1 /* 2 * Copyright © 2017 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): Behdad Esfahbod 25 */ 26 27 #ifndef HB_OT_VAR_FVAR_TABLE_HH 28 #define HB_OT_VAR_FVAR_TABLE_HH 29 30 #include "hb-open-type.hh" 31 32 /* 33 * fvar -- Font Variations 34 * https://docs.microsoft.com/en-us/typography/opentype/spec/fvar 35 */ 36 37 #define HB_OT_TAG_fvar HB_TAG('f','v','a','r') 38 39 40 namespace OT { 41 42 43 struct InstanceRecord 44 { 45 friend struct fvar; 46 get_coordinatesOT::InstanceRecord47 hb_array_t<const Fixed> get_coordinates (unsigned int axis_count) const 48 { return coordinatesZ.as_array (axis_count); } 49 sanitizeOT::InstanceRecord50 bool sanitize (hb_sanitize_context_t *c, unsigned int axis_count) const 51 { 52 TRACE_SANITIZE (this); 53 return_trace (c->check_struct (this) && 54 c->check_array (coordinatesZ.arrayZ, axis_count)); 55 } 56 57 protected: 58 NameID subfamilyNameID;/* The name ID for entries in the 'name' table 59 * that provide subfamily names for this instance. */ 60 HBUINT16 flags; /* Reserved for future use — set to 0. */ 61 UnsizedArrayOf<Fixed> 62 coordinatesZ; /* The coordinates array for this instance. */ 63 //NameID postScriptNameIDX;/*Optional. The name ID for entries in the 'name' 64 // * table that provide PostScript names for this 65 // * instance. */ 66 67 public: 68 DEFINE_SIZE_UNBOUNDED (4); 69 }; 70 71 struct AxisRecord 72 { 73 enum 74 { 75 AXIS_FLAG_HIDDEN = 0x0001, 76 }; 77 sanitizeOT::AxisRecord78 bool sanitize (hb_sanitize_context_t *c) const 79 { 80 TRACE_SANITIZE (this); 81 return_trace (c->check_struct (this)); 82 } 83 84 public: 85 Tag axisTag; /* Tag identifying the design variation for the axis. */ 86 Fixed minValue; /* The minimum coordinate value for the axis. */ 87 Fixed defaultValue; /* The default coordinate value for the axis. */ 88 Fixed maxValue; /* The maximum coordinate value for the axis. */ 89 HBUINT16 flags; /* Axis flags. */ 90 NameID axisNameID; /* The name ID for entries in the 'name' table that 91 * provide a display name for this axis. */ 92 93 public: 94 DEFINE_SIZE_STATIC (20); 95 }; 96 97 struct fvar 98 { 99 enum { tableTag = HB_OT_TAG_fvar }; 100 has_dataOT::fvar101 bool has_data () const { return version.to_int (); } 102 sanitizeOT::fvar103 bool sanitize (hb_sanitize_context_t *c) const 104 { 105 TRACE_SANITIZE (this); 106 return_trace (version.sanitize (c) && 107 likely (version.major == 1) && 108 c->check_struct (this) && 109 axisSize == 20 && /* Assumed in our code. */ 110 instanceSize >= axisCount * 4 + 4 && 111 get_axes ().sanitize (c) && 112 c->check_range (get_instance (0), instanceCount, instanceSize)); 113 } 114 get_axis_countOT::fvar115 unsigned int get_axis_count () const { return axisCount; } 116 get_axis_deprecatedOT::fvar117 void get_axis_deprecated (unsigned int axis_index, 118 hb_ot_var_axis_t *info) const 119 { 120 const AxisRecord &axis = get_axes ()[axis_index]; 121 info->tag = axis.axisTag; 122 info->name_id = axis.axisNameID; 123 info->default_value = axis.defaultValue / 65536.; 124 /* Ensure order, to simplify client math. */ 125 info->min_value = MIN<float> (info->default_value, axis.minValue / 65536.); 126 info->max_value = MAX<float> (info->default_value, axis.maxValue / 65536.); 127 } 128 get_axis_infoOT::fvar129 void get_axis_info (unsigned int axis_index, 130 hb_ot_var_axis_info_t *info) const 131 { 132 const AxisRecord &axis = get_axes ()[axis_index]; 133 info->axis_index = axis_index; 134 info->tag = axis.axisTag; 135 info->name_id = axis.axisNameID; 136 info->flags = (hb_ot_var_axis_flags_t) (unsigned int) axis.flags; 137 info->default_value = axis.defaultValue / 65536.; 138 /* Ensure order, to simplify client math. */ 139 info->min_value = MIN<float> (info->default_value, axis.minValue / 65536.); 140 info->max_value = MAX<float> (info->default_value, axis.maxValue / 65536.); 141 info->reserved = 0; 142 } 143 get_axes_deprecatedOT::fvar144 unsigned int get_axes_deprecated (unsigned int start_offset, 145 unsigned int *axes_count /* IN/OUT */, 146 hb_ot_var_axis_t *axes_array /* OUT */) const 147 { 148 if (axes_count) 149 { 150 /* TODO Rewrite as hb_array_t<>::sub-array() */ 151 unsigned int count = axisCount; 152 start_offset = MIN (start_offset, count); 153 154 count -= start_offset; 155 axes_array += start_offset; 156 157 count = MIN (count, *axes_count); 158 *axes_count = count; 159 160 for (unsigned int i = 0; i < count; i++) 161 get_axis_deprecated (start_offset + i, axes_array + i); 162 } 163 return axisCount; 164 } 165 get_axis_infosOT::fvar166 unsigned int get_axis_infos (unsigned int start_offset, 167 unsigned int *axes_count /* IN/OUT */, 168 hb_ot_var_axis_info_t *axes_array /* OUT */) const 169 { 170 if (axes_count) 171 { 172 /* TODO Rewrite as hb_array_t<>::sub-array() */ 173 unsigned int count = axisCount; 174 start_offset = MIN (start_offset, count); 175 176 count -= start_offset; 177 axes_array += start_offset; 178 179 count = MIN (count, *axes_count); 180 *axes_count = count; 181 182 for (unsigned int i = 0; i < count; i++) 183 get_axis_info (start_offset + i, axes_array + i); 184 } 185 return axisCount; 186 } 187 find_axis_deprecatedOT::fvar188 bool find_axis_deprecated (hb_tag_t tag, 189 unsigned int *axis_index, 190 hb_ot_var_axis_t *info) const 191 { 192 const AxisRecord *axes = get_axes (); 193 unsigned int count = get_axis_count (); 194 for (unsigned int i = 0; i < count; i++) 195 if (axes[i].axisTag == tag) 196 { 197 if (axis_index) 198 *axis_index = i; 199 get_axis_deprecated (i, info); 200 return true; 201 } 202 if (axis_index) 203 *axis_index = HB_OT_VAR_NO_AXIS_INDEX; 204 return false; 205 } 206 find_axis_infoOT::fvar207 bool find_axis_info (hb_tag_t tag, 208 hb_ot_var_axis_info_t *info) const 209 { 210 const AxisRecord *axes = get_axes (); 211 unsigned int count = get_axis_count (); 212 for (unsigned int i = 0; i < count; i++) 213 if (axes[i].axisTag == tag) 214 { 215 get_axis_info (i, info); 216 return true; 217 } 218 return false; 219 } 220 normalize_axis_valueOT::fvar221 int normalize_axis_value (unsigned int axis_index, float v) const 222 { 223 hb_ot_var_axis_info_t axis; 224 get_axis_info (axis_index, &axis); 225 226 v = MAX (MIN (v, axis.max_value), axis.min_value); /* Clamp. */ 227 228 if (v == axis.default_value) 229 return 0; 230 else if (v < axis.default_value) 231 v = (v - axis.default_value) / (axis.default_value - axis.min_value); 232 else 233 v = (v - axis.default_value) / (axis.max_value - axis.default_value); 234 return (int) (v * 16384.f + (v >= 0.f ? .5f : -.5f)); 235 } 236 get_instance_countOT::fvar237 unsigned int get_instance_count () const { return instanceCount; } 238 get_instance_subfamily_name_idOT::fvar239 hb_ot_name_id_t get_instance_subfamily_name_id (unsigned int instance_index) const 240 { 241 const InstanceRecord *instance = get_instance (instance_index); 242 if (unlikely (!instance)) return HB_OT_NAME_ID_INVALID; 243 return instance->subfamilyNameID; 244 } 245 get_instance_postscript_name_idOT::fvar246 hb_ot_name_id_t get_instance_postscript_name_id (unsigned int instance_index) const 247 { 248 const InstanceRecord *instance = get_instance (instance_index); 249 if (unlikely (!instance)) return HB_OT_NAME_ID_INVALID; 250 if (instanceSize >= axisCount * 4 + 6) 251 return StructAfter<NameID> (instance->get_coordinates (axisCount)); 252 return HB_OT_NAME_ID_INVALID; 253 } 254 get_instance_coordsOT::fvar255 unsigned int get_instance_coords (unsigned int instance_index, 256 unsigned int *coords_length, /* IN/OUT */ 257 float *coords /* OUT */) const 258 { 259 const InstanceRecord *instance = get_instance (instance_index); 260 if (unlikely (!instance)) 261 { 262 if (coords_length) 263 *coords_length = 0; 264 return 0; 265 } 266 267 if (coords_length && *coords_length) 268 { 269 hb_array_t<const Fixed> instanceCoords = instance->get_coordinates (axisCount) 270 .sub_array (0, *coords_length); 271 for (unsigned int i = 0; i < instanceCoords.len; i++) 272 coords[i] = instanceCoords.arrayZ[i].to_float (); 273 } 274 return axisCount; 275 } 276 277 protected: get_axesOT::fvar278 hb_array_t<const AxisRecord> get_axes () const 279 { return hb_array (&(this+firstAxis), axisCount); } 280 get_instanceOT::fvar281 const InstanceRecord *get_instance (unsigned int i) const 282 { 283 if (unlikely (i >= instanceCount)) return nullptr; 284 return &StructAtOffset<InstanceRecord> (&StructAfter<InstanceRecord> (get_axes ()), 285 i * instanceSize); 286 } 287 288 protected: 289 FixedVersion<>version; /* Version of the fvar table 290 * initially set to 0x00010000u */ 291 OffsetTo<AxisRecord> 292 firstAxis; /* Offset in bytes from the beginning of the table 293 * to the start of the AxisRecord array. */ 294 HBUINT16 reserved; /* This field is permanently reserved. Set to 2. */ 295 HBUINT16 axisCount; /* The number of variation axes in the font (the 296 * number of records in the axes array). */ 297 HBUINT16 axisSize; /* The size in bytes of each VariationAxisRecord — 298 * set to 20 (0x0014) for this version. */ 299 HBUINT16 instanceCount; /* The number of named instances defined in the font 300 * (the number of records in the instances array). */ 301 HBUINT16 instanceSize; /* The size in bytes of each InstanceRecord — set 302 * to either axisCount * sizeof(Fixed) + 4, or to 303 * axisCount * sizeof(Fixed) + 6. */ 304 305 public: 306 DEFINE_SIZE_STATIC (16); 307 }; 308 309 } /* namespace OT */ 310 311 312 #endif /* HB_OT_VAR_FVAR_TABLE_HH */ 313