harfbuzz/src/hb-buffer.cc

835 lines
18 KiB
C++

/*
* Copyright © 1998-2004 David Turner and Werner Lemberg
* Copyright © 2004,2007,2009,2010 Red Hat, Inc.
* Copyright © 2011 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
*/
#include "hb-buffer-private.hh"
#include <string.h>
#ifndef HB_DEBUG_BUFFER
#define HB_DEBUG_BUFFER (HB_DEBUG+0)
#endif
static hb_buffer_t _hb_buffer_nil = {
HB_OBJECT_HEADER_STATIC,
&_hb_unicode_funcs_default,
{
HB_DIRECTION_INVALID,
HB_SCRIPT_INVALID,
NULL,
},
TRUE, /* in_error */
TRUE, /* have_output */
TRUE /* have_positions */
};
/* Here is how the buffer works internally:
*
* There are two info pointers: info and out_info. They always have
* the same allocated size, but different lengths.
*
* As an optimization, both info and out_info may point to the
* same piece of memory, which is owned by info. This remains the
* case as long as out_len doesn't exceed i at any time.
* In that case, swap_buffers() is no-op and the glyph operations operate
* mostly in-place.
*
* As soon as out_info gets longer than info, out_info is moved over
* to an alternate buffer (which we reuse the pos buffer for!), and its
* current contents (out_len entries) are copied to the new place.
* This should all remain transparent to the user. swap_buffers() then
* switches info and out_info.
*/
/* Internal API */
bool
hb_buffer_t::enlarge (unsigned int size)
{
if (unlikely (in_error))
return FALSE;
unsigned int new_allocated = allocated;
hb_glyph_position_t *new_pos = NULL;
hb_glyph_info_t *new_info = NULL;
bool separate_out = out_info != info;
if (unlikely (_hb_unsigned_int_mul_overflows (size, sizeof (info[0]))))
goto done;
while (size > new_allocated)
new_allocated += (new_allocated >> 1) + 32;
ASSERT_STATIC (sizeof (info[0]) == sizeof (pos[0]));
if (unlikely (_hb_unsigned_int_mul_overflows (new_allocated, sizeof (info[0]))))
goto done;
new_pos = (hb_glyph_position_t *) realloc (pos, new_allocated * sizeof (pos[0]));
new_info = (hb_glyph_info_t *) realloc (info, new_allocated * sizeof (info[0]));
done:
if (unlikely (!new_pos || !new_info))
in_error = TRUE;
if (likely (new_pos))
pos = new_pos;
if (likely (new_info))
info = new_info;
out_info = separate_out ? (hb_glyph_info_t *) pos : info;
if (likely (!in_error))
allocated = new_allocated;
return likely (!in_error);
}
bool
hb_buffer_t::make_room_for (unsigned int num_in,
unsigned int num_out)
{
if (unlikely (!ensure (out_len + num_out))) return FALSE;
if (out_info == info &&
out_len + num_out > idx + num_in)
{
assert (have_output);
out_info = (hb_glyph_info_t *) pos;
memcpy (out_info, info, out_len * sizeof (out_info[0]));
}
return TRUE;
}
void *
hb_buffer_t::get_scratch_buffer (unsigned int *size)
{
have_output = FALSE;
have_positions = FALSE;
out_len = 0;
*size = allocated * sizeof (pos[0]);
return pos;
}
/* HarfBuzz-Internal API */
void
hb_buffer_t::reset (void)
{
if (unlikely (hb_object_is_inert (this)))
return;
hb_unicode_funcs_destroy (unicode);
unicode = _hb_buffer_nil.unicode;
props = _hb_buffer_nil.props;
in_error = FALSE;
have_output = FALSE;
have_positions = FALSE;
idx = 0;
len = 0;
out_len = 0;
serial = 0;
memset (allocated_var_bytes, 0, sizeof allocated_var_bytes);
memset (allocated_var_owner, 0, sizeof allocated_var_owner);
out_info = info;
}
void
hb_buffer_t::add (hb_codepoint_t codepoint,
hb_mask_t mask,
unsigned int cluster)
{
hb_glyph_info_t *glyph;
if (unlikely (!ensure (len + 1))) return;
glyph = &info[len];
memset (glyph, 0, sizeof (*glyph));
glyph->codepoint = codepoint;
glyph->mask = mask;
glyph->cluster = cluster;
len++;
}
void
hb_buffer_t::clear_output (void)
{
if (unlikely (hb_object_is_inert (this)))
return;
have_output = TRUE;
have_positions = FALSE;
out_len = 0;
out_info = info;
}
void
hb_buffer_t::clear_positions (void)
{
if (unlikely (hb_object_is_inert (this)))
return;
have_output = FALSE;
have_positions = TRUE;
memset (pos, 0, sizeof (pos[0]) * len);
}
void
hb_buffer_t::swap_buffers (void)
{
if (unlikely (in_error)) return;
assert (have_output);
if (out_info != info)
{
hb_glyph_info_t *tmp_string;
tmp_string = info;
info = out_info;
out_info = tmp_string;
pos = (hb_glyph_position_t *) out_info;
}
unsigned int tmp;
tmp = len;
len = out_len;
out_len = tmp;
idx = 0;
}
void
hb_buffer_t::replace_glyphs_be16 (unsigned int num_in,
unsigned int num_out,
const uint16_t *glyph_data_be)
{
if (!make_room_for (num_in, num_out)) return;
hb_glyph_info_t orig_info = info[idx];
for (unsigned int i = 1; i < num_in; i++)
{
hb_glyph_info_t *inf = &info[idx + i];
orig_info.cluster = MIN (orig_info.cluster, inf->cluster);
}
hb_glyph_info_t *pinfo = &out_info[out_len];
for (unsigned int i = 0; i < num_out; i++)
{
*pinfo = orig_info;
pinfo->codepoint = hb_be_uint16 (glyph_data_be[i]);
pinfo++;
}
idx += num_in;
out_len += num_out;
}
void
hb_buffer_t::output_glyph (hb_codepoint_t glyph_index)
{
if (!make_room_for (0, 1)) return;
out_info[out_len] = info[idx];
out_info[out_len].codepoint = glyph_index;
out_len++;
}
void
hb_buffer_t::copy_glyph (void)
{
if (!make_room_for (0, 1)) return;
out_info[out_len] = info[idx];
out_len++;
}
void
hb_buffer_t::replace_glyph (hb_codepoint_t glyph_index)
{
out_info[out_len] = info[idx];
out_info[out_len].codepoint = glyph_index;
idx++;
out_len++;
}
void
hb_buffer_t::next_glyph (void)
{
if (have_output)
{
if (out_info != info)
{
if (unlikely (!ensure (out_len + 1))) return;
out_info[out_len] = info[idx];
}
else if (out_len != idx)
out_info[out_len] = info[idx];
out_len++;
}
idx++;
}
void
hb_buffer_t::set_masks (hb_mask_t value,
hb_mask_t mask,
unsigned int cluster_start,
unsigned int cluster_end)
{
hb_mask_t not_mask = ~mask;
value &= mask;
if (!mask)
return;
if (cluster_start == 0 && cluster_end == (unsigned int)-1) {
unsigned int count = len;
for (unsigned int i = 0; i < count; i++)
info[i].mask = (info[i].mask & not_mask) | value;
return;
}
unsigned int count = len;
for (unsigned int i = 0; i < count; i++)
if (cluster_start <= info[i].cluster && info[i].cluster < cluster_end)
info[i].mask = (info[i].mask & not_mask) | value;
}
void
hb_buffer_t::reverse_range (unsigned int start,
unsigned int end)
{
unsigned int i, j;
if (start == end - 1)
return;
for (i = start, j = end - 1; i < j; i++, j--) {
hb_glyph_info_t t;
t = info[i];
info[i] = info[j];
info[j] = t;
}
if (pos) {
for (i = start, j = end - 1; i < j; i++, j--) {
hb_glyph_position_t t;
t = pos[i];
pos[i] = pos[j];
pos[j] = t;
}
}
}
void
hb_buffer_t::reverse (void)
{
if (unlikely (!len))
return;
reverse_range (0, len);
}
void
hb_buffer_t::reverse_clusters (void)
{
unsigned int i, start, count, last_cluster;
if (unlikely (!len))
return;
reverse ();
count = len;
start = 0;
last_cluster = info[0].cluster;
for (i = 1; i < count; i++) {
if (last_cluster != info[i].cluster) {
reverse_range (start, i);
start = i;
last_cluster = info[i].cluster;
}
}
reverse_range (start, i);
}
void
hb_buffer_t::guess_properties (void)
{
/* If script is set to INVALID, guess from buffer contents */
if (props.script == HB_SCRIPT_INVALID) {
for (unsigned int i = 0; i < len; i++) {
hb_script_t script = hb_unicode_script (unicode, info[i].codepoint);
if (likely (script != HB_SCRIPT_COMMON &&
script != HB_SCRIPT_INHERITED &&
script != HB_SCRIPT_UNKNOWN)) {
props.script = script;
break;
}
}
}
/* If direction is set to INVALID, guess from script */
if (props.direction == HB_DIRECTION_INVALID) {
props.direction = hb_script_get_horizontal_direction (props.script);
}
/* If language is not set, use default language from locale */
if (props.language == HB_LANGUAGE_INVALID) {
/* TODO get_default_for_script? using $LANGUAGE */
props.language = hb_language_get_default ();
}
}
static inline void
dump_var_allocation (const hb_buffer_t *buffer)
{
char buf[80];
for (unsigned int i = 0; i < 8; i++)
buf[i] = '0' + buffer->allocated_var_bytes[7 - i];
buf[8] = '\0';
DEBUG_MSG (BUFFER, buffer,
"Current var allocation: %s",
buf);
}
void hb_buffer_t::allocate_var (unsigned int byte_i, unsigned int count, const char *owner)
{
assert (byte_i < 8 && byte_i + count <= 8);
if (DEBUG (BUFFER))
dump_var_allocation (this);
DEBUG_MSG (BUFFER, this,
"Allocating var bytes %d..%d for %s",
byte_i, byte_i + count - 1, owner);
for (unsigned int i = byte_i; i < byte_i + count; i++) {
assert (!allocated_var_bytes[i]);
allocated_var_bytes[i]++;
allocated_var_owner[i] = owner;
}
}
void hb_buffer_t::deallocate_var (unsigned int byte_i, unsigned int count, const char *owner)
{
if (DEBUG (BUFFER))
dump_var_allocation (this);
DEBUG_MSG (BUFFER, this,
"Deallocating var bytes %d..%d for %s",
byte_i, byte_i + count - 1, owner);
assert (byte_i < 8 && byte_i + count <= 8);
for (unsigned int i = byte_i; i < byte_i + count; i++) {
assert (allocated_var_bytes[i]);
assert (0 == strcmp (allocated_var_owner[i], owner));
allocated_var_bytes[i]--;
}
}
void hb_buffer_t::deallocate_var_all (void)
{
memset (allocated_var_bytes, 0, sizeof (allocated_var_bytes));
memset (allocated_var_owner, 0, sizeof (allocated_var_owner));
}
/* Public API */
hb_buffer_t *
hb_buffer_create (unsigned int pre_alloc_size)
{
hb_buffer_t *buffer;
if (!(buffer = hb_object_create<hb_buffer_t> ()))
return &_hb_buffer_nil;
buffer->reset ();
if (pre_alloc_size && !buffer->ensure (pre_alloc_size)) {
hb_buffer_destroy (buffer);
return &_hb_buffer_nil;
}
return buffer;
}
hb_buffer_t *
hb_buffer_get_empty (void)
{
return &_hb_buffer_nil;
}
hb_buffer_t *
hb_buffer_reference (hb_buffer_t *buffer)
{
return hb_object_reference (buffer);
}
void
hb_buffer_destroy (hb_buffer_t *buffer)
{
if (!hb_object_destroy (buffer)) return;
hb_unicode_funcs_destroy (buffer->unicode);
free (buffer->info);
free (buffer->pos);
free (buffer);
}
hb_bool_t
hb_buffer_set_user_data (hb_buffer_t *buffer,
hb_user_data_key_t *key,
void * data,
hb_destroy_func_t destroy)
{
return hb_object_set_user_data (buffer, key, data, destroy);
}
void *
hb_buffer_get_user_data (hb_buffer_t *buffer,
hb_user_data_key_t *key)
{
return hb_object_get_user_data (buffer, key);
}
void
hb_buffer_set_unicode_funcs (hb_buffer_t *buffer,
hb_unicode_funcs_t *unicode)
{
if (unlikely (hb_object_is_inert (buffer)))
return;
if (!unicode)
unicode = _hb_buffer_nil.unicode;
hb_unicode_funcs_reference (unicode);
hb_unicode_funcs_destroy (buffer->unicode);
buffer->unicode = unicode;
}
hb_unicode_funcs_t *
hb_buffer_get_unicode_funcs (hb_buffer_t *buffer)
{
return buffer->unicode;
}
void
hb_buffer_set_direction (hb_buffer_t *buffer,
hb_direction_t direction)
{
if (unlikely (hb_object_is_inert (buffer)))
return;
buffer->props.direction = direction;
}
hb_direction_t
hb_buffer_get_direction (hb_buffer_t *buffer)
{
return buffer->props.direction;
}
void
hb_buffer_set_script (hb_buffer_t *buffer,
hb_script_t script)
{
if (unlikely (hb_object_is_inert (buffer)))
return;
buffer->props.script = script;
}
hb_script_t
hb_buffer_get_script (hb_buffer_t *buffer)
{
return buffer->props.script;
}
void
hb_buffer_set_language (hb_buffer_t *buffer,
hb_language_t language)
{
if (unlikely (hb_object_is_inert (buffer)))
return;
buffer->props.language = language;
}
hb_language_t
hb_buffer_get_language (hb_buffer_t *buffer)
{
return buffer->props.language;
}
void
hb_buffer_reset (hb_buffer_t *buffer)
{
buffer->reset ();
}
hb_bool_t
hb_buffer_pre_allocate (hb_buffer_t *buffer, unsigned int size)
{
return buffer->ensure (size);
}
hb_bool_t
hb_buffer_allocation_successful (hb_buffer_t *buffer)
{
return !buffer->in_error;
}
void
hb_buffer_add (hb_buffer_t *buffer,
hb_codepoint_t codepoint,
hb_mask_t mask,
unsigned int cluster)
{
buffer->add (codepoint, mask, cluster);
}
hb_bool_t
hb_buffer_set_length (hb_buffer_t *buffer,
unsigned int length)
{
if (!buffer->ensure (length))
return FALSE;
/* Wipe the new space */
if (length > buffer->len) {
memset (buffer->info + buffer->len, 0, sizeof (buffer->info[0]) * (length - buffer->len));
if (buffer->have_positions)
memset (buffer->pos + buffer->len, 0, sizeof (buffer->pos[0]) * (length - buffer->len));
}
buffer->len = length;
return TRUE;
}
unsigned int
hb_buffer_get_length (hb_buffer_t *buffer)
{
return buffer->len;
}
/* Return value valid as long as buffer not modified */
hb_glyph_info_t *
hb_buffer_get_glyph_infos (hb_buffer_t *buffer,
unsigned int *length)
{
if (length)
*length = buffer->len;
return (hb_glyph_info_t *) buffer->info;
}
/* Return value valid as long as buffer not modified */
hb_glyph_position_t *
hb_buffer_get_glyph_positions (hb_buffer_t *buffer,
unsigned int *length)
{
if (!buffer->have_positions)
buffer->clear_positions ();
if (length)
*length = buffer->len;
return (hb_glyph_position_t *) buffer->pos;
}
void
hb_buffer_reverse (hb_buffer_t *buffer)
{
buffer->reverse ();
}
void
hb_buffer_reverse_clusters (hb_buffer_t *buffer)
{
buffer->reverse_clusters ();
}
void
hb_buffer_guess_properties (hb_buffer_t *buffer)
{
buffer->guess_properties ();
}
#define ADD_UTF(T) \
HB_STMT_START { \
if (text_length == -1) { \
text_length = 0; \
const T *p = (const T *) text; \
while (*p) { \
text_length++; \
p++; \
} \
} \
if (item_length == -1) \
item_length = text_length - item_offset; \
const T *next = (const T *) text + item_offset; \
const T *end = next + item_length; \
while (next < end) { \
hb_codepoint_t u; \
const T *old_next = next; \
next = UTF_NEXT (next, end, u); \
hb_buffer_add (buffer, u, 1, old_next - (const T *) text); \
} \
} HB_STMT_END
#define UTF8_COMPUTE(Char, Mask, Len) \
if (Char < 128) { Len = 1; Mask = 0x7f; } \
else if ((Char & 0xe0) == 0xc0) { Len = 2; Mask = 0x1f; } \
else if ((Char & 0xf0) == 0xe0) { Len = 3; Mask = 0x0f; } \
else if ((Char & 0xf8) == 0xf0) { Len = 4; Mask = 0x07; } \
else Len = 0;
static inline const uint8_t *
hb_utf8_next (const uint8_t *text,
const uint8_t *end,
hb_codepoint_t *unicode)
{
uint8_t c = *text;
unsigned int mask, len;
/* TODO check for overlong sequences? */
UTF8_COMPUTE (c, mask, len);
if (unlikely (!len || (unsigned int) (end - text) < len)) {
*unicode = -1;
return text + 1;
} else {
hb_codepoint_t result;
unsigned int i;
result = c & mask;
for (i = 1; i < len; i++)
{
if (unlikely ((text[i] & 0xc0) != 0x80))
{
*unicode = -1;
return text + 1;
}
result <<= 6;
result |= (text[i] & 0x3f);
}
*unicode = result;
return text + len;
}
}
void
hb_buffer_add_utf8 (hb_buffer_t *buffer,
const char *text,
unsigned int text_length HB_UNUSED,
unsigned int item_offset,
unsigned int item_length)
{
#define UTF_NEXT(S, E, U) hb_utf8_next (S, E, &(U))
ADD_UTF (uint8_t);
#undef UTF_NEXT
}
static inline const uint16_t *
hb_utf16_next (const uint16_t *text,
const uint16_t *end,
hb_codepoint_t *unicode)
{
uint16_t c = *text++;
if (unlikely (c >= 0xd800 && c < 0xdc00)) {
/* high surrogate */
uint16_t l;
if (text < end && ((l = *text), likely (l >= 0xdc00 && l < 0xe000))) {
/* low surrogate */
*unicode = ((hb_codepoint_t) ((c) - 0xd800) * 0x400 + (l) - 0xdc00 + 0x10000);
text++;
} else
*unicode = -1;
} else
*unicode = c;
return text;
}
void
hb_buffer_add_utf16 (hb_buffer_t *buffer,
const uint16_t *text,
unsigned int text_length HB_UNUSED,
unsigned int item_offset,
unsigned int item_length)
{
#define UTF_NEXT(S, E, U) hb_utf16_next (S, E, &(U))
ADD_UTF (uint16_t);
#undef UTF_NEXT
}
void
hb_buffer_add_utf32 (hb_buffer_t *buffer,
const uint32_t *text,
unsigned int text_length HB_UNUSED,
unsigned int item_offset,
unsigned int item_length)
{
#define UTF_NEXT(S, E, U) ((U) = *(S), (S)+1)
ADD_UTF (uint32_t);
#undef UTF_NEXT
}