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
40namespace OT {
41
42
43struct InstanceRecord
44{
45 friend struct fvar;
46
47 hb_array_t<const HBFixed> get_coordinates (unsigned int axis_count) const
48 { return coordinatesZ.as_array (axis_count); }
49
50 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<HBFixed>
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
71struct AxisRecord
72{
73 int cmp (hb_tag_t key) const { return axisTag.cmp (key); }
74
75 enum
76 {
77 AXIS_FLAG_HIDDEN = 0x0001,
78 };
79
80#ifndef HB_DISABLE_DEPRECATED
81 void get_axis_deprecated (hb_ot_var_axis_t *info) const
82 {
83 info->tag = axisTag;
84 info->name_id = axisNameID;
85 get_coordinates (info->min_value, info->default_value, info->max_value);
86 }
87#endif
88
89 void get_axis_info (unsigned axis_index, hb_ot_var_axis_info_t *info) const
90 {
91 info->axis_index = axis_index;
92 info->tag = axisTag;
93 info->name_id = axisNameID;
94 info->flags = (hb_ot_var_axis_flags_t) (unsigned int) flags;
95 get_coordinates (info->min_value, info->default_value, info->max_value);
96 info->reserved = 0;
97 }
98
99 int normalize_axis_value (float v) const
100 {
101 float min_value, default_value, max_value;
102 get_coordinates (min_value, default_value, max_value);
103
104 v = hb_clamp (v, min_value, max_value);
105
106 if (v == default_value)
107 return 0;
108 else if (v < default_value)
109 v = (v - default_value) / (default_value - min_value);
110 else
111 v = (v - default_value) / (max_value - default_value);
112 return roundf (v * 16384.f);
113 }
114
115 float unnormalize_axis_value (int v) const
116 {
117 float min_value, default_value, max_value;
118 get_coordinates (min_value, default_value, max_value);
119
120 if (v == 0)
121 return default_value;
122 else if (v < 0)
123 return v * (default_value - min_value) / 16384.f + default_value;
124 else
125 return v * (max_value - default_value) / 16384.f + default_value;
126 }
127
128 hb_ot_name_id_t get_name_id () const { return axisNameID; }
129
130 bool sanitize (hb_sanitize_context_t *c) const
131 {
132 TRACE_SANITIZE (this);
133 return_trace (c->check_struct (this));
134 }
135
136 protected:
137 void get_coordinates (float &min, float &default_, float &max) const
138 {
139 default_ = defaultValue / 65536.f;
140 /* Ensure order, to simplify client math. */
141 min = hb_min (default_, minValue / 65536.f);
142 max = hb_max (default_, maxValue / 65536.f);
143 }
144
145 protected:
146 Tag axisTag; /* Tag identifying the design variation for the axis. */
147 HBFixed minValue; /* The minimum coordinate value for the axis. */
148 HBFixed defaultValue; /* The default coordinate value for the axis. */
149 HBFixed maxValue; /* The maximum coordinate value for the axis. */
150 HBUINT16 flags; /* Axis flags. */
151 NameID axisNameID; /* The name ID for entries in the 'name' table that
152 * provide a display name for this axis. */
153
154 public:
155 DEFINE_SIZE_STATIC (20);
156};
157
158struct fvar
159{
160 static constexpr hb_tag_t tableTag = HB_OT_TAG_fvar;
161
162 bool has_data () const { return version.to_int (); }
163
164 bool sanitize (hb_sanitize_context_t *c) const
165 {
166 TRACE_SANITIZE (this);
167 return_trace (version.sanitize (c) &&
168 likely (version.major == 1) &&
169 c->check_struct (this) &&
170 axisSize == 20 && /* Assumed in our code. */
171 instanceSize >= axisCount * 4 + 4 &&
172 get_axes ().sanitize (c) &&
173 c->check_range (get_instance (0), instanceCount, instanceSize));
174 }
175
176 unsigned int get_axis_count () const { return axisCount; }
177
178#ifndef HB_DISABLE_DEPRECATED
179 unsigned int get_axes_deprecated (unsigned int start_offset,
180 unsigned int *axes_count /* IN/OUT */,
181 hb_ot_var_axis_t *axes_array /* OUT */) const
182 {
183 if (axes_count)
184 {
185 hb_array_t<const AxisRecord> arr = get_axes ().sub_array (start_offset, axes_count);
186 for (unsigned i = 0; i < arr.length; ++i)
187 arr[i].get_axis_deprecated (&axes_array[i]);
188 }
189 return axisCount;
190 }
191#endif
192
193 unsigned int get_axis_infos (unsigned int start_offset,
194 unsigned int *axes_count /* IN/OUT */,
195 hb_ot_var_axis_info_t *axes_array /* OUT */) const
196 {
197 if (axes_count)
198 {
199 hb_array_t<const AxisRecord> arr = get_axes ().sub_array (start_offset, axes_count);
200 for (unsigned i = 0; i < arr.length; ++i)
201 arr[i].get_axis_info (start_offset + i, &axes_array[i]);
202 }
203 return axisCount;
204 }
205
206#ifndef HB_DISABLE_DEPRECATED
207 bool
208 find_axis_deprecated (hb_tag_t tag, unsigned *axis_index, hb_ot_var_axis_t *info) const
209 {
210 unsigned i;
211 if (!axis_index) axis_index = &i;
212 *axis_index = HB_OT_VAR_NO_AXIS_INDEX;
213 auto axes = get_axes ();
214 return axes.lfind (tag, axis_index) && (axes[*axis_index].get_axis_deprecated (info), true);
215 }
216#endif
217
218 bool
219 find_axis_info (hb_tag_t tag, hb_ot_var_axis_info_t *info) const
220 {
221 unsigned i;
222 auto axes = get_axes ();
223 return axes.lfind (tag, &i) && (axes[i].get_axis_info (i, info), true);
224 }
225
226 int normalize_axis_value (unsigned int axis_index, float v) const
227 { return get_axes ()[axis_index].normalize_axis_value (v); }
228
229 float unnormalize_axis_value (unsigned int axis_index, int v) const
230 { return get_axes ()[axis_index].unnormalize_axis_value (v); }
231
232 unsigned int get_instance_count () const { return instanceCount; }
233
234 hb_ot_name_id_t get_instance_subfamily_name_id (unsigned int instance_index) const
235 {
236 const InstanceRecord *instance = get_instance (instance_index);
237 if (unlikely (!instance)) return HB_OT_NAME_ID_INVALID;
238 return instance->subfamilyNameID;
239 }
240
241 hb_ot_name_id_t get_instance_postscript_name_id (unsigned int instance_index) const
242 {
243 const InstanceRecord *instance = get_instance (instance_index);
244 if (unlikely (!instance)) return HB_OT_NAME_ID_INVALID;
245 if (instanceSize >= axisCount * 4 + 6)
246 return StructAfter<NameID> (instance->get_coordinates (axisCount));
247 return HB_OT_NAME_ID_INVALID;
248 }
249
250 unsigned int get_instance_coords (unsigned int instance_index,
251 unsigned int *coords_length, /* IN/OUT */
252 float *coords /* OUT */) const
253 {
254 const InstanceRecord *instance = get_instance (instance_index);
255 if (unlikely (!instance))
256 {
257 if (coords_length)
258 *coords_length = 0;
259 return 0;
260 }
261
262 if (coords_length && *coords_length)
263 {
264 hb_array_t<const HBFixed> instanceCoords = instance->get_coordinates (axisCount)
265 .sub_array (0, *coords_length);
266 for (unsigned int i = 0; i < instanceCoords.length; i++)
267 coords[i] = instanceCoords.arrayZ[i].to_float ();
268 }
269 return axisCount;
270 }
271
272 void collect_name_ids (hb_set_t *nameids) const
273 {
274 if (!has_data ()) return;
275
276 + get_axes ()
277 | hb_map (&AxisRecord::get_name_id)
278 | hb_sink (nameids)
279 ;
280
281 + hb_range ((unsigned) instanceCount)
282 | hb_map ([this] (const unsigned _) { return get_instance_subfamily_name_id (_); })
283 | hb_sink (nameids)
284 ;
285
286 + hb_range ((unsigned) instanceCount)
287 | hb_map ([this] (const unsigned _) { return get_instance_postscript_name_id (_); })
288 | hb_sink (nameids)
289 ;
290 }
291
292 protected:
293 hb_array_t<const AxisRecord> get_axes () const
294 { return hb_array (&(this+firstAxis), axisCount); }
295
296 const InstanceRecord *get_instance (unsigned int i) const
297 {
298 if (unlikely (i >= instanceCount)) return nullptr;
299 return &StructAtOffset<InstanceRecord> (&StructAfter<InstanceRecord> (get_axes ()),
300 i * instanceSize);
301 }
302
303 protected:
304 FixedVersion<>version; /* Version of the fvar table
305 * initially set to 0x00010000u */
306 OffsetTo<AxisRecord>
307 firstAxis; /* Offset in bytes from the beginning of the table
308 * to the start of the AxisRecord array. */
309 HBUINT16 reserved; /* This field is permanently reserved. Set to 2. */
310 HBUINT16 axisCount; /* The number of variation axes in the font (the
311 * number of records in the axes array). */
312 HBUINT16 axisSize; /* The size in bytes of each VariationAxisRecord —
313 * set to 20 (0x0014) for this version. */
314 HBUINT16 instanceCount; /* The number of named instances defined in the font
315 * (the number of records in the instances array). */
316 HBUINT16 instanceSize; /* The size in bytes of each InstanceRecord — set
317 * to either axisCount * sizeof(HBFixed) + 4, or to
318 * axisCount * sizeof(HBFixed) + 6. */
319
320 public:
321 DEFINE_SIZE_STATIC (16);
322};
323
324} /* namespace OT */
325
326
327#endif /* HB_OT_VAR_FVAR_TABLE_HH */
328