1 /* 2 * Copyright © 1998-2004 David Turner and Werner Lemberg 3 * Copyright © 2004,2007,2009,2010 Red Hat, Inc. 4 * Copyright © 2011,2012 Google, Inc. 5 * 6 * This is part of HarfBuzz, a text shaping library. 7 * 8 * Permission is hereby granted, without written agreement and without 9 * license or royalty fees, to use, copy, modify, and distribute this 10 * software and its documentation for any purpose, provided that the 11 * above copyright notice and the following two paragraphs appear in 12 * all copies of this software. 13 * 14 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR 15 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES 16 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN 17 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH 18 * DAMAGE. 19 * 20 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, 21 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND 22 * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS 23 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO 24 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS. 25 * 26 * Red Hat Author(s): Owen Taylor, Behdad Esfahbod 27 * Google Author(s): Behdad Esfahbod 28 */ 29 30 #ifndef HB_BUFFER_PRIVATE_HH 31 #define HB_BUFFER_PRIVATE_HH 32 33 #include "hb-private.hh" 34 #include "hb-object-private.hh" 35 #include "hb-unicode-private.hh" 36 37 38 ASSERT_STATIC (sizeof (hb_glyph_info_t) == 20); 39 ASSERT_STATIC (sizeof (hb_glyph_info_t) == sizeof (hb_glyph_position_t)); 40 41 42 /* 43 * hb_buffer_t 44 */ 45 46 struct hb_buffer_t { 47 hb_object_header_t header; 48 ASSERT_POD (); 49 50 /* Information about how the text in the buffer should be treated */ 51 hb_unicode_funcs_t *unicode; /* Unicode functions */ 52 hb_buffer_flags_t flags; /* BOT / EOT / etc. */ 53 hb_codepoint_t replacement; /* U+FFFD or something else. */ 54 55 /* Buffer contents */ 56 hb_buffer_content_type_t content_type; 57 hb_segment_properties_t props; /* Script, language, direction */ 58 59 bool in_error; /* Allocation failed */ 60 bool have_output; /* Whether we have an output buffer going on */ 61 bool have_positions; /* Whether we have positions */ 62 63 unsigned int idx; /* Cursor into ->info and ->pos arrays */ 64 unsigned int len; /* Length of ->info and ->pos arrays */ 65 unsigned int out_len; /* Length of ->out array if have_output */ 66 67 unsigned int allocated; /* Length of allocated arrays */ 68 hb_glyph_info_t *info; 69 hb_glyph_info_t *out_info; 70 hb_glyph_position_t *pos; 71 curhb_buffer_t72 inline hb_glyph_info_t &cur (unsigned int i = 0) { return info[idx + i]; } curhb_buffer_t73 inline hb_glyph_info_t cur (unsigned int i = 0) const { return info[idx + i]; } 74 cur_poshb_buffer_t75 inline hb_glyph_position_t &cur_pos (unsigned int i = 0) { return pos[idx + i]; } cur_poshb_buffer_t76 inline hb_glyph_position_t cur_pos (unsigned int i = 0) const { return pos[idx + i]; } 77 prevhb_buffer_t78 inline hb_glyph_info_t &prev (void) { return out_info[out_len - 1]; } prevhb_buffer_t79 inline hb_glyph_info_t prev (void) const { return info[out_len - 1]; } 80 has_separate_outputhb_buffer_t81 inline bool has_separate_output (void) const { return info != out_info; } 82 83 unsigned int serial; 84 85 /* These reflect current allocations of the bytes in glyph_info_t's var1 and var2. */ 86 uint8_t allocated_var_bytes[8]; 87 const char *allocated_var_owner[8]; 88 89 /* Text before / after the main buffer contents. 90 * Always in Unicode, and ordered outward. 91 * Index 0 is for "pre-context", 1 for "post-context". */ 92 static const unsigned int CONTEXT_LENGTH = 5; 93 hb_codepoint_t context[2][CONTEXT_LENGTH]; 94 unsigned int context_len[2]; 95 96 97 /* Methods */ 98 99 HB_INTERNAL void reset (void); 100 HB_INTERNAL void clear (void); 101 backtrack_lenhb_buffer_t102 inline unsigned int backtrack_len (void) const 103 { return have_output? out_len : idx; } lookahead_lenhb_buffer_t104 inline unsigned int lookahead_len (void) const 105 { return len - idx; } next_serialhb_buffer_t106 inline unsigned int next_serial (void) { return serial++; } 107 108 HB_INTERNAL void allocate_var (unsigned int byte_i, unsigned int count, const char *owner); 109 HB_INTERNAL void deallocate_var (unsigned int byte_i, unsigned int count, const char *owner); 110 HB_INTERNAL void assert_var (unsigned int byte_i, unsigned int count, const char *owner); 111 HB_INTERNAL void deallocate_var_all (void); 112 113 HB_INTERNAL void add (hb_codepoint_t codepoint, 114 unsigned int cluster); 115 HB_INTERNAL void add_info (const hb_glyph_info_t &glyph_info); 116 117 HB_INTERNAL void reverse_range (unsigned int start, unsigned int end); 118 HB_INTERNAL void reverse (void); 119 HB_INTERNAL void reverse_clusters (void); 120 HB_INTERNAL void guess_segment_properties (void); 121 122 HB_INTERNAL void swap_buffers (void); 123 HB_INTERNAL void remove_output (void); 124 HB_INTERNAL void clear_output (void); 125 HB_INTERNAL void clear_positions (void); 126 127 HB_INTERNAL void replace_glyphs (unsigned int num_in, 128 unsigned int num_out, 129 const hb_codepoint_t *glyph_data); 130 131 HB_INTERNAL void replace_glyph (hb_codepoint_t glyph_index); 132 /* Makes a copy of the glyph at idx to output and replace glyph_index */ 133 HB_INTERNAL void output_glyph (hb_codepoint_t glyph_index); 134 HB_INTERNAL void output_info (const hb_glyph_info_t &glyph_info); 135 /* Copies glyph at idx to output but doesn't advance idx */ 136 HB_INTERNAL void copy_glyph (void); 137 HB_INTERNAL bool move_to (unsigned int i); /* i is output-buffer index. */ 138 /* Copies glyph at idx to output and advance idx. 139 * If there's no output, just advance idx. */ 140 inline void next_glyphhb_buffer_t141 next_glyph (void) 142 { 143 if (have_output) 144 { 145 if (unlikely (out_info != info || out_len != idx)) { 146 if (unlikely (!make_room_for (1, 1))) return; 147 out_info[out_len] = info[idx]; 148 } 149 out_len++; 150 } 151 152 idx++; 153 } 154 155 /* Advance idx without copying to output. */ skip_glyphhb_buffer_t156 inline void skip_glyph (void) { idx++; } 157 reset_maskshb_buffer_t158 inline void reset_masks (hb_mask_t mask) 159 { 160 for (unsigned int j = 0; j < len; j++) 161 info[j].mask = mask; 162 } add_maskshb_buffer_t163 inline void add_masks (hb_mask_t mask) 164 { 165 for (unsigned int j = 0; j < len; j++) 166 info[j].mask |= mask; 167 } 168 HB_INTERNAL void set_masks (hb_mask_t value, 169 hb_mask_t mask, 170 unsigned int cluster_start, 171 unsigned int cluster_end); 172 173 HB_INTERNAL void merge_clusters (unsigned int start, 174 unsigned int end); 175 HB_INTERNAL void merge_out_clusters (unsigned int start, 176 unsigned int end); 177 178 /* Internal methods */ 179 HB_INTERNAL bool enlarge (unsigned int size); 180 ensurehb_buffer_t181 inline bool ensure (unsigned int size) 182 { return likely (!size || size < allocated) ? true : enlarge (size); } 183 ensure_inplacehb_buffer_t184 inline bool ensure_inplace (unsigned int size) 185 { return likely (!size || size < allocated); } 186 187 HB_INTERNAL bool make_room_for (unsigned int num_in, unsigned int num_out); 188 HB_INTERNAL bool shift_forward (unsigned int count); 189 190 typedef long scratch_buffer_t; 191 HB_INTERNAL scratch_buffer_t *get_scratch_buffer (unsigned int *size); 192 clear_contexthb_buffer_t193 inline void clear_context (unsigned int side) { context_len[side] = 0; } 194 }; 195 196 197 #define HB_BUFFER_XALLOCATE_VAR(b, func, var, owner) \ 198 b->func (offsetof (hb_glyph_info_t, var) - offsetof(hb_glyph_info_t, var1), \ 199 sizeof (b->info[0].var), owner) 200 #define HB_BUFFER_ALLOCATE_VAR(b, var) \ 201 HB_BUFFER_XALLOCATE_VAR (b, allocate_var, var (), #var) 202 #define HB_BUFFER_DEALLOCATE_VAR(b, var) \ 203 HB_BUFFER_XALLOCATE_VAR (b, deallocate_var, var (), #var) 204 #define HB_BUFFER_ASSERT_VAR(b, var) \ 205 HB_BUFFER_XALLOCATE_VAR (b, assert_var, var (), #var) 206 207 208 #endif /* HB_BUFFER_PRIVATE_HH */ 209