Line data Source code
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 : #include "hb-open-type-private.hh"
28 :
29 : #include "hb-ot-layout-private.hh"
30 : #include "hb-ot-math-table.hh"
31 :
32 : static inline const OT::MATH&
33 0 : _get_math (hb_face_t *face)
34 : {
35 0 : if (unlikely (!hb_ot_shaper_face_data_ensure (face))) return OT::Null(OT::MATH);
36 0 : hb_ot_layout_t * layout = hb_ot_layout_from_face (face);
37 0 : return *(layout->math.get ());
38 : }
39 :
40 : /*
41 : * OT::MATH
42 : */
43 :
44 : /**
45 : * hb_ot_math_has_data:
46 : * @face: #hb_face_t to test
47 : *
48 : * This function allows to verify the presence of an OpenType MATH table on the
49 : * face.
50 : *
51 : * Return value: true if face has a MATH table, false otherwise
52 : *
53 : * Since: 1.3.3
54 : **/
55 : hb_bool_t
56 0 : hb_ot_math_has_data (hb_face_t *face)
57 : {
58 0 : return &_get_math (face) != &OT::Null(OT::MATH);
59 : }
60 :
61 : /**
62 : * hb_ot_math_get_constant:
63 : * @font: #hb_font_t from which to retrieve the value
64 : * @constant: #hb_ot_math_constant_t the constant to retrieve
65 : *
66 : * This function returns the requested math constants as a #hb_position_t.
67 : * If the request constant is HB_OT_MATH_CONSTANT_SCRIPT_PERCENT_SCALE_DOWN,
68 : * HB_OT_MATH_CONSTANT_SCRIPT_SCRIPT_PERCENT_SCALE_DOWN or
69 : * HB_OT_MATH_CONSTANT_SCRIPT_PERCENT_SCALE_DOWN then the return value is
70 : * actually an integer between 0 and 100 representing that percentage.
71 : *
72 : * Return value: the requested constant or 0
73 : *
74 : * Since: 1.3.3
75 : **/
76 : hb_position_t
77 0 : hb_ot_math_get_constant (hb_font_t *font,
78 : hb_ot_math_constant_t constant)
79 : {
80 0 : const OT::MATH &math = _get_math (font->face);
81 0 : return math.get_constant(constant, font);
82 : }
83 :
84 : /**
85 : * hb_ot_math_get_glyph_italics_correction:
86 : * @font: #hb_font_t from which to retrieve the value
87 : * @glyph: glyph index from which to retrieve the value
88 : *
89 : * Return value: the italics correction of the glyph or 0
90 : *
91 : * Since: 1.3.3
92 : **/
93 : hb_position_t
94 0 : hb_ot_math_get_glyph_italics_correction (hb_font_t *font,
95 : hb_codepoint_t glyph)
96 : {
97 0 : const OT::MATH &math = _get_math (font->face);
98 0 : return math.get_math_glyph_info().get_italics_correction (glyph, font);
99 : }
100 :
101 : /**
102 : * hb_ot_math_get_glyph_top_accent_attachment:
103 : * @font: #hb_font_t from which to retrieve the value
104 : * @glyph: glyph index from which to retrieve the value
105 : *
106 : * Return value: the top accent attachment of the glyph or 0
107 : *
108 : * Since: 1.3.3
109 : **/
110 : hb_position_t
111 0 : hb_ot_math_get_glyph_top_accent_attachment (hb_font_t *font,
112 : hb_codepoint_t glyph)
113 : {
114 0 : const OT::MATH &math = _get_math (font->face);
115 0 : return math.get_math_glyph_info().get_top_accent_attachment (glyph, font);
116 : }
117 :
118 : /**
119 : * hb_ot_math_is_glyph_extended_shape:
120 : * @face: a #hb_face_t to test
121 : * @glyph: a glyph index to test
122 : *
123 : * Return value: true if the glyph is an extended shape, false otherwise
124 : *
125 : * Since: 1.3.3
126 : **/
127 : hb_bool_t
128 0 : hb_ot_math_is_glyph_extended_shape (hb_face_t *face,
129 : hb_codepoint_t glyph)
130 : {
131 0 : const OT::MATH &math = _get_math (face);
132 0 : return math.get_math_glyph_info().is_extended_shape (glyph);
133 : }
134 :
135 : /**
136 : * hb_ot_math_get_glyph_kerning:
137 : * @font: #hb_font_t from which to retrieve the value
138 : * @glyph: glyph index from which to retrieve the value
139 : * @kern: the #hb_ot_math_kern_t from which to retrieve the value
140 : * @correction_height: the correction height to use to determine the kerning.
141 : *
142 : * This function tries to retrieve the MathKern table for the specified font,
143 : * glyph and #hb_ot_math_kern_t. Then it browses the list of heights from the
144 : * MathKern table to find one value that is greater or equal to specified
145 : * correction_height. If one is found the corresponding value from the list of
146 : * kerns is returned and otherwise the last kern value is returned.
147 : *
148 : * Return value: requested kerning or 0
149 : *
150 : * Since: 1.3.3
151 : **/
152 : hb_position_t
153 0 : hb_ot_math_get_glyph_kerning (hb_font_t *font,
154 : hb_codepoint_t glyph,
155 : hb_ot_math_kern_t kern,
156 : hb_position_t correction_height)
157 : {
158 0 : const OT::MATH &math = _get_math (font->face);
159 0 : return math.get_math_glyph_info().get_kerning (glyph, kern, correction_height, font);
160 : }
161 :
162 : /**
163 : * hb_ot_math_get_glyph_variants:
164 : * @font: #hb_font_t from which to retrieve the values
165 : * @glyph: index of the glyph to stretch
166 : * @direction: direction of the stretching
167 : * @start_offset: offset of the first variant to retrieve
168 : * @variants_count: maximum number of variants to retrieve after start_offset
169 : * (IN) and actual number of variants retrieved (OUT)
170 : * @variants: array of size at least @variants_count to store the result
171 : *
172 : * This function tries to retrieve the MathGlyphConstruction for the specified
173 : * font, glyph and direction. Note that only the value of
174 : * #HB_DIRECTION_IS_HORIZONTAL is considered. It provides the corresponding list
175 : * of size variants as an array of hb_ot_math_glyph_variant_t structs.
176 : *
177 : * Return value: the total number of size variants available or 0
178 : *
179 : * Since: 1.3.3
180 : **/
181 : unsigned int
182 0 : hb_ot_math_get_glyph_variants (hb_font_t *font,
183 : hb_codepoint_t glyph,
184 : hb_direction_t direction,
185 : unsigned int start_offset,
186 : unsigned int *variants_count, /* IN/OUT */
187 : hb_ot_math_glyph_variant_t *variants /* OUT */)
188 : {
189 0 : const OT::MATH &math = _get_math (font->face);
190 0 : return math.get_math_variants().get_glyph_variants (glyph, direction, font,
191 : start_offset,
192 : variants_count,
193 0 : variants);
194 : }
195 :
196 : /**
197 : * hb_ot_math_get_min_connector_overlap:
198 : * @font: #hb_font_t from which to retrieve the value
199 : * @direction: direction of the stretching
200 : *
201 : * This function tries to retrieve the MathVariants table for the specified
202 : * font and returns the minimum overlap of connecting glyphs to draw a glyph
203 : * assembly in the specified direction. Note that only the value of
204 : * #HB_DIRECTION_IS_HORIZONTAL is considered.
205 : *
206 : * Return value: requested min connector overlap or 0
207 : *
208 : * Since: 1.3.3
209 : **/
210 : hb_position_t
211 0 : hb_ot_math_get_min_connector_overlap (hb_font_t *font,
212 : hb_direction_t direction)
213 : {
214 0 : const OT::MATH &math = _get_math (font->face);
215 0 : return math.get_math_variants().get_min_connector_overlap (direction, font);
216 : }
217 :
218 : /**
219 : * hb_ot_math_get_glyph_assembly:
220 : * @font: #hb_font_t from which to retrieve the values
221 : * @glyph: index of the glyph to stretch
222 : * @direction: direction of the stretching
223 : * @start_offset: offset of the first glyph part to retrieve
224 : * @parts_count: maximum number of glyph parts to retrieve after start_offset
225 : * (IN) and actual number of parts retrieved (OUT)
226 : * @parts: array of size at least @parts_count to store the result
227 : * @italics_correction: italic correction of the glyph assembly
228 : *
229 : * This function tries to retrieve the GlyphAssembly for the specified font,
230 : * glyph and direction. Note that only the value of #HB_DIRECTION_IS_HORIZONTAL
231 : * is considered. It provides the information necessary to draw the glyph
232 : * assembly as an array of #hb_ot_math_glyph_part_t.
233 : *
234 : * Return value: the total number of parts in the glyph assembly
235 : *
236 : * Since: 1.3.3
237 : **/
238 : unsigned int
239 0 : hb_ot_math_get_glyph_assembly (hb_font_t *font,
240 : hb_codepoint_t glyph,
241 : hb_direction_t direction,
242 : unsigned int start_offset,
243 : unsigned int *parts_count, /* IN/OUT */
244 : hb_ot_math_glyph_part_t *parts, /* OUT */
245 : hb_position_t *italics_correction /* OUT */)
246 : {
247 0 : const OT::MATH &math = _get_math (font->face);
248 0 : return math.get_math_variants().get_glyph_parts (glyph, direction, font,
249 : start_offset,
250 : parts_count,
251 : parts,
252 0 : italics_correction);
253 : }
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