1 /* 2 * Copyright © 2018 Adobe Inc. 3 * 4 * This is part of HarfBuzz, a text shaping library. 5 * 6 * Permission is hereby granted, without written agreement and without 7 * license or royalty fees, to use, copy, modify, and distribute this 8 * software and its documentation for any purpose, provided that the 9 * above copyright notice and the following two paragraphs appear in 10 * all copies of this software. 11 * 12 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR 13 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES 14 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN 15 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH 16 * DAMAGE. 17 * 18 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, 19 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND 20 * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS 21 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO 22 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS. 23 * 24 * Adobe Author(s): Michiharu Ariza 25 */ 26 27 #include "hb-ot-cff-common.hh" 28 #include "hb-ot-cff2-table.hh" 29 #include "hb-subset-cff-common.hh" 30 31 /* Disable FDSelect format 0 for compatibility with fonttools which doesn't seem choose it. 32 * Rarely any/much smaller than format 3 anyway. */ 33 #define CFF_SERIALIZE_FDSELECT_0 0 34 35 using namespace CFF; 36 37 /** 38 * hb_plan_subset_cff_fdselect 39 * Determine an optimal FDSelect format according to a provided plan. 40 * 41 * Return value: FDSelect format, size, and ranges for the most compact subset FDSelect 42 * along with a font index remapping table 43 **/ 44 45 bool 46 hb_plan_subset_cff_fdselect (const hb_vector_t<hb_codepoint_t> &glyphs, 47 unsigned int fdCount, 48 const FDSelect &src, /* IN */ 49 unsigned int &subset_fd_count /* OUT */, 50 unsigned int &subset_fdselect_size /* OUT */, 51 unsigned int &subset_fdselect_format /* OUT */, 52 hb_vector_t<code_pair_t> &fdselect_ranges /* OUT */, 53 remap_t &fdmap /* OUT */) 54 { 55 subset_fd_count = 0; 56 subset_fdselect_size = 0; 57 subset_fdselect_format = 0; 58 unsigned int num_ranges = 0; 59 60 unsigned int subset_num_glyphs = glyphs.length; 61 if (subset_num_glyphs == 0) 62 return true; 63 64 { 65 /* use hb_set to determine the subset of font dicts */ 66 hb_set_t *set = hb_set_create (); 67 if (set == &Null (hb_set_t)) 68 return false; 69 hb_codepoint_t prev_fd = CFF_UNDEF_CODE; 70 for (hb_codepoint_t i = 0; i < subset_num_glyphs; i++) 71 { 72 hb_codepoint_t fd = src.get_fd (glyphs[i]); 73 set->add (fd); 74 75 if (fd != prev_fd) 76 { 77 num_ranges++; 78 prev_fd = fd; 79 code_pair_t pair = { fd, i }; 80 fdselect_ranges.push (pair); 81 } 82 } 83 84 subset_fd_count = set->get_population (); 85 if (subset_fd_count == fdCount) 86 { 87 /* all font dicts belong to the subset. no need to subset FDSelect & FDArray */ 88 fdmap.identity (fdCount); 89 hb_set_destroy (set); 90 } 91 else 92 { 93 /* create a fdmap */ 94 if (!fdmap.reset (fdCount)) 95 { 96 hb_set_destroy (set); 97 return false; 98 } 99 100 hb_codepoint_t fd = CFF_UNDEF_CODE; 101 while (set->next (&fd)) 102 fdmap.add (fd); 103 hb_set_destroy (set); 104 if (unlikely (fdmap.get_count () != subset_fd_count)) 105 return false; 106 } 107 108 /* update each font dict index stored as "code" in fdselect_ranges */ 109 for (unsigned int i = 0; i < fdselect_ranges.length; i++) 110 fdselect_ranges[i].code = fdmap[fdselect_ranges[i].code]; 111 } 112 113 /* determine which FDSelect format is most compact */ 114 if (subset_fd_count > 0xFF) 115 { 116 if (unlikely (src.format != 4)) 117 return false; 118 subset_fdselect_format = 4; 119 subset_fdselect_size = FDSelect::min_size + FDSelect4::min_size + FDSelect4_Range::static_size * num_ranges + HBUINT32::static_size; 120 } 121 else 122 { 123 #if CFF_SERIALIZE_FDSELECT_0 124 unsigned int format0_size = FDSelect::min_size + FDSelect0::min_size + HBUINT8::static_size * subset_num_glyphs; 125 #endif 126 unsigned int format3_size = FDSelect::min_size + FDSelect3::min_size + FDSelect3_Range::static_size * num_ranges + HBUINT16::static_size; 127 128 #if CFF_SERIALIZE_FDSELECT_0 129 if (format0_size <= format3_size) 130 { 131 // subset_fdselect_format = 0; 132 subset_fdselect_size = format0_size; 133 } 134 else 135 #endif 136 { 137 subset_fdselect_format = 3; 138 subset_fdselect_size = format3_size; 139 } 140 } 141 142 return true; 143 } 144 145 template <typename FDSELECT3_4> 146 static inline bool 147 serialize_fdselect_3_4 (hb_serialize_context_t *c, 148 const unsigned int num_glyphs, 149 const FDSelect &src, 150 unsigned int size, 151 const hb_vector_t<code_pair_t> &fdselect_ranges) 152 { 153 TRACE_SERIALIZE (this); 154 FDSELECT3_4 *p = c->allocate_size<FDSELECT3_4> (size); 155 if (unlikely (p == nullptr)) return_trace (false); 156 p->nRanges ().set (fdselect_ranges.length); 157 for (unsigned int i = 0; i < fdselect_ranges.length; i++) 158 { 159 p->ranges[i].first.set (fdselect_ranges[i].glyph); 160 p->ranges[i].fd.set (fdselect_ranges[i].code); 161 } 162 p->sentinel().set (num_glyphs); 163 return_trace (true); 164 } 165 166 /** 167 * hb_serialize_cff_fdselect 168 * Serialize a subset FDSelect format planned above. 169 **/ 170 bool 171 hb_serialize_cff_fdselect (hb_serialize_context_t *c, 172 const unsigned int num_glyphs, 173 const FDSelect &src, 174 unsigned int fd_count, 175 unsigned int fdselect_format, 176 unsigned int size, 177 const hb_vector_t<code_pair_t> &fdselect_ranges) 178 { 179 TRACE_SERIALIZE (this); 180 FDSelect *p = c->allocate_min<FDSelect> (); 181 if (unlikely (p == nullptr)) return_trace (false); 182 p->format.set (fdselect_format); 183 size -= FDSelect::min_size; 184 185 switch (fdselect_format) 186 { 187 #if CFF_SERIALIZE_FDSELECT_0 188 case 0: 189 { 190 FDSelect0 *p = c->allocate_size<FDSelect0> (size); 191 if (unlikely (p == nullptr)) return_trace (false); 192 unsigned int range_index = 0; 193 unsigned int fd = fdselect_ranges[range_index++].code; 194 for (unsigned int i = 0; i < num_glyphs; i++) 195 { 196 if ((range_index < fdselect_ranges.len) && 197 (i >= fdselect_ranges[range_index].glyph)) 198 { 199 fd = fdselect_ranges[range_index++].code; 200 } 201 p->fds[i].set (fd); 202 } 203 break; 204 } 205 #endif /* CFF_SERIALIZE_FDSELECT_0 */ 206 207 case 3: 208 return serialize_fdselect_3_4<FDSelect3> (c, 209 num_glyphs, 210 src, 211 size, 212 fdselect_ranges); 213 214 case 4: 215 return serialize_fdselect_3_4<FDSelect4> (c, 216 num_glyphs, 217 src, 218 size, 219 fdselect_ranges); 220 221 default: 222 assert(false); 223 } 224 225 return_trace (true); 226 }