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-buffer.h" 35#include "hb-object-private.hh" 36#include "hb-unicode-private.hh" 37 38 39ASSERT_STATIC (sizeof (hb_glyph_info_t) == 20); 40ASSERT_STATIC (sizeof (hb_glyph_info_t) == sizeof (hb_glyph_position_t)); 41 42 43/* 44 * hb_buffer_t 45 */ 46 47struct hb_buffer_t { 48 hb_object_header_t header; 49 ASSERT_POD (); 50 51 /* Information about how the text in the buffer should be treated */ 52 53 hb_unicode_funcs_t *unicode; /* Unicode functions */ 54 hb_segment_properties_t props; /* Script, language, direction */ 55 hb_buffer_flags_t flags; /* BOT / EOT / etc. */ 56 57 /* Buffer contents */ 58 59 hb_buffer_content_type_t content_type; 60 61 bool in_error; /* Allocation failed */ 62 bool have_output; /* Whether we have an output buffer going on */ 63 bool have_positions; /* Whether we have positions */ 64 65 unsigned int idx; /* Cursor into ->info and ->pos arrays */ 66 unsigned int len; /* Length of ->info and ->pos arrays */ 67 unsigned int out_len; /* Length of ->out array if have_output */ 68 69 unsigned int allocated; /* Length of allocated arrays */ 70 hb_glyph_info_t *info; 71 hb_glyph_info_t *out_info; 72 hb_glyph_position_t *pos; 73 74 inline hb_glyph_info_t &cur (unsigned int i = 0) { return info[idx + i]; } 75 inline hb_glyph_info_t cur (unsigned int i = 0) const { return info[idx + i]; } 76 77 inline hb_glyph_position_t &cur_pos (unsigned int i = 0) { return pos[idx + i]; } 78 inline hb_glyph_position_t cur_pos (unsigned int i = 0) const { return pos[idx + i]; } 79 80 inline hb_glyph_info_t &prev (void) { return out_info[out_len - 1]; } 81 inline hb_glyph_info_t prev (void) const { return info[out_len - 1]; } 82 83 inline bool has_separate_output (void) const { return info != out_info; } 84 85 unsigned int serial; 86 87 /* These reflect current allocations of the bytes in glyph_info_t's var1 and var2. */ 88 uint8_t allocated_var_bytes[8]; 89 const char *allocated_var_owner[8]; 90 91 /* Text before / after the main buffer contents. 92 * Always in Unicode, and ordered outward. 93 * Index 0 is for "pre-context", 1 for "post-context". */ 94 static const unsigned int CONTEXT_LENGTH = 5; 95 hb_codepoint_t context[2][CONTEXT_LENGTH]; 96 unsigned int context_len[2]; 97 98 99 /* Methods */ 100 101 HB_INTERNAL void reset (void); 102 HB_INTERNAL void clear (void); 103 104 inline unsigned int backtrack_len (void) const 105 { return have_output? out_len : idx; } 106 inline unsigned int lookahead_len (void) const 107 { return len - idx; } 108 inline unsigned int next_serial (void) { return serial++; } 109 110 HB_INTERNAL void allocate_var (unsigned int byte_i, unsigned int count, const char *owner); 111 HB_INTERNAL void deallocate_var (unsigned int byte_i, unsigned int count, const char *owner); 112 HB_INTERNAL void assert_var (unsigned int byte_i, unsigned int count, const char *owner); 113 HB_INTERNAL void deallocate_var_all (void); 114 115 HB_INTERNAL void add (hb_codepoint_t codepoint, 116 unsigned int cluster); 117 HB_INTERNAL void add_info (const hb_glyph_info_t &glyph_info); 118 119 HB_INTERNAL void reverse_range (unsigned int start, unsigned int end); 120 HB_INTERNAL void reverse (void); 121 HB_INTERNAL void reverse_clusters (void); 122 HB_INTERNAL void guess_segment_properties (void); 123 124 HB_INTERNAL void swap_buffers (void); 125 HB_INTERNAL void remove_output (void); 126 HB_INTERNAL void clear_output (void); 127 HB_INTERNAL void clear_positions (void); 128 129 HB_INTERNAL void replace_glyphs (unsigned int num_in, 130 unsigned int num_out, 131 const hb_codepoint_t *glyph_data); 132 133 HB_INTERNAL void replace_glyph (hb_codepoint_t glyph_index); 134 /* Makes a copy of the glyph at idx to output and replace glyph_index */ 135 HB_INTERNAL void output_glyph (hb_codepoint_t glyph_index); 136 HB_INTERNAL void output_info (const hb_glyph_info_t &glyph_info); 137 /* Copies glyph at idx to output but doesn't advance idx */ 138 HB_INTERNAL void copy_glyph (void); 139 HB_INTERNAL bool move_to (unsigned int i); /* i is output-buffer index. */ 140 /* Copies glyph at idx to output and advance idx. 141 * If there's no output, just advance idx. */ 142 inline void 143 next_glyph (void) 144 { 145 if (have_output) 146 { 147 if (unlikely (out_info != info || out_len != idx)) { 148 if (unlikely (!make_room_for (1, 1))) return; 149 out_info[out_len] = info[idx]; 150 } 151 out_len++; 152 } 153 154 idx++; 155 } 156 157 /* Advance idx without copying to output. */ 158 inline void skip_glyph (void) { idx++; } 159 160 inline void reset_masks (hb_mask_t mask) 161 { 162 for (unsigned int j = 0; j < len; j++) 163 info[j].mask = mask; 164 } 165 inline void add_masks (hb_mask_t mask) 166 { 167 for (unsigned int j = 0; j < len; j++) 168 info[j].mask |= mask; 169 } 170 HB_INTERNAL void set_masks (hb_mask_t value, 171 hb_mask_t mask, 172 unsigned int cluster_start, 173 unsigned int cluster_end); 174 175 HB_INTERNAL void merge_clusters (unsigned int start, 176 unsigned int end); 177 HB_INTERNAL void merge_out_clusters (unsigned int start, 178 unsigned int end); 179 180 /* Internal methods */ 181 HB_INTERNAL bool enlarge (unsigned int size); 182 183 inline bool ensure (unsigned int size) 184 { return likely (size < allocated) ? true : enlarge (size); } 185 186 HB_INTERNAL bool make_room_for (unsigned int num_in, unsigned int num_out); 187 HB_INTERNAL bool shift_forward (unsigned int count); 188 189 typedef long scratch_buffer_t; 190 HB_INTERNAL scratch_buffer_t *get_scratch_buffer (unsigned int *size); 191 192 inline void clear_context (unsigned int side) { context_len[side] = 0; } 193}; 194 195 196#define HB_BUFFER_XALLOCATE_VAR(b, func, var, owner) \ 197 b->func (offsetof (hb_glyph_info_t, var) - offsetof(hb_glyph_info_t, var1), \ 198 sizeof (b->info[0].var), owner) 199#define HB_BUFFER_ALLOCATE_VAR(b, var) \ 200 HB_BUFFER_XALLOCATE_VAR (b, allocate_var, var (), #var) 201#define HB_BUFFER_DEALLOCATE_VAR(b, var) \ 202 HB_BUFFER_XALLOCATE_VAR (b, deallocate_var, var (), #var) 203#define HB_BUFFER_ASSERT_VAR(b, var) \ 204 HB_BUFFER_XALLOCATE_VAR (b, assert_var, var (), #var) 205 206 207#endif /* HB_BUFFER_PRIVATE_HH */ 208