hb-ot-math.h 13 KB

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