diff options
Diffstat (limited to 'gfx/harfbuzz/src/hb-style.cc')
| -rw-r--r-- | gfx/harfbuzz/src/hb-style.cc | 134 |
1 files changed, 134 insertions, 0 deletions
diff --git a/gfx/harfbuzz/src/hb-style.cc b/gfx/harfbuzz/src/hb-style.cc new file mode 100644 index 0000000000..bd5cb5c6be --- /dev/null +++ b/gfx/harfbuzz/src/hb-style.cc @@ -0,0 +1,134 @@ +/* + * 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 + +#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" + +/** + * SECTION:hb-style + * @title: hb-style + * @short_description: Font Styles + * @include: hb.h + * + * Functions for fetching style information from fonts. + **/ + +static inline float +_hb_angle_to_ratio (float a) +{ + return tanf (a * -HB_PI / 180.f); +} + +static inline float +_hb_ratio_to_angle (float r) +{ + return atanf (r) * -180.f / HB_PI; +} + +/** + * 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: 3.0.0 + **/ +float +hb_style_get_value (hb_font_t *font, hb_style_tag_t style_tag) +{ + if (unlikely (style_tag == HB_STYLE_TAG_SLANT_RATIO)) + return _hb_angle_to_ratio (hb_style_get_value (font, HB_STYLE_TAG_SLANT_ANGLE)); + + 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, design, upper; + return face->table.OS2->v5 ().get_optical_size (&lower, &upper) + ? (float) (lower + upper) / 2.f + : hb_ot_layout_get_size_params (face, &design, nullptr, nullptr, nullptr, nullptr) + ? design / 10.f + : 12.f; + } + case HB_STYLE_TAG_SLANT_ANGLE: + { + float angle = face->table.post->table->italicAngle.to_float (); + + if (font->slant) + angle = _hb_ratio_to_angle (font->slant + _hb_angle_to_ratio (angle)); + + return angle; + } + case HB_STYLE_TAG_WIDTH: + return face->table.OS2->has_data () + ? face->table.OS2->get_width () + : (face->table.head->is_condensed () ? 75 : + face->table.head->is_expanded () ? 125 : + 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 |