diff options
Diffstat (limited to 'third_party/harfbuzz/src/harfbuzz-buffer.c')
| -rw-r--r-- | third_party/harfbuzz/src/harfbuzz-buffer.c | 383 |
1 files changed, 383 insertions, 0 deletions
diff --git a/third_party/harfbuzz/src/harfbuzz-buffer.c b/third_party/harfbuzz/src/harfbuzz-buffer.c new file mode 100644 index 0000000..4d4c167 --- /dev/null +++ b/third_party/harfbuzz/src/harfbuzz-buffer.c @@ -0,0 +1,383 @@ +/* + * 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 "harfbuzz-impl.h" +#include "harfbuzz-buffer-private.h" +#include "harfbuzz-gsub-private.h" +#include "harfbuzz-gpos-private.h" + +/* 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: + * + * - copy_glyph() is called + * - replace_glyph() is called with inplace=TRUE + * - add_output_glyph() and add_output_glyphs() are not called + * + * In that case swap(), and copy_glyph(), and replace_glyph() are all + * mostly no-op. + * + * As soon an add_output_glyph[s]() or replace_glyph() with inplace=FALSE is + * called, out_string is moved over to an alternate buffer (alt_string), 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 alt_string. alt_string is not allocated until its needed, + * but after that it's grown with in_string unconditionally. + * + * The buffer->separate_out boolean keeps status of whether out_string points + * to in_string (FALSE) or alt_string (TRUE). + */ + +/* Internal API */ + +static HB_Error +hb_buffer_ensure( HB_Buffer buffer, + HB_UInt size ) +{ + HB_UInt new_allocated = buffer->allocated; + + if (size > new_allocated) + { + HB_Error error; + + while (size > new_allocated) + new_allocated += (new_allocated >> 1) + 8; + + if ( buffer->positions ) + { + if ( REALLOC_ARRAY( buffer->positions, new_allocated, HB_PositionRec ) ) + return error; + } + + if ( REALLOC_ARRAY( buffer->in_string, new_allocated, HB_GlyphItemRec ) ) + return error; + + if ( buffer->separate_out ) + { + if ( REALLOC_ARRAY( buffer->alt_string, new_allocated, HB_GlyphItemRec ) ) + return error; + + buffer->out_string = buffer->alt_string; + } + else + { + buffer->out_string = buffer->in_string; + + if ( buffer->alt_string ) + { + if ( REALLOC_ARRAY( buffer->alt_string, new_allocated, HB_GlyphItemRec ) ) + return error; + } + } + + buffer->allocated = new_allocated; + } + + return HB_Err_Ok; +} + +static HB_Error +hb_buffer_duplicate_out_buffer( HB_Buffer buffer ) +{ + if ( !buffer->alt_string ) + { + HB_Error error; + + if ( ALLOC_ARRAY( buffer->alt_string, buffer->allocated, HB_GlyphItemRec ) ) + return error; + } + + buffer->out_string = buffer->alt_string; + memcpy( buffer->out_string, buffer->in_string, buffer->out_length * sizeof (buffer->out_string[0]) ); + buffer->separate_out = TRUE; + + return HB_Err_Ok; +} + +/* Public API */ + +HB_Error +hb_buffer_new( HB_Buffer *pbuffer ) +{ + HB_Buffer buffer; + HB_Error error; + + if ( ALLOC( buffer, sizeof( HB_BufferRec ) ) ) + return error; + + buffer->allocated = 0; + buffer->in_string = NULL; + buffer->alt_string = NULL; + buffer->positions = NULL; + + hb_buffer_clear( buffer ); + + *pbuffer = buffer; + + return HB_Err_Ok; +} + +void +hb_buffer_free( HB_Buffer buffer ) +{ + FREE( buffer->in_string ); + FREE( buffer->alt_string ); + buffer->out_string = NULL; + FREE( buffer->positions ); + FREE( buffer ); +} + +void +hb_buffer_clear( HB_Buffer buffer ) +{ + buffer->in_length = 0; + buffer->out_length = 0; + buffer->in_pos = 0; + buffer->out_pos = 0; + buffer->out_string = buffer->in_string; + buffer->separate_out = FALSE; + buffer->max_ligID = 0; +} + +HB_Error +hb_buffer_add_glyph( HB_Buffer buffer, + HB_UInt glyph_index, + HB_UInt properties, + HB_UInt cluster ) +{ + HB_Error error; + HB_GlyphItem glyph; + + error = hb_buffer_ensure( buffer, buffer->in_length + 1 ); + if ( error ) + return error; + + glyph = &buffer->in_string[buffer->in_length]; + glyph->gindex = glyph_index; + glyph->properties = properties; + glyph->cluster = cluster; + glyph->component = 0; + glyph->ligID = 0; + glyph->gproperties = HB_GLYPH_PROPERTIES_UNKNOWN; + + buffer->in_length++; + + return HB_Err_Ok; +} + +/* HarfBuzz-Internal API */ + +HB_INTERNAL void +_hb_buffer_clear_output( HB_Buffer buffer ) +{ + buffer->out_length = 0; + buffer->out_pos = 0; + buffer->out_string = buffer->in_string; + buffer->separate_out = FALSE; +} + +HB_INTERNAL HB_Error +_hb_buffer_clear_positions( HB_Buffer buffer ) +{ + if ( !buffer->positions ) + { + HB_Error error; + + if ( ALLOC_ARRAY( buffer->positions, buffer->allocated, HB_PositionRec ) ) + return error; + } + + memset (buffer->positions, 0, sizeof (buffer->positions[0]) * buffer->in_length); + + return HB_Err_Ok; +} + +HB_INTERNAL void +_hb_buffer_swap( HB_Buffer buffer ) +{ + HB_GlyphItem tmp_string; + int tmp_length; + int tmp_pos; + + if ( buffer->separate_out ) + { + tmp_string = buffer->in_string; + buffer->in_string = buffer->out_string; + buffer->out_string = tmp_string; + buffer->alt_string = buffer->out_string; + } + + tmp_length = buffer->in_length; + buffer->in_length = buffer->out_length; + buffer->out_length = tmp_length; + + tmp_pos = buffer->in_pos; + buffer->in_pos = buffer->out_pos; + buffer->out_pos = tmp_pos; +} + +/* 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 `ligID' is 0xFFFF, the ligID value from buffer->in_pos + will copied `num_out' times, otherwise `ligID' itself will + be used to fill the `ligID' fields. + + The properties 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 */ +HB_INTERNAL HB_Error +_hb_buffer_add_output_glyphs( HB_Buffer buffer, + HB_UShort num_in, + HB_UShort num_out, + HB_UShort *glyph_data, + HB_UShort component, + HB_UShort ligID ) +{ + HB_Error error; + HB_UShort i; + HB_UInt properties; + HB_UInt cluster; + + error = hb_buffer_ensure( buffer, buffer->out_pos + num_out ); + if ( error ) + return error; + + if ( !buffer->separate_out ) + { + error = hb_buffer_duplicate_out_buffer( buffer ); + if ( error ) + return error; + } + + properties = buffer->in_string[buffer->in_pos].properties; + cluster = buffer->in_string[buffer->in_pos].cluster; + if ( component == 0xFFFF ) + component = buffer->in_string[buffer->in_pos].component; + if ( ligID == 0xFFFF ) + ligID = buffer->in_string[buffer->in_pos].ligID; + + for ( i = 0; i < num_out; i++ ) + { + HB_GlyphItem item = &buffer->out_string[buffer->out_pos + i]; + + item->gindex = glyph_data[i]; + item->properties = properties; + item->cluster = cluster; + item->component = component; + item->ligID = ligID; + item->gproperties = HB_GLYPH_PROPERTIES_UNKNOWN; + } + + buffer->in_pos += num_in; + buffer->out_pos += num_out; + + buffer->out_length = buffer->out_pos; + + return HB_Err_Ok; +} + +HB_INTERNAL HB_Error +_hb_buffer_add_output_glyph( HB_Buffer buffer, + HB_UInt glyph_index, + HB_UShort component, + HB_UShort ligID ) +{ + HB_UShort glyph_data = glyph_index; + + return _hb_buffer_add_output_glyphs ( buffer, 1, 1, + &glyph_data, component, ligID ); +} + +HB_INTERNAL HB_Error +_hb_buffer_copy_output_glyph ( HB_Buffer buffer ) +{ + HB_Error error; + + error = hb_buffer_ensure( buffer, buffer->out_pos + 1 ); + if ( error ) + return error; + + if ( buffer->separate_out ) + { + buffer->out_string[buffer->out_pos] = buffer->in_string[buffer->in_pos]; + } + + buffer->in_pos++; + buffer->out_pos++; + buffer->out_length = buffer->out_pos; + + return HB_Err_Ok; +} + +HB_INTERNAL HB_Error +_hb_buffer_replace_output_glyph( HB_Buffer buffer, + HB_UInt glyph_index, + HB_Bool inplace ) +{ + + HB_Error error; + + if ( inplace ) + { + error = _hb_buffer_copy_output_glyph ( buffer ); + if ( error ) + return error; + + buffer->out_string[buffer->out_pos-1].gindex = glyph_index; + } + else + { + return _hb_buffer_add_output_glyph( buffer, glyph_index, 0xFFFF, 0xFFFF ); + } + + return HB_Err_Ok; +} + +HB_INTERNAL HB_UShort +_hb_buffer_allocate_ligid( HB_Buffer buffer ) +{ + buffer->max_ligID++; + if (HB_UNLIKELY (buffer->max_ligID == 0)) + buffer->max_ligID++; + + return buffer->max_ligID; +} |