src/hb-ot-math.h

   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 #ifndef HB_OT_H_IN
  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
  36 HB_BEGIN_DECLS
  37
  38
  39 /*
  40  * MATH
  41  */
  42
  43 #define HB_OT_TAG_MATH HB_TAG('M','A','T','H')
  44
  45 /* Use with hb_buffer_set_script() for math shaping. */
  46 #define HB_OT_MATH_SCRIPT HB_TAG('m','a','t','h')
  47
  48 /* Types */
  49
  50 /**
  51  * hb_ot_math_constant_t:
  52  *
  53  * Since: 1.3.3
  54  */
  55 typedef enum {
  56   HB_OT_MATH_CONSTANT_SCRIPT_PERCENT_SCALE_DOWN = 0,
  57   HB_OT_MATH_CONSTANT_SCRIPT_SCRIPT_PERCENT_SCALE_DOWN = 1,
  58   HB_OT_MATH_CONSTANT_DELIMITED_SUB_FORMULA_MIN_HEIGHT = 2,
  59   HB_OT_MATH_CONSTANT_DISPLAY_OPERATOR_MIN_HEIGHT = 3,
  60   HB_OT_MATH_CONSTANT_MATH_LEADING = 4,
  61   HB_OT_MATH_CONSTANT_AXIS_HEIGHT = 5,
  62   HB_OT_MATH_CONSTANT_ACCENT_BASE_HEIGHT = 6,
  63   HB_OT_MATH_CONSTANT_FLATTENED_ACCENT_BASE_HEIGHT = 7,
  64   HB_OT_MATH_CONSTANT_SUBSCRIPT_SHIFT_DOWN = 8,
  65   HB_OT_MATH_CONSTANT_SUBSCRIPT_TOP_MAX = 9,
  66   HB_OT_MATH_CONSTANT_SUBSCRIPT_BASELINE_DROP_MIN = 10,
  67   HB_OT_MATH_CONSTANT_SUPERSCRIPT_SHIFT_UP = 11,
  68   HB_OT_MATH_CONSTANT_SUPERSCRIPT_SHIFT_UP_CRAMPED = 12,
  69   HB_OT_MATH_CONSTANT_SUPERSCRIPT_BOTTOM_MIN = 13,
  70   HB_OT_MATH_CONSTANT_SUPERSCRIPT_BASELINE_DROP_MAX = 14,
  71   HB_OT_MATH_CONSTANT_SUB_SUPERSCRIPT_GAP_MIN = 15,
  72   HB_OT_MATH_CONSTANT_SUPERSCRIPT_BOTTOM_MAX_WITH_SUBSCRIPT = 16,
  73   HB_OT_MATH_CONSTANT_SPACE_AFTER_SCRIPT = 17,
  74   HB_OT_MATH_CONSTANT_UPPER_LIMIT_GAP_MIN = 18,
  75   HB_OT_MATH_CONSTANT_UPPER_LIMIT_BASELINE_RISE_MIN = 19,
  76   HB_OT_MATH_CONSTANT_LOWER_LIMIT_GAP_MIN = 20,
  77   HB_OT_MATH_CONSTANT_LOWER_LIMIT_BASELINE_DROP_MIN = 21,
  78   HB_OT_MATH_CONSTANT_STACK_TOP_SHIFT_UP = 22,
  79   HB_OT_MATH_CONSTANT_STACK_TOP_DISPLAY_STYLE_SHIFT_UP = 23,
  80   HB_OT_MATH_CONSTANT_STACK_BOTTOM_SHIFT_DOWN = 24,
  81   HB_OT_MATH_CONSTANT_STACK_BOTTOM_DISPLAY_STYLE_SHIFT_DOWN = 25,
  82   HB_OT_MATH_CONSTANT_STACK_GAP_MIN = 26,
  83   HB_OT_MATH_CONSTANT_STACK_DISPLAY_STYLE_GAP_MIN = 27,
  84   HB_OT_MATH_CONSTANT_STRETCH_STACK_TOP_SHIFT_UP = 28,
  85   HB_OT_MATH_CONSTANT_STRETCH_STACK_BOTTOM_SHIFT_DOWN = 29,
  86   HB_OT_MATH_CONSTANT_STRETCH_STACK_GAP_ABOVE_MIN = 30,
  87   HB_OT_MATH_CONSTANT_STRETCH_STACK_GAP_BELOW_MIN = 31,
  88   HB_OT_MATH_CONSTANT_FRACTION_NUMERATOR_SHIFT_UP = 32,
  89   HB_OT_MATH_CONSTANT_FRACTION_NUMERATOR_DISPLAY_STYLE_SHIFT_UP = 33,
  90   HB_OT_MATH_CONSTANT_FRACTION_DENOMINATOR_SHIFT_DOWN = 34,
  91   HB_OT_MATH_CONSTANT_FRACTION_DENOMINATOR_DISPLAY_STYLE_SHIFT_DOWN = 35,
  92   HB_OT_MATH_CONSTANT_FRACTION_NUMERATOR_GAP_MIN = 36,
  93   HB_OT_MATH_CONSTANT_FRACTION_NUM_DISPLAY_STYLE_GAP_MIN = 37,
  94   HB_OT_MATH_CONSTANT_FRACTION_RULE_THICKNESS = 38,
  95   HB_OT_MATH_CONSTANT_FRACTION_DENOMINATOR_GAP_MIN = 39,
  96   HB_OT_MATH_CONSTANT_FRACTION_DENOM_DISPLAY_STYLE_GAP_MIN = 40,
  97   HB_OT_MATH_CONSTANT_SKEWED_FRACTION_HORIZONTAL_GAP = 41,
  98   HB_OT_MATH_CONSTANT_SKEWED_FRACTION_VERTICAL_GAP = 42,
  99   HB_OT_MATH_CONSTANT_OVERBAR_VERTICAL_GAP = 43,
 100   HB_OT_MATH_CONSTANT_OVERBAR_RULE_THICKNESS = 44,
 101   HB_OT_MATH_CONSTANT_OVERBAR_EXTRA_ASCENDER = 45,
 102   HB_OT_MATH_CONSTANT_UNDERBAR_VERTICAL_GAP = 46,
 103   HB_OT_MATH_CONSTANT_UNDERBAR_RULE_THICKNESS = 47,
 104   HB_OT_MATH_CONSTANT_UNDERBAR_EXTRA_DESCENDER = 48,
 105   HB_OT_MATH_CONSTANT_RADICAL_VERTICAL_GAP = 49,
 106   HB_OT_MATH_CONSTANT_RADICAL_DISPLAY_STYLE_VERTICAL_GAP = 50,
 107   HB_OT_MATH_CONSTANT_RADICAL_RULE_THICKNESS = 51,
 108   HB_OT_MATH_CONSTANT_RADICAL_EXTRA_ASCENDER = 52,
 109   HB_OT_MATH_CONSTANT_RADICAL_KERN_BEFORE_DEGREE = 53,
 110   HB_OT_MATH_CONSTANT_RADICAL_KERN_AFTER_DEGREE = 54,
 111   HB_OT_MATH_CONSTANT_RADICAL_DEGREE_BOTTOM_RAISE_PERCENT = 55
 112 } hb_ot_math_constant_t;
 113
 114 /**
 115  * hb_ot_math_kern_t:
 116  *
 117  * Since: 1.3.3
 118  */
 119 typedef enum {
 120   HB_OT_MATH_KERN_TOP_RIGHT = 0,
 121   HB_OT_MATH_KERN_TOP_LEFT = 1,
 122   HB_OT_MATH_KERN_BOTTOM_RIGHT = 2,
 123   HB_OT_MATH_KERN_BOTTOM_LEFT = 3
 124 } hb_ot_math_kern_t;
 125
 126 /**
 127  * hb_ot_math_glyph_variant_t:
 128  *
 129  * Since: 1.3.3
 130  */
 131 typedef struct hb_ot_math_glyph_variant_t {
 132   hb_codepoint_t glyph;
 133   hb_position_t advance;
 134 } hb_ot_math_glyph_variant_t;
 135
 136 /**
 137  * hb_ot_math_glyph_part_flags_t:
 138  *
 139  * Since: 1.3.3
 140  */
 141 typedef enum { /*< flags >*/
 142   HB_MATH_GLYPH_PART_FLAG_EXTENDER      = 0x00000001u  /* Extender glyph */
 143 } hb_ot_math_glyph_part_flags_t;
 144
 145 /**
 146  * hb_ot_math_glyph_part_t:
 147  *
 148  * Since: 1.3.3
 149  */
 150 typedef struct hb_ot_math_glyph_part_t {
 151   hb_codepoint_t glyph;
 152   hb_position_t start_connector_length;
 153   hb_position_t end_connector_length;
 154   hb_position_t full_advance;
 155   hb_ot_math_glyph_part_flags_t flags;
 156 } hb_ot_math_glyph_part_t;
 157
 158 /* Methods */
 159
 160 HB_EXTERN hb_bool_t
 161 hb_ot_math_has_data (hb_face_t *face);
 162
 163 HB_EXTERN hb_position_t
 164 hb_ot_math_get_constant (hb_font_t *font,
 165                          hb_ot_math_constant_t constant);
 166
 167 HB_EXTERN hb_position_t
 168 hb_ot_math_get_glyph_italics_correction (hb_font_t *font,
 169                                          hb_codepoint_t glyph);
 170
 171 HB_EXTERN hb_position_t
 172 hb_ot_math_get_glyph_top_accent_attachment (hb_font_t *font,
 173                                             hb_codepoint_t glyph);
 174
 175 HB_EXTERN hb_bool_t
 176 hb_ot_math_is_glyph_extended_shape (hb_face_t *face,
 177                                     hb_codepoint_t glyph);
 178
 179 HB_EXTERN hb_position_t
 180 hb_ot_math_get_glyph_kerning (hb_font_t *font,
 181                               hb_codepoint_t glyph,
 182                               hb_ot_math_kern_t kern,
 183                               hb_position_t correction_height);
 184
 185 HB_EXTERN unsigned int
 186 hb_ot_math_get_glyph_variants (hb_font_t *font,
 187                                hb_codepoint_t glyph,
 188                                hb_direction_t direction,
 189                                unsigned int start_offset,
 190                                unsigned int *variants_count, /* IN/OUT */
 191                                hb_ot_math_glyph_variant_t *variants /* OUT */);
 192
 193 HB_EXTERN hb_position_t
 194 hb_ot_math_get_min_connector_overlap (hb_font_t *font,
 195                                       hb_direction_t direction);
 196
 197 HB_EXTERN unsigned int
 198 hb_ot_math_get_glyph_assembly (hb_font_t *font,
 199                                hb_codepoint_t glyph,
 200                                hb_direction_t direction,
 201                                unsigned int start_offset,
 202                                unsigned int *parts_count, /* IN/OUT */
 203                                hb_ot_math_glyph_part_t *parts, /* OUT */
 204                                hb_position_t *italics_correction /* OUT */);
 205
 206
 207 HB_END_DECLS
 208
 209 #endif /* HB_OT_MATH_H */