arrayZ[i-1].toCoord +
|
|
((arrayZ[i].toCoord - arrayZ[i-1].toCoord) *
|
|
(value - arrayZ[i-1].fromCoord) + denom/2) / denom;
|
|
}
|
|
|
|
public:
|
|
DEFINE_SIZE_ARRAY (2, *this);
|
|
};
|
|
|
|
struct avar
|
|
{
|
|
static constexpr hb_tag_t tableTag = HB_OT_TAG_avar;
|
|
|
|
bool sanitize (hb_sanitize_context_t *c) const
|
|
{
|
|
TRACE_SANITIZE (this);
|
|
if (unlikely (!(version.sanitize (c) &&
|
|
version.major == 1 &&
|
|
c->check_struct (this))))
|
|
return_trace (false);
|
|
|
|
const SegmentMaps *map = &firstAxisSegmentMaps;
|
|
unsigned int count = axisCount;
|
|
for (unsigned int i = 0; i < count; i++)
|
|
{
|
|
if (unlikely (!map->sanitize (c)))
|
|
return_trace (false);
|
|
map = &StructAfter<SegmentMaps> (*map);
|
|
}
|
|
|
|
return_trace (true);
|
|
}
|
|
|
|
void map_coords (int *coords, unsigned int coords_length) const
|
|
{
|
|
unsigned int count = MIN<unsigned int> (coords_length, axisCount);
|
|
|
|
const SegmentMaps *map = &firstAxisSegmentMaps;
|
|
for (unsigned int i = 0; i < count; i++)
|
|
{
|
|
coords[i] = map->map (coords[i]);
|
|
map = &StructAfter<SegmentMaps> (*map);
|
|
}
|
|
}
|
|
|
|
protected:
|
|
FixedVersion<>version; /* Version of the avar table
|
|
* initially set to 0x00010000u */
|
|
HBUINT16 reserved; /* This field is permanently reserved. Set to 0. */
|
|
HBUINT16 axisCount; /* The number of variation axes in the font. This
|
|
* must be the same number as axisCount in the
|
|
* 'fvar' table. */
|
|
SegmentMaps firstAxisSegmentMaps;
|
|
|
|
public:
|
|
DEFINE_SIZE_MIN (8);
|
|
};
|
|
|
|
} /* namespace OT */
|
|
|
|
|
|
#endif /* HB_OT_VAR_AVAR_TABLE_HH */
|