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Diffstat (limited to 'thirdparty/harfbuzz/src/hb-style.cc')
| -rw-r--r-- | thirdparty/harfbuzz/src/hb-style.cc | 135 |
1 files changed, 135 insertions, 0 deletions
diff --git a/thirdparty/harfbuzz/src/hb-style.cc b/thirdparty/harfbuzz/src/hb-style.cc new file mode 100644 index 0000000000..86b9f7da5f --- /dev/null +++ b/thirdparty/harfbuzz/src/hb-style.cc @@ -0,0 +1,135 @@ +/* + * Copyright © 2019 Ebrahim Byagowi + * + * This is part of HarfBuzz, a text shaping library. + * + * Permission is hereby granted, without written agreement and without + * license or royalty fees, to use, copy, modify, and distribute this + * software and its documentation for any purpose, provided that the + * above copyright notice and the following two paragraphs appear in + * all copies of this software. + * + * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR + * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES + * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN + * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH + * DAMAGE. + * + * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, + * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND + * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS + * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO + * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS. + */ + +#include "hb.hh" + +#ifndef HB_NO_STYLE +#ifdef HB_EXPERIMENTAL_API + +#include "hb-ot-var-avar-table.hh" +#include "hb-ot-var-fvar-table.hh" +#include "hb-ot-stat-table.hh" +#include "hb-ot-os2-table.hh" +#include "hb-ot-head-table.hh" +#include "hb-ot-post-table.hh" +#include "hb-ot-face.hh" + +/** + * hb_style_tag_t: + * @HB_STYLE_TAG_ITALIC: Used to vary between non-italic and italic. + * A value of 0 can be interpreted as "Roman" (non-italic); a value of 1 can + * be interpreted as (fully) italic. + * @HB_STYLE_TAG_OPTICAL_SIZE: Used to vary design to suit different text sizes. + * Non-zero. Values can be interpreted as text size, in points. + * @HB_STYLE_TAG_SLANT: Used to vary between upright and slanted text. Values + * must be greater than -90 and less than +90. Values can be interpreted as + * the angle, in counter-clockwise degrees, of oblique slant from whatever the + * designer considers to be upright for that font design. + * @HB_STYLE_TAG_WIDTH: Used to vary width of text from narrower to wider. + * Non-zero. Values can be interpreted as a percentage of whatever the font + * designer considers “normal width” for that font design. + * @HB_STYLE_TAG_WEIGHT: Used to vary stroke thicknesses or other design details + * to give variation from lighter to blacker. Values can be interpreted in direct + * comparison to values for usWeightClass in the OS/2 table, + * or the CSS font-weight property. + * + * Defined by https://docs.microsoft.com/en-us/typography/opentype/spec/dvaraxisreg + * + * Since: EXPERIMENTAL + **/ +typedef enum { + HB_STYLE_TAG_ITALIC = HB_TAG ('i','t','a','l'), + HB_STYLE_TAG_OPTICAL_SIZE = HB_TAG ('o','p','s','z'), + HB_STYLE_TAG_SLANT = HB_TAG ('s','l','n','t'), + HB_STYLE_TAG_WIDTH = HB_TAG ('w','d','t','h'), + HB_STYLE_TAG_WEIGHT = HB_TAG ('w','g','h','t'), + + _HB_STYLE_TAG_MAX_VALUE = HB_TAG_MAX_SIGNED /*< skip >*/ +} hb_style_tag_t; + +/** + * hb_style_get_value: + * @font: a #hb_font_t object. + * @style_tag: a style tag. + * + * Searches variation axes of a hb_font_t object for a specific axis first, + * if not set, then tries to get default style values from different + * tables of the font. + * + * Returns: Corresponding axis or default value to a style tag. + * + * Since: EXPERIMENTAL + **/ +float +hb_style_get_value (hb_font_t *font, hb_tag_t tag) +{ + hb_style_tag_t style_tag = (hb_style_tag_t) tag; + hb_face_t *face = font->face; + +#ifndef HB_NO_VAR + hb_ot_var_axis_info_t axis; + if (hb_ot_var_find_axis_info (face, style_tag, &axis)) + { + if (axis.axis_index < font->num_coords) return font->design_coords[axis.axis_index]; + /* If a face is variable, fvar's default_value is better than STAT records */ + return axis.default_value; + } +#endif + + if (style_tag == HB_STYLE_TAG_OPTICAL_SIZE && font->ptem) + return font->ptem; + + /* STAT */ + float value; + if (face->table.STAT->get_value (style_tag, &value)) + return value; + + switch ((unsigned) style_tag) + { + case HB_STYLE_TAG_ITALIC: + return face->table.OS2->is_italic () || face->table.head->is_italic () ? 1 : 0; + case HB_STYLE_TAG_OPTICAL_SIZE: + { + unsigned int lower, upper; + return face->table.OS2->v5 ().get_optical_size (&lower, &upper) + ? (float) (lower + upper) / 2.f + : 12.f; + } + case HB_STYLE_TAG_SLANT: + return face->table.post->table->italicAngle.to_float (); + case HB_STYLE_TAG_WIDTH: + return face->table.OS2->has_data () + ? face->table.OS2->get_width () + : (face->table.head->is_condensed () ? 75 : 100); + case HB_STYLE_TAG_WEIGHT: + return face->table.OS2->has_data () + ? face->table.OS2->usWeightClass + : (face->table.head->is_bold () ? 700 : 400); + default: + return 0; + } +} + +#endif +#endif |