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

174 lines
5.0 KiB
C++

/*
* Copyright © 2019 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_OPBD_TABLE_HH
#define HB_AAT_LAYOUT_OPBD_TABLE_HH
#include "hb-aat-layout-common.hh"
#include "hb-open-type.hh"
/*
* opbd -- Optical Bounds
* https://developer.apple.com/fonts/TrueType-Reference-Manual/RM06/Chap6opbd.html
*/
#define HB_AAT_TAG_opbd HB_TAG('o','p','b','d')
namespace AAT {
struct OpticalBounds
{
bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return_trace (likely (c->check_struct (this)));
}
FWORD leftSide;
FWORD topSide;
FWORD rightSide;
FWORD bottomSide;
public:
DEFINE_SIZE_STATIC (8);
};
struct opbdFormat0
{
bool get_bounds (hb_font_t *font, hb_codepoint_t glyph_id,
hb_glyph_extents_t *extents, const void *base) const
{
const Offset16To<OpticalBounds> *bounds_offset = lookupTable.get_value (glyph_id, font->face->get_num_glyphs ());
if (!bounds_offset) return false;
const OpticalBounds &bounds = base+*bounds_offset;
if (extents)
*extents = {
font->em_scale_x (bounds.leftSide),
font->em_scale_y (bounds.topSide),
font->em_scale_x (bounds.rightSide),
font->em_scale_y (bounds.bottomSide)
};
return true;
}
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<Offset16To<OpticalBounds>>
lookupTable; /* Lookup table associating glyphs with the four
* int16 values for the left-side, top-side,
* right-side, and bottom-side optical bounds. */
public:
DEFINE_SIZE_MIN (2);
};
struct opbdFormat1
{
bool get_bounds (hb_font_t *font, hb_codepoint_t glyph_id,
hb_glyph_extents_t *extents, const void *base) const
{
const Offset16To<OpticalBounds> *bounds_offset = lookupTable.get_value (glyph_id, font->face->get_num_glyphs ());
if (!bounds_offset) return false;
const OpticalBounds &bounds = base+*bounds_offset;
hb_position_t left = 0, top = 0, right = 0, bottom = 0, ignore;
if (font->get_glyph_contour_point (glyph_id, bounds.leftSide, &left, &ignore) ||
font->get_glyph_contour_point (glyph_id, bounds.topSide, &ignore, &top) ||
font->get_glyph_contour_point (glyph_id, bounds.rightSide, &right, &ignore) ||
font->get_glyph_contour_point (glyph_id, bounds.bottomSide, &ignore, &bottom))
{
if (extents)
*extents = {left, top, right, bottom};
return true;
}
return false;
}
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<Offset16To<OpticalBounds>>
lookupTable; /* Lookup table associating glyphs with the four
* int16 values for the left-side, top-side,
* right-side, and bottom-side optical bounds. */
public:
DEFINE_SIZE_MIN (2);
};
struct opbd
{
static constexpr hb_tag_t tableTag = HB_AAT_TAG_opbd;
bool get_bounds (hb_font_t *font, hb_codepoint_t glyph_id,
hb_glyph_extents_t *extents) const
{
switch (format)
{
case 0: return u.format0.get_bounds (font, glyph_id, extents, this);
case 1: return u.format1.get_bounds (font, glyph_id, extents, this);
default:return false;
}
}
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 optical bounds
* table (0x00010000 for the current version). */
HBUINT16 format; /* Format of the optical bounds table.
* Format 0 indicates distance and Format 1 indicates
* control point. */
union {
opbdFormat0 format0;
opbdFormat1 format1;
} u;
public:
DEFINE_SIZE_MIN (8);
};
} /* namespace AAT */
#endif /* HB_AAT_LAYOUT_OPBD_TABLE_HH */