2 * Copyright (C) 1998-2004 David Turner and Werner Lemberg
3 * Copyright (C) 2004,2007 Red Hat, Inc.
5 * This is part of HarfBuzz, an OpenType Layout engine library.
7 * Permission is hereby granted, without written agreement and without
8 * license or royalty fees, to use, copy, modify, and distribute this
9 * software and its documentation for any purpose, provided that the
10 * above copyright notice and the following two paragraphs appear in
11 * all copies of this software.
13 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
14 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
15 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
16 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
19 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
20 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
21 * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
22 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
23 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
25 * Red Hat Author(s): Owen Taylor, Behdad Esfahbod
28 #include "harfbuzz-impl.h"
29 #include "harfbuzz-buffer-private.h"
30 #include "harfbuzz-gsub-private.h"
31 #include "harfbuzz-gpos-private.h"
33 /* Here is how the buffer works internally:
35 * There are two string pointers: in_string and out_string. They
36 * always have same allocated size, but different length and positions.
38 * As an optimization, both in_string and out_string may point to the
39 * same piece of memory, which is owned by in_string. This remains the
42 * - copy_glyph() is called
43 * - replace_glyph() is called with inplace=TRUE
44 * - add_output_glyph() and add_output_glyphs() are not called
46 * In that case swap(), and copy_glyph(), and replace_glyph() are all
49 * As soon an add_output_glyph[s]() or replace_glyph() with inplace=FALSE is
50 * called, out_string is moved over to an alternate buffer (alt_string), and
51 * its current contents (out_length entries) are copied to the alt buffer.
52 * This should all remain transparent to the user. swap() then switches
53 * in_string and alt_string. alt_string is not allocated until its needed,
54 * but after that it's grown with in_string unconditionally.
56 * The buffer->separate_out boolean keeps status of whether out_string points
57 * to in_string (FALSE) or alt_string (TRUE).
63 HB_Buffer_ensure( HB_Buffer buffer,
66 HB_UInt new_allocated = buffer->allocated;
68 if (size > new_allocated)
72 while (size > new_allocated)
73 new_allocated += (new_allocated >> 1) + 8;
75 if ( buffer->positions )
77 if ( REALLOC_ARRAY( buffer->positions, new_allocated, HB_PositionRec ) )
81 if ( REALLOC_ARRAY( buffer->in_string, new_allocated, HB_GlyphItemRec ) )
84 if ( buffer->separate_out )
86 if ( REALLOC_ARRAY( buffer->alt_string, new_allocated, HB_GlyphItemRec ) )
89 buffer->out_string = buffer->alt_string;
93 buffer->out_string = buffer->in_string;
95 if ( buffer->alt_string )
97 if ( REALLOC_ARRAY( buffer->alt_string, new_allocated, HB_GlyphItemRec ) )
102 buffer->allocated = new_allocated;
109 HB_Buffer_duplicate_out_buffer( HB_Buffer buffer )
111 if ( !buffer->alt_string )
115 if ( ALLOC_ARRAY( buffer->alt_string, buffer->allocated, HB_GlyphItemRec ) )
119 buffer->out_string = buffer->alt_string;
120 memcpy( buffer->out_string, buffer->in_string, buffer->out_length * sizeof (buffer->out_string[0]) );
121 buffer->separate_out = TRUE;
129 HB_Buffer_new( HB_Buffer *pbuffer )
134 if ( ALLOC( buffer, sizeof( HB_BufferRec ) ) )
137 buffer->allocated = 0;
138 buffer->in_string = NULL;
139 buffer->alt_string = NULL;
140 buffer->positions = NULL;
142 HB_Buffer_clear( buffer );
150 HB_Buffer_free( HB_Buffer buffer )
152 FREE( buffer->in_string );
153 FREE( buffer->alt_string );
154 buffer->out_string = NULL;
155 FREE( buffer->positions );
160 HB_Buffer_clear( HB_Buffer buffer )
162 buffer->in_length = 0;
163 buffer->out_length = 0;
166 buffer->out_string = buffer->in_string;
167 buffer->separate_out = FALSE;
168 buffer->max_ligID = 0;
172 HB_Buffer_add_glyph( HB_Buffer buffer,
180 error = HB_Buffer_ensure( buffer, buffer->in_length + 1 );
184 glyph = &buffer->in_string[buffer->in_length];
185 glyph->gindex = glyph_index;
186 glyph->properties = properties;
187 glyph->cluster = cluster;
188 glyph->component = 0;
190 glyph->gproperties = HB_GLYPH_PROPERTIES_UNKNOWN;
197 /* HarfBuzz-Internal API */
200 _hb_buffer_clear_output( HB_Buffer buffer )
202 buffer->out_length = 0;
204 buffer->out_string = buffer->in_string;
205 buffer->separate_out = FALSE;
209 _hb_buffer_clear_positions( HB_Buffer buffer )
211 if ( !buffer->positions )
215 if ( ALLOC_ARRAY( buffer->positions, buffer->allocated, HB_PositionRec ) )
219 memset (buffer->positions, 0, sizeof (buffer->positions[0]) * buffer->in_length);
225 _hb_buffer_swap( HB_Buffer buffer )
227 HB_GlyphItem tmp_string;
231 if ( buffer->separate_out )
233 tmp_string = buffer->in_string;
234 buffer->in_string = buffer->out_string;
235 buffer->out_string = tmp_string;
236 buffer->alt_string = buffer->out_string;
239 tmp_length = buffer->in_length;
240 buffer->in_length = buffer->out_length;
241 buffer->out_length = tmp_length;
243 tmp_pos = buffer->in_pos;
244 buffer->in_pos = buffer->out_pos;
245 buffer->out_pos = tmp_pos;
248 /* The following function copies `num_out' elements from `glyph_data'
249 to `buffer->out_string', advancing the in array pointer in the structure
250 by `num_in' elements, and the out array pointer by `num_out' elements.
251 Finally, it sets the `length' field of `out' equal to
252 `pos' of the `out' structure.
254 If `component' is 0xFFFF, the component value from buffer->in_pos
255 will copied `num_out' times, otherwise `component' itself will
256 be used to fill the `component' fields.
258 If `ligID' is 0xFFFF, the ligID value from buffer->in_pos
259 will copied `num_out' times, otherwise `ligID' itself will
260 be used to fill the `ligID' fields.
262 The properties for all replacement glyphs are taken
263 from the glyph at position `buffer->in_pos'.
265 The cluster value for the glyph at position buffer->in_pos is used
266 for all replacement glyphs */
268 _hb_buffer_add_output_glyphs( HB_Buffer buffer,
271 HB_UShort *glyph_data,
280 error = HB_Buffer_ensure( buffer, buffer->out_pos + num_out );
284 if ( !buffer->separate_out )
286 error = HB_Buffer_duplicate_out_buffer( buffer );
291 properties = buffer->in_string[buffer->in_pos].properties;
292 cluster = buffer->in_string[buffer->in_pos].cluster;
293 if ( component == 0xFFFF )
294 component = buffer->in_string[buffer->in_pos].component;
295 if ( ligID == 0xFFFF )
296 ligID = buffer->in_string[buffer->in_pos].ligID;
298 for ( i = 0; i < num_out; i++ )
300 HB_GlyphItem item = &buffer->out_string[buffer->out_pos + i];
302 item->gindex = glyph_data[i];
303 item->properties = properties;
304 item->cluster = cluster;
305 item->component = component;
307 item->gproperties = HB_GLYPH_PROPERTIES_UNKNOWN;
310 buffer->in_pos += num_in;
311 buffer->out_pos += num_out;
313 buffer->out_length = buffer->out_pos;
319 _hb_buffer_add_output_glyph( HB_Buffer buffer,
324 HB_UShort glyph_data = glyph_index;
326 return _hb_buffer_add_output_glyphs ( buffer, 1, 1,
327 &glyph_data, component, ligID );
331 _hb_buffer_copy_output_glyph ( HB_Buffer buffer )
335 error = HB_Buffer_ensure( buffer, buffer->out_pos + 1 );
339 if ( buffer->separate_out )
341 buffer->out_string[buffer->out_pos] = buffer->in_string[buffer->in_pos];
346 buffer->out_length = buffer->out_pos;
352 _hb_buffer_replace_output_glyph( HB_Buffer buffer,
361 error = _hb_buffer_copy_output_glyph ( buffer );
365 buffer->out_string[buffer->out_pos-1].gindex = glyph_index;
369 return _hb_buffer_add_output_glyph( buffer, glyph_index, 0xFFFF, 0xFFFF );
375 HB_INTERNAL HB_UShort
376 _hb_buffer_allocate_ligid( HB_Buffer buffer )
379 if (HB_UNLIKELY (buffer->max_ligID == 0))
382 return buffer->max_ligID;