harfbuzz/src/hb-aat-layout-lcar-table.hh

163 lines
5.1 KiB
C++

/*
* Copyright © 2018 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_AAT_LAYOUT_LCAR_TABLE_HH
#define HB_AAT_LAYOUT_LCAR_TABLE_HH
#include "hb-open-type.hh"
#include "hb-aat-layout-common.hh"
/*
* lcar -- Ligature caret
* https://developer.apple.com/fonts/TrueType-Reference-Manual/RM06/Chap6lcar.html
*/
#define HB_AAT_TAG_lcar HB_TAG('l','c','a','r')
namespace AAT {
typedef ArrayOf<HBINT16> LigCaretClassEntry;
struct lcarFormat0
{
unsigned int get_lig_carets (hb_font_t *font,
hb_direction_t direction,
hb_codepoint_t glyph,
unsigned int start_offset,
unsigned int *caret_count /* IN/OUT */,
hb_position_t *caret_array /* OUT */,
const void *base) const
{
const OffsetTo<LigCaretClassEntry>* entry_offset = lookupTable.get_value (glyph,
font->face->get_num_glyphs ());
const LigCaretClassEntry& array = entry_offset ? base+*entry_offset : Null (LigCaretClassEntry);
if (caret_count)
{
hb_array_t<const HBINT16> arr = array.sub_array (start_offset, caret_count);
for (unsigned int i = 0; i < arr.length; ++i)
caret_array[i] = font->em_scale_dir (arr[i], direction);
}
return array.len;
}
bool sanitize (hb_sanitize_context_t *c, const void *base) const
{
TRACE_SANITIZE (this);
return_trace (likely (c->check_struct (this) && lookupTable.sanitize (c, base)));
}
protected:
Lookup<OffsetTo<LigCaretClassEntry>>
lookupTable; /* data Lookup table associating glyphs */
public:
DEFINE_SIZE_MIN (2);
};
struct lcarFormat1
{
unsigned int get_lig_carets (hb_font_t *font,
hb_direction_t direction,
hb_codepoint_t glyph,
unsigned int start_offset,
unsigned int *caret_count /* IN/OUT */,
hb_position_t *caret_array /* OUT */,
const void *base) const
{
const OffsetTo<LigCaretClassEntry>* entry_offset = lookupTable.get_value (glyph,
font->face->get_num_glyphs ());
const LigCaretClassEntry& array = entry_offset ? base+*entry_offset : Null (LigCaretClassEntry);
if (caret_count)
{
hb_array_t<const HBINT16> arr = array.sub_array (start_offset, caret_count);
for (unsigned int i = 0; i < arr.length; ++i)
{
hb_position_t x = 0, y = 0;
font->get_glyph_contour_point_for_origin (glyph, arr[i], direction, &x, &y);
caret_array[i] = HB_DIRECTION_IS_HORIZONTAL (direction) ? x : y;
}
}
return array.len;
}
bool sanitize (hb_sanitize_context_t *c, const void *base) const
{
TRACE_SANITIZE (this);
return_trace (likely (c->check_struct (this) && lookupTable.sanitize (c, base)));
}
protected:
Lookup<OffsetTo<LigCaretClassEntry>>
lookupTable; /* data Lookup table associating glyphs */
public:
DEFINE_SIZE_MIN (2);
};
struct lcar
{
static constexpr hb_tag_t tableTag = HB_AAT_TAG_lcar;
unsigned int get_lig_carets (hb_font_t *font,
hb_direction_t direction,
hb_codepoint_t glyph,
unsigned int start_offset,
unsigned int *caret_count /* IN/OUT */,
hb_position_t *caret_array /* OUT */) const
{
switch (format)
{
case 0: return u.format0.get_lig_carets (font, direction, glyph, start_offset,
caret_count, caret_array, this);
case 1: return u.format1.get_lig_carets (font, direction, glyph, start_offset,
caret_count, caret_array, this);
default:if (caret_count) *caret_count = 0; return 0;
}
}
bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
if (unlikely (!c->check_struct (this) || version.major != 1))
return_trace (false);
switch (format) {
case 0: return_trace (u.format0.sanitize (c, this));
case 1: return_trace (u.format1.sanitize (c, this));
default:return_trace (true);
}
}
protected:
FixedVersion<>version; /* Version number of the ligature caret table */
HBUINT16 format; /* Format of the ligature caret table. */
union {
lcarFormat0 format0;
lcarFormat0 format1;
} u;
public:
DEFINE_SIZE_MIN (8);
};
} /* namespace AAT */
#endif /* HB_AAT_LAYOUT_LCAR_TABLE_HH */