harfbuzz/src/hb-buffer-private.hh

209 lines
7.2 KiB
C++

/*
* 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_PRIVATE_HH
#define HB_BUFFER_PRIVATE_HH
#include "hb-private.hh"
#include "hb-object-private.hh"
#include "hb-unicode-private.hh"
ASSERT_STATIC (sizeof (hb_glyph_info_t) == 20);
ASSERT_STATIC (sizeof (hb_glyph_info_t) == sizeof (hb_glyph_position_t));
/*
* hb_buffer_t
*/
struct hb_buffer_t {
hb_object_header_t header;
ASSERT_POD ();
/* 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_codepoint_t replacement; /* U+FFFD or something else. */
/* Buffer contents */
hb_buffer_content_type_t content_type;
hb_segment_properties_t props; /* Script, language, direction */
bool in_error; /* Allocation failed */
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 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;
inline hb_glyph_info_t &cur (unsigned int i = 0) { return info[idx + i]; }
inline hb_glyph_info_t cur (unsigned int i = 0) const { return info[idx + i]; }
inline hb_glyph_position_t &cur_pos (unsigned int i = 0) { return pos[idx + i]; }
inline hb_glyph_position_t cur_pos (unsigned int i = 0) const { return pos[idx + i]; }
inline hb_glyph_info_t &prev (void) { return out_info[out_len - 1]; }
inline hb_glyph_info_t prev (void) const { return info[out_len - 1]; }
inline bool has_separate_output (void) const { return info != out_info; }
unsigned int serial;
/* These reflect current allocations of the bytes in glyph_info_t's var1 and var2. */
uint8_t allocated_var_bytes[8];
const char *allocated_var_owner[8];
/* Text before / after the main buffer contents.
* Always in Unicode, and ordered outward.
* Index 0 is for "pre-context", 1 for "post-context". */
static const unsigned int CONTEXT_LENGTH = 5;
hb_codepoint_t context[2][CONTEXT_LENGTH];
unsigned int context_len[2];
/* Methods */
HB_INTERNAL void reset (void);
HB_INTERNAL void clear (void);
inline unsigned int backtrack_len (void) const
{ return have_output? out_len : idx; }
inline unsigned int lookahead_len (void) const
{ return len - idx; }
inline unsigned int next_serial (void) { return serial++; }
HB_INTERNAL void allocate_var (unsigned int byte_i, unsigned int count, const char *owner);
HB_INTERNAL void deallocate_var (unsigned int byte_i, unsigned int count, const char *owner);
HB_INTERNAL void assert_var (unsigned int byte_i, unsigned int count, const char *owner);
HB_INTERNAL void deallocate_var_all (void);
HB_INTERNAL void add (hb_codepoint_t codepoint,
unsigned int cluster);
HB_INTERNAL void add_info (const hb_glyph_info_t &glyph_info);
HB_INTERNAL void reverse_range (unsigned int start, unsigned int end);
HB_INTERNAL void reverse (void);
HB_INTERNAL void reverse_clusters (void);
HB_INTERNAL void guess_segment_properties (void);
HB_INTERNAL void swap_buffers (void);
HB_INTERNAL void remove_output (void);
HB_INTERNAL void clear_output (void);
HB_INTERNAL void clear_positions (void);
HB_INTERNAL void replace_glyphs (unsigned int num_in,
unsigned int num_out,
const hb_codepoint_t *glyph_data);
HB_INTERNAL void replace_glyph (hb_codepoint_t glyph_index);
/* Makes a copy of the glyph at idx to output and replace glyph_index */
HB_INTERNAL void output_glyph (hb_codepoint_t glyph_index);
HB_INTERNAL void output_info (const hb_glyph_info_t &glyph_info);
/* Copies glyph at idx to output but doesn't advance idx */
HB_INTERNAL void copy_glyph (void);
HB_INTERNAL bool move_to (unsigned int i); /* i is output-buffer index. */
/* Copies glyph at idx to output and advance idx.
* If there's no output, just advance idx. */
inline void
next_glyph (void)
{
if (have_output)
{
if (unlikely (out_info != info || out_len != idx)) {
if (unlikely (!make_room_for (1, 1))) return;
out_info[out_len] = info[idx];
}
out_len++;
}
idx++;
}
/* Advance idx without copying to output. */
inline void skip_glyph (void) { idx++; }
inline void reset_masks (hb_mask_t mask)
{
for (unsigned int j = 0; j < len; j++)
info[j].mask = mask;
}
inline 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);
HB_INTERNAL void merge_clusters (unsigned int start,
unsigned int end);
HB_INTERNAL void merge_out_clusters (unsigned int start,
unsigned int end);
/* Internal methods */
HB_INTERNAL bool enlarge (unsigned int size);
inline bool ensure (unsigned int size)
{ return likely (!size || size < allocated) ? true : enlarge (size); }
inline bool ensure_inplace (unsigned int size)
{ return likely (!size || size < allocated); }
HB_INTERNAL bool make_room_for (unsigned int num_in, unsigned int num_out);
HB_INTERNAL bool shift_forward (unsigned int count);
typedef long scratch_buffer_t;
HB_INTERNAL scratch_buffer_t *get_scratch_buffer (unsigned int *size);
inline void clear_context (unsigned int side) { context_len[side] = 0; }
};
#define HB_BUFFER_XALLOCATE_VAR(b, func, var, owner) \
b->func (offsetof (hb_glyph_info_t, var) - offsetof(hb_glyph_info_t, var1), \
sizeof (b->info[0].var), owner)
#define HB_BUFFER_ALLOCATE_VAR(b, var) \
HB_BUFFER_XALLOCATE_VAR (b, allocate_var, var (), #var)
#define HB_BUFFER_DEALLOCATE_VAR(b, var) \
HB_BUFFER_XALLOCATE_VAR (b, deallocate_var, var (), #var)
#define HB_BUFFER_ASSERT_VAR(b, var) \
HB_BUFFER_XALLOCATE_VAR (b, assert_var, var (), #var)
#endif /* HB_BUFFER_PRIVATE_HH */