harfbuzz/src/hb-buffer.c

517 lines
13 KiB
C

/*
* Copyright (C) 1998-2004 David Turner and Werner Lemberg
* Copyright (C) 2004,2007 Red Hat, Inc.
*
* This is part of HarfBuzz, an OpenType Layout engine 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
*/
#include "hb-buffer-private.h"
#include <string.h>
static hb_buffer_t _hb_buffer_nil = {
HB_REFERENCE_COUNT_INVALID /* ref_count */
};
/* Here is how the buffer works internally:
*
* There are two string pointers: in_string and out_string. They
* always have same allocated size, but different length and positions.
*
* As an optimization, both in_string and out_string may point to the
* same piece of memory, which is owned by in_string. This remains the
* case as long as out_length doesn't exceed in_length at any time.
* In that case, swap() is no-op and the glyph operations operate mostly
* in-place.
*
* As soon as out_string gets longer than in_string, out_string is moved over
* to an alternate buffer (which we reuse the positions buffer for!), and its
* current contents (out_length entries) are copied to the alt buffer.
* This should all remain transparent to the user. swap() then switches
* in_string and out_string.
*/
/* XXX err handling */
/* Internal API */
static void
hb_buffer_ensure_separate (hb_buffer_t *buffer, unsigned int size)
{
hb_buffer_ensure (buffer, size);
if (buffer->out_string == buffer->in_string)
{
assert (buffer->have_output);
if (!buffer->positions)
buffer->positions = calloc (buffer->allocated, sizeof (buffer->positions[0]));
buffer->out_string = (hb_internal_glyph_info_t *) buffer->positions;
memcpy (buffer->out_string, buffer->in_string, buffer->out_length * sizeof (buffer->out_string[0]));
}
}
/* Public API */
hb_buffer_t *
hb_buffer_create (unsigned int pre_alloc_size)
{
hb_buffer_t *buffer;
if (!HB_OBJECT_DO_CREATE (hb_buffer_t, buffer))
return &_hb_buffer_nil;
if (pre_alloc_size)
hb_buffer_ensure(buffer, pre_alloc_size);
return buffer;
}
hb_buffer_t *
hb_buffer_reference (hb_buffer_t *buffer)
{
HB_OBJECT_DO_REFERENCE (buffer);
}
unsigned int
hb_buffer_get_reference_count (hb_buffer_t *buffer)
{
HB_OBJECT_DO_GET_REFERENCE_COUNT (buffer);
}
void
hb_buffer_destroy (hb_buffer_t *buffer)
{
HB_OBJECT_DO_DESTROY (buffer);
free (buffer->in_string);
free (buffer->positions);
free (buffer);
}
void
hb_buffer_clear (hb_buffer_t *buffer)
{
buffer->have_output = FALSE;
buffer->in_length = 0;
buffer->out_length = 0;
buffer->in_pos = 0;
buffer->out_pos = 0;
buffer->out_string = buffer->in_string;
buffer->max_lig_id = 0;
}
void
hb_buffer_ensure (hb_buffer_t *buffer, unsigned int size)
{
unsigned int new_allocated = buffer->allocated;
if (size > new_allocated)
{
while (size > new_allocated)
new_allocated += (new_allocated >> 1) + 8;
if (buffer->positions)
buffer->positions = realloc (buffer->positions, new_allocated * sizeof (buffer->positions[0]));
if (buffer->out_string != buffer->in_string)
{
buffer->in_string = realloc (buffer->in_string, new_allocated * sizeof (buffer->in_string[0]));
buffer->out_string = (hb_internal_glyph_info_t *) buffer->positions;
}
else
{
buffer->in_string = realloc (buffer->in_string, new_allocated * sizeof (buffer->in_string[0]));
buffer->out_string = buffer->in_string;
}
buffer->allocated = new_allocated;
}
}
void
hb_buffer_add_glyph (hb_buffer_t *buffer,
hb_codepoint_t codepoint,
hb_mask_t mask,
unsigned int cluster)
{
hb_internal_glyph_info_t *glyph;
hb_buffer_ensure (buffer, buffer->in_length + 1);
glyph = &buffer->in_string[buffer->in_length];
glyph->codepoint = codepoint;
glyph->mask = mask;
glyph->cluster = cluster;
glyph->component = 0;
glyph->lig_id = 0;
glyph->gproperty = HB_BUFFER_GLYPH_PROPERTIES_UNKNOWN;
buffer->in_length++;
}
void
hb_buffer_set_direction (hb_buffer_t *buffer,
hb_direction_t direction)
{
buffer->direction = direction;
}
/* HarfBuzz-Internal API */
void
_hb_buffer_clear_output (hb_buffer_t *buffer)
{
buffer->have_output = TRUE;
buffer->out_length = 0;
buffer->out_pos = 0;
buffer->out_string = buffer->in_string;
}
void
hb_buffer_clear_positions (hb_buffer_t *buffer)
{
_hb_buffer_clear_output (buffer);
buffer->have_output = FALSE;
if (HB_UNLIKELY (!buffer->positions))
{
buffer->positions = calloc (buffer->allocated, sizeof (buffer->positions[0]));
return;
}
memset (buffer->positions, 0, sizeof (buffer->positions[0]) * buffer->in_length);
}
void
_hb_buffer_swap (hb_buffer_t *buffer)
{
unsigned int tmp;
assert (buffer->have_output);
if (buffer->out_string != buffer->in_string)
{
hb_internal_glyph_info_t *tmp_string;
tmp_string = buffer->in_string;
buffer->in_string = buffer->out_string;
buffer->out_string = tmp_string;
buffer->positions = (hb_internal_glyph_position_t *) buffer->out_string;
}
tmp = buffer->in_length;
buffer->in_length = buffer->out_length;
buffer->out_length = tmp;
tmp = buffer->in_pos;
buffer->in_pos = buffer->out_pos;
buffer->out_pos = tmp;
}
/* The following function copies `num_out' elements from `glyph_data'
to `buffer->out_string', advancing the in array pointer in the structure
by `num_in' elements, and the out array pointer by `num_out' elements.
Finally, it sets the `length' field of `out' equal to
`pos' of the `out' structure.
If `component' is 0xFFFF, the component value from buffer->in_pos
will copied `num_out' times, otherwise `component' itself will
be used to fill the `component' fields.
If `lig_id' is 0xFFFF, the lig_id value from buffer->in_pos
will copied `num_out' times, otherwise `lig_id' itself will
be used to fill the `lig_id' fields.
The mask for all replacement glyphs are taken
from the glyph at position `buffer->in_pos'.
The cluster value for the glyph at position buffer->in_pos is used
for all replacement glyphs */
void
_hb_buffer_add_output_glyphs (hb_buffer_t *buffer,
unsigned int num_in,
unsigned int num_out,
const uint16_t *glyph_data_be,
unsigned short component,
unsigned short lig_id)
{
unsigned int i;
unsigned int mask;
unsigned int cluster;
if (buffer->out_string != buffer->in_string ||
buffer->out_pos + num_out > buffer->in_pos + num_in)
{
hb_buffer_ensure_separate (buffer, buffer->out_pos + num_out);
}
mask = buffer->in_string[buffer->in_pos].mask;
cluster = buffer->in_string[buffer->in_pos].cluster;
if (component == 0xFFFF)
component = buffer->in_string[buffer->in_pos].component;
if (lig_id == 0xFFFF)
lig_id = buffer->in_string[buffer->in_pos].lig_id;
for (i = 0; i < num_out; i++)
{
hb_internal_glyph_info_t *info = &buffer->out_string[buffer->out_pos + i];
info->codepoint = hb_be_uint16 (glyph_data_be[i]);
info->mask = mask;
info->cluster = cluster;
info->component = component;
info->lig_id = lig_id;
info->gproperty = HB_BUFFER_GLYPH_PROPERTIES_UNKNOWN;
}
buffer->in_pos += num_in;
buffer->out_pos += num_out;
buffer->out_length = buffer->out_pos;
}
void
_hb_buffer_add_output_glyph (hb_buffer_t *buffer,
hb_codepoint_t glyph_index,
unsigned short component,
unsigned short lig_id)
{
hb_internal_glyph_info_t *info;
if (buffer->out_string != buffer->in_string)
{
hb_buffer_ensure (buffer, buffer->out_pos + 1);
buffer->out_string[buffer->out_pos] = buffer->in_string[buffer->in_pos];
}
else if (buffer->out_pos != buffer->in_pos)
buffer->out_string[buffer->out_pos] = buffer->in_string[buffer->in_pos];
info = &buffer->out_string[buffer->out_pos];
info->codepoint = glyph_index;
if (component != 0xFFFF)
info->component = component;
if (lig_id != 0xFFFF)
info->lig_id = lig_id;
info->gproperty = HB_BUFFER_GLYPH_PROPERTIES_UNKNOWN;
buffer->in_pos++;
buffer->out_pos++;
buffer->out_length = buffer->out_pos;
}
void
_hb_buffer_next_glyph (hb_buffer_t *buffer)
{
if (!buffer->have_output)
{
buffer->in_pos++;
return;
}
if (buffer->out_string != buffer->in_string)
{
hb_buffer_ensure (buffer, buffer->out_pos + 1);
buffer->out_string[buffer->out_pos] = buffer->in_string[buffer->in_pos];
}
else if (buffer->out_pos != buffer->in_pos)
buffer->out_string[buffer->out_pos] = buffer->in_string[buffer->in_pos];
buffer->in_pos++;
buffer->out_pos++;
buffer->out_length = buffer->out_pos;
}
void
_hb_buffer_replace_glyph (hb_buffer_t *buffer,
hb_codepoint_t glyph_index)
{
_hb_buffer_add_output_glyph (buffer, glyph_index, 0xFFFF, 0xFFFF);
}
unsigned short
_hb_buffer_allocate_lig_id (hb_buffer_t *buffer)
{
return ++buffer->max_lig_id;
}
unsigned int
hb_buffer_get_len (hb_buffer_t *buffer)
{
return buffer->in_length;
}
/* Return value valid as long as buffer not modified */
hb_glyph_info_t *
hb_buffer_get_glyph_infos (hb_buffer_t *buffer)
{
return (hb_glyph_info_t *) buffer->in_string;
}
/* Return value valid as long as buffer not modified */
hb_glyph_position_t *
hb_buffer_get_glyph_positions (hb_buffer_t *buffer)
{
if (buffer->have_output || (buffer->in_length && !buffer->positions))
hb_buffer_clear_positions (buffer);
return (hb_glyph_position_t *) buffer->positions;
}
void
hb_buffer_reverse (hb_buffer_t *buffer)
{
unsigned int i, j;
for (i = 0, j = buffer->in_length - 1; i < buffer->in_length / 2; i++, j--) {
hb_internal_glyph_info_t t;
t = buffer->in_string[i];
buffer->in_string[i] = buffer->in_string[j];
buffer->in_string[j] = t;
}
if (buffer->positions) {
for (i = 0, j = buffer->in_length - 1; i < buffer->in_length / 2; i++, j--) {
hb_internal_glyph_position_t t;
t = buffer->positions[i];
buffer->positions[i] = buffer->positions[j];
buffer->positions[j] = t;
}
}
}
#define ADD_UTF(T) \
HB_STMT_START { \
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_glyph (buffer, u, 0, 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;
UTF8_COMPUTE (c, mask, len);
if (HB_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 (HB_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,
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 (HB_UNLIKELY (c >= 0xd800 && c < 0xdc00)) {
/* high surrogate */
uint16_t l;
if (text < end && ((l = *text), HB_UNLIKELY (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,
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,
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
}