1 /* 2 * Copyright © 2018 Google, 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 * Google Author(s): Garret Rieger 25 */ 26 27 #ifndef HB_OT_HDMX_TABLE_HH 28 #define HB_OT_HDMX_TABLE_HH 29 30 #include "hb-open-type.hh" 31 32 /* 33 * hdmx -- Horizontal Device Metrics 34 * https://docs.microsoft.com/en-us/typography/opentype/spec/hdmx 35 */ 36 #define HB_OT_TAG_hdmx HB_TAG('h','d','m','x') 37 38 39 namespace OT { 40 41 42 struct DeviceRecord 43 { 44 struct SubsetView 45 { 46 const DeviceRecord *source_device_record; 47 unsigned int sizeDeviceRecord; 48 hb_subset_plan_t *subset_plan; 49 initOT::DeviceRecord::SubsetView50 void init (const DeviceRecord *source_device_record, 51 unsigned int sizeDeviceRecord, 52 hb_subset_plan_t *subset_plan) 53 { 54 this->source_device_record = source_device_record; 55 this->sizeDeviceRecord = sizeDeviceRecord; 56 this->subset_plan = subset_plan; 57 } 58 lenOT::DeviceRecord::SubsetView59 unsigned int len () const 60 { return this->subset_plan->glyphs.len; } 61 operator []OT::DeviceRecord::SubsetView62 const HBUINT8* operator [] (unsigned int i) const 63 { 64 if (unlikely (i >= len ())) return nullptr; 65 hb_codepoint_t gid = this->subset_plan->glyphs [i]; 66 67 if (gid >= sizeDeviceRecord - DeviceRecord::min_size) 68 return nullptr; 69 return &(this->source_device_record->widthsZ[gid]); 70 } 71 }; 72 get_sizeOT::DeviceRecord73 static unsigned int get_size (unsigned int count) 74 { return hb_ceil_to_4 (min_size + count * HBUINT8::static_size); } 75 serializeOT::DeviceRecord76 bool serialize (hb_serialize_context_t *c, const SubsetView &subset_view) 77 { 78 TRACE_SERIALIZE (this); 79 80 unsigned int size = get_size (subset_view.len ()); 81 if (unlikely (!c->allocate_size<DeviceRecord> (size))) 82 { 83 DEBUG_MSG(SUBSET, nullptr, "Couldn't allocate enough space for DeviceRecord: %d.", 84 size); 85 return_trace (false); 86 } 87 88 this->pixelSize.set (subset_view.source_device_record->pixelSize); 89 this->maxWidth.set (subset_view.source_device_record->maxWidth); 90 91 for (unsigned int i = 0; i < subset_view.len (); i++) 92 { 93 const HBUINT8 *width = subset_view[i]; 94 if (!width) 95 { 96 DEBUG_MSG(SUBSET, nullptr, "HDMX width for new gid %d is missing.", i); 97 return_trace (false); 98 } 99 widthsZ[i].set (*width); 100 } 101 102 return_trace (true); 103 } 104 sanitizeOT::DeviceRecord105 bool sanitize (hb_sanitize_context_t *c, unsigned int sizeDeviceRecord) const 106 { 107 TRACE_SANITIZE (this); 108 return_trace (likely (c->check_struct (this) && 109 c->check_range (this, sizeDeviceRecord))); 110 } 111 112 HBUINT8 pixelSize; /* Pixel size for following widths (as ppem). */ 113 HBUINT8 maxWidth; /* Maximum width. */ 114 UnsizedArrayOf<HBUINT8> widthsZ; /* Array of widths (numGlyphs is from the 'maxp' table). */ 115 public: 116 DEFINE_SIZE_ARRAY (2, widthsZ); 117 }; 118 119 120 struct hdmx 121 { 122 enum { tableTag = HB_OT_TAG_hdmx }; 123 get_sizeOT::hdmx124 unsigned int get_size () const 125 { return min_size + numRecords * sizeDeviceRecord; } 126 operator []OT::hdmx127 const DeviceRecord& operator [] (unsigned int i) const 128 { 129 /* XXX Null(DeviceRecord) is NOT safe as it's num-glyphs lengthed. 130 * https://github.com/harfbuzz/harfbuzz/issues/1300 */ 131 if (unlikely (i >= numRecords)) return Null (DeviceRecord); 132 return StructAtOffset<DeviceRecord> (&this->firstDeviceRecord, i * sizeDeviceRecord); 133 } 134 serializeOT::hdmx135 bool serialize (hb_serialize_context_t *c, const hdmx *source_hdmx, hb_subset_plan_t *plan) 136 { 137 TRACE_SERIALIZE (this); 138 139 if (unlikely (!c->extend_min ((*this)))) return_trace (false); 140 141 this->version.set (source_hdmx->version); 142 this->numRecords.set (source_hdmx->numRecords); 143 this->sizeDeviceRecord.set (DeviceRecord::get_size (plan->glyphs.len)); 144 145 for (unsigned int i = 0; i < source_hdmx->numRecords; i++) 146 { 147 DeviceRecord::SubsetView subset_view; 148 subset_view.init (&(*source_hdmx)[i], source_hdmx->sizeDeviceRecord, plan); 149 150 if (!c->start_embed<DeviceRecord> ()->serialize (c, subset_view)) 151 return_trace (false); 152 } 153 154 return_trace (true); 155 } 156 get_subsetted_sizeOT::hdmx157 static size_t get_subsetted_size (const hdmx *source_hdmx, hb_subset_plan_t *plan) 158 { 159 return min_size + source_hdmx->numRecords * DeviceRecord::get_size (plan->glyphs.len); 160 } 161 subsetOT::hdmx162 bool subset (hb_subset_plan_t *plan) const 163 { 164 size_t dest_size = get_subsetted_size (this, plan); 165 hdmx *dest = (hdmx *) malloc (dest_size); 166 if (unlikely (!dest)) 167 { 168 DEBUG_MSG(SUBSET, nullptr, "Unable to alloc %lu for hdmx subset output.", (unsigned long) dest_size); 169 return false; 170 } 171 172 hb_serialize_context_t c (dest, dest_size); 173 hdmx *hdmx_prime = c.start_serialize<hdmx> (); 174 if (!hdmx_prime || !hdmx_prime->serialize (&c, this, plan)) 175 { 176 free (dest); 177 DEBUG_MSG(SUBSET, nullptr, "Failed to serialize write new hdmx."); 178 return false; 179 } 180 c.end_serialize (); 181 182 hb_blob_t *hdmx_prime_blob = hb_blob_create ((const char *) dest, 183 dest_size, 184 HB_MEMORY_MODE_READONLY, 185 dest, 186 free); 187 bool result = plan->add_table (HB_OT_TAG_hdmx, hdmx_prime_blob); 188 hb_blob_destroy (hdmx_prime_blob); 189 190 return result; 191 } 192 sanitizeOT::hdmx193 bool sanitize (hb_sanitize_context_t *c) const 194 { 195 TRACE_SANITIZE (this); 196 return_trace (c->check_struct (this) && 197 !hb_unsigned_mul_overflows (numRecords, sizeDeviceRecord) && 198 sizeDeviceRecord >= DeviceRecord::min_size && 199 c->check_range (this, get_size ())); 200 } 201 202 protected: 203 HBUINT16 version; /* Table version number (0) */ 204 HBUINT16 numRecords; /* Number of device records. */ 205 HBUINT32 sizeDeviceRecord; /* Size of a device record, 32-bit aligned. */ 206 DeviceRecord firstDeviceRecord; /* Array of device records. */ 207 public: 208 DEFINE_SIZE_MIN (8); 209 }; 210 211 } /* namespace OT */ 212 213 214 #endif /* HB_OT_HDMX_TABLE_HH */ 215