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harfbuzz/src/hb-buffer.hh

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/*
* Copyright © 1998-2004 David Turner and Werner Lemberg
* Copyright © 2004,2007,2009,2010 Red Hat, Inc.
* 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.
*
* Red Hat Author(s): Owen Taylor, Behdad Esfahbod
* Google Author(s): Behdad Esfahbod
*/
#ifndef HB_BUFFER_HH
#define HB_BUFFER_HH
#include "hb.hh"
#include "hb-unicode.hh"
#include "hb-set-digest.hh"
static_assert ((sizeof (hb_glyph_info_t) == 20), "");
static_assert ((sizeof (hb_glyph_info_t) == sizeof (hb_glyph_position_t)), "");
HB_MARK_AS_FLAG_T (hb_glyph_flags_t);
HB_MARK_AS_FLAG_T (hb_buffer_flags_t);
HB_MARK_AS_FLAG_T (hb_buffer_serialize_flags_t);
HB_MARK_AS_FLAG_T (hb_buffer_diff_flags_t);
enum hb_buffer_scratch_flags_t {
HB_BUFFER_SCRATCH_FLAG_DEFAULT = 0x00000000u,
HB_BUFFER_SCRATCH_FLAG_HAS_NON_ASCII = 0x00000001u,
HB_BUFFER_SCRATCH_FLAG_HAS_DEFAULT_IGNORABLES = 0x00000002u,
HB_BUFFER_SCRATCH_FLAG_HAS_SPACE_FALLBACK = 0x00000004u,
HB_BUFFER_SCRATCH_FLAG_HAS_GPOS_ATTACHMENT = 0x00000008u,
HB_BUFFER_SCRATCH_FLAG_HAS_CGJ = 0x00000010u,
HB_BUFFER_SCRATCH_FLAG_HAS_GLYPH_FLAGS = 0x00000020u,
HB_BUFFER_SCRATCH_FLAG_HAS_BROKEN_SYLLABLE = 0x00000040u,
/* Reserved for shapers' internal use. */
HB_BUFFER_SCRATCH_FLAG_SHAPER0 = 0x01000000u,
HB_BUFFER_SCRATCH_FLAG_SHAPER1 = 0x02000000u,
HB_BUFFER_SCRATCH_FLAG_SHAPER2 = 0x04000000u,
HB_BUFFER_SCRATCH_FLAG_SHAPER3 = 0x08000000u,
};
HB_MARK_AS_FLAG_T (hb_buffer_scratch_flags_t);
/*
* hb_buffer_t
*/
struct hb_buffer_t
{
hb_object_header_t header;
/*
* Information about how the text in the buffer should be treated.
*/
hb_unicode_funcs_t *unicode; /* Unicode functions */
hb_buffer_flags_t flags; /* BOT / EOT / etc. */
hb_buffer_cluster_level_t cluster_level;
hb_codepoint_t replacement; /* U+FFFD or something else. */
hb_codepoint_t invisible; /* 0 or something else. */
hb_codepoint_t not_found; /* 0 or something else. */
/*
* Buffer contents
*/
hb_buffer_content_type_t content_type;
hb_segment_properties_t props; /* Script, language, direction */
bool successful; /* Allocations successful */
bool shaping_failed; /* Shaping failure */
bool have_output; /* Whether we have an output buffer going on */
bool have_positions; /* Whether we have positions */
unsigned int idx; /* Cursor into ->info and ->pos arrays */
unsigned int len; /* Length of ->info and ->pos arrays */
unsigned int out_len; /* Length of ->out_info array if have_output */
unsigned int allocated; /* Length of allocated arrays */
hb_glyph_info_t *info;
hb_glyph_info_t *out_info;
hb_glyph_position_t *pos;
/* Text before / after the main buffer contents.
* Always in Unicode, and ordered outward.
* Index 0 is for "pre-context", 1 for "post-context". */
static constexpr unsigned CONTEXT_LENGTH = 5u;
hb_codepoint_t context[2][CONTEXT_LENGTH];
unsigned int context_len[2];
/*
* Managed by enter / leave
*/
uint8_t allocated_var_bits;
uint8_t serial;
hb_buffer_scratch_flags_t scratch_flags; /* Have space-fallback, etc. */
unsigned int max_len; /* Maximum allowed len. */
int max_ops; /* Maximum allowed operations. */
/* The bits here reflect current allocations of the bytes in glyph_info_t's var1 and var2. */
/*
* Messaging callback
*/
#ifndef HB_NO_BUFFER_MESSAGE
hb_buffer_message_func_t message_func;
void *message_data;
hb_destroy_func_t message_destroy;
unsigned message_depth; /* How deeply are we inside a message callback? */
#else
static constexpr unsigned message_depth = 0u;
#endif
/* Methods */
HB_NODISCARD bool in_error () const { return !successful; }
void allocate_var (unsigned int start, unsigned int count)
{
unsigned int end = start + count;
assert (end <= 8);
unsigned int bits = (1u<<end) - (1u<<start);
assert (0 == (allocated_var_bits & bits));
allocated_var_bits |= bits;
}
bool try_allocate_var (unsigned int start, unsigned int count)
{
unsigned int end = start + count;
assert (end <= 8);
unsigned int bits = (1u<<end) - (1u<<start);
if (allocated_var_bits & bits)
return false;
allocated_var_bits |= bits;
return true;
}
void deallocate_var (unsigned int start, unsigned int count)
{
unsigned int end = start + count;
assert (end <= 8);
unsigned int bits = (1u<<end) - (1u<<start);
assert (bits == (allocated_var_bits & bits));
allocated_var_bits &= ~bits;
}
void assert_var (unsigned int start, unsigned int count)
{
unsigned int end = start + count;
assert (end <= 8);
HB_UNUSED unsigned int bits = (1u<<end) - (1u<<start);
assert (bits == (allocated_var_bits & bits));
}
void deallocate_var_all ()
{
allocated_var_bits = 0;
}
hb_glyph_info_t &cur (unsigned int i = 0) { return info[idx + i]; }
hb_glyph_info_t cur (unsigned int i = 0) const { return info[idx + i]; }
hb_glyph_position_t &cur_pos (unsigned int i = 0) { return pos[idx + i]; }
hb_glyph_position_t cur_pos (unsigned int i = 0) const { return pos[idx + i]; }
hb_glyph_info_t &prev () { return out_info[out_len ? out_len - 1 : 0]; }
hb_glyph_info_t prev () const { return out_info[out_len ? out_len - 1 : 0]; }
hb_set_digest_t digest () const
{
hb_set_digest_t d;
d.init ();
d.add_array (&info[0].codepoint, len, sizeof (info[0]));
return d;
}
HB_INTERNAL void similar (const hb_buffer_t &src);
HB_INTERNAL void reset ();
HB_INTERNAL void clear ();
/* Called around shape() */
HB_INTERNAL void enter ();
HB_INTERNAL void leave ();
#ifndef HB_NO_BUFFER_VERIFY
HB_INTERNAL
#endif
bool verify (hb_buffer_t *text_buffer,
hb_font_t *font,
const hb_feature_t *features,
unsigned int num_features,
const char * const *shapers)
#ifndef HB_NO_BUFFER_VERIFY
;
#else
{ return true; }
#endif
unsigned int backtrack_len () const { return have_output ? out_len : idx; }
unsigned int lookahead_len () const { return len - idx; }
uint8_t next_serial () { return ++serial ? serial : ++serial; }
HB_INTERNAL void add (hb_codepoint_t codepoint,
unsigned int cluster);
HB_INTERNAL void add_info (const hb_glyph_info_t &glyph_info);
void reverse_range (unsigned start, unsigned end)
{
hb_array_t<hb_glyph_info_t> (info, len).reverse (start, end);
if (have_positions)
hb_array_t<hb_glyph_position_t> (pos, len).reverse (start, end);
}
void reverse () { reverse_range (0, len); }
template <typename FuncType>
void reverse_groups (const FuncType& group,
bool merge_clusters = false)
{
if (unlikely (!len))
return;
unsigned start = 0;
unsigned i;
for (i = 1; i < len; i++)
{
if (!group (info[i - 1], info[i]))
{
if (merge_clusters)
this->merge_clusters (start, i);
reverse_range (start, i);
start = i;
}
}
if (merge_clusters)
this->merge_clusters (start, i);
reverse_range (start, i);
reverse ();
}
template <typename FuncType>
unsigned group_end (unsigned start, const FuncType& group) const
{
while (++start < len && group (info[start - 1], info[start]))
;
return start;
}
static bool _cluster_group_func (const hb_glyph_info_t& a,
const hb_glyph_info_t& b)
{ return a.cluster == b.cluster; }
void reverse_clusters () { reverse_groups (_cluster_group_func); }
HB_INTERNAL void guess_segment_properties ();
HB_INTERNAL bool sync ();
HB_INTERNAL int sync_so_far ();
HB_INTERNAL void clear_output ();
HB_INTERNAL void clear_positions ();
template <typename T>
HB_NODISCARD bool replace_glyphs (unsigned int num_in,
unsigned int num_out,
const T *glyph_data)
{
if (unlikely (!make_room_for (num_in, num_out))) return false;
assert (idx + num_in <= len);
merge_clusters (idx, idx + num_in);
hb_glyph_info_t &orig_info = idx < len ? cur() : prev();
hb_glyph_info_t *pinfo = &out_info[out_len];
for (unsigned int i = 0; i < num_out; i++)
{
*pinfo = orig_info;
pinfo->codepoint = glyph_data[i];
pinfo++;
}
idx += num_in;
out_len += num_out;
return true;
}
HB_NODISCARD bool replace_glyph (hb_codepoint_t glyph_index)
{ return replace_glyphs (1, 1, &glyph_index); }
/* Makes a copy of the glyph at idx to output and replace glyph_index */
HB_NODISCARD bool output_glyph (hb_codepoint_t glyph_index)
{ return replace_glyphs (0, 1, &glyph_index); }
HB_NODISCARD bool output_info (const hb_glyph_info_t &glyph_info)
{
if (unlikely (!make_room_for (0, 1))) return false;
out_info[out_len] = glyph_info;
out_len++;
return true;
}
/* Copies glyph at idx to output but doesn't advance idx */
HB_NODISCARD bool copy_glyph ()
{
/* Extra copy because cur()'s return can be freed within
* output_info() call if buffer reallocates. */
return output_info (hb_glyph_info_t (cur()));
}
/* Copies glyph at idx to output and advance idx.
* If there's no output, just advance idx. */
HB_NODISCARD bool next_glyph ()
{
if (have_output)
{
if (out_info != info || out_len != idx)
{
if (unlikely (!make_room_for (1, 1))) return false;
out_info[out_len] = info[idx];
}
out_len++;
}
idx++;
return true;
}
/* Copies n glyphs at idx to output and advance idx.
* If there's no output, just advance idx. */
HB_NODISCARD bool next_glyphs (unsigned int n)
{
if (have_output)
{
if (out_info != info || out_len != idx)
{
if (unlikely (!make_room_for (n, n))) return false;
memmove (out_info + out_len, info + idx, n * sizeof (out_info[0]));
}
out_len += n;
}
idx += n;
return true;
}
/* Advance idx without copying to output. */
void skip_glyph () { idx++; }
void reset_masks (hb_mask_t mask)
{
for (unsigned int j = 0; j < len; j++)
info[j].mask = mask;
}
void add_masks (hb_mask_t mask)
{
for (unsigned int j = 0; j < len; j++)
info[j].mask |= mask;
}
HB_INTERNAL void set_masks (hb_mask_t value, hb_mask_t mask,
unsigned int cluster_start, unsigned int cluster_end);
void merge_clusters (unsigned int start, unsigned int end)
{
if (end - start < 2)
return;
merge_clusters_impl (start, end);
}
HB_INTERNAL void merge_clusters_impl (unsigned int start, unsigned int end);
HB_INTERNAL void merge_out_clusters (unsigned int start, unsigned int end);
/* Merge clusters for deleting current glyph, and skip it. */
HB_INTERNAL void delete_glyph ();
HB_INTERNAL void delete_glyphs_inplace (bool (*filter) (const hb_glyph_info_t *info));
/* Adds glyph flags in mask to infos with clusters between start and end.
* The start index will be from out-buffer if from_out_buffer is true.
* If interior is true, then the cluster having the minimum value is skipped. */
void _set_glyph_flags (hb_mask_t mask,
unsigned start = 0,
unsigned end = (unsigned) -1,
bool interior = false,
bool from_out_buffer = false)
{
end = hb_min (end, len);
if (interior && !from_out_buffer && end - start < 2)
return;
scratch_flags |= HB_BUFFER_SCRATCH_FLAG_HAS_GLYPH_FLAGS;
if (!from_out_buffer || !have_output)
{
if (!interior)
{
for (unsigned i = start; i < end; i++)
info[i].mask |= mask;
}
else
{
unsigned cluster = _infos_find_min_cluster (info, start, end);
_infos_set_glyph_flags (info, start, end, cluster, mask);
}
}
else
{
assert (start <= out_len);
assert (idx <= end);
if (!interior)
{
for (unsigned i = start; i < out_len; i++)
out_info[i].mask |= mask;
for (unsigned i = idx; i < end; i++)
info[i].mask |= mask;
}
else
{
unsigned cluster = _infos_find_min_cluster (info, idx, end);
cluster = _infos_find_min_cluster (out_info, start, out_len, cluster);
_infos_set_glyph_flags (out_info, start, out_len, cluster, mask);
_infos_set_glyph_flags (info, idx, end, cluster, mask);
}
}
}
void unsafe_to_break (unsigned int start = 0, unsigned int end = -1)
{
_set_glyph_flags (HB_GLYPH_FLAG_UNSAFE_TO_BREAK | HB_GLYPH_FLAG_UNSAFE_TO_CONCAT,
start, end,
true);
}
void safe_to_insert_tatweel (unsigned int start = 0, unsigned int end = -1)
{
if ((flags & HB_BUFFER_FLAG_PRODUCE_SAFE_TO_INSERT_TATWEEL) == 0)
{
unsafe_to_break (start, end);
return;
}
_set_glyph_flags (HB_GLYPH_FLAG_SAFE_TO_INSERT_TATWEEL,
start, end,
true);
}
void unsafe_to_concat (unsigned int start = 0, unsigned int end = -1)
{
if (likely ((flags & HB_BUFFER_FLAG_PRODUCE_UNSAFE_TO_CONCAT) == 0))
return;
_set_glyph_flags (HB_GLYPH_FLAG_UNSAFE_TO_CONCAT,
start, end,
true);
}
void unsafe_to_break_from_outbuffer (unsigned int start = 0, unsigned int end = -1)
{
_set_glyph_flags (HB_GLYPH_FLAG_UNSAFE_TO_BREAK | HB_GLYPH_FLAG_UNSAFE_TO_CONCAT,
start, end,
true, true);
}
void unsafe_to_concat_from_outbuffer (unsigned int start = 0, unsigned int end = -1)
{
if (likely ((flags & HB_BUFFER_FLAG_PRODUCE_UNSAFE_TO_CONCAT) == 0))
return;
_set_glyph_flags (HB_GLYPH_FLAG_UNSAFE_TO_CONCAT,
start, end,
false, true);
}
/* Internal methods */
HB_NODISCARD HB_INTERNAL bool move_to (unsigned int i); /* i is output-buffer index. */
HB_NODISCARD HB_INTERNAL bool enlarge (unsigned int size);
HB_NODISCARD bool ensure (unsigned int size)
{ return likely (!size || size < allocated) ? true : enlarge (size); }
HB_NODISCARD bool ensure_inplace (unsigned int size)
{ return likely (!size || size < allocated); }
void assert_glyphs ()
{
assert ((content_type == HB_BUFFER_CONTENT_TYPE_GLYPHS) ||
(!len && (content_type == HB_BUFFER_CONTENT_TYPE_INVALID)));
}
void assert_unicode ()
{
assert ((content_type == HB_BUFFER_CONTENT_TYPE_UNICODE) ||
(!len && (content_type == HB_BUFFER_CONTENT_TYPE_INVALID)));
}
HB_NODISCARD bool ensure_glyphs ()
{
if (unlikely (content_type != HB_BUFFER_CONTENT_TYPE_GLYPHS))
{
if (content_type != HB_BUFFER_CONTENT_TYPE_INVALID)
return false;
assert (len == 0);
content_type = HB_BUFFER_CONTENT_TYPE_GLYPHS;
}
return true;
}
HB_NODISCARD bool ensure_unicode ()
{
if (unlikely (content_type != HB_BUFFER_CONTENT_TYPE_UNICODE))
{
if (content_type != HB_BUFFER_CONTENT_TYPE_INVALID)
return false;
assert (len == 0);
content_type = HB_BUFFER_CONTENT_TYPE_UNICODE;
}
return true;
}
HB_NODISCARD HB_INTERNAL bool make_room_for (unsigned int num_in, unsigned int num_out);
HB_NODISCARD HB_INTERNAL bool shift_forward (unsigned int count);
typedef long scratch_buffer_t;
HB_INTERNAL scratch_buffer_t *get_scratch_buffer (unsigned int *size);
void clear_context (unsigned int side) { context_len[side] = 0; }
HB_INTERNAL void sort (unsigned int start, unsigned int end, int(*compar)(const hb_glyph_info_t *, const hb_glyph_info_t *));
bool messaging ()
{
#ifdef HB_NO_BUFFER_MESSAGE
return false;
#else
return unlikely (message_func);
#endif
}
bool message (hb_font_t *font, const char *fmt, ...) HB_PRINTF_FUNC(3, 4)
{
#ifdef HB_NO_BUFFER_MESSAGE
return true;
#else
if (likely (!messaging ()))
return true;
va_list ap;
va_start (ap, fmt);
bool ret = message_impl (font, fmt, ap);
va_end (ap);
return ret;
#endif
}
HB_INTERNAL bool message_impl (hb_font_t *font, const char *fmt, va_list ap) HB_PRINTF_FUNC(3, 0);
static void
set_cluster (hb_glyph_info_t &inf, unsigned int cluster, unsigned int mask = 0)
{
if (inf.cluster != cluster)
inf.mask = (inf.mask & ~HB_GLYPH_FLAG_DEFINED) | (mask & HB_GLYPH_FLAG_DEFINED);
inf.cluster = cluster;
}
void
_infos_set_glyph_flags (hb_glyph_info_t *infos,
unsigned int start, unsigned int end,
unsigned int cluster,
hb_mask_t mask)
{
if (unlikely (start == end))
return;
unsigned cluster_first = infos[start].cluster;
unsigned cluster_last = infos[end - 1].cluster;
if (cluster_level == HB_BUFFER_CLUSTER_LEVEL_CHARACTERS ||
(cluster != cluster_first && cluster != cluster_last))
{
for (unsigned int i = start; i < end; i++)
if (cluster != infos[i].cluster)
{
scratch_flags |= HB_BUFFER_SCRATCH_FLAG_HAS_GLYPH_FLAGS;
infos[i].mask |= mask;
}
return;
}
/* Monotone clusters */
if (cluster == cluster_first)
{
for (unsigned int i = end; start < i && infos[i - 1].cluster != cluster_first; i--)
{
scratch_flags |= HB_BUFFER_SCRATCH_FLAG_HAS_GLYPH_FLAGS;
infos[i - 1].mask |= mask;
}
}
else /* cluster == cluster_last */
{
for (unsigned int i = start; i < end && infos[i].cluster != cluster_last; i++)
{
scratch_flags |= HB_BUFFER_SCRATCH_FLAG_HAS_GLYPH_FLAGS;
infos[i].mask |= mask;
}
}
}
unsigned
_infos_find_min_cluster (const hb_glyph_info_t *infos,
unsigned start, unsigned end,
unsigned cluster = UINT_MAX)
{
if (unlikely (start == end))
return cluster;
if (cluster_level == HB_BUFFER_CLUSTER_LEVEL_CHARACTERS)
{
for (unsigned int i = start; i < end; i++)
cluster = hb_min (cluster, infos[i].cluster);
return cluster;
}
return hb_min (cluster, hb_min (infos[start].cluster, infos[end - 1].cluster));
}
void clear_glyph_flags (hb_mask_t mask = 0)
{
for (unsigned int i = 0; i < len; i++)
info[i].mask = (info[i].mask & ~HB_GLYPH_FLAG_DEFINED) | (mask & HB_GLYPH_FLAG_DEFINED);
}
};
DECLARE_NULL_INSTANCE (hb_buffer_t);
#define foreach_group(buffer, start, end, group_func) \
for (unsigned int \
_count = buffer->len, \
start = 0, end = _count ? buffer->group_end (0, group_func) : 0; \
start < _count; \
start = end, end = buffer->group_end (start, group_func))
#define foreach_cluster(buffer, start, end) \
foreach_group (buffer, start, end, hb_buffer_t::_cluster_group_func)
#define HB_BUFFER_XALLOCATE_VAR(b, func, var) \
b->func (offsetof (hb_glyph_info_t, var) - offsetof(hb_glyph_info_t, var1), \
sizeof (b->info[0].var))
#define HB_BUFFER_ALLOCATE_VAR(b, var) HB_BUFFER_XALLOCATE_VAR (b, allocate_var, var ())
#define HB_BUFFER_TRY_ALLOCATE_VAR(b, var) HB_BUFFER_XALLOCATE_VAR (b, try_allocate_var, var ())
#define HB_BUFFER_DEALLOCATE_VAR(b, var) HB_BUFFER_XALLOCATE_VAR (b, deallocate_var, var ())
#define HB_BUFFER_ASSERT_VAR(b, var) HB_BUFFER_XALLOCATE_VAR (b, assert_var, var ())
#endif /* HB_BUFFER_HH */
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