/*
* Copyright © 2018 Adobe 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.
*
* Adobe Author(s): Michiharu Ariza
*/
#include "hb-ot-cff-common.hh"
#include "hb-ot-cff2-table.hh"
#include "hb-subset-cff-common.hh"
/* Disable FDSelect format 0 for compatibility with fonttools which doesn't seem choose it.
* Rarely any/much smaller than format 3 anyway. */
#define CFF_SERIALIZE_FDSELECT_0 0
using namespace CFF;
/**
* hb_plan_subset_cff_fdselect
* Determine an optimal FDSelect format according to a provided plan.
*
* Return value: FDSelect format, size, and ranges for the most compact subset FDSelect
* along with a font index remapping table
**/
bool
hb_plan_subset_cff_fdselect (const hb_vector_t<hb_codepoint_t> &glyphs,
unsigned int fdCount,
const FDSelect &src, /* IN */
unsigned int &subset_fd_count /* OUT */,
unsigned int &subset_fdselect_size /* OUT */,
unsigned int &subset_fdselect_format /* OUT */,
hb_vector_t<code_pair> &fdselect_ranges /* OUT */,
Remap &fdmap /* OUT */)
{
subset_fd_count = 0;
subset_fdselect_size = 0;
subset_fdselect_format = 0;
unsigned int num_ranges = 0;
unsigned int subset_num_glyphs = glyphs.len;
if (subset_num_glyphs == 0)
return true;
{
/* use hb_set to determine the subset of font dicts */
hb_set_t *set = hb_set_create ();
if (set == &Null (hb_set_t))
return false;
hb_codepoint_t prev_fd = CFF_UNDEF_CODE;
for (hb_codepoint_t i = 0; i < subset_num_glyphs; i++)
{
hb_codepoint_t fd = src.get_fd (glyphs[i]);
set->add (fd);
if (fd != prev_fd)
{
num_ranges++;
prev_fd = fd;
code_pair pair = { fd, i };
fdselect_ranges.push (pair);
}
}
subset_fd_count = set->get_population ();
if (subset_fd_count == fdCount)
{
/* all font dicts belong to the subset. no need to subset FDSelect & FDArray */
fdmap.identity (fdCount);
hb_set_destroy (set);
}
else
{
/* create a fdmap */
if (!fdmap.reset (fdCount))
{
hb_set_destroy (set);
return false;
}
hb_codepoint_t fd = CFF_UNDEF_CODE;
while (set->next (&fd))
fdmap.add (fd);
hb_set_destroy (set);
if (unlikely (fdmap.get_count () != subset_fd_count))
return false;
}
/* update each font dict index stored as "code" in fdselect_ranges */
for (unsigned int i = 0; i < fdselect_ranges.len; i++)
fdselect_ranges[i].code = fdmap[fdselect_ranges[i].code];
}
/* determine which FDSelect format is most compact */
if (subset_fd_count > 0xFF)
{
if (unlikely (src.format != 4))
return false;
subset_fdselect_format = 4;
subset_fdselect_size = FDSelect::min_size + FDSelect4::min_size + FDSelect4_Range::static_size * num_ranges + HBUINT32::static_size;
}
else
{
#if CFF_SERIALIZE_FDSELECT_0
unsigned int format0_size = FDSelect::min_size + FDSelect0::min_size + HBUINT8::static_size * subset_num_glyphs;
#endif
unsigned int format3_size = FDSelect::min_size + FDSelect3::min_size + FDSelect3_Range::static_size * num_ranges + HBUINT16::static_size;
#if CFF_SERIALIZE_FDSELECT_0
if (format0_size <= format3_size)
{
// subset_fdselect_format = 0;
subset_fdselect_size = format0_size;
}
else
#endif
{
subset_fdselect_format = 3;
subset_fdselect_size = format3_size;
}
}
return true;
}
template <typename FDSELECT3_4>
static inline bool
serialize_fdselect_3_4 (hb_serialize_context_t *c,
const unsigned int num_glyphs,
const FDSelect &src,
unsigned int size,
const hb_vector_t<code_pair> &fdselect_ranges)
{
TRACE_SERIALIZE (this);
FDSELECT3_4 *p = c->allocate_size<FDSELECT3_4> (size);
if (unlikely (p == nullptr)) return_trace (false);
p->nRanges.set (fdselect_ranges.len);
for (unsigned int i = 0; i < fdselect_ranges.len; i++)
{
p->ranges[i].first.set (fdselect_ranges[i].glyph);
p->ranges[i].fd.set (fdselect_ranges[i].code);
}
p->sentinel().set (num_glyphs);
return_trace (true);
}
/**
* hb_serialize_cff_fdselect
* Serialize a subset FDSelect format planned above.
**/
bool
hb_serialize_cff_fdselect (hb_serialize_context_t *c,
const unsigned int num_glyphs,
const FDSelect &src,
unsigned int fd_count,
unsigned int fdselect_format,
unsigned int size,
const hb_vector_t<code_pair> &fdselect_ranges)
{
TRACE_SERIALIZE (this);
FDSelect *p = c->allocate_min<FDSelect> ();
if (unlikely (p == nullptr)) return_trace (false);
p->format.set (fdselect_format);
size -= FDSelect::min_size;
switch (fdselect_format)
{
#if CFF_SERIALIZE_FDSELECT_0
case 0:
{
FDSelect0 *p = c->allocate_size<FDSelect0> (size);
if (unlikely (p == nullptr)) return_trace (false);
unsigned int range_index = 0;
unsigned int fd = fdselect_ranges[range_index++].code;
for (unsigned int i = 0; i < num_glyphs; i++)
{
if ((range_index < fdselect_ranges.len) &&
(i >= fdselect_ranges[range_index].glyph))
{
fd = fdselect_ranges[range_index++].code;
}
p->fds[i].set (fd);
}
break;
}
#endif /* CFF_SERIALIZE_FDSELECT_0 */
case 3:
return serialize_fdselect_3_4<FDSelect3> (c,
num_glyphs,
src,
size,
fdselect_ranges);
case 4:
return serialize_fdselect_3_4<FDSelect4> (c,
num_glyphs,
src,
size,
fdselect_ranges);
default:
assert(false);
}
return_trace (true);
}