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/*
* Copyright © 2026 Behdad Esfahbod
*
* 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.
*
* Author(s): Behdad Esfahbod
*/
#include "hb.hh"
#include "hb-face.hh"
#include "hb-vector-svg-subset.hh"
#include "OT/Color/svg/svg.hh"
#include "hb-vector-svg-utils.hh"
#include "hb-map.hh"
#include "hb-ot-color.h"
#include <ctype.h>
#include <stdio.h>
#include <string.h>
static bool
hb_svg_append_with_prefix (hb_vector_t<char> *out,
const char *s,
unsigned n,
const char *prefix,
unsigned prefix_len)
{
unsigned i = 0;
while (i < n)
{
if (i + 4 <= n && !memcmp (s + i, "id=\"", 4))
{
if (!hb_svg_append_len (out, s + i, 4)) return false;
i += 4;
if (!hb_svg_append_len (out, prefix, prefix_len)) return false;
while (i < n && s[i] != '"')
{
if (!hb_svg_append_c (out, s[i])) return false;
i++;
}
continue;
}
if (i + 4 <= n && !memcmp (s + i, "id='", 4))
{
if (!hb_svg_append_len (out, s + i, 4)) return false;
i += 4;
if (!hb_svg_append_len (out, prefix, prefix_len)) return false;
while (i < n && s[i] != '\'')
{
if (!hb_svg_append_c (out, s[i])) return false;
i++;
}
continue;
}
if (i + 7 <= n && !memcmp (s + i, "href=\"#", 7))
{
if (!hb_svg_append_len (out, s + i, 7)) return false;
i += 7;
if (!hb_svg_append_len (out, prefix, prefix_len)) return false;
while (i < n && s[i] != '"')
{
if (!hb_svg_append_c (out, s[i])) return false;
i++;
}
continue;
}
if (i + 7 <= n && !memcmp (s + i, "href='#", 7))
{
if (!hb_svg_append_len (out, s + i, 7)) return false;
i += 7;
if (!hb_svg_append_len (out, prefix, prefix_len)) return false;
while (i < n && s[i] != '\'')
{
if (!hb_svg_append_c (out, s[i])) return false;
i++;
}
continue;
}
if (i + 13 <= n && !memcmp (s + i, "xlink:href=\"#", 13))
{
if (!hb_svg_append_len (out, s + i, 13)) return false;
i += 13;
if (!hb_svg_append_len (out, prefix, prefix_len)) return false;
while (i < n && s[i] != '"')
{
if (!hb_svg_append_c (out, s[i])) return false;
i++;
}
continue;
}
if (i + 13 <= n && !memcmp (s + i, "xlink:href='#", 13))
{
if (!hb_svg_append_len (out, s + i, 13)) return false;
i += 13;
if (!hb_svg_append_len (out, prefix, prefix_len)) return false;
while (i < n && s[i] != '\'')
{
if (!hb_svg_append_c (out, s[i])) return false;
i++;
}
continue;
}
if (i + 5 <= n && !memcmp (s + i, "url(#", 5))
{
if (!hb_svg_append_len (out, s + i, 5)) return false;
i += 5;
if (!hb_svg_append_len (out, prefix, prefix_len)) return false;
while (i < n && s[i] != ')')
{
if (!hb_svg_append_c (out, s[i])) return false;
i++;
}
continue;
}
if (i + 6 <= n && !memcmp (s + i, "url(\"#", 6))
{
if (!hb_svg_append_len (out, s + i, 6)) return false;
i += 6;
if (!hb_svg_append_len (out, prefix, prefix_len)) return false;
while (i < n && s[i] != '"')
{
if (!hb_svg_append_c (out, s[i])) return false;
i++;
}
continue;
}
if (i + 6 <= n && !memcmp (s + i, "url('#", 6))
{
if (!hb_svg_append_len (out, s + i, 6)) return false;
i += 6;
if (!hb_svg_append_len (out, prefix, prefix_len)) return false;
while (i < n && s[i] != '\'')
{
if (!hb_svg_append_c (out, s[i])) return false;
i++;
}
continue;
}
if (!hb_svg_append_c (out, s[i]))
return false;
i++;
}
return true;
}
static bool
hb_svg_add_unique_id (hb_vector_t<OT::SVG::svg_id_span_t> *v,
hb_hashmap_t<OT::SVG::svg_id_span_t, hb_bool_t> *seen_ids,
const char *p,
unsigned n)
{
if (!n) return false;
OT::SVG::svg_id_span_t key = {p, n};
if (seen_ids->has (key))
return false;
if (unlikely (!seen_ids->set (key, true)))
return false;
auto *slot = v->push ();
if (!slot) return false;
*slot = key;
return true;
}
static bool
hb_svg_collect_refs (const char *s,
unsigned n,
hb_vector_t<OT::SVG::svg_id_span_t> *ids,
hb_hashmap_t<OT::SVG::svg_id_span_t, hb_bool_t> *seen_ids)
{
unsigned i = 0;
while (i < n)
{
if (i + 7 <= n && !memcmp (s + i, "href=\"#", 7))
{
i += 7;
unsigned b = i;
while (i < n && s[i] != '"' && s[i] != '\'' && s[i] != ' ' && s[i] != '>') i++;
if (i > b && unlikely (!hb_svg_add_unique_id (ids, seen_ids, s + b, i - b))) return false;
continue;
}
if (i + 7 <= n && !memcmp (s + i, "href='#", 7))
{
i += 7;
unsigned b = i;
while (i < n && s[i] != '\'' && s[i] != '"' && s[i] != ' ' && s[i] != '>') i++;
if (i > b && unlikely (!hb_svg_add_unique_id (ids, seen_ids, s + b, i - b))) return false;
continue;
}
if (i + 13 <= n && !memcmp (s + i, "xlink:href=\"#", 13))
{
i += 13;
unsigned b = i;
while (i < n && s[i] != '"' && s[i] != '\'' && s[i] != ' ' && s[i] != '>') i++;
if (i > b && unlikely (!hb_svg_add_unique_id (ids, seen_ids, s + b, i - b))) return false;
continue;
}
if (i + 13 <= n && !memcmp (s + i, "xlink:href='#", 13))
{
i += 13;
unsigned b = i;
while (i < n && s[i] != '\'' && s[i] != '"' && s[i] != ' ' && s[i] != '>') i++;
if (i > b && unlikely (!hb_svg_add_unique_id (ids, seen_ids, s + b, i - b))) return false;
continue;
}
if (i + 5 <= n && !memcmp (s + i, "url(#", 5))
{
i += 5;
unsigned b = i;
while (i < n && s[i] != ')') i++;
if (i > b && unlikely (!hb_svg_add_unique_id (ids, seen_ids, s + b, i - b))) return false;
continue;
}
if (i + 6 <= n && !memcmp (s + i, "url(\"#", 6))
{
i += 6;
unsigned b = i;
while (i < n && s[i] != '"') i++;
if (i > b && unlikely (!hb_svg_add_unique_id (ids, seen_ids, s + b, i - b))) return false;
continue;
}
if (i + 6 <= n && !memcmp (s + i, "url('#", 6))
{
i += 6;
unsigned b = i;
while (i < n && s[i] != '\'') i++;
if (i > b && unlikely (!hb_svg_add_unique_id (ids, seen_ids, s + b, i - b))) return false;
continue;
}
i++;
}
return true;
}
bool
hb_svg_subset_glyph_image (hb_face_t *face,
hb_blob_t *image,
hb_codepoint_t glyph,
unsigned *image_counter,
hb_vector_t<char> *defs_dst,
hb_vector_t<char> *body_dst)
{
if (glyph == HB_CODEPOINT_INVALID || !image_counter || !defs_dst || !body_dst)
return false;
unsigned len;
const char *svg = hb_blob_get_data (image, &len);
if (!svg || !len)
return false;
unsigned doc_index = 0;
if (!hb_ot_color_glyph_get_svg_document_index (face, glyph, &doc_index))
return false;
hb_codepoint_t start_glyph = HB_CODEPOINT_INVALID;
hb_codepoint_t end_glyph = HB_CODEPOINT_INVALID;
if (!hb_ot_color_get_svg_document_glyph_range (face, doc_index, &start_glyph, &end_glyph))
return false;
auto *doc_cache = face->table.SVG->get_or_create_doc_cache (image, svg, len,
doc_index, start_glyph, end_glyph);
if (!doc_cache)
return false;
svg = face->table.SVG->doc_cache_get_svg (doc_cache, &len);
unsigned glyph_start = 0, glyph_end = 0;
if (!face->table.SVG->doc_cache_get_glyph_span (doc_cache, glyph, &glyph_start, &glyph_end))
return false;
auto *defs_entries = face->table.SVG->doc_cache_get_defs_entries (doc_cache);
hb_vector_t<OT::SVG::svg_id_span_t> needed_ids;
needed_ids.alloc (16);
hb_hashmap_t<OT::SVG::svg_id_span_t, hb_bool_t> needed_ids_set;
if (!hb_svg_collect_refs (svg + glyph_start, glyph_end - glyph_start,
&needed_ids, &needed_ids_set))
return false;
hb_vector_t<unsigned> chosen_defs;
chosen_defs.alloc (16);
hb_vector_t<uint8_t> chosen_def_marks;
if (unlikely (!chosen_def_marks.resize ((int) defs_entries->length)))
return false;
hb_memset (chosen_def_marks.arrayZ, 0, defs_entries->length);
for (unsigned qi = 0; qi < needed_ids.length; qi++)
{
const auto &need = needed_ids.arrayZ[qi];
for (unsigned i = 0; i < defs_entries->length; i++)
{
const auto &e = defs_entries->arrayZ[i];
if (e.id.len == need.len && !memcmp (e.id.p, need.p, need.len))
{
if (!chosen_def_marks.arrayZ[i])
{
chosen_def_marks.arrayZ[i] = 1;
if (unlikely (!chosen_defs.push (i)))
return false;
if (!hb_svg_collect_refs (svg + e.start, e.end - e.start,
&needed_ids, &needed_ids_set))
return false;
}
break;
}
}
}
char prefix[32];
int prefix_len = snprintf (prefix, sizeof (prefix), "hbimg%u_", (*image_counter)++);
if (prefix_len <= 0 || (unsigned) prefix_len >= sizeof (prefix))
return false;
body_dst->alloc (body_dst->length + (glyph_end - glyph_start) + (unsigned) prefix_len + 32);
for (unsigned i = 0; i < chosen_defs.length; i++)
{
const auto &e = defs_entries->arrayZ[chosen_defs.arrayZ[i]];
if (!hb_svg_append_with_prefix (defs_dst, svg + e.start, e.end - e.start, prefix, (unsigned) prefix_len))
return false;
if (!hb_svg_append_c (defs_dst, '\n')) return false;
}
return hb_svg_append_with_prefix (body_dst,
svg + glyph_start,
glyph_end - glyph_start,
prefix,
(unsigned) prefix_len);
}