1/*
2 * Copyright © 2016 Igalia S.L.
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 * Igalia Author(s): Frédéric Wang
25 */
26
27#if !defined(HB_OT_H_IN) && !defined(HB_NO_SINGLE_HEADER_ERROR)
28#error "Include <hb-ot.h> instead."
29#endif
30
31#ifndef HB_OT_MATH_H
32#define HB_OT_MATH_H
33
34#include "hb.h"
35
36HB_BEGIN_DECLS
37
38
39/*
40 * MATH
41 */
42
43/**
44 * HB_OT_TAG_MATH:
45 *
46 * OpenType [Mathematical Typesetting Table](https://docs.microsoft.com/en-us/typography/opentype/spec/math).
47 *
48 * Since: 1.3.3
49 */
50#define HB_OT_TAG_MATH HB_TAG('M','A','T','H')
51
52/**
53 * HB_OT_TAG_MATH_SCRIPT:
54 *
55 * OpenType script tag, `math`, for features specific to math shaping.
56 *
57 * <note>#HB_OT_TAG_MATH_SCRIPT is not a valid #hb_script_t and should only be
58 * used with functions that accept raw OpenType script tags, such as
59 * #hb_ot_layout_collect_features. In other cases, #HB_SCRIPT_MATH should be
60 * used instead.</note>
61 *
62 * Since: 3.4.0
63 */
64#define HB_OT_TAG_MATH_SCRIPT HB_TAG('m','a','t','h')
65
66/* Types */
67
68/**
69 * hb_ot_math_constant_t:
70 * @HB_OT_MATH_CONSTANT_SCRIPT_PERCENT_SCALE_DOWN: scriptPercentScaleDown
71 * @HB_OT_MATH_CONSTANT_SCRIPT_SCRIPT_PERCENT_SCALE_DOWN: scriptScriptPercentScaleDown
72 * @HB_OT_MATH_CONSTANT_DELIMITED_SUB_FORMULA_MIN_HEIGHT: delimitedSubFormulaMinHeight
73 * @HB_OT_MATH_CONSTANT_DISPLAY_OPERATOR_MIN_HEIGHT: displayOperatorMinHeight
74 * @HB_OT_MATH_CONSTANT_MATH_LEADING: mathLeading
75 * @HB_OT_MATH_CONSTANT_AXIS_HEIGHT: axisHeight
76 * @HB_OT_MATH_CONSTANT_ACCENT_BASE_HEIGHT: accentBaseHeight
77 * @HB_OT_MATH_CONSTANT_FLATTENED_ACCENT_BASE_HEIGHT: flattenedAccentBaseHeight
78 * @HB_OT_MATH_CONSTANT_SUBSCRIPT_SHIFT_DOWN: subscriptShiftDown
79 * @HB_OT_MATH_CONSTANT_SUBSCRIPT_TOP_MAX: subscriptTopMax
80 * @HB_OT_MATH_CONSTANT_SUBSCRIPT_BASELINE_DROP_MIN: subscriptBaselineDropMin
81 * @HB_OT_MATH_CONSTANT_SUPERSCRIPT_SHIFT_UP: superscriptShiftUp
82 * @HB_OT_MATH_CONSTANT_SUPERSCRIPT_SHIFT_UP_CRAMPED: superscriptShiftUpCramped
83 * @HB_OT_MATH_CONSTANT_SUPERSCRIPT_BOTTOM_MIN: superscriptBottomMin
84 * @HB_OT_MATH_CONSTANT_SUPERSCRIPT_BASELINE_DROP_MAX: superscriptBaselineDropMax
85 * @HB_OT_MATH_CONSTANT_SUB_SUPERSCRIPT_GAP_MIN: subSuperscriptGapMin
86 * @HB_OT_MATH_CONSTANT_SUPERSCRIPT_BOTTOM_MAX_WITH_SUBSCRIPT: superscriptBottomMaxWithSubscript
87 * @HB_OT_MATH_CONSTANT_SPACE_AFTER_SCRIPT: spaceAfterScript
88 * @HB_OT_MATH_CONSTANT_UPPER_LIMIT_GAP_MIN: upperLimitGapMin
89 * @HB_OT_MATH_CONSTANT_UPPER_LIMIT_BASELINE_RISE_MIN: upperLimitBaselineRiseMin
90 * @HB_OT_MATH_CONSTANT_LOWER_LIMIT_GAP_MIN: lowerLimitGapMin
91 * @HB_OT_MATH_CONSTANT_LOWER_LIMIT_BASELINE_DROP_MIN: lowerLimitBaselineDropMin
92 * @HB_OT_MATH_CONSTANT_STACK_TOP_SHIFT_UP: stackTopShiftUp
93 * @HB_OT_MATH_CONSTANT_STACK_TOP_DISPLAY_STYLE_SHIFT_UP: stackTopDisplayStyleShiftUp
94 * @HB_OT_MATH_CONSTANT_STACK_BOTTOM_SHIFT_DOWN: stackBottomShiftDown
95 * @HB_OT_MATH_CONSTANT_STACK_BOTTOM_DISPLAY_STYLE_SHIFT_DOWN: stackBottomDisplayStyleShiftDown
96 * @HB_OT_MATH_CONSTANT_STACK_GAP_MIN: stackGapMin
97 * @HB_OT_MATH_CONSTANT_STACK_DISPLAY_STYLE_GAP_MIN: stackDisplayStyleGapMin
98 * @HB_OT_MATH_CONSTANT_STRETCH_STACK_TOP_SHIFT_UP: stretchStackTopShiftUp
99 * @HB_OT_MATH_CONSTANT_STRETCH_STACK_BOTTOM_SHIFT_DOWN: stretchStackBottomShiftDown
100 * @HB_OT_MATH_CONSTANT_STRETCH_STACK_GAP_ABOVE_MIN: stretchStackGapAboveMin
101 * @HB_OT_MATH_CONSTANT_STRETCH_STACK_GAP_BELOW_MIN: stretchStackGapBelowMin
102 * @HB_OT_MATH_CONSTANT_FRACTION_NUMERATOR_SHIFT_UP: fractionNumeratorShiftUp
103 * @HB_OT_MATH_CONSTANT_FRACTION_NUMERATOR_DISPLAY_STYLE_SHIFT_UP: fractionNumeratorDisplayStyleShiftUp
104 * @HB_OT_MATH_CONSTANT_FRACTION_DENOMINATOR_SHIFT_DOWN: fractionDenominatorShiftDown
105 * @HB_OT_MATH_CONSTANT_FRACTION_DENOMINATOR_DISPLAY_STYLE_SHIFT_DOWN: fractionDenominatorDisplayStyleShiftDown
106 * @HB_OT_MATH_CONSTANT_FRACTION_NUMERATOR_GAP_MIN: fractionNumeratorGapMin
107 * @HB_OT_MATH_CONSTANT_FRACTION_NUM_DISPLAY_STYLE_GAP_MIN: fractionNumDisplayStyleGapMin
108 * @HB_OT_MATH_CONSTANT_FRACTION_RULE_THICKNESS: fractionRuleThickness
109 * @HB_OT_MATH_CONSTANT_FRACTION_DENOMINATOR_GAP_MIN: fractionDenominatorGapMin
110 * @HB_OT_MATH_CONSTANT_FRACTION_DENOM_DISPLAY_STYLE_GAP_MIN: fractionDenomDisplayStyleGapMin
111 * @HB_OT_MATH_CONSTANT_SKEWED_FRACTION_HORIZONTAL_GAP: skewedFractionHorizontalGap
112 * @HB_OT_MATH_CONSTANT_SKEWED_FRACTION_VERTICAL_GAP: skewedFractionVerticalGap
113 * @HB_OT_MATH_CONSTANT_OVERBAR_VERTICAL_GAP: overbarVerticalGap
114 * @HB_OT_MATH_CONSTANT_OVERBAR_RULE_THICKNESS: overbarRuleThickness
115 * @HB_OT_MATH_CONSTANT_OVERBAR_EXTRA_ASCENDER: overbarExtraAscender
116 * @HB_OT_MATH_CONSTANT_UNDERBAR_VERTICAL_GAP: underbarVerticalGap
117 * @HB_OT_MATH_CONSTANT_UNDERBAR_RULE_THICKNESS: underbarRuleThickness
118 * @HB_OT_MATH_CONSTANT_UNDERBAR_EXTRA_DESCENDER: underbarExtraDescender
119 * @HB_OT_MATH_CONSTANT_RADICAL_VERTICAL_GAP: radicalVerticalGap
120 * @HB_OT_MATH_CONSTANT_RADICAL_DISPLAY_STYLE_VERTICAL_GAP: radicalDisplayStyleVerticalGap
121 * @HB_OT_MATH_CONSTANT_RADICAL_RULE_THICKNESS: radicalRuleThickness
122 * @HB_OT_MATH_CONSTANT_RADICAL_EXTRA_ASCENDER: radicalExtraAscender
123 * @HB_OT_MATH_CONSTANT_RADICAL_KERN_BEFORE_DEGREE: radicalKernBeforeDegree
124 * @HB_OT_MATH_CONSTANT_RADICAL_KERN_AFTER_DEGREE: radicalKernAfterDegree
125 * @HB_OT_MATH_CONSTANT_RADICAL_DEGREE_BOTTOM_RAISE_PERCENT: radicalDegreeBottomRaisePercent
126 *
127 * The 'MATH' table constants, refer to
128 * [OpenType documentation](https://docs.microsoft.com/en-us/typography/opentype/spec/math#mathconstants-table)
129 * For more explanations.
130 *
131 * Since: 1.3.3
132 */
133typedef enum {
134 HB_OT_MATH_CONSTANT_SCRIPT_PERCENT_SCALE_DOWN = 0,
135 HB_OT_MATH_CONSTANT_SCRIPT_SCRIPT_PERCENT_SCALE_DOWN = 1,
136 HB_OT_MATH_CONSTANT_DELIMITED_SUB_FORMULA_MIN_HEIGHT = 2,
137 HB_OT_MATH_CONSTANT_DISPLAY_OPERATOR_MIN_HEIGHT = 3,
138 HB_OT_MATH_CONSTANT_MATH_LEADING = 4,
139 HB_OT_MATH_CONSTANT_AXIS_HEIGHT = 5,
140 HB_OT_MATH_CONSTANT_ACCENT_BASE_HEIGHT = 6,
141 HB_OT_MATH_CONSTANT_FLATTENED_ACCENT_BASE_HEIGHT = 7,
142 HB_OT_MATH_CONSTANT_SUBSCRIPT_SHIFT_DOWN = 8,
143 HB_OT_MATH_CONSTANT_SUBSCRIPT_TOP_MAX = 9,
144 HB_OT_MATH_CONSTANT_SUBSCRIPT_BASELINE_DROP_MIN = 10,
145 HB_OT_MATH_CONSTANT_SUPERSCRIPT_SHIFT_UP = 11,
146 HB_OT_MATH_CONSTANT_SUPERSCRIPT_SHIFT_UP_CRAMPED = 12,
147 HB_OT_MATH_CONSTANT_SUPERSCRIPT_BOTTOM_MIN = 13,
148 HB_OT_MATH_CONSTANT_SUPERSCRIPT_BASELINE_DROP_MAX = 14,
149 HB_OT_MATH_CONSTANT_SUB_SUPERSCRIPT_GAP_MIN = 15,
150 HB_OT_MATH_CONSTANT_SUPERSCRIPT_BOTTOM_MAX_WITH_SUBSCRIPT = 16,
151 HB_OT_MATH_CONSTANT_SPACE_AFTER_SCRIPT = 17,
152 HB_OT_MATH_CONSTANT_UPPER_LIMIT_GAP_MIN = 18,
153 HB_OT_MATH_CONSTANT_UPPER_LIMIT_BASELINE_RISE_MIN = 19,
154 HB_OT_MATH_CONSTANT_LOWER_LIMIT_GAP_MIN = 20,
155 HB_OT_MATH_CONSTANT_LOWER_LIMIT_BASELINE_DROP_MIN = 21,
156 HB_OT_MATH_CONSTANT_STACK_TOP_SHIFT_UP = 22,
157 HB_OT_MATH_CONSTANT_STACK_TOP_DISPLAY_STYLE_SHIFT_UP = 23,
158 HB_OT_MATH_CONSTANT_STACK_BOTTOM_SHIFT_DOWN = 24,
159 HB_OT_MATH_CONSTANT_STACK_BOTTOM_DISPLAY_STYLE_SHIFT_DOWN = 25,
160 HB_OT_MATH_CONSTANT_STACK_GAP_MIN = 26,
161 HB_OT_MATH_CONSTANT_STACK_DISPLAY_STYLE_GAP_MIN = 27,
162 HB_OT_MATH_CONSTANT_STRETCH_STACK_TOP_SHIFT_UP = 28,
163 HB_OT_MATH_CONSTANT_STRETCH_STACK_BOTTOM_SHIFT_DOWN = 29,
164 HB_OT_MATH_CONSTANT_STRETCH_STACK_GAP_ABOVE_MIN = 30,
165 HB_OT_MATH_CONSTANT_STRETCH_STACK_GAP_BELOW_MIN = 31,
166 HB_OT_MATH_CONSTANT_FRACTION_NUMERATOR_SHIFT_UP = 32,
167 HB_OT_MATH_CONSTANT_FRACTION_NUMERATOR_DISPLAY_STYLE_SHIFT_UP = 33,
168 HB_OT_MATH_CONSTANT_FRACTION_DENOMINATOR_SHIFT_DOWN = 34,
169 HB_OT_MATH_CONSTANT_FRACTION_DENOMINATOR_DISPLAY_STYLE_SHIFT_DOWN = 35,
170 HB_OT_MATH_CONSTANT_FRACTION_NUMERATOR_GAP_MIN = 36,
171 HB_OT_MATH_CONSTANT_FRACTION_NUM_DISPLAY_STYLE_GAP_MIN = 37,
172 HB_OT_MATH_CONSTANT_FRACTION_RULE_THICKNESS = 38,
173 HB_OT_MATH_CONSTANT_FRACTION_DENOMINATOR_GAP_MIN = 39,
174 HB_OT_MATH_CONSTANT_FRACTION_DENOM_DISPLAY_STYLE_GAP_MIN = 40,
175 HB_OT_MATH_CONSTANT_SKEWED_FRACTION_HORIZONTAL_GAP = 41,
176 HB_OT_MATH_CONSTANT_SKEWED_FRACTION_VERTICAL_GAP = 42,
177 HB_OT_MATH_CONSTANT_OVERBAR_VERTICAL_GAP = 43,
178 HB_OT_MATH_CONSTANT_OVERBAR_RULE_THICKNESS = 44,
179 HB_OT_MATH_CONSTANT_OVERBAR_EXTRA_ASCENDER = 45,
180 HB_OT_MATH_CONSTANT_UNDERBAR_VERTICAL_GAP = 46,
181 HB_OT_MATH_CONSTANT_UNDERBAR_RULE_THICKNESS = 47,
182 HB_OT_MATH_CONSTANT_UNDERBAR_EXTRA_DESCENDER = 48,
183 HB_OT_MATH_CONSTANT_RADICAL_VERTICAL_GAP = 49,
184 HB_OT_MATH_CONSTANT_RADICAL_DISPLAY_STYLE_VERTICAL_GAP = 50,
185 HB_OT_MATH_CONSTANT_RADICAL_RULE_THICKNESS = 51,
186 HB_OT_MATH_CONSTANT_RADICAL_EXTRA_ASCENDER = 52,
187 HB_OT_MATH_CONSTANT_RADICAL_KERN_BEFORE_DEGREE = 53,
188 HB_OT_MATH_CONSTANT_RADICAL_KERN_AFTER_DEGREE = 54,
189 HB_OT_MATH_CONSTANT_RADICAL_DEGREE_BOTTOM_RAISE_PERCENT = 55
190} hb_ot_math_constant_t;
191
192/**
193 * hb_ot_math_kern_t:
194 * @HB_OT_MATH_KERN_TOP_RIGHT: The top right corner of the glyph.
195 * @HB_OT_MATH_KERN_TOP_LEFT: The top left corner of the glyph.
196 * @HB_OT_MATH_KERN_BOTTOM_RIGHT: The bottom right corner of the glyph.
197 * @HB_OT_MATH_KERN_BOTTOM_LEFT: The bottom left corner of the glyph.
198 *
199 * The math kerning-table types defined for the four corners
200 * of a glyph.
201 *
202 * Since: 1.3.3
203 */
204typedef enum {
205 HB_OT_MATH_KERN_TOP_RIGHT = 0,
206 HB_OT_MATH_KERN_TOP_LEFT = 1,
207 HB_OT_MATH_KERN_BOTTOM_RIGHT = 2,
208 HB_OT_MATH_KERN_BOTTOM_LEFT = 3
209} hb_ot_math_kern_t;
210
211/**
212 * hb_ot_math_kern_entry_t:
213 * @max_correction_height: The maximum height at which this entry should be used
214 * @kern_value: The kern value of the entry
215 *
216 * Data type to hold math kerning (cut-in) information for a glyph.
217 *
218 * Since: 3.4.0
219 */
220typedef struct {
221 hb_position_t max_correction_height;
222 hb_position_t kern_value;
223} hb_ot_math_kern_entry_t;
224
225/**
226 * hb_ot_math_glyph_variant_t:
227 * @glyph: The glyph index of the variant
228 * @advance: The advance width of the variant
229 *
230 * Data type to hold math-variant information for a glyph.
231 *
232 * Since: 1.3.3
233 */
234typedef struct hb_ot_math_glyph_variant_t {
235 hb_codepoint_t glyph;
236 hb_position_t advance;
237} hb_ot_math_glyph_variant_t;
238
239/**
240 * hb_ot_math_glyph_part_flags_t:
241 * @HB_OT_MATH_GLYPH_PART_FLAG_EXTENDER: This is an extender glyph part that
242 * can be repeated to reach the desired length.
243 *
244 * Flags for math glyph parts.
245 *
246 * Since: 1.3.3
247 */
248typedef enum { /*< flags >*/
249 HB_OT_MATH_GLYPH_PART_FLAG_EXTENDER = 0x00000001u /* Extender glyph */
250} hb_ot_math_glyph_part_flags_t;
251
252/**
253 * hb_ot_math_glyph_part_t:
254 * @glyph: The glyph index of the variant part
255 * @start_connector_length: The length of the connector on the starting side of the variant part
256 * @end_connector_length: The length of the connector on the ending side of the variant part
257 * @full_advance: The total advance of the part
258 * @flags: #hb_ot_math_glyph_part_flags_t flags for the part
259 *
260 * Data type to hold information for a "part" component of a math-variant glyph.
261 * Large variants for stretchable math glyphs (such as parentheses) can be constructed
262 * on the fly from parts.
263 *
264 * Since: 1.3.3
265 */
266typedef struct hb_ot_math_glyph_part_t {
267 hb_codepoint_t glyph;
268 hb_position_t start_connector_length;
269 hb_position_t end_connector_length;
270 hb_position_t full_advance;
271 hb_ot_math_glyph_part_flags_t flags;
272} hb_ot_math_glyph_part_t;
273
274/* Methods */
275
276HB_EXTERN hb_bool_t
277hb_ot_math_has_data (hb_face_t *face);
278
279HB_EXTERN hb_position_t
280hb_ot_math_get_constant (hb_font_t *font,
281 hb_ot_math_constant_t constant);
282
283HB_EXTERN hb_position_t
284hb_ot_math_get_glyph_italics_correction (hb_font_t *font,
285 hb_codepoint_t glyph);
286
287HB_EXTERN hb_position_t
288hb_ot_math_get_glyph_top_accent_attachment (hb_font_t *font,
289 hb_codepoint_t glyph);
290
291HB_EXTERN hb_bool_t
292hb_ot_math_is_glyph_extended_shape (hb_face_t *face,
293 hb_codepoint_t glyph);
294
295HB_EXTERN hb_position_t
296hb_ot_math_get_glyph_kerning (hb_font_t *font,
297 hb_codepoint_t glyph,
298 hb_ot_math_kern_t kern,
299 hb_position_t correction_height);
300
301HB_EXTERN unsigned int
302hb_ot_math_get_glyph_kernings (hb_font_t *font,
303 hb_codepoint_t glyph,
304 hb_ot_math_kern_t kern,
305 unsigned int start_offset,
306 unsigned int *entries_count, /* IN/OUT */
307 hb_ot_math_kern_entry_t *kern_entries /* OUT */);
308
309HB_EXTERN unsigned int
310hb_ot_math_get_glyph_variants (hb_font_t *font,
311 hb_codepoint_t glyph,
312 hb_direction_t direction,
313 unsigned int start_offset,
314 unsigned int *variants_count, /* IN/OUT */
315 hb_ot_math_glyph_variant_t *variants /* OUT */);
316
317HB_EXTERN hb_position_t
318hb_ot_math_get_min_connector_overlap (hb_font_t *font,
319 hb_direction_t direction);
320
321HB_EXTERN unsigned int
322hb_ot_math_get_glyph_assembly (hb_font_t *font,
323 hb_codepoint_t glyph,
324 hb_direction_t direction,
325 unsigned int start_offset,
326 unsigned int *parts_count, /* IN/OUT */
327 hb_ot_math_glyph_part_t *parts, /* OUT */
328 hb_position_t *italics_correction /* OUT */);
329
330
331HB_END_DECLS
332
333#endif /* HB_OT_MATH_H */
334