harfbuzz/src/hb-ot-maxp-table.hh

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4.6 KiB
C++

/*
* Copyright © 2011,2012 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_MAXP_TABLE_HH
#define HB_OT_MAXP_TABLE_HH
#include "hb-open-type.hh"
namespace OT {
/*
* maxp -- Maximum Profile
* https://docs.microsoft.com/en-us/typography/opentype/spec/maxp
*/
#define HB_OT_TAG_maxp HB_TAG('m','a','x','p')
struct maxpV1Tail
{
bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return_trace (c->check_struct (this));
}
HBUINT16 maxPoints; /* Maximum points in a non-composite glyph. */
HBUINT16 maxContours; /* Maximum contours in a non-composite glyph. */
HBUINT16 maxCompositePoints; /* Maximum points in a composite glyph. */
HBUINT16 maxCompositeContours; /* Maximum contours in a composite glyph. */
HBUINT16 maxZones; /* 1 if instructions do not use the twilight zone (Z0),
* or 2 if instructions do use Z0; should be set to 2 in
* most cases. */
HBUINT16 maxTwilightPoints; /* Maximum points used in Z0. */
HBUINT16 maxStorage; /* Number of Storage Area locations. */
HBUINT16 maxFunctionDefs; /* Number of FDEFs, equal to the highest function number + 1. */
HBUINT16 maxInstructionDefs; /* Number of IDEFs. */
HBUINT16 maxStackElements; /* Maximum stack depth. (This includes Font and CVT
* Programs, as well as the instructions for each glyph.) */
HBUINT16 maxSizeOfInstructions; /* Maximum byte count for glyph instructions. */
HBUINT16 maxComponentElements; /* Maximum number of components referenced at
* "top level" for any composite glyph. */
HBUINT16 maxComponentDepth; /* Maximum levels of recursion; 1 for simple components. */
public:
DEFINE_SIZE_STATIC (26);
};
struct maxp
{
static constexpr hb_tag_t tableTag = HB_OT_TAG_maxp;
unsigned int get_num_glyphs () const { return numGlyphs; }
void set_num_glyphs (unsigned int count)
{
numGlyphs = count;
}
bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
if (unlikely (!c->check_struct (this)))
return_trace (false);
if (version.major == 1)
{
const maxpV1Tail &v1 = StructAfter<maxpV1Tail> (*this);
return_trace (v1.sanitize (c));
}
return_trace (likely (version.major == 0 && version.minor == 0x5000u));
}
bool subset (hb_subset_plan_t *plan) const
{
hb_blob_t *maxp_blob = hb_sanitize_context_t().reference_table<maxp> (plan->source);
hb_blob_t *maxp_prime_blob = hb_blob_copy_writable_or_fail (maxp_blob);
hb_blob_destroy (maxp_blob);
if (unlikely (!maxp_prime_blob)) {
return false;
}
maxp *maxp_prime = (maxp *) hb_blob_get_data (maxp_prime_blob, nullptr);
maxp_prime->set_num_glyphs (plan->num_output_glyphs ());
if (plan->drop_hints)
drop_hint_fields (plan, maxp_prime);
bool result = plan->add_table (HB_OT_TAG_maxp, maxp_prime_blob);
hb_blob_destroy (maxp_prime_blob);
return result;
}
static void drop_hint_fields (hb_subset_plan_t *plan HB_UNUSED, maxp *maxp_prime)
{
if (maxp_prime->version.major == 1)
{
maxpV1Tail &v1 = StructAfter<maxpV1Tail> (*maxp_prime);
v1.maxZones = 1;
v1.maxTwilightPoints = 0;
v1.maxStorage = 0;
v1.maxFunctionDefs = 0;
v1.maxInstructionDefs = 0;
v1.maxStackElements = 0;
v1.maxSizeOfInstructions = 0;
}
}
protected:
FixedVersion<>version; /* Version of the maxp table (0.5 or 1.0),
* 0x00005000u or 0x00010000u. */
HBUINT16 numGlyphs; /* The number of glyphs in the font. */
/*maxpV1Tail v1Tail[VAR]; */
public:
DEFINE_SIZE_STATIC (6);
};
} /* namespace OT */
#endif /* HB_OT_MAXP_TABLE_HH */